CN117835163A

CN117835163A - Communication method and device

Info

Publication number: CN117835163A
Application number: CN202211378635.6A
Authority: CN
Inventors: 沙桐; 李秉肇; 张海森; 许斌
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-09-29
Filing date: 2022-11-04
Publication date: 2024-04-05

Abstract

A communication method and a communication device. The method may include: when the terminal equipment is in a connection state, the first network equipment pre-configures a multicast configuration resource pool to the terminal equipment, wherein the multicast configuration resource pool can comprise a plurality of multicast configuration information related to a first multicast session, and further the second network equipment can indicate first multicast configuration information required for receiving the first multicast session to the terminal equipment through first index information in the second information. Therefore, on one hand, the potential safety hazard caused by receiving the multicast configuration information in a broadcast mode can be avoided, and on the other hand, the signaling overhead and time delay caused by the terminal equipment entering the RRC connection state to receive the multicast configuration information can be avoided.

Description

Communication method and device

The present application claims priority to chinese patent application No. 2022, 9, 29, 202211203248.9, entitled "method and apparatus for communication", the entire contents of which are incorporated herein by reference.

Technical Field

The embodiments of the present application relate to the field of communications, and more particularly, to a method and apparatus for communications.

Background

Multicast broadcast services (multicast and broadcast service, MBS) can provide data simultaneously with fewer resources for a large number of users with the same needs so that network resources can be shared. In the third generation partnership project (3rd generation partnership project,3GPP) release 17, the terminal device receives MBS in the connected state. For terminal devices that join an MBS session and are in an RRC-connected state, the network device may first send an MBS configuration to the terminal device, and further, the terminal device may receive the MBS according to the MBS configuration.

In order to alleviate network congestion, R18 proposes supporting terminal devices to receive MBS in RRC inactive state. For example, when the terminal device has no unicast service and only the MBS, the network may release the terminal device to the RRC inactive state, and the terminal device may receive the MBS in the RRC inactive state. Therefore, the number of the terminal devices in the RRC connection state in the network can be reduced, the network congestion can be relieved, and the energy saving of the terminal devices is also facilitated.

However, how to obtain the MBS configuration in the RRC inactive state for the terminal device is a problem to be solved for MBS reception.

Disclosure of Invention

The communication method and device provided by the application enable the terminal equipment to receive MBS in the RRC inactive state, thereby being beneficial to relieving network congestion and saving energy of the terminal equipment.

In a first aspect, a communication method is provided, which may be performed by a terminal device, or may also be performed by a component part (such as a chip or a circuit) of the terminal device, which is not limited in this application.

The method may include: the method comprises the steps that a terminal device receives first information from a first network device, wherein the first information comprises at least one piece of multicast configuration information and index information corresponding to the at least one piece of multicast configuration information, the at least one piece of multicast configuration information comprises the first multicast configuration information, and the index information corresponding to the at least one piece of multicast configuration information comprises the first index information; the terminal equipment receives second information from second network equipment, wherein the second information is used for indicating a first multicast session to be associated with first index information, and the first index information indicates first multicast configuration information; the terminal device receives a first multicast session from the second network device in a Radio Resource Control (RRC) inactive state or idle state according to the first multicast configuration information.

According to the above scheme, when the terminal device is in a connection state, the first network device pre-configures the multicast configuration resource pool to the terminal device, where the multicast configuration resource pool may include a plurality of multicast configuration information associated with the first multicast session, and further the second network device may indicate, to the terminal device, through the second information, the first multicast configuration information required for receiving the first multicast session. Therefore, on one hand, the potential safety hazard caused by receiving the multicast configuration information in a broadcast mode can be avoided, and on the other hand, the signaling overhead and time delay caused by the terminal equipment entering the RRC connection state to receive the multicast configuration information can be avoided.

Optionally, the first information further includes identification information of a cell or network device corresponding to the at least one multicast configuration information.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: the terminal equipment acquires a first identifier, wherein the first identifier is an identifier of a resident cell of the terminal equipment or an identifier of network equipment corresponding to the resident cell, and a corresponding relation exists between the first identifier and first multicast configuration information; the terminal equipment determines first multicast configuration information according to the first identifier and the first index information.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: the terminal device receives third information from the first network device, the third information being used to indicate an effective area of the at least one multicast configuration information.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: the terminal equipment receives fourth information from the first network equipment or the second network equipment, wherein the fourth information is used for indicating a first G-RNTI corresponding to a first multicast session; the terminal equipment descrambles the first multicast session according to the first G-RNTI.

With reference to the first aspect, in certain implementations of the first aspect, the fourth information is information of the first G-RNTI; or the fourth information is index information of the first G-RNTI, and the index information of the first G-RNTI has a corresponding relation with the first G-RNTI; or the fourth information is information of a second G-RNTI, and the second G-RNTI has a corresponding relation with the first G-RNTI.

With reference to the first aspect, in certain implementations of the first aspect, the first index information includes one or more of: multicast radio bearer, MRB, configuration index, physical channel configuration index, discontinuous reception, DRX, configuration index, neighbor cell configuration index, common frequency domain resource, CFR, configuration index, semi-persistent scheduling (SPS) configuration index.

With reference to the first aspect, in certain implementations of the first aspect, the terminal device receives the second information if any one of the following conditions is met: the terminal equipment reselects to a cell managed by the second network equipment; or the terminal equipment receives fifth information, wherein the fifth information is used for notifying the system message change; or, the fifth information is used for notifying the multicast control channel message change; or, the fifth information is used for notifying the first multicast session to be activated; the fifth information is used for indicating the terminal equipment to receive the multicast session in the RRC inactive state or the idle state;

wherein the system change notification message or the notification multicast control channel message change is used for:

notifying the multicast configuration information of the first multicast session to change to the first multicast configuration information, or notifying the cell managed by the second network device to start providing the first multicast session in an inactive state or an idle state.

With reference to the first aspect, in certain implementations of the first aspect, the method further includes: the terminal device receives a first message from the second network device, where the first message is a system message or a multicast control channel message, and the first message is used to instruct to stop receiving the first multicast session or stop providing the first multicast session in an inactive state by a cell managed by the second network device.

Optionally, the method further comprises: and the terminal equipment determines whether to recover the RRC connection according to the first message.

Optionally, the first message indicates that the first multicast session is deactivated, and the terminal device remains in an RRC inactive state or an idle state, and stops receiving the first multicast session.

Optionally, the terminal device receives the first message, where the first message does not include the identifier of the first multicast session.

Optionally, the terminal device receives the first message, where the first message includes an identifier of the first multicast session and does not include the first index information.

Specifically, if the first message includes the identifier of the first multicast session and does not include the first index information, the terminal device stops receiving the first multicast session; or the first message does not include the identifier of the first multicast session, the terminal device sends an RRC recovery request message to the second network device, and enters an RRC connection state to receive the first multicast session.

Optionally, the second information is carried by any one of: system messages, multicast control channel messages, RRC release messages.

In a second aspect, a communication method is provided, which may be performed by the third network device, or may also be performed by a component (e.g. a chip or a circuit) of the third network device, which is not limited in this application. The third network device may be the first network device in the first aspect, or the second network device in the first aspect.

The method may include: the third network device sends second information, wherein the second information is used for indicating first multicast session association first index information, and the first index information indicates first multicast configuration information; the third network device sends the first multicast session according to the first multicast configuration information.

According to the above scheme, the third network device can indicate the first multicast configuration information required for receiving the first multicast session to the terminal device through the second information. Therefore, on one hand, the potential safety hazard caused by receiving the multicast configuration information in a broadcast mode can be avoided, and on the other hand, the signaling overhead and time delay caused by the terminal equipment entering the RRC connection state to receive the multicast configuration information can be avoided.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the third network equipment sends first information to the terminal equipment, wherein the first information comprises at least one piece of multicast configuration information and index information corresponding to the at least one piece of multicast configuration information, the at least one piece of multicast configuration information comprises the first multicast configuration information, and the index information corresponding to the at least one piece of multicast configuration information comprises the first index information;

with reference to the second aspect, in some implementations of the second aspect, the first information further includes identification information of a cell or a network device corresponding to the at least one multicast configuration information.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the third network equipment sends a first identifier, wherein the first identifier is the identifier of the third network equipment or the identifier of a cell corresponding to the second information.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the third network device obtains the first information.

With reference to the second aspect, in certain implementations of the second aspect, the third network device obtains the first information, including: the third network device receives sixth information from the fourth network device, wherein the sixth information comprises M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information; the third network equipment determines N pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information; the at least one piece of multicast configuration information comprises M pieces of multicast configuration information and N pieces of configuration information, wherein M and N are positive integers.

With reference to the second aspect, in certain implementations of the second aspect, the third network device obtains the first information, including: the third network device determines N pieces of multicast configuration information; the third network device receives sixth information from the fourth network device, the sixth information including M pieces of multicast configuration information; the third network device determines M pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information according to the M pieces of configuration information and the N pieces of multicast configuration information; the at least one piece of multicast configuration information comprises M pieces of multicast configuration information and N pieces of configuration information, wherein M and N are positive integers.

Optionally, the sixth information further includes identification information of cells corresponding to the M multicast configuration information.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the third network device sends the first information to the fourth network device.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: and the third network equipment sends third information to the terminal equipment, wherein the third information is used for indicating the effective area of the at least one multicast configuration information.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the third network device sends fourth information to the terminal device, the fourth information being used to indicate a first G-RNTI, the first G-RNTI being used to scramble the first multicast session.

Optionally, the fourth information is information of the first G-RNTI; or the fourth information is index information of the first G-RNTI, and the index information of the first G-RNTI has a corresponding relation with the first G-RNTI; or the fourth information is information of a second G-RNTI, and the second G-RNTI has a corresponding relation with the first G-RNTI.

With reference to the second aspect, in some implementations of the second aspect, the fourth information is information of the first G-RNTI, and the method further includes: the third network equipment receives a first G-RNRI from the core network equipment; or, the third network device determines the first G-RNTI according to the identification of the first multicast session.

With reference to the second aspect, in certain implementations of the second aspect, the first index information includes one or more of: multicast radio bearer, MRB, configuration index, physical channel configuration index, discontinuous reception, DRX, configuration index, neighbor cell configuration index, common frequency domain resource, CFR, configuration index, semi-persistent scheduling, SPS, configuration index.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the third network device sends fifth information, the fifth information is used for notifying system message change or notifying multicast control channel message change, and the fifth information is used for receiving the second information by the terminal device.

With reference to the second aspect, in some implementations of the second aspect, the third network device sends fifth information to the terminal device if any of the following conditions are met: changing the multicast configuration information of the first multicast session into first multicast configuration information; or, the third network device managed cell begins to provide the first multicast session in an inactive state or an idle state.

With reference to the second aspect, in certain implementations of the second aspect, the method further includes: the third network device sends a first message, where the first message is a system message or a multicast control channel message, and the first message is used to instruct the first multicast session to be in a deactivated state or released, or instruct a cell managed by the second network device to stop providing the first multicast session in the deactivated state.

Optionally, the third network device determines that the first multicast session is in a deactivated state or released, the third network device sends a first message, the first message including an identification of the first multicast session, and the first message not including the first index information; or, the cell managed by the third network device stops providing the first multicast session in the RRC inactive state or the idle state, and the third network device sends a first message, where the first message does not include an identifier of the first multicast session.

In a third aspect, a communication method is provided, which may be performed by the fourth network device, or may also be performed by a component (e.g. a chip or a circuit) of the fourth network device, which is not limited in this application.

The method may include: the fourth network device sends sixth information to the third network device, wherein the sixth information comprises M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information; or, the sixth information includes M pieces of multicast configuration information, where M is a positive integer; the fourth network device receives first information from the third network device, the first information including at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, the at least one multicast configuration information including M multicast configuration information.

According to the above scheme, the fourth network device may send the M pieces of multicast configuration information determined by the fourth network device to the third network device. In this way, the third network device is enabled to determine the first information. Furthermore, the third network device can indicate the multicast configuration to the terminal device through the first information and the index information, so that on one hand, potential safety hazards caused by receiving the multicast configuration information in a broadcast mode can be avoided, and on the other hand, signaling overhead and time delay caused by the terminal device entering the RRC connection state to receive the multicast configuration information can be avoided.

With reference to the third aspect, in certain implementations of the third aspect, the method further includes: the fourth network device sends seventh information, the seventh information is used for indicating the first multicast session to associate with second index information, the second index information indicates second multicast configuration information, at least one multicast configuration information comprises the second multicast configuration information, and index information corresponding to at least one multicast configuration information comprises the second index information; and the fourth network equipment transmits the first multicast session according to the second multicast configuration information.

In a fourth aspect, a communication method is provided, which may be performed by a terminal device, or may also be performed by a component (e.g., a chip or a circuit) of the terminal device, which is not limited in this application.

The method may include: the terminal equipment receives eighth information from the first network equipment, wherein the eighth information comprises first multicast configuration information and information of a cell corresponding to the first multicast configuration information, the first multicast configuration corresponds to a first multicast session, and the cell information corresponding to the first multicast configuration information comprises a first cell; the terminal equipment receives a second message from the second network equipment, wherein the second message comprises first indication information, and the first indication information is used for indicating the state of a first multicast session provided by a first cell; and under the condition that the first cell is a resident cell of the terminal equipment, the terminal equipment receives the first multicast session according to the first multicast configuration information.

Based on the above scheme, when the terminal device is in a connection state, the first network device pre-configures the information of the cell corresponding to the first multicast configuration information to the terminal device, the second network device may indicate the state of the multicast session of each cell to the terminal device through the first indication information in the second message, and in a certain cell, the cell is a serving cell of the terminal device, and the cell starts to provide the multicast session in an inactive state or an idle state, and the terminal device may receive the multicast session using the first multicast configuration information. Therefore, on one hand, the potential safety hazard caused by receiving the multicast configuration information in a broadcast mode can be avoided, and on the other hand, the signaling overhead and time delay caused by the terminal equipment entering the RRC connection state to receive the multicast configuration information can be avoided.

Wherein the state of the first multicast session comprises: the first cell is or is not providing the first multicast session in the RRC inactive state or idle state, or the first cell starts or stops providing the first multicast session in the RRC inactive state or idle state; or, the multicast configuration information corresponding to the first multicast session is changed.

With reference to the fourth aspect, in some implementations of the fourth aspect, the terminal device receives a first multicast session according to the first multicast configuration information, including: under the condition that the first indication information indicates that the first cell starts to provide the first multicast session in the RRC inactive state or the idle state, the terminal equipment receives the first multicast session in the RRC inactive state or the idle state according to the first multicast configuration information; or, in case that the first indication information indicates that the first cell stops providing the first multicast session in the RRC inactive state or the idle state, the terminal device sends an RRC resume request message to the network device corresponding to the first cell.

Optionally, the second message is a paging message or an RRC release message.

For example, the RRC release message instructs the UE to enter an inactive state to receive multicast, and the UE receives multicast using the first multicast configuration; or, the RRC release message indicates EU to enter an intra-active state for multicast reception, and the RRC release message carries updated multicast configuration, and the UE receives the multicast according to the updated multicast configuration.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the eighth information is carried on an RRC release message or an RRC reconfiguration message.

With reference to the fourth aspect, in some implementations of the fourth aspect, the first indication information is a bit map, at least one bit in the bit map being associated with the first cell.

With reference to the fourth aspect, in some implementations of the fourth aspect, the cell information corresponding to the first multicast configuration information includes Q cells, and the bit map includes Q bits, where the Q bits and the Q cells are in one-to-one correspondence.

With reference to the fourth aspect, in some implementations of the fourth aspect, the eighth information further includes at least one multicast configuration information, index information corresponding to the at least one multicast configuration information, and cell information corresponding to the at least one multicast configuration information, the at least one multicast configuration information includes first multicast configuration information, the index information corresponding to the at least one multicast configuration information includes first index information, and the cell information corresponding to the at least one multicast configuration information includes first cells.

With reference to the fourth aspect, in some implementations of the fourth aspect, the second message further includes second information, where the second information is used to indicate that the first multicast session is associated with first index information, and the first index information indicates first multicast configuration information.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the first index information includes one or more of: MRB configuration index, physical channel configuration index, discontinuous reception DRX configuration index, neighbor cell configuration index, CFR configuration index, SPS configuration index.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the method further includes: the terminal equipment receives fourth information from the first network equipment or the second network equipment, wherein the fourth information is used for indicating a first G-RNTI corresponding to a first multicast session; the terminal equipment descrambles the first multicast session according to the first G-RNTI.

With reference to the fourth aspect, in some implementations of the fourth aspect, the fourth information is information of the first G-RNTI; or the fourth information is index information of the first G-RNTI, and the index information of the first G-RNTI has a corresponding relation with the first G-RNTI; or the fourth information is information of a second G-RNTI, and the second G-RNTI has a corresponding relation with the first G-RNTI.

In a fifth aspect, a communication method is provided, which may be performed by the third network device, or may also be performed by a component (e.g. a chip or a circuit) of the third network device, which is not limited in this application. The third network device may be the first network device in the fourth aspect, or the second network device in the fourth aspect.

The method may include: the third network equipment sends a second message, wherein the second message comprises first indication information, and the first indication information is used for indicating that the state of a first multicast session provided by a first cell is changed; the third network device sends the first multicast session according to the first multicast configuration information.

Based on the above scheme, when the terminal device is in a connection state, the third network device pre-configures the information of the cell corresponding to the first multicast configuration information to the terminal device, and the third network device may further indicate the multicast session state of each cell to the terminal device through the first indication information in the second message, so that: a serving cell of the terminal device is a certain cell, and the cell starts to provide a multicast session in an inactive state or an idle state, and the terminal device may receive the multicast session using the first multicast configuration information. Therefore, on one hand, the potential safety hazard caused by receiving the multicast configuration information in a broadcast mode can be avoided, and on the other hand, the signaling overhead and time delay caused by the terminal equipment entering the RRC connection state to receive the multicast configuration information can be avoided.

Optionally, the third network device is the first network device in the fourth aspect, or is the second network device in the fourth aspect.

Optionally, the method further comprises: the third network device sends eighth information to the terminal device, the eighth information includes first multicast configuration information and cell information corresponding to the first multicast configuration information, the first multicast configuration corresponds to the first multicast session, and the cell information corresponding to the first multicast configuration information includes the first cell.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the eighth information is carried on an RRC release message or an RRC reconfiguration message.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the method further includes: the third network device receives ninth information from the fourth network device, where the ninth information is used to indicate identities of R cells corresponding to the first multicast configuration information, and the cell information corresponding to the first multicast configuration information includes R cells, where R is a positive integer.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the first indication information is a bit map, and at least one bit in the bit map is associated with the first cell.

Optionally, the cell information corresponding to the first multicast configuration information includes Q cells, and the bit map includes Q bits, where the Q bits and the Q cells correspond to each other one by one.

With reference to the fifth aspect, in some implementations of the fifth aspect, the eighth information further includes at least one multicast configuration information, index information corresponding to the at least one multicast configuration information, and cell information corresponding to the at least one multicast configuration information, the at least one multicast configuration information includes first multicast configuration information, the index information corresponding to the at least one multicast configuration information includes first index information, and the cell information corresponding to the at least one multicast configuration information includes first cells.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the method further includes: the third network device receives sixth information from the fourth network device, wherein the sixth information comprises M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information; the third network equipment determines N pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information;

the at least one piece of multicast configuration information comprises M pieces of multicast configuration information and N pieces of configuration information, wherein M and N are positive integers.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the third network device obtains the first information, including:

the third network device determines N pieces of multicast configuration information; the third network device receives sixth information from the fourth network device, the sixth information including M pieces of multicast configuration information; the third network device determines M pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information according to the M pieces of configuration information and the N pieces of multicast configuration information;

With reference to the fifth aspect, in some implementations of the fifth aspect, the sixth information further includes identification information of cells corresponding to the M multicast configuration information.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the method further includes: the third network device sends eighth information to the fourth network device.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the second message further includes second information, where the second information is used to indicate that the first multicast session is associated with first index information, and the first index information indicates first multicast configuration information.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the first index information includes one or more of:

MRB configuration index, physical channel configuration index, discontinuous reception DRX configuration index, neighbor cell configuration index, CFR configuration index, SPS configuration index.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the method further includes: the third network device sends fourth information to the terminal device, the fourth information being used to indicate a first G-RNTI, the first G-RNTI being used to scramble the first multicast session.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the fourth information is information of the first G-RNTI; or the fourth information is index information of the first G-RNTI, and the index information of the first G-RNTI has a corresponding relation with the first G-RNTI; or the fourth information is information of a second G-RNTI, and the second G-RNTI has a corresponding relation with the first G-RNTI.

With reference to the fifth aspect, in some implementations of the fifth aspect, the fourth information is information of the first G-RNTI, and the method further includes: the third network equipment receives a first G-RNRI from the core network equipment; or, the third network device determines the first G-RNTI according to the identification of the first multicast session.

With reference to the fifth aspect, in certain implementations of the fifth aspect, the first cell is a cell managed by the third network device.

With reference to the fifth aspect, in certain implementations of the fifth aspect, before the third network device sends the second message to the terminal device, the method further includes: the third network device receives second indication information from the fourth network device, where the second indication information is used to indicate a state transmission change of the first multicast session provided by the first cell, and the first cell is a cell managed by the fourth network device.

In a sixth aspect, a communication method is provided, which may be performed by the fourth network device, or may also be performed by a component (e.g., a chip or a circuit) of the fourth network device, which is not limited in this application.

The method may include: the fourth network device sends second indication information to the third network device, wherein the second indication information is used for indicating a state of a first multicast session in a non-connection state or an idle state provided by a first cell, and the first cell is a cell managed by the second network device; the fourth network device sends a second message, where the second message includes first indication information, where the first indication information is used to indicate a state of a first multicast session in a non-connected state or an idle state provided by the first cell.

According to the above scheme, the fourth network device may send the state of the first multicast session in the non-connected state or the idle state provided by the cell managed by the fourth network device to the third network device. In addition, the fourth network device can also send a second message, and indicate the state of the multicast session of each cell to the terminal device through the first indication information, so that: a serving cell of the terminal device is a certain cell, and the cell starts to provide a multicast session in an inactive state or an idle state, and the terminal device may receive the multicast session using the first multicast configuration information. On one hand, the potential safety hazard caused by receiving the multicast configuration information in a broadcast mode can be avoided, and on the other hand, the signaling overhead and time delay caused by the terminal equipment entering the RRC connection state to receive the multicast configuration information can be avoided.

With reference to the sixth aspect, in certain implementations of the sixth aspect, the method further includes: the fourth network device sends sixth information to the third network device, wherein the sixth information comprises M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information; or, the sixth information includes M pieces of multicast configuration information, where M is a positive integer; the fourth network device receives eighth information from the third network device, the first information including at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, the at least one multicast configuration information including M multicast configuration information.

In a seventh aspect, a communication method is provided, which may be performed by a terminal device, or may also be performed by a component (e.g., a chip or a circuit) of the terminal device, which is not limited in this application.

The method may include: the terminal equipment receives first multicast configuration information and tenth information from fifth network equipment, wherein the first multicast configuration information is used for configuring a first multicast session, and the tenth information is used for indicating an effective area of the first multicast configuration information; and the terminal equipment receives the first multicast session in a Radio Resource Control (RRC) inactive state or idle state according to the first multicast configuration information in the service area.

Based on the above scheme, the terminal device can obtain the first multicast configuration information for receiving the first multicast session, and can also obtain the effective area of the first multicast configuration information, when the terminal device moves in the area, the terminal device can continue to use the multicast configuration information to receive the multicast session, so that the continuity of the terminal device for receiving the multicast service can be ensured.

On the other hand, the method can avoid the condition that the terminal equipment triggers RRC connection recovery when the cell reselects to a new cell every time, can save the energy consumption of the terminal equipment and can also save the overhead of air interface signaling.

In an eighth aspect, a communication method is provided, which may be performed by the fifth network device, or may also be performed by a component (such as a chip or a circuit) of the fifth network device, which is not limited in this application.

The method may include: the fifth network device sends a third message to the first device, wherein the third message is used for requesting multicast configuration information of the first multicast session; the fifth network device receives first multicast configuration information from the first device, the first multicast configuration information is determined according to the third message and the value range of the multicast configuration parameter, and the first multicast configuration information is used for configuring the terminal device to receive the first multicast session in a Radio Resource Control (RRC) inactive state or idle state.

Based on the above scheme, the first device may determine the first multicast configuration information for the first multicast session provided by the one or more fifth network devices, in other words, the first device may determine the first multicast configuration information that may be used by the one or more fifth network devices for the first multicast session, so that, for the same multicast session, different network devices supporting the first multicast session in one area may use the same multicast configuration information, and thus, the multicast configuration information in the area can be synchronized.

On the other hand, when the terminal equipment moves in the area, the terminal equipment can continue to use the multicast configuration information to receive the multicast session, so that the continuity of the terminal equipment for receiving the multicast service can be ensured.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the method further includes: the fifth network device sends the first multicast configuration information to the terminal device.

With reference to the eighth aspect, in some implementations of the eighth aspect, the range of values of the multicast configuration parameter includes at least one of: the method comprises the steps of selecting a value range of a G-RNTI, selecting a value range of a multicast radio bearer MRB identifier, selecting a value range of a logic channel LCH identifier, selecting a value range of a physical channel configuration parameter, selecting a value range of a discontinuous reception DRX configuration parameter and selecting a value range of a common frequency domain resource CFR configuration parameter.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the third message includes at least one of: the identity of the first multicast session, the number of MRBs required for the first multicast session, the number of logical channels LCHs required for the first MRB of the first multicast session.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the third message includes an identification of a second cell, the second cell being a cell managed by the fifth network device that provides the first multicast session in the RRC inactive state or in the idle state.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the method further includes: the fifth network device receives tenth information from the first device, the tenth information indicating an effective area of the first multicast configuration information.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the method further includes: the fifth network device sends a fourth message to the first device, the fourth message including a range of values for the multicast configuration parameters.

With reference to the eighth aspect, in some implementations of the eighth aspect, the fourth message further includes identification information of a second area, where the second area is a valid area of the range of values of the multicast configuration parameters.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the cells in the second area provide at least one multicast session, where the at least one multicast session includes a first multicast session, multicast configuration information of other multicast sessions in the at least one multicast session except the first multicast session is different from the first multicast configuration information, and multicast configuration information of the at least one multicast session is different from each other.

With reference to the eighth aspect, in some implementations of the eighth aspect, the second area is a notification area RNA based on a radio access network where the fifth network device is located.

With reference to the eighth aspect, in certain implementations of the eighth aspect, the method further includes: the fifth network device sends eleventh information to the first device, the eleventh information being used to instruct the third cell managed by the fifth network device to stop providing the first multicast session in a radio resource control RRC inactive state or idle state.

In a ninth aspect, a communication method is provided, which may be performed by the fourth network device, or may also be performed by a component (e.g. a chip or a circuit) of the fourth network device, which is not limited in this application.

The method may include: the first device receives a third message from the fifth network device, the third message being used to request multicast configuration information for the first multicast session; the first device determines first multicast configuration information according to the third message and the value range of the multicast configuration parameter, wherein the first multicast configuration information is used for configuring the terminal device to receive the first multicast session in a Radio Resource Control (RRC) inactive state or idle state; the first device sends first multicast configuration information to a fifth network device.

With reference to the ninth aspect, in some implementations of the ninth aspect, the third message includes an identifier of the first multicast session, the range of values of the multicast configuration parameters includes a range of values of the G-RNTI, and the first device determines the first multicast configuration information according to the third message and the range of values of the multicast configuration parameters, including: the first device selects a value from a value range of the G-RNTI as the G-RNTI of the first multicast session, and the first multicast configuration information comprises the G-RNTI of the first multicast session.

With reference to the ninth aspect, in some implementations of the ninth aspect, the third message includes an identifier of the first multicast session and a number X of multicast radio bearers MRBs required for the first multicast session, a range of values of the multicast configuration parameters includes a range of values of the MRB identifier, and the first device determines the first multicast configuration information according to the third message and the range of values of the multicast configuration parameters, including: the first device selects X values from the value range of the MRB identifier as the MRB identifier of the first multicast session, wherein the first multicast configuration information comprises the MRB identifier of the first multicast session, and X is a positive integer.

With reference to the ninth aspect, in some implementations of the ninth aspect, the third message includes an identifier of the first multicast session and a number Y of logical channels LCHs required by the first MRB of the first multicast session, a range of values of the multicast configuration parameter includes a range of values of LCH identifiers, and the first device determines the first multicast configuration information according to the third message and the range of values of the multicast configuration parameter, including: the first device selects Y values from a value range of the LCH identifier as the LCH identifier of the first MRB, the first multicast configuration information comprises the LCH identifier of the first MRB, and Y is a positive integer.

With reference to the ninth aspect, in some implementations of the ninth aspect, the third message includes an identifier of the first multicast session, the range of values of the multicast configuration parameters includes a range of values of the physical channel configuration parameters, and the first device determines the first multicast configuration information according to the third message and the range of values of the multicast configuration parameters, including: the first device selects at least one value from a range of values of physical channel configuration parameters as the physical channel configuration parameters of the first multicast session, the first multicast configuration information including the physical channel configuration parameters of the first multicast session.

With reference to the ninth aspect, in some implementations of the ninth aspect, the third message includes an identifier of the first multicast session, the range of values of the multicast configuration parameters includes a range of values of the discontinuous reception DRX configuration parameters, and the first device determines the first multicast configuration information according to the third message and the range of values of the multicast configuration parameters, including: the first device selects at least one value from a range of values of DRX configuration parameters as the DRX configuration parameters of the first multicast session, the first multicast configuration information including the DRX configuration parameters of the first multicast session.

With reference to the ninth aspect, in some implementations of the ninth aspect, the third message includes an identifier of the first multicast session, the range of values of the multicast configuration parameters includes a range of values of the common frequency domain resource CFR configuration parameters, and the first device determines the first multicast configuration information according to the third message and the range of values of the multicast configuration parameters, including: the first device selects at least one value from a range of values of the CFR configuration parameters as the CFR configuration parameters of the first multicast session, the first multicast configuration information including the CFR configuration parameters of the first multicast session.

With reference to the ninth aspect, in certain implementations of the ninth aspect, the third message includes an identification of a second cell, the second cell being a cell managed by the fifth network device that provides the first multicast session in the RRC inactive state or the idle state, the method further comprising: the first device determines tenth information from third messages from the one or more fifth network devices, the tenth information indicating an effective area of the first multicast configuration information.

With reference to the ninth aspect, in certain implementations of the ninth aspect, the method further includes: the first device sends tenth information to the fifth network device.

With reference to the ninth aspect, in certain implementations of the ninth aspect, the method further includes: the first device receives a fourth message from the fifth network device, the fourth message including a range of values for the multicast configuration parameters.

With reference to the ninth aspect, in some implementations of the ninth aspect, the fourth message further includes identification information of a second area, where the second area is an effective area of a range of values of the multicast configuration parameter.

With reference to the ninth aspect, in certain implementations of the ninth aspect, the cells in the second area provide at least one multicast session, the at least one multicast session including a first multicast session, the method further comprising: the first device determines mutually different multicast configuration information for at least one multicast session. In other words, the multicast configuration information of the other multicast sessions except the first multicast session in the at least one multicast session is different from the first multicast configuration information.

With reference to the ninth aspect, in some implementations of the ninth aspect, the second area is a notification area RNA based on a radio access network where the fifth network device is located.

With reference to the ninth aspect, in certain implementations of the ninth aspect, the method further includes: the first device receiving eleventh information from the fifth network device, the eleventh information being for instructing the third cell managed by the fifth network device to stop providing the first multicast session in a radio resource control RRC inactive state or an idle state; the first device removes the third cell from the active area of the first multicast configuration information.

Optionally, in the method of any one of the above aspects, the first multicast configuration information includes at least one of: G-RNTI, MRB configuration, CFR configuration, DRX configuration, physical channel configuration of the first multicast session.

In a tenth aspect, there is provided a communication apparatus, which may be executed by a terminal device, or may be a component (such as a chip or a circuit) of the terminal device, which is not limited in this application.

The apparatus may include: a transceiver unit, configured to receive first information from a first network device, where the first information includes at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, the at least one multicast configuration information includes the first multicast configuration information, and the index information corresponding to the at least one multicast configuration information includes the first index information; the transceiver unit is further configured to: receiving second information from a second network device, wherein the second information is used for indicating a first multicast session to associate with first index information, and the first index information indicates first multicast configuration information; a processing unit for: and receiving the first multicast session from the second network device in a Radio Resource Control (RRC) inactive state or idle state according to the first multicast configuration information.

With reference to the tenth aspect, in certain implementations of the tenth aspect, the transceiver unit is further configured to: acquiring a first identifier, wherein the first identifier is an identifier of a resident cell of the terminal equipment or an identifier of network equipment corresponding to the resident cell, and the first identifier has a corresponding relation with first multicast configuration information; the processing unit is further configured to: and determining first multicast configuration information according to the first identification and the first index information.

With reference to the tenth aspect, in certain implementations of the tenth aspect, the transceiver unit is further configured to: third information is received from the first network device, the third information indicating an effective area of at least one multicast configuration information.

With reference to the tenth aspect, in certain implementations of the tenth aspect, the transceiver unit is further configured to: receiving fourth information from the first network device or the second network device, wherein the fourth information is used for indicating a first G-RNTI corresponding to the first multicast session; the terminal equipment descrambles the first multicast session according to the first G-RNTI.

With reference to the tenth aspect, in certain implementations of the tenth aspect, the fourth information is information of the first G-RNTI; or the fourth information is index information of the first G-RNTI, and the index information of the first G-RNTI has a corresponding relation with the first G-RNTI; or the fourth information is information of a second G-RNTI, and the second G-RNTI has a corresponding relation with the first G-RNTI.

With reference to the tenth aspect, in certain implementations of the tenth aspect, the first index information includes one or more of: multicast radio bearer, MRB, configuration index, physical channel configuration index, discontinuous reception, DRX, configuration index, neighbor cell configuration index, common frequency domain resource, CFR, configuration index, semi-persistent scheduling (SPS) configuration index.

With reference to the tenth aspect, in certain implementations of the tenth aspect, the processing unit is further configured to: receiving the second information when any one of the following conditions is satisfied: the conditions include: the terminal equipment reselects to a cell managed by the second network equipment; or the terminal equipment receives fifth information, wherein the fifth information is used for notifying the system message change; or, the fifth information is used for notifying the multicast control channel message change; or, the fifth information is used for notifying the first multicast session to be activated; the fifth information is used for indicating the terminal equipment to receive the multicast session in the RRC inactive state or the idle state;

With reference to the tenth aspect, in certain implementations of the tenth aspect, the transceiver unit is further configured to: and receiving a first message from the second network device, wherein the first message is a system message or a multicast control channel message, and the first message is used for indicating that the first multicast session is stopped to be received or that a cell managed by the second network device stops providing the first multicast session in an inactive state.

Optionally, the processing unit is further configured to: and determining whether to recover the RRC connection according to the first message.

In an eleventh aspect, there is provided an apparatus for communication, where the apparatus may be the third network device, or may also be a component (such as a chip or a circuit) of the third network device, and this application is not limited thereto. The third network device may be the first network device in the first aspect, or the second network device in the first aspect.

The apparatus may include: the receiving and transmitting unit is used for transmitting second information, the second information is used for indicating first multicast session related first index information, and the first index information indicates first multicast configuration information; and the processing unit is used for sending the first multicast session according to the first multicast configuration information.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the transceiver unit is further configured to: and sending first information to the terminal equipment, wherein the first information comprises at least one piece of multicast configuration information and index information corresponding to the at least one piece of multicast configuration information, the at least one piece of multicast configuration information comprises the first multicast configuration information, and the index information corresponding to the at least one piece of multicast configuration information comprises the first index information.

With reference to the eleventh aspect, in some implementations of the eleventh aspect, the first information further includes identification information of a cell or a network device corresponding to the at least one multicast configuration information.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the transceiver unit is further configured to: and sending the first identifier, wherein the first identifier is the identifier of the third network equipment or the identifier of the cell corresponding to the second information.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the transceiver unit is further configured to: first information is acquired.

With reference to the eleventh aspect, in some implementations of the eleventh aspect, the transceiver unit is specifically configured to: receiving sixth information from fourth network equipment, wherein the sixth information comprises M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information; the processing unit is further configured to: determining N pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information; the at least one piece of multicast configuration information comprises M pieces of multicast configuration information and N pieces of configuration information, wherein M and N are positive integers.

With reference to the eleventh aspect, in some implementations of the eleventh aspect, the transceiver unit is specifically configured to: determining N pieces of multicast configuration information; receiving sixth information from the fourth network device, the sixth information including M multicast configuration information; the processing unit is further configured to: determining index information corresponding to the M pieces of multicast configuration information and the N pieces of multicast configuration information according to the M pieces of configuration information and the N pieces of multicast configuration information; the at least one piece of multicast configuration information comprises M pieces of multicast configuration information and N pieces of configuration information, wherein M and N are positive integers.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the transceiver unit is further configured to: the first information is sent to a fourth network device.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the transceiver unit is further configured to: the terminal device sends third information, where the third information is used to indicate an effective area of at least one multicast configuration information.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the transceiver unit is further configured to: and sending fourth information to the terminal equipment, wherein the fourth information is used for indicating a first G-RNTI, and the first G-RNTI is used for scrambling the first multicast session.

With reference to the eleventh aspect, in some implementations of the eleventh aspect, the fourth information is information of the first G-RNTI, and the transceiver unit is further configured to: receiving a first G-RNRI from a core network device; or, the processing unit is further configured to: and determining the first G-RNTI according to the identification of the first multicast session.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the first index information includes one or more of: multicast radio bearer, MRB, configuration index, physical channel configuration index, discontinuous reception, DRX, configuration index, neighbor cell configuration index, common frequency domain resource, CFR, configuration index, semi-persistent scheduling, SPS, configuration index.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the transceiver unit is further configured to: and transmitting fifth information, wherein the fifth information is used for notifying system message change or notifying multicast control channel message change, and the fifth information is used for receiving the second information by the terminal equipment.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the processing unit is further configured to: transmitting fifth information to the terminal device when any one of the following conditions is satisfied, the conditions including: changing the multicast configuration information of the first multicast session into first multicast configuration information; or, the third network device managed cell begins to provide the first multicast session in an inactive state or an idle state.

With reference to the eleventh aspect, in certain implementations of the eleventh aspect, the transceiver unit is further configured to: and sending a first message, wherein the first message is a system message and a multicast control channel message, and the first message is used for indicating that the first multicast session is in a deactivated state or released or used for indicating that a cell managed by the second network equipment stops providing the first multicast session in the deactivated state.

In a twelfth aspect, there is provided an apparatus for communication, which may be the fourth network device, or may also be a component (such as a chip or a circuit) of the fourth network device, which is not limited in this application.

The apparatus may include: a transceiver unit, configured to send sixth information to the third network device, where the sixth information includes M multicast configuration information and index information corresponding to the M multicast configuration information; or, the sixth information includes M pieces of multicast configuration information, where M is a positive integer; the transceiver unit is further configured to: first information from a third network device is received, the first information including at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, the at least one multicast configuration information including M multicast configuration information.

With reference to the twelfth aspect, in some implementations of the twelfth aspect, the transceiver unit is further configured to: transmitting seventh information, wherein the seventh information is used for indicating the first multicast session to associate with second index information, the second index information indicates second multicast configuration information, at least one piece of multicast configuration information comprises the second multicast configuration information, and index information corresponding to at least one piece of multicast configuration information comprises the second index information; the apparatus may also include a processing unit configured to send the first multicast session according to the second multicast configuration information.

In a thirteenth aspect, there is provided a communication apparatus, which may be executed by a terminal device, or may be a component (such as a chip or a circuit) of the terminal device, which is not limited in this application.

The apparatus may include: a transceiver unit, configured to receive eighth information from the first network device, where the eighth information includes first multicast configuration information and information of a cell corresponding to the first multicast configuration information, the first multicast configuration corresponds to a first multicast session, and the cell information corresponding to the first multicast configuration information includes a first cell; the transceiver unit is further configured to: receiving a second message from a second network device, the second message including first indication information for indicating a state of a first multicast session provided by a first cell; and the receiving and transmitting unit is used for receiving the first multicast session according to the first multicast configuration information under the condition that the first cell is the resident cell of the terminal equipment.

With reference to the thirteenth aspect, in some implementations of the thirteenth aspect, the transceiver unit is specifically configured to: receiving a first multicast session in an RRC inactive state or an idle state according to first multicast configuration information under the condition that the first indication information indicates that the first cell starts to provide the first multicast session in the RRC inactive state or the idle state; or, in case the first indication information indicates that the first cell stops providing the first multicast session in the RRC inactive state or the idle state, sending an RRC resume request message to a network device corresponding to the first cell.

Optionally, the second message is a paging message or an RRC release message.

With reference to the thirteenth aspect, in certain implementations of the thirteenth aspect, the eighth information is carried on an RRC release message or an RRC reconfiguration message.

With reference to the thirteenth aspect, in certain implementations of the thirteenth aspect, the first indication information is a bit map, at least one bit in the bit map being associated with the first cell.

With reference to the thirteenth aspect, in some implementations of the thirteenth aspect, the cell information corresponding to the first multicast configuration information includes Q cells, and the bit map includes Q bits, where the Q bits and the Q cells are in one-to-one correspondence.

With reference to the thirteenth aspect, in some implementations of the thirteenth aspect, the eighth information further includes at least one multicast configuration information, index information corresponding to the at least one multicast configuration information, and cell information corresponding to the at least one multicast configuration information, the at least one multicast configuration information includes first multicast configuration information, the index information corresponding to the at least one multicast configuration information includes first index information, and the cell information corresponding to the at least one multicast configuration information includes first cells.

With reference to the thirteenth aspect, in certain implementations of the thirteenth aspect, the second message further includes second information, where the second information is used to indicate that the first multicast session is associated with first index information, and the first index information indicates the first multicast configuration information.

With reference to the thirteenth aspect, in certain implementations of the thirteenth aspect, the first index information includes one or more of: MRB configuration index, physical channel configuration index, discontinuous reception DRX configuration index, neighbor cell configuration index, CFR configuration index, SPS configuration index.

With reference to the thirteenth aspect, in certain implementations of the thirteenth aspect, the transceiver unit is further configured to: receiving fourth information from the first network device or the second network device, wherein the fourth information is used for indicating a first G-RNTI corresponding to the first multicast session; the terminal equipment descrambles the first multicast session according to the first G-RNTI.

With reference to the thirteenth aspect, in certain implementations of the thirteenth aspect, the fourth information is information of the first G-RNTI; or the fourth information is index information of the first G-RNTI, and the index information of the first G-RNTI has a corresponding relation with the first G-RNTI; or the fourth information is information of a second G-RNTI, and the second G-RNTI has a corresponding relation with the first G-RNTI.

In a fourteenth aspect, there is provided an apparatus for communication, which may be the third network device, or may also be a component (such as a chip or a circuit) of the third network device, which is not limited in this application. The third network device may be the first network device in the fourth aspect, or the second network device in the fourth aspect.

The apparatus may include: the receiving and transmitting unit is used for transmitting a second message, wherein the second message comprises first indication information, and the first indication information is used for indicating the state of a first multicast session provided by a first cell to change; and the processing unit is used for sending the first multicast session according to the first multicast configuration information.

Optionally, the third network device is the first network device in the tenth aspect, or is the second network device in the tenth aspect.

Optionally, the transceiver unit is further configured to: and transmitting eighth information to the terminal equipment, wherein the eighth information comprises first multicast configuration information and cell information corresponding to the first multicast configuration information, the first multicast configuration corresponds to a first multicast session, and the cell information corresponding to the first multicast configuration information comprises a first cell.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the eighth information is carried on an RRC release message or an RRC reconfiguration message.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the transceiver unit is further configured to: and receiving ninth information from fourth network equipment, wherein the ninth information is used for indicating the identification of R cells corresponding to the first multicast configuration information, the cell information corresponding to the first multicast configuration information comprises R cells, and R is a positive integer.

With reference to the fourteenth aspect, in certain implementations of the fourteenth aspect, the first indication information is a bit map, at least one bit in the bit map being associated with the first cell.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the eighth information further includes at least one multicast configuration information, index information corresponding to the at least one multicast configuration information, and cell information corresponding to the at least one multicast configuration information, the at least one multicast configuration information includes first multicast configuration information, the index information corresponding to the at least one multicast configuration information includes first index information, and the cell information corresponding to the at least one multicast configuration information includes first cells.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the transceiver unit is further configured to: receiving sixth information from fourth network equipment, wherein the sixth information comprises M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information; the processing unit is further configured to: determining N pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information;

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the processing unit is specifically configured to: determining N pieces of multicast configuration information; the receiving and transmitting unit is specifically used for: receiving sixth information from the fourth network device, the sixth information including M multicast configuration information; the processing unit is specifically configured to: determining index information corresponding to the M pieces of multicast configuration information and the N pieces of multicast configuration information according to the M pieces of configuration information and the N pieces of multicast configuration information;

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the sixth information further includes identification information of cells corresponding to the M multicast configuration information.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the transceiver unit is further configured to: and sending eighth information to the fourth network device.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the second message further includes second information, where the second information is used to indicate that the first multicast session is associated with first index information, and the first index information indicates first multicast configuration information.

With reference to the fourteenth aspect, in certain implementations of the fourteenth aspect, the first index information includes one or more of:

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the transceiver unit is further configured to: and sending fourth information to the terminal equipment, wherein the fourth information is used for indicating a first G-RNTI, and the first G-RNTI is used for scrambling the first multicast session.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the fourth information is information of the first G-RNTI; or the fourth information is index information of the first G-RNTI, and the index information of the first G-RNTI has a corresponding relation with the first G-RNTI; or the fourth information is information of a second G-RNTI, and the second G-RNTI has a corresponding relation with the first G-RNTI.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the fourth information is information of the first G-RNTI, and the transceiver unit is further configured to: the third network equipment receives a first G-RNRI from the core network equipment; or, the processing unit is further configured to: and determining the first G-RNTI according to the identification of the first multicast session.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the first cell is a cell managed by the third network device.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, the transceiver unit is further configured to: and receiving second indication information from the fourth network device, wherein the second indication information is used for indicating the state transmission change of the first multicast session provided by the first cell, and the first cell is a cell managed by the fourth network device.

In a fifteenth aspect, there is provided an apparatus for communication, which may be the fourth network device, or may also be a component (such as a chip or a circuit) of the fourth network device, which is not limited in this application.

The apparatus may include: the receiving and transmitting unit is used for transmitting second indication information to the third network equipment, wherein the second indication information is used for indicating the state of a first multicast session in a non-connection state or an idle state provided by a first cell, and the first cell is a cell managed by the second network equipment; the transceiver unit is further configured to: and sending a second message, wherein the second message comprises first indication information, and the first indication information is used for indicating the state of a first multicast session in a non-connection state or an idle state provided by the first cell.

With reference to the fifteenth aspect, in certain implementations of the fifteenth aspect, the transceiver unit is further configured to: transmitting sixth information to the third network device, wherein the sixth information comprises M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information; or, the sixth information includes M pieces of multicast configuration information, where M is a positive integer; and receiving eighth information from the third network device, wherein the first information comprises at least one piece of multicast configuration information and index information corresponding to the at least one piece of multicast configuration information, and the at least one piece of multicast configuration information comprises M pieces of multicast configuration information.

In a sixteenth aspect, there is provided an apparatus for communication, which may be executed by a terminal device, or may be a component (such as a chip or a circuit) of the terminal device, which is not limited in this application.

The apparatus may include: a transceiver unit, configured to receive first multicast configuration information and tenth information from a fifth network device, where the first multicast configuration information is used to configure a first multicast session, and the tenth information is used to indicate an effective area of the first multicast configuration information; and the processing unit is used for receiving the first multicast session in the Radio Resource Control (RRC) inactive state or idle state according to the first multicast configuration information in the effective area.

In a seventeenth aspect, there is provided an apparatus for communication, which may be the fifth network device, or may also be a component (such as a chip or a circuit) of the fifth network device, which is not limited in this application.

The apparatus may include: a transceiver unit, configured to send a third message to the first device, where the third message is used to request multicast configuration information of the first multicast session; the transceiver unit is further configured to: and receiving first multicast configuration information from the first equipment, wherein the first multicast configuration information is determined according to the third message and the value range of the multicast configuration parameter, and the first multicast configuration information is used for configuring the terminal equipment to receive the first multicast session in a Radio Resource Control (RRC) inactive state or idle state.

With reference to the seventeenth aspect, in certain implementations of the seventeenth aspect, the transceiver unit is further configured to: and sending the first multicast configuration information to the terminal equipment.

With reference to the seventeenth aspect, in certain implementations of the seventeenth aspect, the range of values of the multicast configuration parameter includes at least one of: the method comprises the steps of selecting a value range of a G-RNTI, selecting a value range of a multicast radio bearer MRB identifier, selecting a value range of a logic channel LCH identifier, selecting a value range of a physical channel configuration parameter, selecting a value range of a discontinuous reception DRX configuration parameter and selecting a value range of a common frequency domain resource CFR configuration parameter.

With reference to the seventeenth aspect, in certain implementations of the seventeenth aspect, the third message includes at least one of: the identity of the first multicast session, the number of MRBs required for the first multicast session, the number of logical channels LCHs required for the first MRB of the first multicast session.

With reference to the seventeenth aspect, in certain implementations of the seventeenth aspect, the third message includes an identification of a second cell, the second cell being a cell managed by the fifth network device that provides the first multicast session in the RRC inactive state or in the idle state.

With reference to the seventeenth aspect, in certain implementations of the seventeenth aspect, the transceiver unit is further configured to: tenth information is received from the first device, the tenth information indicating an effective area of the first multicast configuration information.

With reference to the seventeenth aspect, in certain implementations of the seventeenth aspect, the transceiver unit is further configured to: and sending a fourth message to the first device, wherein the fourth message comprises the value range of the multicast configuration parameters.

With reference to the seventeenth aspect, in some implementations of the seventeenth aspect, the fourth message further includes identification information of a second area, where the second area is an effective area of a range of values of the multicast configuration parameter.

With reference to the seventeenth aspect, in some implementations of the seventeenth aspect, the cells in the second area provide at least one multicast session, where the at least one multicast session includes a first multicast session, multicast configuration information of other multicast sessions in the at least one multicast session except the first multicast session is different from the first multicast configuration information, and multicast configuration information of the at least one multicast session is different from each other.

With reference to the seventeenth aspect, in some implementations of the seventeenth aspect, the second area is a notification area RNA based on a radio access network where the fifth network device is located.

With reference to the seventeenth aspect, in certain implementations of the seventeenth aspect, the transceiver unit is further configured to: and transmitting eleventh information to the first device, the eleventh information being used to instruct the third cell managed by the fifth network device to stop providing the first multicast session in the radio resource control RRC inactive state or idle state.

In an eighteenth aspect, there is provided an apparatus for communication, which may be the first device, or may also be a component (such as a chip or a circuit) of the first device, which is not limited in this application.

The apparatus may include: a transceiver unit, configured to receive a third message from a fifth network device, where the third message is used to request multicast configuration information of the first multicast session; the processing unit is used for determining first multicast configuration information according to the third message and the value range of the multicast configuration parameters, and the first multicast configuration information is used for configuring the terminal equipment to receive the first multicast session in a Radio Resource Control (RRC) inactive state or idle state; the transceiver unit is further configured to: and sending the first multicast configuration information to the fifth network device.

With reference to the eighteenth aspect, in some implementations of the eighteenth aspect, the third message includes an identifier of the first multicast session, and the range of values of the multicast configuration parameter includes a range of values of the G-RNTI, and the processing unit is specifically configured to: and selecting a value from the value range of the G-RNTI as the G-RNTI of the first multicast session, wherein the first multicast configuration information comprises the G-RNTI of the first multicast session.

With reference to the eighteenth aspect, in some implementations of the eighteenth aspect, the third message includes an identifier of the first multicast session and a number X of multicast radio bearers MRBs required for the first multicast session, and the range of values of the multicast configuration parameters includes a range of values of the MRB identifier, and the processing unit is specifically configured to: and selecting X values from the value range of the MRB identifiers as the MRB identifiers of the first multicast session, wherein the first multicast configuration information comprises the MRB identifiers of the first multicast session, and X is a positive integer.

With reference to the eighteenth aspect, in certain implementations of the eighteenth aspect, the third message includes an identifier of the first multicast session and a number Y of logical channels LCHs required by the first MRB of the first multicast session, and the range of values of the multicast configuration parameter includes a range of values of LCH identifiers, and the processing unit is specifically configured to: y values are selected from the value range of the LCH identification to be used as the LCH identification of the first MRB, the first multicast configuration information comprises the LCH identification of the first MRB, and Y is a positive integer.

With reference to the eighteenth aspect, in certain implementation manners of the eighteenth aspect, the third message includes an identifier of the first multicast session, and the range of values of the multicast configuration parameters includes a range of values of physical channel configuration parameters, and the processing unit is specifically configured to: at least one value is selected from the value range of the physical channel configuration parameter as the physical channel configuration parameter of the first multicast session, and the first multicast configuration information comprises the physical channel configuration parameter of the first multicast session.

With reference to the eighteenth aspect, in certain implementation manners of the eighteenth aspect, the third message includes an identifier of the first multicast session, and the range of values of the multicast configuration parameter includes a range of values of the discontinuous reception DRX configuration parameter, and the processing unit is specifically configured to: at least one value is selected from a range of values of DRX configuration parameters as the DRX configuration parameters of the first multicast session, and the first multicast configuration information comprises the DRX configuration parameters of the first multicast session.

With reference to the eighteenth aspect, in certain implementation manners of the eighteenth aspect, the third message includes an identifier of the first multicast session, and the range of values of the multicast configuration parameters includes a range of values of common frequency domain resource CFR configuration parameters, and the processing unit is specifically configured to: at least one value is selected from the value range of the CFR configuration parameters to serve as the CFR configuration parameters of the first multicast session, and the first multicast configuration information comprises the CFR configuration parameters of the first multicast session.

With reference to the eighteenth aspect, in certain implementations of the eighteenth aspect, the third message includes an identification of a second cell, the second cell being a cell managed by the fifth network device and providing the first multicast session in the RRC inactive state or in the idle state, and the processing unit is further configured to: tenth information is determined from third messages from the one or more fifth network devices, the tenth information indicating an effective area of the first multicast configuration information.

With reference to the eighteenth aspect, in certain implementations of the eighteenth aspect, the transceiver is further configured to: and transmitting tenth information to the fifth network device.

With reference to the eighteenth aspect, in certain implementations of the eighteenth aspect, the transceiver is further configured to: a fourth message is received from the fifth network device, the fourth message including a range of values for the multicast configuration parameters.

With reference to the eighteenth aspect, in some implementations of the eighteenth aspect, the fourth message further includes identification information of a second area, where the second area is an effective area of a range of values of the multicast configuration parameter.

With reference to the eighteenth aspect, in certain implementations of the eighteenth aspect, the cells in the second area provide at least one multicast session, the at least one multicast session including a first multicast session, the processing unit is further configured to: multicast configuration information that is different from each other is determined for at least one multicast session. In other words, the multicast configuration information of the other multicast sessions except the first multicast session in the at least one multicast session is different from the first multicast configuration information.

With reference to the eighteenth aspect, in certain implementations of the eighteenth aspect, the second area is a notification area RNA based on a radio access network where the fifth network device is located.

With reference to the eighteenth aspect, in certain implementations of the eighteenth aspect, the transceiver is further configured to: receiving eleventh information from the fifth network device, the eleventh information being used to instruct the third cell managed by the fifth network device to stop providing the first multicast session in a radio resource control RRC inactive state or an idle state; the processing unit is further configured to: the third cell is removed from the active area of the first multicast configuration information.

Optionally, in the apparatus of any one of the above aspects, the first multicast configuration information includes at least one of: G-RNTI, MRB configuration, CFR configuration, DRX configuration, physical channel configuration of the first multicast session.

In a nineteenth aspect, there is provided a communication apparatus comprising: at least one processor configured to execute a computer program or instructions stored in a memory to perform a method according to any one of the possible implementations of the first to ninth aspects. Optionally, the apparatus further comprises a memory for storing a computer program or instructions. Optionally, the apparatus further comprises a communication interface through which the processor reads the computer program or instructions stored in the memory.

In one implementation, the apparatus is a terminal device or a first network device.

In another implementation, the apparatus is a chip, a system-on-chip or a circuit for a terminal device or a first network device.

In a twentieth aspect, the present application provides a processor configured to perform the methods provided in the first to ninth aspects.

The operations such as transmitting and acquiring/receiving, etc. related to the processor may be understood as operations such as outputting and receiving, inputting, etc. by the processor, or may be understood as operations such as transmitting and receiving by the radio frequency circuit and the antenna, if not specifically stated, or if not contradicted by actual function or inherent logic in the related description, which is not limited in this application.

In a twenty-first aspect, a computer-readable storage medium is provided, the computer-readable medium storing program code for execution by a device, the program code comprising instructions for performing the method of any one of the possible implementations of the first to ninth aspects described above.

In a twenty-second aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any one of the possible implementations of the first to ninth aspects described above.

In a twenty-third aspect, a communication system is provided, comprising the third network device of the eleventh aspect and the fourth network device of the twelfth aspect, or comprising the third network device of the fourteenth aspect and the fourth network device of the fifteenth aspect.

In a twenty-fourth aspect, there is provided a communication method comprising the method performed by the fifth network device of the eighth aspect and the method performed by the first device of the ninth aspect.

Illustratively, the method includes: the fifth network device sends a third message to the first device, wherein the third message is used for requesting multicast configuration information of the first multicast session; the first device determines first multicast configuration information according to the third message and the value range of the multicast configuration parameter, wherein the first multicast configuration information is used for configuring the terminal device to receive the first multicast session in a Radio Resource Control (RRC) inactive state or idle state; the first device sends first multicast configuration information to a fifth network device.

Drawings

Fig. 1 shows a schematic diagram of a wireless communication system suitable for use in embodiments of the present application.

Fig. 2 shows a schematic diagram of several architectures suitable for use in embodiments of the present application.

Fig. 3 shows another schematic diagram of a scenario suitable for use in embodiments of the present application.

Fig. 4 is a schematic diagram of transmission resources of information for a multicast broadcast session.

Fig. 5 is a schematic diagram of a communication method 200 according to an embodiment of the present application.

Fig. 6 is a schematic structural diagram of the TMGI.

Fig. 7 is a schematic diagram of a method 300 of communication provided in an embodiment of the present application.

Fig. 8 is a schematic diagram of a communication method 400 according to an embodiment of the present application.

Fig. 9 is a schematic diagram of a communication method 500 according to an embodiment of the present application.

Fig. 10 is a schematic diagram of a method 600 of communication provided in an embodiment of the present application.

Fig. 11 is a schematic diagram of a method 700 of communication provided in an embodiment of the present application.

Fig. 12 is a schematic diagram of a method 800 of communication provided in an embodiment of the present application.

Fig. 13 is a schematic diagram of a method 900 of communication provided in an embodiment of the present application.

Fig. 14 is a schematic diagram of a communication device 2800 provided in an embodiment of the present application.

Fig. 15 is a schematic diagram of another communication device 2900 provided in an embodiment of the present application.

Fig. 16 is a schematic diagram of a chip system 3000 provided in an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

The technical scheme provided by the application can be applied to various communication systems, such as: fifth generation (5th generation,5G) or New Radio (NR) systems, long term evolution (long term evolution, LTE) systems, LTE frequency division duplex (frequency division duplex, FDD) systems, LTE time division duplex (time division duplex, TDD) systems, and the like. The technical scheme provided by the application can also be applied to future communication systems, such as a sixth generation mobile communication system. The technical solutions provided herein may also be applied to device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine (machine to machine, M2M) communication, machine type communication (machine type communication, MTC), and internet of things (internet of things, ioT) communication systems or other communication systems. As an example, V2X may include vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), vehicle-to-infrastructure (V2I). The infrastructure is, for example, a Road Side Unit (RSU) or a network device.

The method provided by the embodiment of the application is applicable to but not limited to the following fields: MBMS, SC-PTM, multicast broadcast service, MBSFN, dual channel smart unicast (Dual-channel intelligent unicast, DC-IU), broadcast, multicast, broadcast multicast (Multicast Broadcast), groupcast, V2X, public safety (public safety), mission critical (transmission critical), IPv4/IPv6 multicast transmission (transmission IPv4/IPv6 multicast delivery), IPTV, software delivery over wireless (software delivery over wireless), group communication (group communications), internet of things (Internet of things, ioT), television Video (TV Video), television (TV), linear television (linear TV), live, broadcast services (radio services), device-to-device (D2D), unmanned driving (automated driving, ADS), assisted driving (driver assistance, ADS), intelligent driving (intelligent driving), internet driving (connected driving), intelligent driving (intelligent network driving), car sharing (car sharing), and the like.

The terminal device in the embodiment of the present application includes various devices having a wireless communication function, which can be used for connecting people, things, machines, and the like. The terminal device can be widely applied to various scenes, for example: cellular communication, D2D, V2X, peer to peer (P2P), M2M, MTC, ioT, virtual Reality (VR), augmented reality (augmented reality, AR), industrial control, autopilot, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city drone, robot, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery, and other scenarios. The terminal device may be a terminal in any of the above scenarios, such as an MTC terminal, an IoT terminal, etc. The terminal device may be a User Equipment (UE) standard of the third generation partnership project (3rd generation partnership project,3GPP), a terminal (terminal), a fixed device, a mobile station (mobile station) device or a mobile device, a subscriber unit (subscriber unit), a handheld device, a vehicle-mounted device, a wearable device, a cellular phone (smart phone), a smart phone (smart phone), a SIP phone, a wireless data card, a personal digital assistant (personal digital assistant, PDA), a computer, a tablet computer, a notebook computer, a wireless modem, a handheld device (handset), a laptop computer (laptop computer), a computer with wireless transceiver function, a smart book, a vehicle, a satellite, a global positioning system (globalpositioning system, GPS) device, a target tracking device, an aircraft (e.g., a drone, a helicopter, a multi-helicopter, a tetra-helicopter, a plane, etc.), a ship, a remote control device, a smart home device, an industrial device, or a device built in the above device (e.g., a communication module in the above device, a modem, a chip, a wireless modem, or the like), or a processor connected to the wireless modem. For convenience of description, the terminal device will be described below by taking a terminal or UE as an example.

It should be appreciated that in some scenarios, the UE may also be used to act as a base station. For example, the UEs may act as scheduling entities that provide sidelink signals between UEs in a V2X, D2D or P2P or the like scenario.

In the embodiment of the present application, the device for implementing the function of the terminal device, that is, the terminal device, may be the terminal device, or may be a device capable of supporting the terminal device to implement the function, for example, a chip system or a chip, and the device may be installed in the terminal device. In the embodiment of the application, the chip system may be formed by a chip, and may also include a chip and other discrete devices.

The network device in the embodiments of the present application may be a device for communicating with a terminal device, which may also be referred to as an access network device or a radio access network device, e.g. the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (radio access network, RAN) node (or device) that accesses the terminal device to the wireless network. The base station may broadly cover or replace various names in the following, such as: a node B (NodeB), an evolved NodeB (eNB), a next generation NodeB (gNB), a relay station, an access point, a transmission point (transmitting and receiving point, TRP), a transmission point (transmitting point, TP), a master station, a secondary station, a multi-mode wireless (motor slide retainer, MSR) node, a home base station, a network controller, an access node, a wireless node, an Access Point (AP), a transmission node, a transceiver node, a baseband unit (BBU), a remote radio unit (remote radio unit, RRU), an active antenna unit (active antenna unit, AAU), a radio head (remote radio head, RRH), a Central Unit (CU), a Distributed Unit (DU), a positioning node, and the like. The base station may be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof. A base station may also refer to a communication module, modem, or chip for placement within the aforementioned device or apparatus. The base station may be a mobile switching center, a device that performs a base station function in D2D, V2X, M M communication, a network side device in a 6G network, a device that performs a base station function in a future communication system, or the like. The base stations may support networks of the same or different access technologies. The embodiment of the application does not limit the specific technology and the specific device form adopted by the network device.

The base station may be fixed or mobile. For example, a helicopter or drone may be configured to act as a mobile base station, and one or more cells may move according to the location of the mobile base station. In other examples, a helicopter or drone may be configured to function as a device to communicate with another base station.

Network devices and terminal devices may be deployed on land, including indoors or outdoors, hand-held or vehicle-mounted; the device can be deployed on the water surface; but also on aerial planes, balloons and satellites. In the embodiment of the application, the scene where the network device and the terminal device are located is not limited.

Alternatively, the network device in the embodiments of the present application may be a module or a unit that performs a function of a base station part, for example, may be a CU in a cloud access network (cloud radio access network, C-RAN) system or may be a DU. The embodiment of the application does not limit the specific technology and the specific device form adopted by the network device. All or part of the functionality of the network device may also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (e.g., a cloud platform). In the present application, the network device refers to a radio access network device, if not specified.

Alternatively, the CU may perform User Plane and Control Plane decoupling, forming a CU-Control Plane (CU-CP) and a CU-User Plane (CU-UP), which support flexible deployment.

In this embodiment of the present application, the term "wireless communication" may also be simply referred to as "communication", and the term "communication" may also be described as "data transmission", "information transmission" or "transmission".

It should also be understood that "terminal device" is also referred to as "terminal apparatus", "terminal", etc., and "network device" is also referred to as "network apparatus", "network side", etc., and "core network device" is also referred to as "core network apparatus", "core network", etc.

A network architecture suitable for the present application will first be briefly described as follows.

Fig. 1 shows a schematic diagram of a wireless communication system suitable for use in an embodiment of the present application. As shown in fig. 1, the wireless communication system 100 may include at least one network device, such as the network device 110 shown in fig. 1, and may further include at least one terminal device, such as the terminal device 120 and the terminal device 130 shown in fig. 1. The network device and the terminal device may each be configured with multiple antennas, and the network device and the terminal device may communicate using multiple antenna technology. The terminal device 120 and the terminal device 130 may communicate directly or may communicate through the network device 110.

Wherein, when the network device and the terminal device communicate, the network device can manage one or more cells, and one or more terminal devices can be arranged in one cell. Alternatively, the network device and the terminal device constitute a single-cell communication system, and the cell is referred to as cell #1 without loss of generality. The network device 110 in fig. 1 may be a network device in cell #1, or the network device 110 may serve a terminal device (e.g., terminal device 120) in cell #1.

A cell is understood to be an area within the coverage of a radio signal of a network device.

The present application may also be used in dual connectivity (dual connectivity, DC) scenarios including, but not limited to, evolved universal radio access network (evolved universal terrestrial radio access network, EUTRAN) and dual connectivity (EUTRAN-NR dual connectivity, EN-DC) scenarios for NR networks, dual connectivity (NR-NR dual connectivity, NR-DC or NR-DC) scenarios for NR networks.

Fig. 2 shows another schematic diagram of several architectures suitable for embodiments of the present application. As shown in fig. 2 (a), the scenario is a 5G system architecture diagram, as shown in fig. 2 (a), the RAN in 5G may be referred to as next generation RAN (NG-RAN), and the NG-RAN includes two types, that is, a gNB and a next generation eNB (next generationeNB, NG-eNB) based on LTE evolution, and the two types of access network devices may be connected to a core network (5G core,5 GC) of 5G, where the 5GC includes a plurality of network elements, including but not limited to an access and mobility management function (access and mobility management function, AMF) and a user plane function (user plane function, UPF). In addition, the access network devices can communicate through an Xn interface, the access network devices and the 5G core network can communicate through an NG interface, and relevant architecture details are defined in a protocol.

The method and the device can also be used for carrier aggregation (carrier aggregation, CA) scenes, under the CA scenes, a plurality of cell groups can serve terminal equipment, namely, a plurality of component carriers (component carrier, CC) can be aggregated together, and the peak rate and the system capacity of the terminal are improved, so that the network rate requirements of the terminal are met. CA has two important concepts: a primary component carrier in a primary cell (Pcell) and a secondary component carrier in a secondary cell (Scell). After the radio resource control (radio resource control, RRC) connection is established, the secondary cell may be configured to provide additional radio resources for data transmission to increase system capacity.

As shown in fig. 2 (b), the scenario is a scenario in which a CU and a DU are deployed separately, in which a network device includes the CU and the DU, the CU is for communication with a core network, and the DU is for communication with a terminal device.

As shown in fig. 2 (c), the scenario is a scenario in which CU-CP, CI-UP, and DU are deployed respectively, in which a network device includes CU-CP, CI-UP, and DU, the CU-CP is used for communication with a control plane of a core network, the CU-UP is used for communication with a user plane of the core network, and the DU is used for communication with a terminal device.

Fig. 3 shows another schematic diagram of a scenario suitable for use in embodiments of the present application. As shown in fig. 3, the network device may manage a plurality of cells, where cell #1 is a primary cell of the terminal device, cell #2, cell #3, and cell #4 are secondary cells of the terminal device, and CCs of cell #1, cell #2, cell #3, and cell #4 may collectively provide services for the terminal device through CA technology.

For ease of understanding, a brief explanation of the relevant concepts is provided.

1. Status of terminal equipment

The terminal device in NR has three RRC states: an RRC idle (state), an RRC inactive (active) state, and an RRC connected (connected) state. In the RRC connected state (abbreviated as connected state), an RRC connection is established between the terminal device and the network device, and when there is no data transmission, the network device may release the terminal device to an RRC idle state (abbreviated as idle state) or release the terminal device to an RRC inactive state, and suspend (suspend) the RRC connection. In the RRC idle state, no RRC connection is established between the network device and the terminal device (abbreviated as inactive state). In the RRC inactive state, the network device still maintains the context information of the terminal device. The advantage of introducing the RRC inactive state is that compared to the RRC idle state, the network device still retains the terminal device context in the RRC inactive state, so that the RRC connection can be restored more quickly, and the delay can be reduced when a service arrives.

2. Paging (paging)

Since the terminal device has mobility, when the terminal device is in RRC idle state, the network needs a Core Network (CN) to send paging messages under all cells under all Tracking Areas (TAs) in a tracking area identity (tracking area identity, TAI) list in order to find the terminal device, and CN-initiated paging (CN-initiated paging) may be simply referred to as CN paging. Obviously, with this level of terminal tracking, a high paging message transmission overhead is incurred since most paging messages are issued in cells where the terminal device is not located. In order to save transmission overhead, for terminal devices in RRC inactive state, a smaller range than the TA range is introduced, i.e. a radio access network based notification area (RAN-based Notification Area, RNA), one TA range may include multiple RNAs, one RNA may include multiple cells, the RNAs are managed by a network device, the network device may send paging messages to the cells within the RNA range, and network device initiated paging (RAN-initiated paging) may be abbreviated as RAN paging. For RAN paging, when a last serving base station (last serving nb) of the terminal device receives downlink data from the UPF or downlink signaling from the AMF, the terminal device will be paged on a cell in the RNA area, and if the cell of the neighboring network device is included in the RNA area, the last serving base station will transmit RAN paging to the neighboring network device through an Xn interface, and the neighboring network device pages the terminal device in its cell. Upon receipt of the paging message, the terminal device in the RRC inactive state or the RRC idle state triggers RRC recovery (RRC resume) or RRC connection establishment.

3. Multicast broadcast service (multicast and broadcast service, MBS)

The MBS can simultaneously provide data for a large number of users with the same demands with fewer resources, so that network resources can be shared. MBS includes multicast services and broadcast services, which refers to communication services in which network devices simultaneously provide the same specific content data to all terminal devices in a certain geographical area. Multicast services refer to a network device providing communication services to a group of terminal devices joining a multicast session (multicast session). The multicast service can be issued to the terminal device through the multicast session, the multicast service can be received only after the authentication process is performed between the terminal device receiving the multicast and the core network, and the authentication process can also understand the process of joining the terminal device into the multicast session, so that the multicast service can be received, namely the multicast session or the MBS session (MBS session), and the MBS session can be identified through the temporary mobile group identifier (Temporary mobile group identity, TMGI). The multicast service may also be called as a multicast service, in this application, "multicast" and "multicast" may be replaced with each other, and the multicast session and the multicast service may be replaced with each other, and the identifier of the multicast service, the identifier of the multicast session, and the TMGI may be replaced with each other, without limitation.

4. Multicast broadcast control channel and multicast broadcast traffic channel

Two logical channels, a multicast broadcast control channel (MBS control channel, MCCH) and a multicast broadcast traffic channel (MBS traffic channel, MTCH), are introduced in the broadcast technology of the NR MBS, where the MCCH is used to transmit control information, and contains configuration information of the MTCH, such as a group radio network temporary identity (group radio network temporary identifier, G-RNTI) corresponding to the MTCH and discontinuous reception (discontinuous reception, DRX) parameters. The MCCH is transmitted in a periodic manner. The MTCH logical channel is used to carry user data of a broadcast service. MTCH is scheduled through MCCH. The configuration of the MTCH is in g-RNTI per (per) level, which can be also called per MBS service level. Wherein, the base station schedules service data to a plurality of UEs simultaneously through g-RNTIs, each g-RNTI may be associated with at least one broadcast service.

It should be appreciated that the above-described channels may correspond to different names in different communication systems. For example, in the fourth generation (4th generation,4G) communication system, the multicast broadcast service control channel may be a single cell multicast broadcast service control channel (SC-MCCH). As another example, in a 5G communication system, the multicast broadcast traffic control channel may be the MC-MCCH. In the future technological development, channels similar to the multicast broadcast service control channel function may be referred to by other names, or channels with the same function may be referred to by different names in different communication environments, communication scenes or communication technologies, but the different names of the channels with similar or same function in different systems do not limit the content and the function of the channels. The multicast broadcast control channel in the present application may be used to transmit control information and the multicast broadcast traffic channel may be used to transmit user data.

The MCCH is used to represent the multicast broadcast traffic control channel and the MTCH is used to represent the multicast broadcast traffic channel in the present application unless otherwise specified. It should be further understood that other english abbreviations in this application are similar thereto and will not be repeated.

5. Multicast broadcast control channel change notification (MCCH change notification)

As shown in fig. 4, the MCCH is repeatedly transmitted in each modification period (Modification period, MP), which includes repetition periods (repetition period, RP). In one MP, the content of the MCCH is the same, i.e., the same MCCH is repeatedly transmitted several times according to the scheduled repetition period. When the MCCH of different MP changes, the network equipment sends PDCCH containing MCCH change notification. When the UE detects a field corresponding to MCCH change Notification, for example, 2 bits, on the PDCCH, that is, it considers that the change notification is detected, the UE reacquires the MCCH. When the UE acquires the MCCH, the PDCCH scrambled by the MCCH-RNTI needs to be detected to acquire the scheduling information of the MCCH. Wherein, the first bit in the MCCH change notification indicates that the cause of MCCH modification is session start, and the second bit in the MCCH change notification indicates that the cause of MCCH modification is session modification, session stop or neighbor cell list update. Generally, the MCCH modification period is equal to or greater than the MCCH repetition period.

6. Mapping of quality of service (quality of service, qoS) and radio bearers

The protocol data unit (protocol data unit, PDU) session (session) includes a PDU session for transmitting unicast and a PDU session for transmitting MBS, which may also be referred to as MBS session. When the core network establishes a PDU session, one or more QoS flows (flows) are established, each with corresponding QoS parameters (e.g., 5G QoS identification (5G QoS Identifier,5QI), allocation and retention priority (Allocation and Retention Priority, ARP), etc.) in order to guarantee the quality of service that provides the PDU session. The NG-RAN determines the mapping rules for QoS flows and radio bearers (including DRBs and MRBs) based on QoS parameters (QoS profiles and QFI). One PDU session may correspond to one or more QoS flows and one QoS flow may correspond to one or more radio bearers, as determined by implementation policies of the NG-RAN. In the non-access stratum AS layer, the downlink direction transmitting side (NG-RAN) processes the mapping of QoS flow and radio bearer by the service data adaptation protocol (Service Data Adaptation Protocol, SDAP) layer, the data packet on one radio bearer goes to the radio link control (radio link control, RLC) layer through packet data convergence control (Packet Data Convergence Control, PDCP) layer processing (e.g., header compression, integrity protection, ciphering/deciphering, etc.), one PDCP entity may correspond to one, two or four RLC entities according to RB characteristics or RLC mode, and the RLC entities may segment and reassemble RLC service data units (service data unit, SDU) from the PDCP layer, compose RLC PDUs, and put into corresponding logical channels, one RLC entity corresponds to one logical channel. RLC PDUs (also referred to as MAC SDUs) from one or more logical channels are multiplexed by the MAC layer into one data block (TB) and submitted to the physical channel for physical layer transmission. In the MAC header (MAC header) a logical channel identification of the received RLC PDU will be included. The receiving side (UE) processes according to the opposite procedure, and after receiving the TBs, the MAC layer is responsible for demultiplexing the TBs, and after processing to obtain one or more MAC SDUs (RLC PDUs), the receiving side can obtain logical channel identifiers corresponding to the one or more MAC SDUs. According to the configuration of the network side, the UE can learn the identifier of the logical channel corresponding to one radio bearer, so as to ensure that the MAC layer of the UE submits the RLC PDU obtained from a certain logical channel to the correct RLC entity, and corresponds to the corresponding PDCP entity and radio bearer.

In NR R17, a terminal device supporting NR MBS broadcasting may acquire a broadcast communication service in an RRC connected state, an RRC idle state, and an RRC inactive state. In Rel-17, MBS broadcast configuration adopts a two-step configuration manner, first, the network device indicates MCCH configuration for MBS broadcast in a system message, for example, a system information block (system information block, SIB) 20, including repetition period and offset of MCCH, MCCH window duration, MCCH window start slot, MCCH modification period, etc. The MCCH may be received according to the MCCH configuration, and the MCCH (or information transmitted through the MCCH channel) is periodically transmitted in a configured repetition period within a configured MCCH transmission window. The MCCH includes configuration information of a broadcast session and MTCH scheduling information, the configuration information of the broadcast session includes an identifier of the broadcast session, an MBS Radio Bearer (MRB) configuration, a G-RNTI, etc., and the terminal device may correctly receive the MBS broadcast session by reading the configuration information of the broadcast session and the MTCH scheduling information.

The terminal device should perform the MCCH information acquisition procedure when interested in receiving MBS broadcast services. The terminal device interested in receiving the MBS broadcast service should perform the MCCH information acquisition procedure upon entering the cell providing the SIB20, for example, when the terminal device receiving or interested in receiving the MBS broadcast service receives a modification notification, the SIB20 is reacquired to acquire a new MCCH. Before the terminal device acquires the new MCCH information, the terminal device may apply the previously acquired MCCH information. As another example, since the MCCH is configured per (per) cell, the MBS configuration carried by the MCCH per cell may be different, and when the idle or inactive terminal device performs cell reselection, the SIB20 of the reselected cell needs to be read to obtain the MCCH. It should be appreciated that the MBS broadcast support employs MCCH modification notification to notify UEs of the start of a broadcast session and the ongoing modification of MCCH information of the broadcast session, including MBS session stop.

In Rel-17, the terminal device receives the multicast session in the RRC connected state. For terminal devices in RRC connected state joining the multicast session, the network device sends MBS multicast configurations, including, for example, multicast MRB configuration, multicast common frequency domain resource (common frequency resource, CFR) configuration, physical layer configuration (which may also be referred to as layer 1/L1 configuration), multicast G-RNTI, etc., to the terminal devices through dedicated signaling, such as RRC reconfiguration message (RRCReconfiguration message). When (temporarily) there is no data for the multicast session to be sent to the terminal device, the network device may switch the terminal device to an RRC idle or RRC inactive state.

When the number of users receiving a multicast session in one cell is excessive, the following may occur: the number of users receiving multicast sessions exceeds the number of connected state users that the cell can accommodate, which can cause network congestion. In order to alleviate network congestion, the terminal device is supported in Rel-18 to receive multicast in RRC inactive state. For example, when the terminal device has no unicast service and only multicast service, the network may release the terminal device to the RRC inactive state to receive multicast. In this way, the number of terminal devices in RRC connected state in the network can be reduced, which is beneficial to alleviating network congestion and saving energy for the terminal devices.

However, there is no definition in the protocol as to how the terminal device acquires the MBS configuration in the RRC inactive state.

Specifically, similar to the broadcast session, for a terminal device receiving a multicast session in an RRC inactive state, the terminal device needs to acquire a multicast configuration before receiving the multicast session, so that the multicast session can be received according to the multicast configuration.

The multicast configuration is provided to the terminal device by means of a system message broadcast by the cell by means of broadcasting, e.g. the multicast configuration is sent to the terminal device in the MCCH, which may still indicate the MCCH in the SIB, in a similar way as the broadcast session described above. However, by broadcasting, the terminal device that does not join the multicast session can also receive the multicast configuration, which has potential safety hazard. In addition, when the terminal equipment reselects the cell, the multicast service can be continuously received only after the MCCH is read again to obtain the multicast configuration, and the re-acquisition configuration and the reading configuration have a certain time delay, so that the continuity of the multicast service reception is not facilitated.

The network device sends the multicast configuration to the terminal device through dedicated signaling (e.g., RRC reconfiguration message or RRC release message, etc.). The terminal equipment needs to recover the RRC connection, and after the terminal equipment enters the RRC connection state, the network equipment can send the multicast configuration to the terminal equipment through the special signaling. The terminal device enters the RRC connected state to receive the multicast configuration, which increases the power consumption of the terminal device and increases the overhead of air interface signaling.

Based on the analysis, the application provides a communication method and device, which can avoid the terminal equipment to enter the RRC connection state or trigger the RRC recovery under the conditions of cell reselection, multicast configuration update and the like, can reduce the energy consumption of the terminal equipment and reduce the signaling overhead.

It will be appreciated that the term "and/or" is merely one association relationship describing the associated object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

It is also understood that in this application, "indicating" may include direct indication, indirect indication, display indication, implicit indication. When a certain indication information is described for indicating a, it can be understood that the indication information carries a, directly indicates a, or indirectly indicates a.

In addition, "corresponding to" and "associated with" in the present application mean that there is a correspondence or mapping relationship between the two. The correspondence may be one-to-one, one-to-many, or many-to-one.

In the present application, information indicated by the indication information is referred to as information to be indicated. In a specific implementation process, there are various ways to indicate the information to be indicated, for example, but not limited to, the information to be indicated may be directly indicated, such as the information to be indicated itself or an index of the information to be indicated. The information to be indicated can also be indicated indirectly by indicating other information, wherein the other information and the information to be indicated have an association relation. It is also possible to indicate only a part of the information to be indicated, while other parts of the information to be indicated are known or agreed in advance. For example, the indication of the specific information may also be achieved by means of a pre-agreed (e.g., protocol-specified) arrangement sequence of the respective information, thereby reducing the indication overhead to some extent.

The method provided by the embodiment of the present application will be described in detail below with reference to the accompanying drawings. The embodiments provided in the present application may be applied to the network architecture shown in fig. 1, fig. 2, or fig. 3, and are not limited thereto.

Fig. 5 is a schematic diagram of a communication method 200 according to an embodiment of the present application. The method 200 may include the following steps.

S210, the first network equipment sends first information to the terminal equipment, and accordingly, the terminal equipment receives the first information.

The first information includes at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, the at least one multicast configuration information includes the first multicast configuration information, and the index information corresponding to the at least one multicast configuration information includes the first index information.

Illustratively, the multicast configuration information and corresponding index information are shown in table 1 below.

Table 1 a mapping schematic of multicast configuration and index

It should be understood that table 1 is exemplified by three configurations, and the actual number is not limited. Here, a logical correspondence between configuration and index is shown.

The index information corresponding to the at least one multicast configuration information may be indicated in a display or implicit manner. The indication is performed in a display manner, that is, the multicast configuration and the corresponding index are indicated in the first information at the same time, for example, according to the above table, the multicast configuration 1, the index 1, the multicast configuration 2, the index 2, the multicast configuration 3 and the index 3 are indicated; the indication is performed in an implicit manner, that is, only the list of multicast configurations is indicated in the first information, and the index of the multicast configuration is obtained according to the sequence of at least one multicast configuration in the multicast configuration list, for example, the multicast configuration of the first row in the multicast configuration list corresponds to index 1, and the multicast configuration of the second row corresponds to index 2.

It should be noted that, the value of the index information corresponding to the multicast configuration may be any value, and the present invention does not limit the value range of the index information, and does not limit the value of the index information to be continuous.

Alternatively, as an implementation, the first network device may not be arranged in order, but may be randomly allocated within a range of indices when determining the index associated with each multicast configuration. For example, the first network device needs to determine the index for 10 multicast configurations, then these 10 indexes may be discontinuous, i.e. not 10 numbers that are continuous, such as 1-10 or 0-9, but optionally 10 in a range of more than 10 numbers, e.g. optionally 10 in 1-100000, as shown in table 2. This may allow for randomness in the index of the multicast configuration.

Table 2 a mapping schematic of multicast configuration and index

Multicast configuration 1	Index 4997
		Multicast configuration 2	Index 232
Multicast configuration 3	Index 5690

It should be understood that table 2 is exemplified by three configurations, and the actual number is not limited. Here, a logical correspondence between configuration and index is shown.

In this implementation, the terminal device may compare the index in the second information with the index in the first information, and may determine that the second information is invalid if the index indicated in the second information does not exist in the first information. Based on the above scheme, when the pseudo base station transmits the second information and indicates an index, the terminal device may recognize that the index is invalid. For example, the mapping relationship between the multicast configuration and the index indicated in the first information obtained by the terminal device through the dedicated signaling is shown in table 2, when the UE resides in the cell 1, the cell 1 sends the second information to indicate the first multicast session association index 4997, corresponding to the multicast configuration 1; when a pseudo base station exists in the area, the change of the multicast configuration of the cell 1 to the first multicast session is indicated, the second information is sent to indicate that the first multicast session is associated with the index 1, and the terminal device can judge that the index 1 is not the index indicated in the first information, so that it is determined that the multicast configuration of the cell 1 is not changed, and still the first multicast session is received according to the multicast configuration associated with the index 4997. By the method, communication safety can be improved.

Optionally, as an implementation manner, the value of the index in the second information and the index in the multicast configuration list have fixed offset values, and the value of the index in the second information+the fixed offset value=the index in the multicast configuration list. As an example, the fixed offset value is 500, which may be transmitted to the terminal device through the first information. Alternatively, the fixed offset value may be configured per multicast session, and different multicast sessions may be configured with different fixed offset values. As shown in table 3-a, when index information in the first information is indicated by way of display, the index of the multicast configuration #1 is index=503, and if the multicast configuration #1 is to be indicated, the value of the index in the second information may be index=3. In the multicast configuration list, the index of the multicast configuration #2 is index=581. If multicast configuration #2 is to be indicated, the value of the index in the second information may be index=81.

Table 3 a mapping scheme for multicast configuration and index

It should be understood that table 3 is exemplified by three configurations, and the actual number is not limited. Here, a logical correspondence between configuration and index is shown.

As shown in table 3, when the index information in the first information is implicitly indicated, the index of the multicast configuration #1 is index=501, and the value of the index in the second information may be index=1 if the multicast configuration #1 is to be indicated, corresponding to the first row of the configuration list. The index of the multicast configuration #2 is index=502, and corresponds to the second row of the configuration list, and if the multicast configuration #2 is to be indicated, the value of the index in the second information may be index=2.

Based on the scheme, the safety of the second information can be improved.

Wherein, the multicast configuration information is also called MBS multicast configuration information or multicast configuration, and refers to configuration parameters for receiving a multicast session in the MBS. The multicast configuration information in the present application refers to multicast configuration of the terminal device in an RRC inactive state or an idle state, and is used for the terminal device to receive a multicast session in the RRC inactive state or the idle state.

In particular, the multicast configuration information may include one or more of the following: each of the multicast MRB configuration, physical channel configuration, discontinuous reception DRX configuration, G-RNTI configuration, neighbor cell configuration, common frequency domain resource (common frequency resource, CFR) configuration, multicast MRB configuration, physical channel configuration, discontinuous reception DRX configuration, G-RNTI configuration, neighbor cell configuration, CFR configuration, semi-persistent scheduling (semi-persistent scheduling, SPS) configuration may be referred to as a sub-configuration. Wherein the physical channel configuration comprises one or more of: physical downlink control channel (physical downlink control channel, PDCCH) configuration, physical downlink shared channel (physical downlink shared channel, PDSCH) configuration, PDCCH timing (occalation) configuration, SSB mapping window configuration, search space configuration, common control resource set configuration. The MRB configuration includes one or more of the following: MRB identity, packet data convergence protocol (Packet Data Convergence Protocol, PDCP) configuration, radio link control (Radio Link Control, RLC) bearer configuration. The CFR configuration includes: CFR bandwidth and location.

The index information (index) is also called identification Information (ID) or an index, and may be an index or an index set, where an index set includes one or more sub-indexes, for example, one index information is composed of one or more of an MRB configuration index, a physical channel configuration index, a DRX configuration index, a neighbor cell configuration index, a CFR configuration index, and an SPS configuration index, where each of the MRB configuration index, the physical channel configuration index, the DRX configuration index, the neighbor cell configuration index, the CFR configuration index, and the SPS configuration index may be called a sub-index. In this scenario, the multiple indexes can be flexibly combined, so that the flexibility is higher.

An index information is a set of indices, including one or more sub-indices. For example, the at least one multicast configuration comprises { multicast configuration a, multicast configuration B, multicast configuration C }; the first multicast configuration information is a multicast configuration a, and the configuration information of the multicast configuration a may be a configuration information list, where the list includes { a multicast configuration a_multicast MRB configuration list, a multicast configuration a_physical channel configuration list, a multicast configuration a_drx configuration list, a multicast configuration a_g-RNTI configuration list, a multicast configuration a_neighbor cell configuration list, a multicast configuration a_cfr configuration list, a multicast configuration a_sps configuration list } or a combination including at least one of them.

Correspondingly, the first index information corresponding to the first multicast configuration information includes { multicast configuration a_multicast MRB configuration index, multicast configuration a_physical channel configuration index, multicast configuration a_drx configuration index, multicast configuration a_g-RNTI configuration, multicast configuration a_neighbor cell configuration index, multicast configuration a_cfr configuration index, multicast configuration a_sps configuration index }.

The case where one index information is one index is, for example, that at least one multicast configuration includes { multicast configuration a, multicast configuration B, multicast configuration C }; the first multicast configuration information is multicast configuration A and corresponds to first index information; the configuration information of the multicast configuration A comprises { multicast configuration A_multicast MRB configuration, multicast configuration A_physical channel configuration, multicast configuration A_DRX configuration, multicast configuration A_G-RNTI configuration, multicast configuration A_neighbor cell configuration, multicast configuration A_CFR configuration, multicast configuration A_SPS configuration }.

The first information includes at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, i.e., the first information includes a multicast configuration list. In the multicast configuration list, each piece of multicast configuration information corresponds to one piece of index information. The one or more pieces of multicast configuration information include first multicast configuration information, and the first multicast configuration information corresponds to the first index information. In other words, the index information corresponding to the one or more multicast configuration information includes the first index information.

Alternatively, the multicast configuration list may be a list, and a plurality of items in the list respectively correspond to one item of multicast configuration information. The multicast configuration list may also be composed of a plurality of sub-lists, for example, the multicast configuration list includes one or more of an MRB configuration list, a physical channel configuration list, a DRX configuration list, a neighbor cell configuration list, a CFR configuration list, and an SPS configuration list. In this case, each sub-list may correspond to one sub-index, that is, one index information is composed of a plurality of sub-indexes through which one multicast configuration information may be corresponding.

In addition, the multicast configuration information may be associated with a particular multicast session, and each multicast configuration information may also be associated with one or more multicast sessions, i.e., multiple multicast sessions may share the same multicast configuration information. Similarly, each multicast session may be associated with one or more multicast configurations, i.e., each session may have multiple multicast configurations to accommodate different scenarios.

It will be appreciated that the at least one multicast configuration in the first information is a configuration associated with a multicast session to which the terminal device has joined, i.e. the multicast configuration resource pool provided by the first network device to the terminal device comprises a multicast configuration resource pool of a multicast session to which the terminal device has joined.

Optionally, when the terminal device joins the new multicast session, the terminal device requests to recover the RRC connection state from the network device, and the network device sends updated first information to the terminal device according to the multicast session that the terminal device currently joins.

For each multicast session (MBS session), within one effective area, the partial configuration may be an area common configuration, e.g., an MRB configuration, and the common configuration may be preconfigured by OAM; the partial configuration is the configuration of the Per network device or Per cell, i.e. different cells may have different configurations. For the case that different cells have different configurations, the mapping relationship between the multicast configuration information and the index information of the cells in the area needs to be synchronized between the network devices in the area.

In addition, the index information and the multicast configuration have a corresponding relationship, and the relationship may be a one-to-one relationship or a one-to-many relationship. When the correspondence between the index information and the multicast configuration is one-to-one, the terminal device may determine the first configuration information through the first index information. When the correspondence between the index information and the multicast configuration is one-to-many, the terminal device may determine the first configuration information through the first index information and other information, which may be, for example, a first identity, which may be a cell identity or an identity of the network device.

Optionally, the terminal device accesses the first multicast session, and the at least one piece of multicast configuration information in the first information includes one or more pieces of multicast configuration information of the first multicast session.

The first information may be referred to as a multicast configuration resource pool, and the terminal device may store the first information after receiving the first information.

Wherein the first information is sent by the network device through a dedicated signaling when the terminal device is in a connected state, the dedicated signaling may also be called ciphering signaling, and the dedicated signaling may be an RRC release message or an RRC reconfiguration message.

S220a, the second network device sends the second information to the terminal device, and accordingly, the terminal device receives the second information.

The second information is used for indicating that the first multicast session is associated with first index information, and the first index information indicates first multicast configuration information.

The second information is used to indicate that the first multicast session is associated with the first index information, in other words, the second information may include an identification of the first multicast session, which may also be referred to as a session identification (session ID), which may be a TMGI, and the first index information. And the terminal device can learn the corresponding first multicast configuration information through the first index information.

It will be appreciated that the second information is sent by the second network device to the terminal device on managed cells, which may each have the same or different second information.

The second information may be carried in a cell common signaling, which is sent in a broadcast form, i.e. in an unencrypted form. The common signaling may be a system message of the cell, which may be a system information (system information block, SI) or a system information block (system information block, SIB) message, for example, SIB20, as well as any other SIB other than SIB 20. The common signaling may also be the MCCH, i.e. a message sent through the MCCH. Alternatively, the second information may also be carried in dedicated signaling, e.g. RRC release message.

Alternatively, when the second information is transmitted through the MCCH, the MCCH for transmitting the second information may use the same MCCH-RNTI as the MCCH currently used for indicating the broadcast configuration information, but both are associated with different logical channels and logical channel identities (LCIDs or LCH IDs). Alternatively, the MCCH for transmitting the second information and the MCCH indicating the broadcast configuration information use the same logical channel and logical channel identity, but are scrambled using different MCCH-RNTIs. Alternatively, the second information is carried in the same RRC message as the broadcast configuration information and on the same MCCH, and the indication that the second information is for multicast is displayed in the message.

Optionally, when the second information is sent through an RRC release message, the RRC release message further instructs the terminal device to enter an RRC inactive state or an idle state to receive the first multicast session. In this way, before entering the RRC inactive state or idle state, the terminal device may obtain the first multicast configuration of the first multicast session by the camping cell, without obtaining the first multicast configuration by obtaining the cell common signaling (e.g., a system message or an MCCH message), which may reduce interruption of receiving the multicast service during the process of switching from the RRC connection state to the RRC inactive state by the terminal device, and improve continuity of receiving the multicast service.

Alternatively, the granularity of the second information may also be the granularity of the per multicast session per MRB. For example, the first multicast session may be associated with M MRBs, where each MRB may be associated with one index information (optionally, including multiple sub-index information), and different MRBs may correspond to different index information corresponding to the corresponding MBS configuration. Alternatively, the granularity of the second information may be per multicast session, where one multicast session corresponds to one index information, that is, one or more MRBs associated with the multicast session corresponds to one index information (optionally, including multiple sub-index information), and corresponds to the corresponding MBS configuration.

As an example, one possible mapping of multicast sessions, configuration of multicast sessions, and index information of configuration provided by a cell is shown in table 4.

Table 4 a mapping scheme of cells, multicast sessions, multicast configuration and index

And S230, the second network equipment sends the first multicast session to the terminal equipment according to the first multicast configuration.

If step S220a in the method 200 is performed, the terminal device receives the first multicast session in an RRC inactive state or idle state according to the first multicast configuration after S230.

Specifically, since the second information indicates that the first multicast session is associated with the first index information, and the first index information indicates the first configuration information, according to the second information, the terminal device may determine the first multicast configuration information corresponding to the first multicast session, and further receive the first multicast session according to the first multicast configuration.

Optionally, there may be information #a in the common signaling carrying the second information, where the information #a may indicate a neighbor cell list providing the same multicast session with the cell, and indicate whether the neighbor cell has the same multicast configuration as the cell, where the multicast configuration is configured that the terminal device receives the configuration of the multicast session in an RRC inactive state. The information #a may indicate for each multicast session (per MBS session) provided by the cell, for example, for each multicast session TMGI provided by the cell, the information #a indicates a cell list providing the multicast session and having the same multicast configuration; or, for each multicast session TMGI, the information a# indicates a cell list providing the multicast session, and further includes an information #b indicating whether each cell in the cell list has the same multicast configuration. If the configuration of the neighbor cells is the same, the UE cell reselects to the neighbor cells without re-acquiring SIB or MCCH of the cell, the UE can acquire the configuration information of the neighbor cells in advance, the time delay caused by acquiring the configuration is reduced, and the continuity of receiving the multicast service is improved.

It should be understood that in the method 200, the second network device may be a network device corresponding to the camping cell of the terminal device, that is, the second network device may be a serving base station of the terminal device, and the first network device may be understood as an anchor base station of the terminal device, where the first network device stores a context of the terminal device and the core network.

Alternatively, the first network device and the second network device may be the same, for example, the terminal device performs cell reselection after receiving the first information, and the reselected cell is still managed by the first network device, where the second network device is the same as the first network device. In other words, the steps performed by the first network device described in method 200 may also be performed by the second network device, and the steps performed by the second network device may also be performed by the first network device.

Optionally, the method 200 further comprises: the first network device obtains first information.

The first information may have an effective area, which indicates that the preconfigured first information is valid in the area, and it may be understood that at least one multicast configuration in the first information is valid in the area, or that a correspondence between at least one multicast configuration in the first information and index information of the at least one multicast configuration information is valid. The present application does not limit that for cells outside the active area, the same multicast configuration may not be provided as for cells within the active area. For cells outside the active area, the same multicast configuration may be mapped to the same index information, or different index information. The effective area can be a geographical area range, and the effective area can be composed of a plurality of cells; the validation area may be configured by an open mobile alliance (open mobile alliance, OAM). The plurality of network devices within the validation area may coordinate determining the first information. In this application, an example of the first network device acquiring the first information is described. The first network device acquiring the first information may be implemented in the following manner.

Mode 1: the first network device receives sixth information from the fourth network device, where the sixth information includes M multicast configuration information and index information corresponding to the M multicast configuration information. The first network device determines N pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information. The at least one piece of multicast configuration information comprises M pieces of multicast configuration information and N pieces of configuration information, wherein M and N are positive integers. In other words, the first information includes sixth information.

In this manner, the sixth information may include identification information of cells or network devices corresponding to the M multicast configuration information.

Specifically, for one multicast session, each gNB in the effective area, or a cell of the gNB may determine at least one multicast configuration information and index information corresponding to the multicast configuration information, and the gNB sends, to the adjacent gNB through the Xn interface, the determined multicast configuration information, index information, identifier of the gNB, or identifier of the cell corresponding to each multicast session, so that the first information of each gNB in the effective area includes the received multicast configuration information and index information, and the multicast configuration information and index information determined by the first information. The cell identity may be an NR cell global identity (NR cell global identifier, NCGI) or a physical cell identity (physical cell identifier, PCI), or may be a cell identity allocated in an effective area. For example, if there are 32 cells in the effective area, the length of the cell identifier may be 5 bits (bit) to indicate 32 cells. The cell identity in the effective area may be configured by an open mobile alliance (open mobile alliance, OAM) or may be allocated by one of the gnbs in the effective area.

For example, for multicast session 1, gNB_1 determines 2 multicast configurations and identifies as index_1, index_2, respectively; gNB_2 determines 3 multicast configurations and is identified as index_1, index_2, index_3, respectively. gNB_1 may send the identifier of gNB_1, multicast session 1, index_1, index_2, and multicast configuration corresponding to index_1, index_2 to gNB_2; gNB_2 may send the identification of gNB_2, multicast session 1, index_1, index_2, index_3, and index_1, index_2, index_3 to gNB_1. Thus, in both gNB_1 and gNB_2, multicast Session_1 includes 5 multicast configurations. In this case, the gNB identity and index may uniquely determine a multicast configuration. The granularity of the index is not limited, and may be granularity of a per multicast session, granularity of a per mrb, or different sub-configurations may have different sub-indexes, for example only.

Mode 2: the first network device determines N multicast configuration information, and the first network device receives sixth information from the fourth network device, the sixth information including M multicast configuration information. The first network device determines M pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information according to the M pieces of configuration information and the N pieces of multicast configuration information. The at least one piece of multicast configuration information comprises M pieces of multicast configuration information and N pieces of configuration information, wherein M and N are positive integers. In other words, the first information includes sixth information.

Specifically, in mode 2, the first network device may coordinate configuration of the first information with the network devices in the coverage area, which may be understood as a central gNB in the coverage area. And the gNB in the effective area transmits the determined or supported at least one multicast configuration to the central gNB, the central gNB determines indexes corresponding to the multicast configurations, namely, the central gNB determines the mapping relation between the multicast configuration and the indexes and transmits the mapping relation to network equipment in the effective area.

For example, gnb_1 indicates to the central gNB its determined multicast configuration_1, multicast configuration_2, optionally, gnb_1 also indicates each multicast configuration associated multicast session TMGI; gNB2 indicates to the central gNB its determined multicast configuration_1, multicast configuration_2, multicast configuration_3, optionally gNB_2 also indicates each multicast configuration associated multicast session TMGI. The central gNB determines 5 multicast configurations in total and respectively marks index_1, index_2, index_3, index_4 and index_5, and sends the allocated multicast configurations and indexes to other gNBs in the effective area. The granularity of the index is not limited, and may be granularity of a per multicast session, granularity of a per mrb, or different sub-configurations may have different sub-indexes, for example only.

Alternatively, in the above example, if the multicast configuration determined by gnb_1 and the multicast configuration determined by gnb_2 may have one or more multicast configurations that are the same, then the central gNB determines that the multicast configuration of multicast session_1 will be less than 5. For example, if the central gNB determines that the multicast configuration_1 sent by the gnb_1 and the multicast configuration 2 sent by the gnb_2 are the same configuration, the central gNB determines that there are 4 multicast configurations in total and identifies the 4 multicast configurations as index_1, index_2, index_3, and index_4 respectively, and the central gNB sends the allocated multicast configuration and index to other gnbs in the effective area.

Here, between the gnb_1 and the gnb_2 are two network devices with Xn interfaces, and the configuration information is sent to the neighboring network device through the Xn interface message. It is to be understood that gnb_1 and gnb_2 are merely examples, and that 1 or more access network devices in the area may be used, and only configuration interaction between any two gnbs is described herein. When there are multiple access network devices in the area, the above manner may be applied to any two gnbs with Xn interfaces in the area.

In mode 2, the method 200 further includes: the first network device sends the first information to the fourth network device.

Mode 3: the first network device determines N pieces of multicast configuration information, the first network device sends the N pieces of multicast configuration information to the fourth network device, and the first network device receives first information from the fourth network device, wherein the first information comprises the N pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information.

Mode 3 is similar to mode 2 except that in mode 3, the fourth network device is a central gNB and the first network device is a non-central gNB.

Based on the scheme, the network equipment coordinates and determines the first information, so that a unified understanding mode is provided for the mapping relation between the first multicast configuration and the index information of the first multicast configuration among cells in one area, different cells in the area are allowed to have different multicast configurations, and one or more multicast configurations can be allowed to exist in one cell; in this way, when the terminal device moves between cells in the area, or when the multicast configuration of the cell to the multicast session changes, the corresponding multicast configuration is determined according to the index information indicated by the cell to one multicast session, and the terminal device can keep in an RRC inactive state or an idle state to receive the multicast session according to the multicast configuration, so that the terminal device is prevented from entering an RRC connection state to obtain the multicast configuration of the cell, so that the energy consumption of the terminal device can be reduced, and the continuity of the terminal device for receiving the multicast session is also facilitated to be ensured.

It should be understood that in the above-described modes 1 to 3, the fourth network device generally refers to a network device that determines the first information in coordination with the first network device, and may be any network device within the coverage area.

Optionally, the method 200 further comprises: the fourth network device sends seventh information, where the seventh information is used to indicate that the first multicast session is associated with second index information, the second index information indicates second multicast configuration information, at least one piece of multicast configuration information includes the second multicast configuration information, and index information corresponding to at least one piece of multicast configuration information includes the second index information. The second network device sends the first multicast session according to the second multicast configuration information.

Specifically, if the terminal device moves to the coverage area of the cell managed by the fourth network device, the terminal device may receive the seventh information sent by the fourth network device in the RRC inactive state or the idle state, determine the second multicast configuration according to the seventh information, and then continue to receive the first multicast session in the RRC inactive state or the idle state according to the second multicast configuration. Wherein the seventh information may be carried in a system message or MCCH. Therefore, the terminal equipment can be prevented from entering the RRC connection state to receive the multicast configuration information, the energy consumption of the terminal equipment can be reduced, and the continuity of the multicast session received by the terminal equipment can be ensured.

It should be understood that the case where the fourth network device transmits the seventh information is similar to the process where the second network device transmits the second information, and reference may be made to S220a specifically, which is not described herein.

As an implementation manner, the first information further includes identification information of a cell or network device corresponding to the at least one multicast configuration information.

In this implementation, the method 200 further includes: the second network device sends a first identifier to the terminal device, wherein the first identifier is an identifier of the second network device or an identifier of a cell corresponding to the second information, that is, the first identifier is an identifier of a resident cell of the terminal device or an identifier of a network device corresponding to the resident cell, and the first identifier has a corresponding relationship with the first multicast configuration information. The terminal device may determine the first multicast configuration information according to the first identification and the first index information.

The second network device may send the first identifier and the second information to the terminal device at the same time, or the terminal device may obtain the first identifier in other system messages.

In this way, the first multicast configuration information corresponding to the first multicast session can be uniquely determined based on the first identifier and the first index information, so that flexibility of providing the RRC inactive state multicast service configuration by the cell is improved. Different cells within a region may have different multicast configurations and a cell may also have one or more multicast configurations. For a multicast session, the cell may indicate, through the change of index information corresponding to the multicast session indicated by the second information, the change of configuration information corresponding to the multicast session. When the terminal equipment moves between cells in the area or when the multicast configuration of the cells to the multicast session changes, the terminal equipment can keep in an RRC inactive state or an idle state to receive the multicast session according to the multicast configuration, so that energy consumption overhead and signaling overhead caused by entering an RRC connection state are avoided.

As an example, one possible mapping relationship of the index information indicated by the cell identity and the second information and the multicast configuration is shown in table 5.

Table 5 a mapping scheme of cell identity, index information and multicast configuration

Index information	Cell identification	Multicast configuration information
			Index 1	Cell #1	Multicast configuration a
Index 1	Cell #2	Multicast configuration a
			Index 1	Cell #3	Multicast configuration B
Index 2	Cell #3	Multicast configuration C
			Index 1	Cell#4	Multicast configuration D

Optionally, the method 200 further comprises: the first network device sends third information to the terminal device, and accordingly, the terminal device receives the third information, where the third information is used to indicate an effective area of at least one multicast configuration information.

It should be understood that the "effective area" can also be said to be a usable area, an applicable range, an applicable area, an effective area, or the like. The effective area of the at least one multicast configuration information may be understood as an effective area of the at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, or an effective area of the first information.

Wherein the third information may be a list of cells constituting the effective area. The identity of the cell may be PCI, NCGI, etc. Alternatively, the effective region may be less than or equal in scope to RNA.

As an implementation, the third information may be sent simultaneously with the first information, e.g. in the same message. One implementation is that the third information is carried in an RRC reconfiguration message or an RRC release message. As a further implementation, the terminal device learns the validation area through an application layer message.

Based on the above scheme, the first network device can indicate the effective area of the first information to the terminal device, so that when the terminal device moves in the effective area, the first information can be continuously used for determining the required multicast configuration information without repeatedly receiving the first information, thus, the energy consumption of the terminal device can be reduced, and the continuity of the multicast session received by the terminal device can be ensured.

Optionally, the method 200 further comprises: the first network device or the second network device sends fourth information to the terminal device, and accordingly, the terminal device receives the fourth information, wherein the fourth information is used for indicating a first G-RNTI corresponding to the first multicast session, the second network device can scramble the first multicast session through the first G-RNTI, and the terminal device can descramble the received first multicast session through the first G-RNTI.

The first G-RNTI associated with the first multicast session may be configured as follows.

Configuration mode 1: the first network equipment receives a first G-RNRI from core network equipment; or, the first network device determines the first G-RNTI according to the identifier of the first multicast session.

In particular, the core network may allocate a corresponding G-RNTI for each multicast session, and thus the core network may send the identity of the first multicast session and the first G-RNTI to the first network device. Or the core network only sends the identifier of the first multicast session to the terminal equipment, the first network equipment determines the first G-RNTI according to the identifier of the first multicast session, and the first network equipment can send the corresponding relation between the identifier of the multicast session and the first G-RNTI to the second network equipment.

In configuration mode 1, since each multicast session has a unique session identifier, the first G-RNTI and the first multicast session have a one-to-one correspondence, and the G-RNTI associated with one multicast session is common in the effective area. At this time, the fourth information may be information of the first G-RNTI.

Optionally, in configuration mode 1, the network device may send the first G-RNTI to the terminal device through dedicated signaling, where the dedicated signaling may be an RRC reconfiguration message or an RRC release message. And in configuration mode 1, the first information may not include the first G-RNTI. The first multicast configuration information may include a first G-RNTI indicated by the fourth information.

A method for the first network device to determine the first G-RNTI according to the identity of the first multicast session in configuration mode 1 is described below.

Fig. 6 is a schematic diagram of a TMGI structure, and as shown in fig. 6, the TGMI includes an MBS service identifier (MBS service identifier), a mobile country code (mobile countrycode, MCC) and a mobile network number (mobile network code, MNC). Wherein, the MBS service identification consists of 6-bit fixed-length hexadecimal numbers (digit), which is between 000000 and FFFFFF, the MCC consists of 3-bit fixed-length hexadecimal numbers, and the MBS service identification consists of 2 or 3-bit hexadecimal numbers. A specific bit string in the TMGI may be referred to as a G-RNTI reference value (G-RNTI-reference), for example, the G-RNTI reference value is a bit string formed from an x-th bit to a y-th bit from the leftmost bit in the TMGI, and the G-RNTI reference value may be formed from some or all bits used to indicate the MBS service identifier in the TMGI. Wherein the start bit position and the end bit position of the G-RNTI reference value are configurable, e.g. configurable via OAM, or indicated by the core network.

As one example, the G-RNTI associated with the multicast session may be a G-RNTI-reference. As yet another example, the G-RNTI associated with the multicast session may also be associated with a public land mobile network (public land mobile network, PLMN) providing the multicast session. For example, a PLMN providing the multicast session may be associated with an offset value, denoted G-RNTI-base, which may be configured by OAM. There may be a correspondence between the G-RNTI associated with the multicast session and the offset value, G-RNTI reference value. Illustratively, the correspondence may be: G-rnti=g-RNTI-base +/-G-RNTI-reference.

Alternatively, in the configuration mode 1, the first network device may send the first information and the fourth information simultaneously, for example, the first information and the fourth information are both carried in the RRC release message.

Configuration mode 2: the second network device determines a first G-RNTI for the first multicast session.

Specifically, as an implementation, the gNB or the gNB cell (an example of the second network device) may allocate a G-RNTI for each multicast session and determine an index of the G-RNTI. For a multicast session, the gNB may send a gNB identifier or a cell identifier, a TMGI, a G-RNTI, and a G-RNTI index to a neighboring gNB (an example of the first network device), where, in the service area, for a multicast session, a G-RNTI may be uniquely identified by the gNB ID or the cell identifier, and the G-RNTI index.

As another implementation manner, the first network device is a central gNB in the coverage area, the central gNB receives G-RNTIs determined by other gnbs (an example of the second network device) in the coverage area, and the central gNB may determine mapping relationships between all G-RNTIs and G-RNTIs of a multicast session, further, the central gNB may send the mapping relationships to other gnbs (an example of the second network device) in the coverage area, where, for a multicast session, the G-RNTIs index may uniquely identify one G-RNTI.

In configuration mode 2, the fourth information is an index of the G-RNTI or an index of the G-RNTI, and the index of the G-RNTI has a correspondence relationship with the G-RNTI. The first network device may pre-configure the G-RNTI configuration list to the terminal device. The second network device may broadcast the index of the G-RNTI so that when the terminal device needs to receive the multicast session, the first G-RNTI actually used may be determined according to the index of the G-RNTI and the preconfigured G-RNTI configuration list.

Alternatively, in configuration mode 2, the G-RNTI configuration list and the first information may be transmitted simultaneously, or the first information may include the G-RNTI configuration list.

Configuration mode 3: the second network device determines a second G-RNTI for the first multicast session.

Specifically, there is one G-RNTI common value (G-RNTI-common) within the effective area, which is an initial offset value for each network device or cell, and the G-RNTI common value may be for per multicast sessions, i.e., different multicast sessions may have different initial offset values. The G-RNTI public value may be configured to the gNB in the effective area by way of OAM. Each network device or cell actually has an association relationship between a G-RNTI and a G-RNTI common value used for one multicast session, for example, the association relationship is: G-RNTI = G-RNTI common value +/-a second G-RNTI, where the second G-RNTI may be denoted as G-RNTI-additional, which is a network device or a cell of a network device (an example of a second network device) autonomously determined G-RNTI. The first network device may pre-configure the G-RNTI common value to the terminal device. The second network device may broadcast the second G-RNTI such that when the terminal device needs to receive the multicast session, the first G-RNTI actually used may be determined according to the second G-RNTI and the preconfigured G-RNTI common value.

Therefore, in the configuration 3, the fourth information is information of the second G-RNTI, and the second G-RNTI has a correspondence relationship with the first G-RNTI.

Alternatively, in the configuration mode 3, the G-RNTI common value and the first information may be transmitted simultaneously, or in other words, the first information may include the G-RNTI common value.

Optionally, in configuration 2 and configuration 3, the second network device may send fourth information and second information together to the terminal device, and the terminal device may determine a first multicast configuration according to the second information and the fourth information, where the first multicast configuration information includes the determined first G-RNTI. For example, the fourth information and the second information are both carried in SIB, and for example, the fourth information and the second information are both carried in MCCH message.

Based on the above scheme, the network device can indicate the first G-RNTI for scrambling and descrambling to the terminal device through the fourth information, and because the fourth information is sent through the dedicated use, or the fourth information is the index of the first G-RNTI or the second G-RNTI, the terminal device that does not join the first multicast session can be prevented from acquiring the first G-RNTI, which is helpful for ensuring communication security.

As a possible implementation, S210 and S220a may be performed simultaneously, for example, the first network device is to release the terminal device to an idle state or an inactive state, and instruct the terminal device to receive the multicast session in the idle state or the inactive state. Then, when the terminal device is in the connected state, the first network device may send the first information and the second information to the terminal device through the RRC release message. The terminal device enters an idle state or a non-activated state according to the RRC release message, determines a first multicast configuration according to the first information and the second information, and then receives the first multicast session according to the first multicast configuration.

Alternatively, the triggering condition for the terminal device to receive the second information may be any one of the following: the terminal equipment reselects to a cell managed by the second network equipment; or the terminal equipment receives fifth information from the second network equipment, wherein the fifth information is used for notifying the system message change; or, the fifth information is used for notifying the multicast control channel message change; or, the fifth information is used for notifying the first multicast session to be activated; or, the fifth information is used to instruct the terminal device to receive the multicast session in the RRC inactive state or idle state.

Specifically, as a scenario, when the terminal device reselects to a cell managed by the second network device, the terminal device may acquire system information and/or MCCH, thereby acquiring the second information.

Therefore, when the terminal device performs cell reselection, according to the method 200, the terminal device can obtain index information corresponding to the multicast session through a message broadcasted by the cell, and determine multicast configuration corresponding to the multicast session through the index information, so as to continuously keep receiving the multicast session in an RRC inactive state or an idle state, so that the terminal device can be prevented from entering an RRC connection state to increase energy consumption, and also can be prevented from delaying in the RRC state transition process, so that the terminal device can quickly start receiving the multicast session, and service interruption is avoided.

As yet another scenario, when the multicast configuration information of the first multicast session is changed to the first multicast configuration information; or when the cell managed by the second network device starts to provide the first multicast session in the inactive state or the idle state, the second network device sends fifth information to the terminal device, where the fifth information is used to notify the system information change or notify the multicast control channel message change. The terminal device may acquire the system information and/or the MCCH under the triggering of the fifth information, thereby acquiring the second information.

It should be understood that starting to provide a multicast session in an inactive state or an idle state means that a cell starts to provide a multicast session in an idle state or an inactive state, or that a cell starts to transmit a multicast session to a terminal device when the terminal device is in an inactive state or an idle state, or that a cell opens a switch to transmit a multicast session in an inactive state or an idle state. After starting or opening, the terminal device supporting the multicast session reception in the inactive state or the idle state will receive the multicast session in the inactive state or the idle state. If the cell stops providing the multicast session in the inactive state or the idle state, the terminal device cannot receive the multicast session in the inactive state or the idle state even though the terminal device supports receiving the multicast session in the inactive state or the idle state.

Therefore, when the multicast configuration information of a certain multicast session is updated, according to the method 200, the terminal device can quickly obtain the updated multicast configuration information, or when a certain cell starts to provide the multicast session in an inactive state or an idle state, according to the method 200, the terminal device can quickly obtain the multicast configuration information of the multicast session to be received, thereby quickly receiving the multicast session, so that the terminal device can quickly start to receive the multicast session, and avoid service interruption.

As yet another scenario, when the first multicast session is active, the second network device may send fifth information to the terminal device, the fifth information being used to notify the first multicast session of the activation; or, when the second network device needs the terminal device to receive the multicast session in the RRC inactive state or the idle state, the second network device may send fifth information to the terminal device, where the fifth information is used to indicate that the terminal device receives the multicast session in the RRC inactive state or the idle state, or the fifth information indicates that the terminal device is allowed to receive the multicast session in the RRC inactive state or the idle state. In this way, the terminal device may acquire the system information and/or the MCCH under the triggering of the fifth information, thereby acquiring the second information.

Therefore, when the first multicast session is activated, or when the terminal device is allowed to receive the multicast session in the RRC inactive state or the idle state, according to the method 200, the terminal device can quickly obtain multicast configuration information of the multicast session to be received, thereby quickly receiving the multicast session, so that the terminal device can quickly start to receive the multicast session, and avoid service interruption.

As yet another scenario, when the fifth information is used to instruct the terminal device to receive the multicast session in the RRC inactive state or the idle state, it may also be understood that the fifth information indicates that the purpose of letting the terminal device enter the RRC inactive state or the idle state is to receive the multicast session. Illustratively, the fifth information is carried in an RRC release message. After receiving the fifth information, the terminal equipment starts to acquire the system information and/or the MCCH, thereby acquiring the second information.

Optionally, when the first multicast session is in a deactivated state or the first multicast session is released, step S220a in the method 200 is replaced with: s220b, the second network device sends a first message, the first message comprising an identification of the first multicast session, and the first message not comprising the first index information. The first message is a system message, a multicast control channel message or an RRC release message.

Specifically, when the system message, the multicast control channel message or the RRC release message sent by the cell includes the identifier of the first multicast session, but does not include the index information of the multicast configuration, the multicast session is indicated to be in a deactivated state or has been released. The terminal device may stop receiving the first multicast session, avoiding unnecessary energy consumption.

A possible implementation way, when the second network device determines that the state of the first multicast session on its managed cell changes, a system message change notification or an MCCH change notification is sent. And after the terminal equipment residing in the cell receives the system message change notification or the MCCH change notification, acquiring a first message.

And when the first multicast session is deactivated, the terminal equipment acquires the deactivation of the first multicast session by acquiring a first message sent by the cell of the second network equipment. In this scenario, the terminal device stops receiving the first multicast session and the terminal device may remain in the RRC inactive state or idle state without entering the RRC connected state because the multicast configuration for the RRC inactive state is not available on the cell of the camped second network device, because the terminal device has determined that the first multicast session has been deactivated or released, and thus does not need to enter the RRC connected state for the purpose of receiving the first multicast session, energy consumption overhead and signaling overhead for entering the RRC connected state may be saved.

Optionally, the second network device managed cell stops providing the first multicast session in the inactive state or the idle state, and step S220a in the method 200 is replaced with: s220c, the second network device sends a first message, the first message not including an identification of the first multicast session. The first message is a system message, a multicast control channel message or an RRC release message.

Specifically, when the system message, the multicast control channel message or the RRC release message sent by the cell does not include an identifier of a certain multicast session, the cell is instructed to stop providing the multicast session in an RRC inactive or idle state, and the terminal device may request to resume RRC connection to a network device corresponding to the resident cell, so as to request to receive the first multicast session in an RRC connected state. Further, the terminal device determines whether the first multicast session is in an active state to determine whether to resume the RRC connection: if the first multicast session is still in an active state, the terminal equipment requests to recover the RRC connection from the network equipment corresponding to the resident cell; if the first multicast session is in a deactivated state, the terminal device does not request the network device to resume the RRC connection. For example, if the terminal device has previously received a deactivation/release notification of the first multicast session, after cell reselection, the terminal device may not trigger RRC connection restoration if the identity of the first multicast session is not included in the first message. One possible behaviour is that the terminal device may wait for the network to issue an indication informing about the activation of the first multicast session. It should be noted that the cell may be a cell indicating to provide the multicast session to the terminal device in the inactive state or the idle state, for example, the cell is a cell in the multicast configuration effective area indicated in the third information. When the terminal device receives the third information, the cell may be providing a first multicast session in an RRC inactive state; but at some later point the state of the cell may change, stopping providing the first multicast session in the RRC inactive state, e.g. when congestion of the cell is relieved, the cell may only provide the first multicast session in the RRC connected state; or stopping providing the first multicast session in the RRC deactivated state by the cell when the number of terminal devices in the RRC deactivated state receiving the first multicast session is smaller on the cell.

In this way, for the cell in the area, the cell itself is a cell capable of providing the multicast session in the RRC inactive state or the idle state, and the cell provides the first multicast session in the RRC inactive state at time 1, but stops providing the first multicast session at time 2, where the cell may send a system message change notification or an MCCH change notification, and after receiving the change notification, the terminal device obtains the first message sent by the cell, so as to learn that the cell stops providing the first multicast session. In this way, the terminal device may timely request to the second network device to revert to the RRC connected state to continue receiving the first multicast session.

Optionally, the method 200 further comprises: the cell managed by the second network device does not support providing the multicast session in the inactive state or the idle state, or the cell managed by the second network device does not support the multicast session, the second network device sends a first message, and the first message does not include an identifier of the multicast session.

Specifically, when none of the system message, the multicast control channel message, or the RRC release message sent by the cell includes an identifier of one multicast session, the cell is indicated not to support providing the multicast session in the inactive state or the idle state, and the network device corresponding to the cell may be a network device that does not support the multicast session in the idle state or the inactive state, but may support connection-state multicast, for example, the network device is a network device of R17. Or may indicate that the cell does not support the multicast session, and the network device corresponding to the cell may be a network device that does not support the multicast session, e.g., a network device before R17.

Based on the scheme, the method and the device not only can instruct the terminal equipment to receive the multicast configuration information of the multicast session, but also can instruct the multicast session to be deactivated or released, so that the method and the device have higher efficiency, and meanwhile, unnecessary energy consumption can be avoided.

Optionally, the method 200 further comprises: when the first information changes, the second network device notifies other network devices in the effective area through the Xn interface, the network devices in the area send group notification or group paging to the terminal device joining the multicast session, after monitoring the group notification or group paging message including the identification of the first multicast session, the terminal device triggers RRC connection recovery, and the second network device sends dedicated signaling (e.g., RRC reconfiguration message or RRC release message) to the terminal device to indicate the updated first information.

The change of the first information includes at least one multicast configuration change indicated by the first information, or it is understood that a resource pool of the multicast configuration changes, such as adding, modifying or deleting one multicast configuration; the method may further include that the effective area of the at least one multicast configuration changes, that is, the third information changes, such as adding or deleting a cell to which the at least one multicast configuration is applicable.

Fig. 7 is a schematic diagram of a method 300 of communication provided in an embodiment of the present application, and the method 300 may be regarded as a specific implementation of the method 200. The method 300 may include the following steps. In this method 300, it is assumed that the second information in the method 200 is carried in a SIB.

S301, the gnb#1 (an example of the first network device) acquires the determination information#1 (an example of the first information).

The gnb#2 (an example of the second network device) may send, to the gnb#1, one or more multicast configurations determined by the gnb#2, the gnb#1 determining different indexes for different multicast configurations of a same multicast session according to the one or more multicast configurations determined by itself and the one or more multicast configurations from the gnb#2, where the information#1 includes a correspondence of the session, the multicast configuration, and the indexes. Or, the gnb#2 transmits, to the gnb#1, the index corresponding to the multicast configuration and the one or more multicast configurations determined by the gnb#2, and the gnb#1 uses the index corresponding to the multicast configuration and the one or more multicast configurations determined by itself and the index corresponding to the multicast configuration and the one or more multicast configurations received together as the information #1.

S302, the gnb#1 transmits information#1 to the UE.

Information #1 may be transmitted through an RRC release message or an RRC reconfiguration message.

The signaling format of information #1 is exemplified as follows:

wherein the "Multicast-area" cell includes a cell identity that provides a Multicast session in an inactive state or an idle state. "MRB-ConfigList" indicates a plurality of MRB configurations, "DRX-Config-List" indicates a plurality of DRX configurations, "PDSCH-ConfigList" indicates a plurality of PDSCH configurations, "SSB-MappingWindow List" indicates a PDCCH opportunity and a mapping window configuration of SSB. It should be understood that this signaling format is merely an example.

Optionally, before S302, the UE joins multicast session #1 and multicast session #2. Thus, information #1 includes the configuration of multicast session #1 and multicast session #2.

After S302, the gnb#1 may release the UE to an inactive state.

S303, gNB#1 broadcasts the SIB.

In the inactive state, the UE may acquire SIB including information #2 (an example of the second information). The information #2 includes a multicast session #1 associated index #1, and according to the multicast session #1, the index #1, and the information #1, the UE can determine a multicast configuration #1 corresponding to the multicast session #1, so that the UE can receive the multicast session #1 according to the multicast configuration #1.

S304, the UE performs cell reselection and moves to a cell managed by gNB#2.

S305, gnb#2 broadcasts SIB.

For multicast session #1, the multicast configuration of the ue's reselected cell is multicast configuration #2. The gnb#2 may carry information #3 of the multicast session#1 associated index #2 (an example of seventh information) through a broadcasted SIB. After the UE reselects the cell, the UE may acquire the SIB of the new cell, thereby acquiring information #3. According to multicast session #1 and index #2, the UE may determine multicast configuration #2 corresponding to multicast session #1, so that the UE may continue to receive multicast session #1 according to multicast configuration #2.

S306, the gnb#2 starts to provide the multicast session#2 in an inactive state.

S307, the gnb#2 transmits a system message change notification.

The UE may acquire the SIB according to the system change message.

S308, gNB#2 broadcasts SIB.

Multicast session #2 is provided when gNB #2 begins in either the inactive state or the idle state. The gnb#2 may carry information #4 of the multicast session#2 associated index #1 through a broadcasted SIB (still another example of seventh information). The UE may acquire the SIB according to the system change message, thereby acquiring information #4. From the multicast session #2 and the index #1, the UE may determine the multicast configuration #1 corresponding to the multicast session #2, so that the UE may receive the multicast session #2 according to the multicast configuration # 1.

From the above, in the situations of cell reselection or providing inactive multicast in the beginning of the cell, the terminal device can obtain the multicast configuration corresponding to the multicast session to be received without entering the connection state, so that the energy consumption of the UE can be reduced and the service interruption can be avoided.

Fig. 8 is a schematic diagram of a communication method 400 according to an embodiment of the present application. The method 400 may include the following steps.

S410, the first network device sends eighth information to the terminal device, and accordingly, the terminal device receives the eighth information.

The eighth information includes the first multicast configuration information and information of a cell corresponding to the first multicast configuration information, where the cell corresponding to the first multicast configuration information includes the first cell.

For the same multicast session, different cells within the first area may send the multicast session using the same multicast configuration information. For example, different cells in the first area may each send the first multicast session using the first multicast configuration, so the first network device may further indicate, when sending the multicast configuration information to the terminal device, information of the cell to which the multicast configuration information corresponds to the terminal device. The information of the cell may be a cell list in the first area, or the cell information is an identifier of the first area, where the first area is associated with a cell list, and the terminal device may learn, through an application layer message or through preset information, a group of cells associated with the first area, that is, cells corresponding to the cell list.

Wherein the first multicast configuration corresponds to a first multicast session.

Alternatively, the first region may be identical to or smaller than RNA.

It should be understood that the specific description of the multicast configuration information may refer to the method 200, which is not repeated here.

Alternatively, the eighth information may be carried in dedicated signaling, for example, an RRC release message or an RRC reconfiguration message. In other words, the first network device may pre-configure the eighth information for the terminal device when the terminal device is in the RRC connected state.

S420, the second network device sends a second message to the terminal device, wherein the second message comprises the first indication information.

Wherein the first indication information may be a bit map, each bit of the bit map being associated with a cell. For example, if the cells corresponding to the first multicast configuration information include Q bits, the bit map includes Q bits, where Q bits and Q cells are in one-to-one correspondence, and Q is a positive integer.

Specifically, each multicast session corresponds to a bit map (bitmap), where each bit in the bit map corresponds to a cell, for example, starting with the first bit, the order of the bits corresponds to cells in the cell list in the first area one-to-one. Illustratively, the first area includes 32 cells, and the bitmap has a length of 32 bits and corresponds to the 32 cells in the first area one by one.

As an implementation manner, the first indication information is used for indicating a state of a first multicast session provided by a cell corresponding to the first multicast configuration information. The cell corresponding to the first multicast configuration information includes a first cell, which may be said to be a first indication information for indicating a state of a first multicast session provided by the first cell.

The state of the first multicast session provided by the cell corresponding to the first multicast configuration information may include: the cell corresponding to the first multicast configuration information is or is not providing a first multicast session in an RRC inactive state or idle state.

For example, for multicast session #1 corresponding to bit map #1, bit position 1 indicates that the cell corresponding to the bit currently supports providing multicast session #1 in the inactive state or idle state, or that the cell is currently providing multicast session #1 in the inactive state or idle state. bit position 0 indicates that the cell to which the bit corresponds is not currently supporting the multicast session #1 in the inactive state or the idle state, or that the cell is not currently providing the multicast session #1 in the inactive state or the idle state.

Alternatively, the cell corresponding to the first multicast configuration information may constitute an effective area of the first multicast configuration information.

For example, when the first cell starts or stops providing the first multicast session in the RRC inactive state or idle state, the second network device sends a second message to the terminal device, the second message including the first indication information.

In this implementation, according to the first indication information, the terminal device may know which cell or cells are currently providing the multicast session #1 in the inactive state or the idle state, and if the terminal device joins the multicast session #1 and the cell #2 is the serving cell of the terminal device, the terminal device may receive the multicast session #1 using the first multicast configuration information assuming that the cell providing the multicast session #1 in the inactive state or the idle state includes the cell # 2.

As yet another implementation manner, the first indication information is used to indicate that a state of a first multicast session provided by a cell corresponding to the first multicast configuration information changes. Specifically, it may include: the cell corresponding to the first multicast configuration information starts or stops providing the first multicast session in the RRC inactive state or idle state.

For example, for multicast session #1 corresponding to bit bitmap #1, bit position 1 indicates that the cell to which the bit corresponds is currently beginning to provide inactive or idle multicast session #1.bit position 0 indicates that the cell to which the bit corresponds is currently stopped in an inactive state or an idle state to provide the multicast session #1, or, for the multicast session of the cell, the terminal device can only receive in a connected state.

In this implementation manner, according to the first indication information, the terminal device may know which cell or cells of the multicast session #1 that are currently starting to provide the multicast session #1 in the inactive state or the idle state, and if the terminal device joins the multicast session #1 and the cell #2 is a serving cell of the terminal device, the terminal device may receive the multicast session #1 using the first multicast configuration information, assuming that the cell or cells of the multicast session #1 that are currently starting to provide the multicast session #1 in the inactive state or the idle state include the cell # 2.

Optionally, the second message is a paging message or an RRC release message.

Optionally, the terminal device is in an idle state or inactive state when performing S420.

And S430, the second network equipment sends the first multicast session according to the first multicast configuration, and the terminal equipment receives the first multicast session according to the first multicast configuration information under the condition that the first cell is a resident cell of the terminal equipment.

The first cell may be a cell that is providing the multicast session #1 in the inactive state or the idle state, or may be a cell that starts providing the multicast session #1 in the inactive state or the idle state.

Specifically, the terminal device receives a first multicast session according to the first multicast configuration information, including: and under the condition that the first indication information indicates the first cell to start providing the first multicast session in the inactive state or the idle state, the terminal equipment receives the first multicast session in the inactive state or the idle state according to the first multicast configuration information. And under the condition that the first indication information indicates that the first cell stops providing the first multicast session in the inactive state or the idle state, the terminal equipment sends an RRC recovery request message to the network equipment corresponding to the first cell. Further, the network device corresponding to the first cell may send an RRC release message or an RRC restore message to the terminal device according to the RRC restore request message. For example, if the first cell still supports providing the first multicast session in the inactive state or the idle state at this time, the network device corresponding to the first cell may send an RRC release message to the terminal device according to the RRC resume request message, and the terminal device may continue to maintain the RRC inactive state or the idle state according to the RRC release message, and receive the first multicast session according to the first multicast configuration information. For another example, if the first cell does not support providing the first multicast session in the inactive state or the idle state at this time, the network device corresponding to the first cell may send an RRC resume message to the terminal device according to the RRC resume request message, and further, the terminal device may enter a connection state according to the RRC resume message, and receive the first multicast session in the RRC connection state according to the first multicast configuration information.

The network device corresponding to the first cell refers to a network device for managing the first cell, which may be the first network device, or may be the second network device, or may be another network device in the first area.

Optionally, the first cell is a cell managed by the fourth network device. The method further comprises the steps of: the second network device receives second indication information from the fourth network device before the second network device sends the second message to the terminal device, the second indication information being used to instruct the first cell to start or stop providing the first multicast session in the inactive state or the idle state.

Specifically, when any cell in the first area stops or starts to provide an inactive state or idle state multicast session, assuming that the cell is a cell of the gNB2, the gNB2 sends multicast configuration change indication information to the neighboring base station through the Xn interface, where the cell including the gNB stops or starts to provide a cell identifier of the inactive state multicast session, and an identifier of the multicast session that stops or starts to be provided. At this time, the gNB in the area triggers group paging, and the paging message indicates the identifier of the multicast session and the first indication information corresponding to the multicast session.

Based on the above scheme, any cell in the first area stops or starts to provide the multicast session in the inactive state or the idle state, and the network device in the first area triggers the group paging, so that no matter which cell in the first area the terminal device moves to, the terminal device can quickly acquire the starting or stopping situation of the multicast session in the area. In addition, when a certain cell starts to provide the multicast session in the inactive state or the idle state, the terminal equipment can also receive the multicast session in time, so that the communication efficiency is higher.

Optionally, before S410, the method further includes: the first network device receives ninth information from the fourth network device, where the ninth information is used to indicate identities of R cells corresponding to the first multicast configuration information, and the cell information corresponding to the first multicast configuration information includes R cells, where R is a positive integer.

In particular, network devices within the first region may coordinate determining a list of cells included in the first region.

Optionally, only the cell whose multicast session state is changed is indicated in the second message. If the cell associated with the multicast session is unchanged, the multicast session and the associated cell are not included in the second message. And if the terminal equipment does not receive the second message, the multicast session provided by the cell is considered unchanged.

As an implementation manner, when the second network device sends the group page, the second network device calculates the position of Paging Occasion (PO) according to the identifier of the terminal device joining the multicast session, and sends the group page on the corresponding PO.

Fig. 9 is a schematic diagram of a communication method 500 according to an embodiment of the present application. Method 500 may be considered a combination of method 200 and method 400, and method 500 may include the following steps.

S510, the first network device sends eighth information to the terminal device, and accordingly, the terminal device receives the eighth information.

The eighth information includes at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, the eighth information further includes cell information corresponding to the at least one multicast configuration information, the at least one multicast configuration information includes first multicast configuration information, the index information corresponding to the at least one multicast configuration information includes first index information, the cell information corresponding to the at least one multicast configuration information includes cell information corresponding to the first multicast configuration information, and the cell information corresponding to the first configuration information includes a first cell.

For the same multicast session, different cells within the first area may send the multicast session using different multicast configuration information. For each multicast session, the first network device may pre-configure multicast configuration information, and index information and cell information corresponding to the multicast configuration information, to the terminal device. For example, the index of the multicast configuration_1 of tmgi_1 is index1, and the corresponding cells are cell_1, cell_2, and cell_3; the index of the multicast configuration_1 corresponding to the TMGI_1 is index2, and the corresponding cells are cell_1, cell_2, cell_3 and cell_4.

S520, the second network device sends a second message to the terminal device, where the second message includes first indication information and second information, the first indication information is used to indicate a state of a first multicast session provided by the first cell, the second information is used to indicate that the first multicast session is associated with first index information, and the first index information indicates first configuration information.

For example, when the first cell in the first area starts or stops providing the first multicast session in the inactive state or the idle state, or when the multicast configuration information of the first cell in the first area changes, the second network device sends a second message to the terminal device, where the second message includes first indication information and second information, the first indication information is used to instruct the first cell to start or stop providing the first multicast session in the inactive state or the idle state, and the second information is used to instruct the first multicast configuration.

In the method 500, the terminal device may determine the first configuration information according to the first indication information and the first index information.

For a specific description of the first indication information and the first index information, reference may be made to the methods 200 and 400.

And S530, the second network equipment sends a first multicast session according to the first multicast configuration, and the terminal equipment receives the first multicast session according to the first multicast configuration information under the condition that the first cell is a resident cell of the terminal equipment.

For a specific description of S530, reference may be made to S430.

Based on the above scheme, when the terminal device is in a connection state, the first network device pre-configures the cell information corresponding to the first multicast configuration information to the terminal device, and the second network device can obtain the multicast session state of each cell through the first indication information in the second message and indicate the first multicast configuration information to the terminal device through the second information. A serving cell of the terminal device is a certain cell, and the cell starts to provide a multicast session in an inactive state or an idle state, and the terminal device may receive the multicast session using the first multicast configuration information. Therefore, on one hand, the potential safety hazard caused by receiving the multicast configuration information in a broadcast mode can be avoided, and on the other hand, the signaling overhead and time delay caused by the terminal equipment entering the RRC connection state to receive the multicast configuration information can be avoided.

In addition, compared to method 400, in method 500, different cells in the first area may use different multicast configuration information for the same multicast session, and thus have greater flexibility.

Optionally, the method 400 further comprises: the first network device determines to acquire eighth information. Specifically, reference may be made to the method for obtaining the first information by the first network device in the method 200.

Optionally, the method 400 further comprises: the first network device or the second network device sends fourth information to the terminal device, and accordingly, the terminal device receives the fourth information, where the fourth information is used to indicate a first G-RNTI corresponding to the first multicast session, the first network device may scramble the first multicast session through the first G-RNTI, and the terminal device may descramble the received first multicast session through the first G-RNTI.

It should be appreciated that details not described in detail in method 400 may refer to methods 200 and 300.

The present application also provides a communication method, and the communication method may be further used to solve the problem of how to synchronize multicast configuration information between network devices in an area, where, by using the method, for the same multicast session, different cells in the area may use the same multicast configuration information to send the multicast session.

Fig. 10 is a schematic diagram of a method 600 of communication provided in an embodiment of the present application, the method including the following steps.

The fifth network device sends a third message to the first device S610.

The third message is used for requesting multicast configuration information of the first multicast session, or the third message is used for requesting multicast configuration information corresponding to the first multicast session, where the multicast configuration information corresponding to the first multicast session may be used for configuring the first multicast session. Wherein, the multicast configuration information is also called MBS multicast configuration information or multicast configuration, and refers to configuration parameters for receiving multicast session in MBS, and the multicast configuration information is composed of the multicast configuration parameters. As another example, the multicast configuration information may include one or more of the following: multicast MRB configuration, physical channel configuration, DRX configuration, G-RNTI configuration, neighbor cell configuration, CFR configuration, each of which can be understood as a multicast configuration parameter, and the explanation of multicast configuration information can refer to the method 200, which is not repeated herein.

Illustratively, the third message includes an identification of the first multicast session, which may be a TMGI.

Wherein the first device refers to a device on the non-terminal side. The functions performed by the first device may be performed by a functional module or a network element of a certain entity device, in other words, the first device may refer to a functional module or a network element of a certain entity device.

As an example, the first device may be a core network (core network) device, e.g. the first device refers to an access and mobility management function (access and mobility management function, AMF) network element or a session management function (session management function, SMF) network element in the core network device.

As another example, the first device may also be a sixth network device, e.g., the fifth network device may send the third message directly to the sixth network device. Alternatively, the fifth network device may send the third message to the sixth network device through forwarding of another device, where the other device may be a core network device, in other words, the fifth network device may communicate with the sixth network device directly or may communicate indirectly through the core network.

Alternatively, the triggering condition of S610 may be that the cell managed by the fifth network device starts to provide the first multicast session for the terminal device in the inactive state or the idle state, or that the terminal device joins the first multicast session in the cell managed by the fifth network device.

The multicast session is provided for the terminal device in the inactive state or the idle state, which can be said to be that the multicast session is provided in the inactive state or the idle state, or the cell starts to provide the multicast session in the idle state or the inactive state, or the cell starts to send the multicast session to the terminal device when the terminal device is in the inactive state or the idle state, or the cell opens a switch for sending the multicast session in the inactive state or the idle state. After starting or opening, the terminal device supporting the multicast session reception in the inactive state or the idle state will receive the multicast session in the inactive state or the idle state. If the cell stops providing the multicast session in the inactive state or the idle state, the terminal device cannot receive the multicast session in the inactive state or the idle state even though the terminal device supports receiving the multicast session in the inactive state or the idle state.

It should be understood that the fifth network device performing S610 may be one or more, and the plurality of fifth network devices may belong to the same area, and for any network device in the area, if the managed cell thereof meets the above triggering condition, it may send a third message to the first device, so as to request the multicast configuration information of the first multicast session.

S620, the first device determines the first multicast configuration information according to the third message and the value range of the multicast configuration parameters.

The first multicast configuration information may be used to configure the terminal device to receive the first multicast session in an RRC inactive state or an idle state.

The range of values of the multicast configuration parameters may include at least one of the following: the method comprises the steps of selecting a value range of a G-RNTI, selecting a value range of an MRB identifier, selecting a value range of an LCH identifier, selecting a value range of a physical channel configuration parameter, selecting a value range of a discontinuous reception DRX configuration parameter and selecting a value range of a common frequency domain resource CFR configuration parameter. For example, the G-RNTI has a value range of 10000-15000, the MRB identifier has a value range of 100-200, and the LCH identifier has a value range of 5000-10000.

Alternatively, the value range of the multicast configuration parameter may be understood as a shared value range of a plurality of multicast sessions, that is, the value range does not distinguish between a multicast session or a multicast service, or the value range of the multicast configuration parameter is applicable to any multicast session or multicast service in the area. For example, the first multicast session, the second multicast session, the third multicast session, etc. within the area may all use the values in this range of values.

The first device may determine first multicast configuration information for the first multicast session based on the range of values of the multicast configuration parameters and a third message from the one or more fifth network devices. For example, when there are a plurality of different ranges of values of the multicast configuration parameters, the first device may select the first multicast configuration information from an intersection of the plurality of different ranges. For another example, when the multicast configuration parameter has only one value range, the first device may select the first multicast configuration information for the first multicast session in the value range. For another example, when the plurality of fifth network devices request multicast configuration information for a first multicast session, the first device may determine multicast configuration information shared by the plurality of fifth network devices for the first multicast session.

It should be understood that when there are a plurality of fifth network devices, it is understood that there are a plurality of third messages, or there are a plurality of value ranges of multicast configuration information, where one fifth network device sends one third message, and each third message carries a value range of a multicast configuration parameter preconfigured or determined by the fifth network device.

S630, the first device sends the first multicast configuration information to the fifth network device.

In one implementation, the third message includes an identifier of the first multicast session, and the range of values of the multicast configuration parameter includes a range of values of the G-RNTI, where S620 specifically includes: the first device selects a value from a value range of the G-RNTI as the G-RNTI of the first multicast session, and the first multicast configuration information comprises the G-RNTI of the first multicast session.

In yet another implementation manner, the third message includes an identifier of the first multicast session and the number X of multicast radio bearers MRBs required for the first multicast session, and the range of values of the multicast configuration parameters includes the range of values of the MRB identifier, where S620 specifically includes: the first device selects X values from the value range of the MRB identifier as the MRB identifier of the first multicast session, wherein the first multicast configuration information comprises the MRB identifier of the first multicast session, and X is a positive integer.

In yet another implementation, the third message includes an identifier of the first multicast session and a number Y of logical channels LCHs required by the first MRB of the first multicast session, and the range of values of the multicast configuration parameter includes a range of values of LCH identifiers, where S620 specifically includes: the first device selects Y values from a value range of the LCH identifier as the LCH identifier of the first MRB, the first multicast configuration information comprises the LCH identifier of the first MRB, and Y is a positive integer.

In yet another implementation, the third message includes an identifier of the first multicast session, and the range of values of the multicast configuration parameter includes a range of values of the physical channel configuration parameter, where S620 specifically includes: the first device selects at least one value from a range of values of physical channel configuration parameters as the physical channel configuration parameters of the first multicast session, the first multicast configuration information including the physical channel configuration parameters of the first multicast session.

In yet another implementation, the third message includes an identifier of the first multicast session, and the range of values of the multicast configuration parameter includes a range of values of the discontinuous reception DRX configuration parameter, where S620 specifically includes: the first device selects at least one value from a range of values of DRX configuration parameters as the DRX configuration parameters of the first multicast session, the first multicast configuration information including the DRX configuration parameters of the first multicast session.

In yet another implementation, the third message includes an identifier of the first multicast session, and the range of values of the multicast configuration parameter includes a range of values of the common frequency domain resource CFR configuration parameter, where S620 specifically includes: the first device selects at least one value from a range of values of the CFR configuration parameters as the CFR configuration parameters of the first multicast session, the first multicast configuration information including the CFR configuration parameters of the first multicast session.

It should be understood that the various implementations described above may be combined with one another without limitation. As an example, the third message includes an identifier of the first multicast session, a number of multicast radio bearers MRBs required for the first multicast session, and a number of logical channels LCHs required for each MRB of the first multicast session, and the range of values of the multicast configuration parameters includes a range of values of the MRB identifier and a range of values of the LCH identifier, where S620 specifically includes: the first device selects a corresponding number of MRB identifiers for the first multicast session from a range of values of the MRB identifiers, and selects a corresponding number of LCH identifiers for each MRB from a range of values of the LCH identifiers. For example, the third message indicates that 2 MRBs are needed for the multicast service TMGI-1, wherein one MRB needs 2 LCHs and the other MRB needs 3 LCHs, the first device determines that MRB ID-1 and MRB ID-2, and determines that LCHs corresponding to MRB ID-1 are LCH ID-1 and LCH ID-2, and LCHs corresponding to MRB ID-2 are LCH ID-3, LCH ID-4 and LCH ID-5.

Optionally, if the third message includes the number of MRBs and the number of Logical Channels (LCHs) required for the first multicast session, the number of MRBs and the number of LCHs may be determined by the fifth network device according to the quality of service (quality of service, qoS) of the first multicast session. Illustratively, for the same multicast service, the gnbs in one area (e.g., RNA area) may have the same QoS and mapping rules for MRB/LCH, and it is understood that for the same service, the same number of MRB/LCH may be determined by the gnbs in the area.

Alternatively, the third message may not include the number of MRBs and the number of Logical Channels (LCHs) required for the first multicast session. In this case, the SMF may determine the number of MRBs and the number of LCHs according to the QoS of the first multicast session, and if the first device is the SMF, S620 is performed by the SMF. If the first device is an AMF or a sixth network device, the SMF may transmit the determined number of MRBs and the determined number of LCHs required for the first multicast session to the AMF or the sixth network device, which performs S620.

Optionally, S620, the first device determines the first multicast configuration information according to the third message and the range of values of the multicast configuration parameters, including: the first device determines the G-RNTI of the first multicast session according to the identifier of the first multicast session in the third message, and determines other multicast configuration information except the G-RNTI in the first multicast configuration information according to the value range of the multicast configuration parameter, for example, MRB identifier, LCH identifier, DRX configuration parameter, CFR configuration parameter, etc. The specific method for determining the other multicast configuration information except the G-RNTI in the first multicast configuration information according to the value range of the multicast configuration parameter may be described above. The specific manner in which the first device determines the G-RNTI for the first multicast session based on the identity of the first multicast session may refer to configuration 1 in method 200. It should be appreciated that the above-described manner may be considered an example of a combination of method 600 and method 200.

As one implementation, the range of values of the multicast configuration parameters is preconfigured in the first device. For example, the first device is a sixth network device, and the range of values of the multicast configuration parameters is configured by OAM. In this case, the OAM may configure the value ranges of the same multicast configuration parameters to the plurality of network devices in one area, and when determining the first multicast configuration information, the first device may determine the corresponding first multicast configuration information for the first multicast session in the value ranges.

As another implementation, the range of values of the multicast configuration parameters is sent by the fifth network device to the first device. In this implementation, the method 600 may further include: the fifth network device sends a fourth message to the first device, the fourth message including a range of values for the multicast configuration parameters.

For example, if the value range of the multicast configuration parameter is determined by the fifth network device, the fifth network device sends the determined value range to the first device, where the first device may be a sixth network device or a core network device. For another example, the value range of the multicast configuration parameter is configured by the OAM to the fifth network device, and the first device is a core network device, and then the fifth network device may send the value range to the core network device.

Optionally, in this implementation, since the range of values of the multicast configuration parameters is determined by the fifth network device, the range of values determined by the different fifth network device may be different, for example, gNB1 determines that the range of values of G-RNTIs is 10000-20000, and gNB2 determines that the range of values of G-RNTIs is 5000-15000. In this case, each fifth network device may send its determined range of values to the first device, respectively. Each fifth network device may indicate an updated range of values to the first device when the range of values of the multicast configuration parameters determined by each fifth network device changes. In addition, the first device may first determine an intersection of a plurality of different ranges in determining the first multicast configuration information, and determine corresponding first multicast configuration information for the first multicast session from the intersection.

Illustratively, the fourth message is in a PDU session resource establishment request transmission (PDU session resource setup request transfer) message or a PDU session resource establishment modification request transmission (PDU session resource setup modify request transfer message). The fifth network device may send a fourth message to the first device at the time of the first multicast session or any of the multicast sessions being established.

It should be understood that, since the multicast configuration parameters (e.g., the RNTI value, the MRB identifier, the LCH identifier) are also used for other service types such as unicast and broadcast, when the fifth network device has the demand of the multicast service in the inactive state, the value of some parameters (e.g., the RNTI value) may already be occupied by unicast or broadcast, if the first device directly designates the multicast configuration parameters for a certain multicast service, a conflict occurs with the configuration parameters of the unicast or broadcast already used, and at this time, the fifth network device needs to reconfigure the configuration parameters used by the unicast or broadcast service that have the conflict, which affects the user experience and increases the signaling overhead of reconfiguration. Based on the above scheme, the fifth network device may indicate the value range of the multicast configuration parameter to the first device or the value range of the pre-configured multicast configuration parameter in the first device, so that conflicts (for example, value conflicts of RNTI and LCH identifier conflicts) between the inactive multicast configuration and the configuration of other services may be avoided, thereby avoiding the occurrence of the reconfiguration, avoiding additional signaling overhead, and improving user experience.

Optionally, the method 600 may further include: and the fifth network device sends the identification information of a second area to the first device, wherein the second area is an effective area of the value range of the multicast configuration parameters.

Wherein the cells in the second area provide at least one multicast session, the at least one multicast session comprising a first multicast session, the method may further comprise: the first device determines, for each of the at least one multicast session, multicast configuration information that is different from each other, or that is, multicast configuration information of other multicast sessions in the at least one multicast session other than the first multicast session is different from the first multicast configuration information. In other words, in the second area, the first device determines multicast configuration information for the multicast session in the area from the range of the multicast configuration parameter, and the multicast configuration information of different multicast sessions are different. Outside the second area, the other multicast sessions are allowed to be identical to the multicast configuration information of the multicast session in the second area.

Illustratively, the effective area of the range of values of the multicast configuration parameters may be RNA, which includes the fifth network device. The effective area of the value range of the multicast configuration parameter may also be a preconfigured area, for example, an area configured for OAM.

It should be understood that the purpose of the fifth network device sending the identification information of the second area to the first device is that the range of values of the configuration parameters supported by the terminal device is limited, and when the total number of multicast sessions is more, it may not be possible to determine unique multicast configuration information for each session. Thus, by indicating the second zone, the first device may only need to ensure that one session within a zone has unique multicast configuration information (e.g., unique G-RNTI, MRB ID, LCH ID, etc.), while other sessions outside the zone may still use the multicast configuration information within the zone.

Based on the above scheme, the fifth network device may send the identification information of the second area to the first device, so as to allow multiplexing of the same configuration parameters in different areas (for example, two different RNA areas) within the management range of the first device, and thus, the utilization efficiency of the configuration parameters may be improved.

It should be appreciated that when the available range of values of some configuration parameters is limited (for example, the existing protocol specifies that the maximum value of the MRB identifier is 512, and when the number of multicast sessions that need to be established by each fifth network device in the first device management range exceeds 512), the multicast configuration parameters between the multicast sessions overlap, and the multicast configuration parameters cannot uniquely correspond to one multicast session. Furthermore, continuing to take the MRB identifier as an example, on the one hand, according to the QoS requirements of the multicast session, one multicast session may correspond to one or more MRBs, which may aggravate the shortage of the MRB identifier. On the other hand, various service forms such as multicast, unicast, broadcast and the like all need to use radio bearers and correspond to corresponding MRB identifiers, and the range of available MRB identifiers of the multicast is further narrowed in consideration of the fact that other service types possibly occupy part of the MRB identifiers.

Optionally, the third message includes an identification of a second cell, the second cell being a cell managed by the fifth network device that provides the first multicast session in the RRC inactive state or in the idle state, the method 600 may further include: the first device determines tenth information from third messages from the one or more fifth network devices, the tenth information indicating an effective area of the first multicast configuration information. The effective area can be understood as a configured synchronization area.

In one implementation, the effective area of the first multicast configuration information is determined from the second cells included in the one or more third messages.

In one example, the range of values of the multicast configuration parameters is OAM preconfigured, where the range of values of the multicast configuration parameters configured by the plurality of network devices in the second area is the same. In this example, the first device may determine each of the second cells of the plurality of fifth network devices as an active area of the first multicast configuration information. For example, gNB1 (an example of the fifth network device) indicates to CN (an example of the first device) that cell 1 (an example of the second cell) it manages provides multicast session #1 in RRC inactive state or idle state, gNB2 (another example of the fifth network device) indicates to CN (another example of the second cell) that cell 3 (another example of the second cell) it manages provides multicast session #1 in RRC inactive state or idle state, and cell 5 (another example of the second cell) determines multicast configuration information #1 for multicast session #1 and determines that the effective area of multicast configuration information #1 is that of cell 1, cell 3, cell 5, or that the effective area of multicast configuration information #1 is that of gNB1 and gNB 2.

In yet another example, the range of values of the multicast configuration parameters is determined by the fifth network device, at which time the ranges of values of the multicast configuration parameters configured by the plurality of network devices in the second area may be different. In this example, the first device may determine an intersection of the value ranges of the multicast configuration parameters indicated by the plurality of fifth network devices, and for the network devices corresponding to the value ranges where the intersection exists, the second cell managed by the first device may form an effective area of the first multicast configuration information, in other words, the first device determines that the multicast configuration information available to all of the plurality of fifth network devices is the multicast configuration information corresponding to the multicast session. For example, the gNB1 (an example of the fifth network device) indicates to the CN (an example of the first device) that the cell 1 (an example of the second cell) it manages is provided with the multicast session #1 in the RRC inactive state or in the idle state, the gNB2 (another example of the fifth network device) indicates to the CN that the cell 3 (another example of the second cell) it manages is provided with the multicast session #1 in the RRC inactive state or in the idle state, the cell 5 (another example of the second cell) indicates that the value range of the G-RNTI determined by the gNB1 is 5000-10000, the gNB2 indicates that the value range of the G-RNTI determined by the gNB1 is 10000-15000, and since the value range of the G-RNTI determined by the gNB1 indicates that the value range of the G-RNTI determined by the G-RNTI is not intersected with the value range of the G-RNTI determined by the gNB2, the first device may determine the multicast configuration information #1 from among the value ranges of the G-RNTI determined by the gNB2, and determine that the multicast configuration information #1 is valid for the multicast session #1, and determine that the area of the multicast configuration information #1 is the cell 3, the area of the multicast configuration information #1, the area 5, or that the area of the multicast configuration information #1 is not valid is the area 1, or the area of the cell 2.

In this example, if the intersection cannot be obtained between the value range of the multicast configuration parameter determined by a fifth network device and the value range of the multicast configuration parameter determined by other network devices in the second area, the first device may indicate a configuration failure to the fifth network device; optionally, the first device does not join the fifth network device in the effective area of the multicast configuration information, and the identifier of the fifth network device or the identifier of the cell managed by the fifth network device is not included in the effective area of the multicast configuration information.

In another implementation, the effective area of the first multicast configuration information may also be determined not according to the second cell in the third message. For example, the effective area of the first multicast configuration information may be equal to the effective area of the second area (i.e., the effective area of the range of values of the multicast configuration parameters, such as the RNA area). In this manner, the effective area of the first multicast configuration information is independent of whether network devices in the second area are providing the first multicast session. That is, the network devices in the second region may not be providing the first multicast session in the RRC inactive state or the idle state; or a first multicast session in an RRC inactive state idle state is being provided. If a network device within the area is providing a first multicast session in an RRC inactive state idle state, a cell providing the first multicast session may configure the first multicast session using the first multicast configuration information. In other words, in this manner, the effective area of the first multicast configuration information may not need to be updated dynamically, i.e. the effective area of the first multicast configuration information is not updated by a network device starting or stopping providing the first multicast session in the RRC inactive state idle state.

In this implementation, the method may further include: if the cell managed by the fifth network device does not support providing the first multicast session in the inactive state or the idle state, or the cell managed by the fifth network device does not support the multicast session, the fifth network device sends a first message, where the first message does not include an identifier of the multicast session. In particular, reference may be made to method 200.

It should be understood that, in the present application, the effective area of the first multicast configuration information does not limit that the terminal device must receive the first multicast session corresponding to the first multicast configuration information in the area. In this way, when the current multicast session of the cell in the effective area changes, for example, the provisioning is started or stopped, and no synchronization update is needed between the network devices.

Optionally, the method 600 further includes: the first device sends tenth information to the fifth network device.

Optionally, the method 600 further includes: the fifth network device sends twelfth information to the first device, where the twelfth information is used to indicate whether the first multicast configuration information is accepted, or indicate whether the multicast configuration information of the first multicast session is configured successfully.

Specifically, after receiving the first multicast configuration information, the fifth network device may further determine whether the first multicast configuration information meets a value range of the multicast configuration parameter determined or configured by the first network device, if so, the twelfth information indicates that the first multicast configuration information is accepted, and if not, the twelfth information indicates that the first multicast configuration information is rejected. Further, the first device may update the effective area of the first multicast configuration information according to the twelfth information.

Optionally, for a certain multicast service TMGI, after a new network device joins an effective area, the first device updates the effective area to the network device in the existing effective area, that is, joins the identifier of the new network device or the cell identifier of the network device.

Optionally, the method 600 further includes: the fifth network device sends eleventh information to the first device, where the eleventh information is used to instruct the third cell managed by the fifth network device to stop providing the first multicast session in the radio resource control RRC inactive state or idle state, and the first device removes the third cell from the effective area of the first multicast configuration information, or the first device determines an updated effective area corresponding to the first multicast configuration information, where the updated effective area does not include the third cell.

In one implementation, when the fifth network device stops providing the first multicast session in the inactive state or the idle state (e.g., no connected terminal device receives the first multicast session), the fifth network device may indicate to the first device that the multicast configuration request is stopped (an example of eleventh information), and the first device removes the fifth network device from the validation area of the first multicast configuration information. In addition, when the fifth network device stops providing the first multicast session in the inactive state or the idle state, the first device will stop sending the updated effective area to the fifth network device in case that the effective area of the first multicast configuration information is updated. In addition, when the fifth network device stops providing the first multicast session in the inactive state or the idle state, the fifth network device may notify the terminal device of the update of the multicast configuration in the inactive state: for example, the updated active state multicast configuration indicated by the fifth network device to the terminal device does not include the multicast configuration of the first multicast session, and further, when the active state terminal device residing on the cell of the fifth network device still desires to receive the first multicast session, the terminal device may trigger RRC connection restoration.

Optionally, when the fifth network device no longer has multicast configuration information in the second area requesting to provide the first multicast session to the first device, the first device deletes the stored first multicast configuration information.

It should be appreciated that the method 600 described above may be used in combination with other methods, for example, two implementation scenarios are presented below.

In one implementation scenario, the method 600 further comprises: the fifth network device transmits the first multicast configuration information and tenth information to the terminal device.

The fifth network device may send the first multicast configuration information and the tenth information to the terminal device by dedicated signaling or common signaling, for example. Wherein, the dedicated signaling may be an RRC release message, and the common signaling may be an MCCH or SIB.

Optionally, the meaning of the effective area means that the terminal device receives the first multicast session in the radio resource control RRC inactive state or idle state according to the first multicast configuration information in the effective area of the first multicast configuration information, in other words, in the effective area, the terminal device may continue to receive the first multicast session without entering the connection state additionally. When the terminal device is outside the validation area, or the terminal device moves out of the validation area, the terminal device may trigger an RRC connection recovery procedure.

Based on the above scheme, when the terminal equipment moves in the area, the terminal equipment can continue to use the multicast configuration information to receive the multicast session, so that the continuity of the terminal equipment for receiving the multicast service can be ensured.

In another implementation scenario, the method 600 described above may be applied to the method 400, e.g., a first network device in the method 400 may perform a method performed by a fifth network device in the method 600, and a fourth network device in the method 400 may perform the steps performed by the first device in the method 600. Illustratively, when the method 600 is applied to the method 400, the method 400 includes the steps of:

s610, the first network device sends a third message to the first device.

S610, the first device determines the first multicast configuration information according to the third message and the range of values of the multicast configuration parameters.

S630, the first device sends the first multicast configuration information to the first network device.

S410, the first network device sends eighth information to the terminal device.

Alternatively, in the method 400, "the identities of R cells corresponding to the first multicast configuration information" may be understood as the effective area of the first multicast configuration information in the method 600.

S420, the second network device sends a second message to the terminal device.

It should be appreciated that the detailed description of the above steps may refer to the methods 400 and 600, and are not repeated herein.

Fig. 11 is a schematic diagram of a method 700 of communication provided in an embodiment of the present application, and the method 700 may be regarded as a specific implementation of the method 600. The method 700 may include the following steps.

S701, the gNB (an example of the fifth network device) transmits a message #1 (an example of the fourth message) to the CN (an example of the first device).

The message #1 includes the range of values of the multicast configuration parameters and the identification of the area #1 (an example of the second area). Illustratively, the range of values of the multicast configuration parameters includes a range of values of MRB identification and a range of values of LCH identification.

Alternatively, the range of values of the multicast configuration parameters may be OAM preconfigured.

S702, the gNB sends a message #2 (an example of a third message) to the CN.

Message #2 is used to request multicast configuration for multicast session #1, message #2 includes an identification of multicast session #1, e.g., TMGI-1.

Optionally, message #2 includes the number of MRBs and the number of LCHs.

The message #2 may further include an identifier of the cell #1 (an example of the second cell), where the identifier of the cell #1 is used to instruct the gcb managed cell #1 to start providing the active multicast session #1.

This step may refer to S610.

S703, the CN determines multicast configuration #1 (an example of the first multicast configuration information) and area #2 (an example of the effective area of the first multicast configuration information) from message #1 and message # 2.

For example, the multicast configuration #1 includes MRB identifiers and LCH identifiers, the CN selects a corresponding number of MRB identifiers for the multicast session #1 from a range of values of the MRB identifiers, and selects a corresponding number of LCH identifiers for each MRB of the multicast session #1 from a range of values of the LCH identifiers.

Wherein zone #2 may include an identification of cell #1.

S704, the CN sends the multicast configuration #1 to the gNB, and indicates the identity of the area # 2.

S705, the gNB transmits information #5 (an example of twelfth information) to the CN, the information #5 indicating acceptance of the multicast configuration #1.

S706, the gNB sends the UE the identities of multicast configuration #1 and zone # 2.

For example, the gNB sends the identity of multicast configuration #1 and zone #2 to the UE via an RRC release message.

S707, the gNB sends information #6 (an example of eleventh information) to the CN, where the information #6 instructs the cell #1 to stop providing the active multicast session #1.

When the gNB managed cell #1 stops providing the inactive state multicast session #1, the gNB performs S707.

S708, the CN updates the area #2 according to the information #6, i.e. removes the cell #1 from the active area of the multicast configuration #1.

Fig. 12 is a schematic diagram of a method 800 of communication provided in an embodiment of the present application, and the method 800 may be regarded as a specific implementation of the method 600. The method 700 may include the following steps.

S801, the gnb#1 (an example of the fifth network device) transmits a message#3 (an example of the third message) to the gnb#2 (an example of the first device, also an example of the sixth network device).

Message #3 is used to request multicast configuration for multicast session #1, message #3 including an identification of multicast session #1, e.g., TMGI-1.

The message #3 may further include an identifier of a cell #2 (an example of the second cell), where the identifier of the cell #2 is used to instruct the cell #2 managed by the gNB #1 to start providing the active multicast session #1.

Optionally, message #3 includes the number of MRBs and the number of LCHs.

This step may refer to S610.

S802, the gnb#2 determines a multicast configuration#2 (an example of the first multicast configuration information) and an area#3 (an example of the effective area of the first multicast configuration information) from the message#3 and the range of values of the multicast configuration parameters.

The value range of the multicast configuration parameter may be preconfigured by OAM to a gNB within an RNA range, where the gNB within the RNA range includes gNB1 and gNB2.

For example, multicast configuration #2 includes MRB identities and LCH identities, gNB #2 selects a corresponding number of MRB identities for multicast session #1 from a range of values of the MRB identities, and selects a corresponding number of LCH identities for each MRB of multicast session #1 from a range of values of the LCH identities.

Wherein zone #3 may include an identification of cell # 2.

S803, the gnb#2 transmits the multicast configuration#2 to the gnb#1, and instructs the identification of the region#3.

S804, the gnb#1 transmits the identities of the multicast configuration#2 and the zone#3 to the UE.

For example, the gNB#1 transmits the identities of the multicast configuration#2 and the zone#3 to the UE through an RRC release message.

S805, the gnb#1 transmits information#7 (an example of eleventh information) to the gnb#2, the information#7 instructing the cell#2 to stop providing the active state multicast session#1.

When the cell #2 managed by the gnb#1 stops providing the inactive state multicast session #1, the gnb#1 performs S805.

S806, the gnb#2 updates the zone#3 according to the information #7, i.e., removes the cell#2 from the effective zone of the multicast configuration#1.

Fig. 13 is a schematic diagram of a method 900 of communication provided in an embodiment of the present application, where the method 900 may be regarded as a specific implementation of the method 600. The method 900 may include the following steps.

S901, the gnb#1 (an example of the fifth network device) transmits a message#4 (an example of the third message) to the CN (an example of the first device).

Message #4 is used to request multicast configuration for multicast session #1, message #4 including an identification of multicast session #1, e.g., TMGI-1.

Optionally, message #4 includes the number of MRBs and the number of LCHs.

The message #4 may further include an identifier of the cell #2 (an example of the second cell), where the identifier of the cell #2 is used to instruct the cell #2 managed by the gNB #1 to start providing the active multicast session #1.

This step may refer to S610.

S902, the CN sends a message #4 to the gNB # 2.

S903, the gnb#2 determines a multicast configuration#2 (an example of the first multicast configuration information) and an area#3 (an example of the effective area of the first multicast configuration information) from the message#4 and the range of values of the multicast configuration parameters.

S903 may refer to S802.

S904, the gnb#2 transmits the multicast configuration#2 to the CN, and instructs an identification of the region#3.

Alternatively, the CN may store multicast configuration #2 and zone #3.

S905, the CN sends multicast configuration #2 to the gNB #1 and instructs the identification of zone #3.

S906, the gnb#1 transmits the identities of the multicast configuration#2 and the zone#3 to the UE.

S906 refers to S804.

S907, the gnb#1 transmits information#7 (an example of eleventh information) to the CN, the information#7 instructing the cell#2 to stop providing the active state multicast session#1.

When the cell #2 managed by the gnb#1 stops providing the inactive state multicast session #1, the gnb#1 performs S907.

S908, the CN sends information #7 to the gNB # 2.

S909, the gnb#2 updates the zone#3 according to the information #7, i.e., removes the cell#2 from the effective zone of the multicast configuration#1.

The method 900 may be applicable to scenarios where there is no communication interface between gnb#1 and gnb#2.

It should be understood that, the network device mentioned in the embodiments of the present application may refer to a base station, and the steps performed by any network device may be performed by the base station, or may be performed by the CU of the base station, or may be performed by a module of the base station.

It will also be appreciated that some optional features of the various embodiments of the application may, in some circumstances, be independent of other features, or may, in some circumstances, be combined with other features, without limitation.

It is also to be understood that the aspects of the embodiments of the present application may be used in any reasonable combination, and that the explanation or illustration of the terms presented in the embodiments may be referred to or explained in the various embodiments without limitation.

It should also be understood that, in the foregoing embodiments of the methods and operations implemented by the terminal device, the methods and operations may also be implemented by component parts (e.g., chips or circuits) of the terminal device; furthermore, the methods and operations implemented by the network device may also be implemented by, but not limited to, constituent components (e.g., chips or circuits) of the network device.

Corresponding to the methods given by the above method embodiments, the embodiments of the present application also provide corresponding apparatuses, where the apparatuses include corresponding modules for performing the above method embodiments. The module may be software, hardware, or a combination of software and hardware. It will be appreciated that the technical features described in the method embodiments described above are equally applicable to the device embodiments described below.

Fig. 14 is a schematic diagram of a communication device 2800 provided in an embodiment of the present application. The apparatus 2800 includes a transceiver unit 2810, and the transceiver unit 2810 may be used to implement corresponding communication functions. The transceiver unit 2810 may also be referred to as a communication interface or a communication unit.

Optionally, the apparatus 2800 may further include a processing unit 2820, where the processing unit 2820 may be used to perform data processing.

Optionally, the apparatus 2800 further includes a storage unit, where the storage unit may be used to store instructions and/or data, and the processing unit 2820 may read the instructions and/or data in the storage unit, so that the apparatus implements actions performed by the terminal device or the network device in the foregoing method embodiments.

One possible design of the apparatus 2800 may be the terminal device in the foregoing embodiment, or may be a component (such as a module or chip) of the terminal device. The apparatus 2800 may implement steps or processes performed by a terminal device in the above method embodiment, where the transceiving unit 2810 may be configured to perform transceiving related operations of the terminal device in the above method embodiment, and the processing unit 2820 may be configured to perform processing related operations of the terminal device in the above method embodiment.

In one implementation of this design, apparatus 2800 is used to implement the functionality of the terminal device in the method embodiments shown in methods 200 or 300.

Illustratively, the transceiver unit 2810 is configured to receive first information from a first network device, where the first information includes at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, the at least one multicast configuration information includes the first multicast configuration information, and the index information corresponding to the at least one multicast configuration information includes the first index information; the transceiver unit 2810 is also configured to: receiving second information from a second network device, wherein the second information is used for indicating a first multicast session to associate with first index information, and the first index information indicates first multicast configuration information; the processing unit 2820 is configured to: and receiving the first multicast session from the second network device in a Radio Resource Control (RRC) inactive state or idle state according to the first multicast configuration information.

It should be understood that the foregoing is merely exemplary, and the apparatus 2800 can also implement other steps, actions, or methods related to the terminal device in the above method 200 or 300, which are not described herein.

In another implementation of this design, the apparatus 2800 is used to implement the functionality of the terminal device in the method embodiment shown in method 400 or 500.

Illustratively, the transceiver unit 2810 is configured to receive eighth information from the first network device, where the eighth information includes first multicast configuration information and information of a cell corresponding to the first multicast configuration information, the first multicast configuration corresponds to the first multicast session, and the cell information corresponding to the first multicast configuration information includes the first cell; the transceiver unit 2810 is also configured to: receiving a second message from a second network device, the second message including first indication information for indicating a state of a first multicast session provided by a first cell; the processing unit 2820 is configured to: and receiving a first multicast session according to the first multicast configuration information under the condition that the first cell is a resident cell of the terminal equipment.

It should be understood that the foregoing is merely exemplary, and the apparatus 2800 can also implement other steps, actions, or methods related to a terminal device in the above method 400 or 500, which are not described herein.

In another implementation of this design, the apparatus 2800 is used to implement the functionality of the terminal device in the method embodiments shown in methods 600, 700, 800, or 900.

Illustratively, the transceiver unit 2810 is configured to receive first multicast configuration information and tenth information from a fifth network device, where the first multicast configuration information is used to configure the first multicast session, and the tenth information is used to indicate an effective area of the first multicast configuration information; the processing unit 2820 is configured to receive the first multicast session in a radio resource control RRC inactive state or idle state according to the first multicast configuration information in the active area.

It should be understood that the foregoing is merely exemplary, and the apparatus 2800 can also implement other steps, actions, or methods related to the terminal device in the methods 600, 700, 800, or 900, which are not described herein.

In yet another possible design, the apparatus 2800 may be the third network device in the foregoing embodiment, or may be a component (such as a module or chip) of the third network device. The apparatus 2800 may implement steps or processes performed by a third network device in the above method embodiment, where the transceiver unit 2810 may be configured to perform operations related to transceiver by the third network device in the above method embodiment, and the processing unit 2820 may be configured to perform operations related to processing by the third network device in the above method embodiment.

In one implementation of this design, apparatus 2800 is used to implement the functionality of the third network device in the method embodiment shown in method 200 or 300. The third network device may be the first network device or the second network device in the method 200 or 300.

Illustratively, the transceiver unit 2810 is configured to send second information, where the second information is used to indicate that the first multicast session is associated with first index information, and the first index information indicates first multicast configuration information; the transceiver unit 2810 is further configured to send a first multicast session according to the first multicast configuration information.

Optionally, the transceiver unit 2810 is further configured to send first information to the terminal device, where the first information includes at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, the at least one multicast configuration information includes the first multicast configuration information, and the index information corresponding to the at least one multicast configuration information includes the first index information.

It should be understood that the foregoing is merely exemplary, and the apparatus 2800 can also implement other steps, actions, or methods related to the third network device in the method 200 or 300, which are not described herein.

In another implementation of the design, the apparatus 2800 is configured to implement a function of the third network device in the method embodiment shown in the method 400 or 500. The third network device may be the first network device or the second network device in the method 400 or 500.

Illustratively, the transceiver unit 2810 is configured to send a second message, where the second message includes first indication information, where the first indication information is used to indicate that a state of a first multicast session provided by a first cell changes; the transceiver unit 2810 is further configured to send a first multicast session according to the first multicast configuration information.

Optionally, the transceiver unit 2810 is further configured to send eighth information to the terminal device, where the eighth information includes first multicast configuration information and cell information corresponding to the first multicast configuration information, the first multicast configuration corresponds to the first multicast session, and the cell information corresponding to the first multicast configuration information includes the first cell.

It should be understood that the foregoing is merely exemplary, and the apparatus 2800 can also implement other steps, actions, or methods related to the third network device in the method 400 or 500 described above, which are not described herein.

In yet another possible design, the apparatus 2800 may be the fourth network device in the foregoing embodiment, or may be a component (such as a module or chip) of the fourth network device. The apparatus 2800 may implement steps or processes performed by a fourth network device in the above method embodiment, where the transceiver unit 2810 may be configured to perform operations related to transceiver by the fourth network device in the above method embodiment, and the processing unit 2820 may be configured to perform operations related to processing by the fourth network device in the above method embodiment.

In one implementation of this design, apparatus 2800 is used to implement the functionality of the fourth network device in the method embodiment shown in method 200 or 300.

Illustratively, the transceiver unit 2810 is configured to send sixth information to the third network device, where the sixth information includes M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information; or, the sixth information includes M pieces of multicast configuration information, where M is a positive integer; the transceiver unit 2810 is further configured to receive first information from a third network device, where the first information includes at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, and the at least one multicast configuration information includes M multicast configuration information.

In yet another possible design, the apparatus 2800 may be the fifth network device in the foregoing embodiment, or may be a component (such as a module or chip) of the fifth network device. The apparatus 2800 may implement steps or processes performed by a fifth network device in the above method embodiment, where the transceiver unit 2810 may be configured to perform operations related to transceiver by the fifth network device in the above method embodiment, and the processing unit 2820 may be configured to perform operations related to processing by the fifth network device in the above method embodiment.

In one implementation of this design, apparatus 2800 is used to implement the functionality of the fifth network device in the method embodiments shown in methods 600, 700, 800, or 900.

Illustratively, the transceiver unit 2810 is configured to send a third message to the first device, where the third message is used to request multicast configuration information of the first multicast session, and the transceiver unit 2810 is further configured to: and receiving first multicast configuration information from the first equipment, wherein the first multicast configuration information is determined according to the third message and the value range of the multicast configuration parameter, and the first multicast configuration information is used for configuring the terminal equipment to receive the first multicast session in a Radio Resource Control (RRC) inactive state or idle state.

It should be understood that the foregoing is merely exemplary, and the apparatus 2800 can also implement other steps, actions, or methods related to the fifth network device in the methods 600, 700, 800, or 900, which are not described herein.

In yet another possible design, the apparatus 2800 may be the first device in the foregoing embodiment, or may be a component (such as a module or chip) of the first device. The apparatus 2800 may implement steps or processes corresponding to those performed by the first device in the above method embodiments, where the transceiver unit 2810 may be configured to perform transceiver-related operations of the first device in the above method embodiments, and the processing unit 2820 may be configured to perform processing-related operations of the first device in the above method embodiments.

In one implementation of this design, apparatus 2800 is used to implement the functionality of the first device in the method embodiments shown in methods 600, 700, 800, or 900.

Illustratively, the transceiver unit 2810 is configured to receive a third message from the fifth network device, where the third message is used to request multicast configuration information for the first multicast session. A processing unit 2820, configured to determine first multicast configuration information according to the third message and a value range of the multicast configuration parameter, where the first multicast configuration information is used to configure the terminal device to receive the first multicast session in a radio resource control RRC inactive state or idle state; the transceiver unit 2810 is also configured to: and sending the first multicast configuration information to the fifth network device.

It should be understood that the foregoing is merely exemplary, and the apparatus 2800 can also implement other steps, actions, or methods related to the first device in the methods 600, 700, 800, or 900 described above, which are not described herein.

It should be understood that the foregoing is merely exemplary, and the apparatus 2800 can also implement other steps, actions, or methods related to the fourth network device in the method 200 or 300, which are not described herein.

In another implementation of the design, the apparatus 2800 is configured to implement a function of a fourth network device in the method embodiment shown in the method 400 or 500.

Illustratively, the transceiver unit 2810 is configured to send second indication information to the third network device, where the second indication information is used to indicate a state of a first multicast session in a non-connected state or an idle state provided by a first cell, and the first cell is a cell managed by the second network device; the transceiver unit 2810 is further configured to send a second message, where the second message includes first indication information, where the first indication information is used to indicate a state of a first multicast session in a non-connected state or an idle state provided by the first cell.

It should be understood that the foregoing is merely exemplary, and the apparatus 2800 can also implement other steps, actions, or methods related to the fourth network device in the method 400 or 500, which are not described herein.

It should also be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

Furthermore, the apparatus 2800 herein is embodied in the form of functional units. The term "unit" herein may refer to an application specific integrated circuit (application specific integrated circuit, ASIC), an electronic circuit, a processor (e.g., a shared, dedicated, or group processor, etc.) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that support the described functionality. In an alternative example, it may be understood by those skilled in the art that the apparatus 2800 may be specifically a terminal device in the foregoing embodiment, may be used to perform each flow and/or step corresponding to the terminal device in the foregoing method embodiments, or the apparatus 2800 may be specifically a third network device in the foregoing embodiment, may be used to perform each flow and/or step corresponding to the third network device in the foregoing method embodiments, or the apparatus 2800 may be specifically a fourth network device in the foregoing embodiment, may be used to perform each flow and/or step corresponding to the fourth network device in the foregoing method embodiments, which is not repeated herein.

The apparatus 2800 of each aspect has a function of implementing a corresponding step performed by a terminal device in the method, or the apparatus 2800 of each aspect has a function of implementing a corresponding step performed by a third network device in the method, or the apparatus 2800 of each aspect has a function of implementing a corresponding step performed by a fourth network device in the method, or the apparatus 2800 of each aspect has a function of implementing a corresponding step performed by a fifth network device in the method, or the apparatus 2800 of each aspect has a function of implementing a corresponding step performed by a first device in the method. The functions may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or software comprises one or more modules corresponding to the functions; for example, the transceiver unit may be replaced by a transceiver (e.g., a transmitting unit in the transceiver unit may be replaced by a transmitter, a receiving unit in the transceiver unit may be replaced by a receiver), and other units, such as a processing unit, etc., may be replaced by a processor, to perform the transceiver operations and related processing operations in the various method embodiments, respectively.

The transceiver 2810 may be a transceiver circuit (e.g., may include a receiver circuit and a transmitter circuit), and the processing unit may be a processing circuit.

It should be noted that the apparatus in fig. 10 may be a network element or a device in the foregoing embodiment, or may be a chip or a chip system, for example: system on chip (SoC). The receiving and transmitting unit can be an input and output circuit and a communication interface; the processing unit is an integrated processor or microprocessor or integrated circuit on the chip. And are not limited herein.

Fig. 15 is a schematic diagram of another communication device 2900 provided in an embodiment of the present application. The apparatus 2900 includes a processor 2910, the processor 2910 being coupled to a memory 2920, the memory 2920 for storing computer programs or instructions and/or data, the processor 2910 for executing the computer programs or instructions stored by the memory 2920 or for reading data stored by the memory 2920 to perform the methods in the method embodiments above.

Optionally, the processor 2910 is one or more.

Optionally, memory 2920 is one or more.

Optionally, the memory 2920 is integrated with the processor 2910 or separately provided.

Optionally, as shown in fig. 15, the apparatus 2900 further includes an interface circuit 2930. The interface circuit 2930 is used for receiving and/or transmitting signals. The processor 2910 and the interface circuit 2930 are coupled to each other. For example, the processor 2910 is configured to control the interface circuit 2930 to receive and/or transmit signals. It is to be appreciated that the interface circuit 2930 may be a transceiver or an input-output interface.

When the apparatus 2900 is configured to implement the method shown in fig. 5, 7, 8, 9, 10, 11, 12, or 13, the processor 2910 is configured to implement the function of the processing unit 920, and the interface circuit 2930 is configured to implement the function of the transceiver unit 910.

As an aspect, the apparatus 2900 is configured to implement the operations performed by the terminal device in the above method embodiments.

For example, the processor 2910 is configured to execute computer programs or instructions stored in the memory 2920 to implement the relevant operations of the terminal device in the method embodiments above. For example, the method performed by the terminal device in the embodiment shown in fig. 5 or fig. 7, and for example, the method performed by the terminal device in the embodiment shown in fig. 8 or fig. 9. As another example, the method performed by the terminal device in the embodiment of fig. 10, 11, 12 or 13.

As an option, the apparatus 2900 is configured to implement the operations performed by the third network device in the method embodiments above.

For example, the processor 2910 is configured to execute computer programs or instructions stored in the memory 2920 to implement the relevant operations of the third network device in the method embodiments above. For example, the method performed by the third network device in the embodiment shown in fig. 5 or fig. 7, and for example, the method performed by the third network device in the embodiment shown in fig. 8 or fig. 9.

As yet another approach, the apparatus 2900 is configured to implement the operations performed by the fourth network device in the various method embodiments above.

For example, the processor 2910 is configured to execute computer programs or instructions stored in the memory 2920 to implement the relevant operations of the fourth network device in the method embodiments above. For example, the method performed by the fourth network device in the embodiment shown in fig. 5 or fig. 7, and for example, the method performed by the fourth network device in the embodiment shown in fig. 8 or fig. 9.

As yet another approach, the apparatus 2900 is configured to implement the operations performed by the fifth network device in the various method embodiments above.

For example, the processor 2910 is configured to execute a computer program or instructions stored in the memory 2920 to implement the relevant operations of the fifth network device in the above respective method embodiments. For example, the fifth network device in the embodiments shown in fig. 10, 11, 12, or 13.

As yet another approach, the apparatus 2900 is configured to implement the operations performed by the first device in the various method embodiments above.

For example, the processor 2910 is configured to execute computer programs or instructions stored in the memory 2920 to implement the relevant operations of the first device in the method embodiments above. For example, the first device in the embodiments shown in fig. 10, 11, 12, or 13 performs the method.

When the communication device is a chip applied to the terminal, the terminal chip realizes the functions of the terminal in the embodiment of the method. The terminal chip receives information from other modules (such as a radio frequency module or an antenna) in the terminal, and the information is sent to the terminal by the base station; alternatively, the terminal chip sends information to other modules in the terminal (e.g., radio frequency modules or antennas) that the terminal sends to the base station.

It should be appreciated that the processors referred to in the embodiments of the present application may be central processing units (central processing unit, CPU), but may also be other general purpose processors, digital signal processors (digital signal processor, DSP), application specific integrated circuits (application specific integrated circuit, ASIC), off-the-shelf programmable gate arrays (field programmable gate array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should also be understood that the memories mentioned in the embodiments of the present application may be volatile memories and/or nonvolatile memories. The nonvolatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. The volatile memory may be random access memory (random access memory, RAM). For example, RAM may be used as an external cache. By way of example, and not limitation, RAM includes the following forms: static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous DRAM (SLDRAM), and direct memory bus RAM (DR RAM).

It should be noted that when the processor is a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, the memory (storage module) may be integrated into the processor.

It should also be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

Fig. 16 is a schematic diagram of a chip system 3000 provided in an embodiment of the present application. The system-on-chip 3000 (or may also be referred to as a processing system) includes logic 3010 and input/output interface 3020.

Logic 3010 may be a processing circuit in system-on-chip 3000. Logic 3010 may be coupled to a memory unit to invoke instructions in the memory unit so that system-on-chip 3000 may implement the methods and functions of embodiments of the present application. The input/output interface 3020 may be an input/output circuit in the chip system 3000, outputting information processed by the chip system 3000, or inputting data or signaling information to be processed into the chip system 3000 for processing.

As an aspect, the chip system 3000 is configured to implement the operations performed by the terminal device in the above method embodiments.

For example, the logic circuit 3010 is configured to implement operations related to processing performed by the terminal device in the above method embodiment, such as operations related to processing performed by the terminal device in the embodiment illustrated in fig. 5, 7, 8, 9, 10, 11, 12, or 13; the input/output interface 3020 is used to implement the operations related to transmission and/or reception performed by the terminal device in the above method embodiments, for example, the operations related to transmission and/or reception performed by the terminal device in the embodiments shown in fig. 5, fig. 7, fig. 8, fig. 9, fig. 10, fig. 11, fig. 12, or fig. 13.

Alternatively, the system-on-chip 3000 is configured to implement the operations performed by the third network device in the method embodiments above.

For example, the logic 3010 is configured to implement the operations related to processing performed by the third network device in the above method embodiment, e.g., the operations related to processing performed by the third network device in the embodiment shown in fig. 5, 7, 8, or 9; the input/output interface 3020 is used to implement the operations related to transmission and/or reception performed by the third network device in the above method embodiments, for example, the operations related to transmission and/or reception performed by the third network device in the embodiments shown in fig. 5, 7, 8, or 9.

Alternatively, the system-on-chip 3000 is configured to implement the operations performed by the fourth network device in the various method embodiments above.

For example, the logic 3010 is configured to implement the operations related to processing performed by the fourth network device in the above method embodiment, e.g., the operations related to processing performed by the fourth network device in the embodiment shown in fig. 5, 7, 8, or 9; the input/output interface 3020 is used to implement the operations related to transmission and/or reception performed by the fourth network device in the above method embodiments, for example, the operations related to transmission and/or reception performed by the fourth network device in the embodiments shown in fig. 5, 7, 8, or 9.

Alternatively, the system-on-chip 3000 is configured to implement the operations performed by the fifth network device in the above method embodiments.

For example, the logic circuit 3010 is configured to implement the operations related to processing performed by the fifth network device in the above method embodiment, for example, the operations related to processing performed by the fifth network device in the embodiment shown in fig. 10, 11, 12, or 13; the input/output interface 3020 is used to implement the operations related to transmission and/or reception performed by the fifth network device in the above method embodiments, for example, the operations related to transmission and/or reception performed by the fifth network device in the embodiments shown in fig. 10, 11, 12, or 13.

Alternatively, the chip system 3000 is configured to implement the operations performed by the first device in the above method embodiments.

For example, the logic circuit 3010 is configured to implement the operations related to the processing performed by the first device in the above method embodiment, for example, the operations related to the processing performed by the first device in the embodiment shown in fig. 10, 11, 12, or 13; the input/output interface 3020 is used to implement the operations related to transmission and/or reception performed by the first device in the above method embodiments, for example, the operations related to transmission and/or reception performed by the first device in the embodiments shown in fig. 10, 11, 12, or 13.

The embodiment of the application further provides a computer readable storage medium, on which computer instructions for implementing the method executed by the terminal device, the third network device, the fourth network device, the fifth network device or the first device in the above method embodiments are stored.

For example, the computer program when executed by a computer, makes the computer implement the method performed by the terminal device, the third network device, the fourth network device, the fifth network device, or the first device in the embodiments of the method described above.

The embodiments of the present application also provide a computer program product, which includes instructions that, when executed by a computer, implement a method performed by a terminal device, a third network device, a fourth network device, a fifth network device, or a first device in the above method embodiments.

The embodiment of the application also provides a communication system, which comprises the third network device and the fourth network device in each embodiment. For example, the system includes the third network device and the fourth network device in the embodiment shown in fig. 5 or fig. 7, and for another example, the system includes the third network device and the fourth network device in the embodiment shown in fig. 8 or fig. 9.

The embodiment of the application also provides a communication system, which includes the fifth network device and the first device in the above embodiments. For example, the system includes a fifth network device and a first device in the embodiments shown in fig. 10, 11, 12, or 13.

The explanation and beneficial effects of the related content in any of the above-mentioned devices can refer to the corresponding method embodiments provided above, and are not repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Furthermore, the coupling or direct coupling or communication connection shown or discussed with each other may be through some interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. For example, the computer may be a personal computer, a server, or a network device, etc. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, optical fiber, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. For example, the aforementioned usable media include, but are not limited to, U disk, removable hard disk, read-only memory (ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other various media that can store program code.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of communication, comprising:

the method comprises the steps that a terminal device receives first information from a first network device, wherein the first information comprises at least one piece of multicast configuration information and index information corresponding to the at least one piece of multicast configuration information, the at least one piece of multicast configuration information comprises first multicast configuration information, and the index information corresponding to the at least one piece of multicast configuration information comprises first index information;

the terminal equipment receives second information from second network equipment, wherein the second information is used for indicating a first multicast session to be associated with first index information, and the first index information indicates first multicast configuration information;

the terminal equipment receives the first multicast session from the second network equipment in a Radio Resource Control (RRC) inactive state or idle state according to the first multicast configuration information.

2. The method of claim 1, wherein the first information further comprises identification information of a cell or network device to which the at least one multicast configuration information corresponds.

3. The method according to claim 2, wherein the method further comprises:

the terminal equipment acquires a first identifier, wherein the first identifier is an identifier of a resident cell of the terminal equipment or an identifier of network equipment corresponding to the resident cell, and a corresponding relation exists between the first identifier and the first multicast configuration information;

and the terminal equipment determines the first multicast configuration information according to the first identifier and the first index information.

4. A method according to any one of claims 1 to 3, further comprising:

the terminal device receives third information from the first network device, where the third information is used to indicate an effective area of the at least one multicast configuration information.

5. The method according to any one of claims 1 to 4, further comprising:

the terminal equipment receives fourth information from the first network equipment or the second network equipment, wherein the fourth information is used for indicating a first G-RNTI corresponding to the first multicast session;

And the terminal equipment descrambles the first multicast session according to the first G-RNTI.

6. The method of any one of claims 1 to 5, wherein the first index information comprises one or more of:

multicast radio bearer, MRB, configuration index, physical channel configuration index, discontinuous reception, DRX, configuration index, neighbor cell configuration index, common frequency domain resource, CFR, configuration index, semi-persistent scheduling (SPS) configuration index.

7. The method according to any of claims 1 to 6, wherein the terminal device receives the second information if any of the following conditions is met:

the terminal equipment reselects to a cell managed by the second network equipment; or alternatively, the first and second heat exchangers may be,

the terminal device receives the information from the fifth information, wherein,

the fifth information is used for notifying the system of message change; or alternatively, the first and second heat exchangers may be,

the fifth information is used for notifying the multicast control channel message change; or alternatively, the first and second heat exchangers may be,

the fifth information is used for notifying the first multicast session to be activated;

the fifth information is used for indicating the terminal equipment to receive the multicast session in an RRC inactive state or an idle state;

wherein the system change notification message or the notification multicast control channel message change is for:

Notifying the multicast configuration information of the first multicast session to be changed into the first multicast configuration information, or notifying the cell managed by the second network device to start providing the first multicast session in an inactive state or an idle state.

8. The method according to any one of claims 1 to 7, further comprising:

the terminal device receives a first message from the second network device, where the first message is a system message or a multicast control channel message, and the first message is used to instruct to stop receiving the first multicast session or stop providing the first multicast session in an inactive state by a cell managed by the second network device.

9. A method of communication, comprising:

the third network equipment sends second information, wherein the second information is used for indicating first multicast session association first index information, and the first index information indicates first multicast configuration information;

and the third network equipment sends the first multicast session according to the first multicast configuration information.

10. The method according to claim 9, wherein the method further comprises:

the third network device sends first information to the terminal device, wherein the first information comprises at least one piece of multicast configuration information and index information corresponding to the at least one piece of multicast configuration information, the at least one piece of multicast configuration information comprises the first multicast configuration information, and the index information corresponding to the at least one piece of multicast configuration information comprises the first index information.

11. The method of claim 10, wherein the first information further comprises identification information of a cell or network device to which the at least one multicast configuration information corresponds.

12. The method of claim 11, wherein the method further comprises:

the third network device sends a first identifier, and the first identifier is the identifier of the third network device or the identifier of the cell corresponding to the second information.

13. The method according to any one of claims 9 to 12, further comprising:

the third network device obtains the first information.

14. The method of claim 13, wherein the third network device obtaining the first information comprises:

the third network device receives sixth information from the fourth network device, wherein the sixth information comprises M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information;

the third network device determines N pieces of multicast configuration information and index information corresponding to the N pieces of multicast configuration information;

wherein the at least one multicast configuration information includes the M multicast configuration information and the N configuration information, and M and N are positive integers.

15. The method of claim 13, wherein the third network device obtaining the first information comprises:

the third network device determines N pieces of multicast configuration information;

the third network device receives sixth information from the fourth network device, wherein the sixth information comprises M pieces of multicast configuration information;

the third network device determines index information corresponding to the M pieces of multicast configuration information and the N pieces of multicast configuration information according to the M pieces of configuration information and the N pieces of multicast configuration information;

16. The method according to claim 14 or 15, wherein the sixth information further includes identification information of cells corresponding to the M multicast configuration information.

17. The method according to any one of claims 14 to 16, further comprising:

the third network device sends the first information to a fourth network device.

18. The method according to any one of claims 10 to 17, further comprising:

And the third network equipment sends third information to the terminal equipment, wherein the third information is used for indicating the effective area of the at least one multicast configuration information.

19. The method according to any one of claims 9 to 18, further comprising:

the third network device sends fourth information to the terminal device, where the fourth information is used to indicate the first G-RNTI, and the first G-RNTI is used to scramble the first multicast session.

20. The method of claim 19, wherein the fourth information is information of the first G-RNTI, the method further comprising:

the third network device receives the first G-RNRI from a core network device; or alternatively, the first and second heat exchangers may be,

and the third network equipment determines the first G-RNTI according to the identification of the first multicast session.

21. The method of any one of claims 9 to 20, wherein the first index information comprises one or more of:

multicast radio bearer, MRB, configuration index, physical channel configuration index, discontinuous reception, DRX, configuration index, neighbor cell configuration index, common frequency domain resource, CFR, configuration index, semi-persistent scheduling, SPS, configuration index.

22. The method according to any one of claims 9 to 21, further comprising:

the third network device sends fifth information, wherein the fifth information is used for notifying system message change or notifying multicast control channel message change, and the fifth information is used for receiving the second information by the terminal device.

23. The method according to claim 22, wherein the third network device sends the fifth information to the terminal device if any of the following conditions are met:

changing the multicast configuration information of the first multicast session into the first multicast configuration information; or alternatively, the first and second heat exchangers may be,

the third network device managed cell begins providing the first multicast session in an inactive state or an idle state.

24. The method according to any one of claims 9 to 23, further comprising:

the third network device sends a first message, where the first message is a system message or a multicast control channel message, and the first message is used to instruct the first multicast session to be in a deactivated state or to be released, or is used to instruct a cell managed by the second network device to stop providing the first multicast session in a deactivated state.

25. A method of communication, comprising:

the fourth network device sends sixth information to the third network device, wherein the sixth information comprises M pieces of multicast configuration information and index information corresponding to the M pieces of multicast configuration information; or, the sixth information includes M pieces of multicast configuration information, where M is a positive integer;

the fourth network device receives first information from the third network device, wherein the first information comprises at least one multicast configuration information and index information corresponding to the at least one multicast configuration information, and the at least one multicast configuration information comprises the M multicast configuration information.

26. The method of claim 25, wherein the method further comprises:

the fourth network device sends seventh information, where the seventh information is used to indicate that the first multicast session is associated with second index information, the second index information indicates second multicast configuration information, the at least one piece of multicast configuration information includes the second multicast configuration information, and index information corresponding to the at least one piece of multicast configuration information includes the second index information;

and the fourth network equipment sends the first multicast session according to the second multicast configuration information.

27. A method of communication, comprising:

the method comprises the steps that terminal equipment receives first multicast configuration information and tenth information from fifth network equipment, wherein the first multicast configuration information is used for configuring a first multicast session, and the tenth information is used for indicating an effective area of the first multicast configuration information;

and the terminal equipment receives the first multicast session in a Radio Resource Control (RRC) inactive state or idle state according to the first multicast configuration information in the effective area.

28. A method of communication, comprising:

the fifth network device sends a third message to the first device, where the third message is used to request multicast configuration information of the first multicast session;

the fifth network device receives first multicast configuration information from the first device, the first multicast configuration information is determined according to the third message and the value range of the multicast configuration parameter, and the first multicast configuration information is used for configuring the terminal device to receive the first multicast session in a Radio Resource Control (RRC) inactive state or idle state.

29. The method of claim 28, wherein the method further comprises:

And the fifth network equipment sends the first multicast configuration information to the terminal equipment.

30. The method according to claim 28 or 29, wherein the range of values of the multicast configuration parameters comprises at least one of:

the method comprises the steps of selecting a value range of a G-RNTI, selecting a value range of a multicast radio bearer MRB identifier, selecting a value range of a logic channel LCH identifier, selecting a value range of a physical channel configuration parameter, selecting a value range of a discontinuous reception DRX configuration parameter and selecting a value range of a common frequency domain resource CFR configuration parameter.

31. The method according to any one of claims 28 to 30, wherein the third message comprises at least one of:

the identification of the first multicast session, the number of MRBs required for the first multicast session, the number of logical channels LCHs required for the first MRB of the first multicast session.

32. The method according to any of claims 28 to 31, wherein the third message comprises an identification of a second cell, the second cell being a cell managed by the fifth network device providing the first multicast session in RRC inactive state or idle state.

33. The method according to any one of claims 28 to 32, further comprising:

The fifth network device receives tenth information from the first device, the tenth information indicating an effective area of the first multicast configuration information.

34. The method according to any one of claims 28 to 33, further comprising:

the fifth network device sends a fourth message to the first device, where the fourth message includes a range of values for the multicast configuration parameters.

35. The method of claim 34, wherein the fourth message further includes identification information of a second area, the second area being an effective area of the range of values of the multicast configuration parameters.

36. The method of claim 35, wherein cells within the second area provide at least one multicast session, the at least one multicast session comprising the first multicast session, wherein multicast configuration information for other multicast sessions of the at least one multicast session than the first multicast session is different from the first multicast configuration information, and wherein multicast configuration information for other multicast sessions of the at least one multicast session than the first multicast session is different from each other.

37. The method according to claim 34 or 35, wherein the second area is a notification area RNA based on a radio access network where the fifth network device is located.

38. The method according to any one of claims 28 to 37, further comprising:

the fifth network device sends eleventh information to the first device, where the eleventh information is used to instruct a third cell managed by the fifth network device to stop providing the first multicast session in a radio resource control RRC inactive state or idle state.

39. A method of communication, comprising:

the first device receives a third message from the fifth network device, wherein the third message is used for requesting multicast configuration information of the first multicast session;

the first device determines first multicast configuration information according to the third message and the value range of the multicast configuration parameter, wherein the first multicast configuration information is used for configuring the terminal device to receive the first multicast session in a Radio Resource Control (RRC) inactive state or idle state;

the first device sends the first multicast configuration information to the fifth network device.

40. The method of claim 39, wherein the third message includes an identification of the first multicast session, wherein the range of values for the multicast configuration parameters includes a range of values for G-RNTIs, wherein the first device determines the first multicast configuration information based on the third message and the range of values for the multicast configuration parameters, comprising:

The first device selects a value from the value range of the G-RNTI as the G-RNTI of the first multicast session, and the first multicast configuration information comprises the G-RNTI of the first multicast session.

41. The method of claim 39 or 40, wherein the third message includes an identification of the first multicast session and a number X of multicast radio bearers MRBs required for the first multicast session, wherein the range of values of the multicast configuration parameters includes a range of values of MRB identifications, wherein the first device determines first multicast configuration information based on the third message and the range of values of the multicast configuration parameters, comprising:

and the first equipment selects X values from the value range of the MRB identifier as the MRB identifier of the first multicast session, wherein the first multicast configuration information comprises the MRB identifier of the first multicast session, and X is a positive integer.

42. The method of any one of claims 39 to 41, wherein the third message includes an identification of the first multicast session and a number Y of logical channels LCHs required by a first MRB of the first multicast session, wherein the range of values of the multicast configuration parameters includes a range of values of LCH identifications, and wherein the first device determines first multicast configuration information based on the third message and the range of values of multicast configuration parameters, comprising:

And the first equipment selects Y values from the value range of the LCH identifier as the LCH identifier of the first MRB, wherein the first multicast configuration information comprises the LCH identifier of the first MRB, and Y is a positive integer.

43. The method according to any of claims 39 to 42, wherein the third message comprises an identification of a second cell, the second cell being a cell managed by the fifth network device providing the first multicast session in RRC inactive state or idle state, the method further comprising:

the first device determines tenth information according to the third message from one or more fifth network devices, wherein the tenth information is used for indicating an effective area of the first multicast configuration information.

44. The method of claim 43, further comprising:

the first device sends the tenth information to the fifth network device.

45. The method of any one of claims 39 to 44, further comprising:

the first device receives a fourth message from the fifth network device, the fourth message including a range of values for the multicast configuration parameters.

46. The method of claim 45, wherein the fourth message further includes identification information of a second area, the second area being an effective area of a range of values of the multicast configuration parameters.

47. The method of claim 46, wherein cells within the second area provide at least one multicast session, the at least one multicast session comprising the first multicast session, the method further comprising:

the first device determines multicast configuration information that is different from each other for other multicast sessions of the at least one multicast session than the first multicast session, and the multicast configuration information of the other multicast sessions of the at least one multicast session than the first multicast session is different from the first multicast configuration information.

48. The method of claim 46 or 47, wherein the second area is a radio access network based notification area RNA in which the fifth network device is located.

49. The method of any one of claims 39 to 48, further comprising:

the first device receiving eleventh information from the fifth network device, the eleventh information being for instructing a third cell managed by the fifth network device to stop providing the first multicast session in a radio resource control RRC inactive state or an idle state;

The first device removes the third cell from an active area of the first multicast configuration information.

50. A method of communication, comprising:

51. A communication device, comprising:

a processor for executing a computer program stored in a memory to cause the apparatus to perform the method of any one of claims 1 to 8, or to cause the apparatus to perform the method of any one of claims 9 to 24, or to cause the apparatus to perform the method of claim 25 or 26, or to cause the apparatus to perform the method of claim 27, or to cause the apparatus to perform the method of any one of claims 28 to 38, or to cause the apparatus to perform the method of any one of claims 39 to 49.

52. The apparatus of claim 51, further comprising the memory and/or a communication interface coupled with the processor,

the communication interface is used for inputting and/or outputting information.

53. A computer-readable storage medium, on which a computer program is stored, which, when run on a computer, causes the computer to perform the method of any one of claims 1 to 8, or to cause the computer to perform the method of any one of claims 9 to 24, or to cause the computer to perform the method of claim 25 or 26, or to cause the computer to perform the method of claim 27, or to cause the computer to perform the method of any one of claims 28 to 38, or to cause the computer to perform the method of any one of claims 39 to 49.

54. A computer program product comprising instructions for performing the method of any one of claims 1 to 8, or for performing the method of any one of claims 9 to 24, or for performing the method of claim 25 or 26, or for performing the method of claim 27, or for performing the method of any one of claims 28 to 38, or for performing the method of any one of claims 39 to 49.