WO2024032448A1

WO2024032448A1 - Multicast communication method and apparatus

Info

Publication number: WO2024032448A1
Application number: PCT/CN2023/110834
Authority: WO
Inventors: 李濛; 张海森; 杨艳梅
Original assignee: 华为技术有限公司
Priority date: 2022-08-09
Filing date: 2023-08-02
Publication date: 2024-02-15
Also published as: CN117641249A

Abstract

The present application relates to the field of wireless communications, and discloses a multicast communication method and apparatus. In the method, an access network device determines that the last terminal connected to the access network device in a multicast group leaves the access network device and there is no terminal in an inactive state associated with the access network device in the multicast group, and the access network device releases the context of a multicast session of the access network device. In this way, the context of a multicast session corresponding to a multicast group can be released in time while it is ensured that a terminal in the multicast group receives multicast data, so as to save resources.

Description

Multicast communication method and device

"This application claims priority to the patent application filed with the State Intellectual Property Office on August 9, 2022, with the application number 202210950564.6 and the invention title "Multicast Communication Method and Device", the entire content of which is incorporated into this application by reference. ".

Technical field

The present application relates to the field of wireless communications, and in particular to multicast communication methods and devices.

Background technique

In the communication system, the access network device switches the terminal in the multicast group from the radio resource control connected (RRC-connected) state (hereinafter referred to as the connected state) to the radio resource control inactive (radio resource control control inactive, RRC-inactive) state (hereinafter referred to as inactive state), the terminal may move, for example, from the coverage area of the access network device to the coverage area of another access network device. Since another access network device has not established the context of the multicast session corresponding to the multicast group, the terminal cannot receive the multicast data of the multicast group through another access network device.

In order to solve the above problem, a solution is proposed: multiple access network devices in a certain area establish the context of the multicast session corresponding to the multicast group. However, this solution introduces a new technical problem, that is, when the terminal returns from the inactive state to the connected state, how does the access network device in a certain area maintain the context of the multicast session corresponding to the multicast group? .

Contents of the invention

Embodiments of the present application provide multicast communication methods and devices, so that when a terminal in a multicast group returns from an inactive state to a connected state, the access network device can promptly release the context of the multicast session corresponding to the multicast group. .

In order to achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

In a first aspect, a multicast communication method is provided. The communication device that executes the method may be a first access network device; it may also be a module applied in the first access network device, such as a chip or a chip system. The following description takes the execution subject as the first access network device as an example. The method includes: determining that the last terminal in the multicast group connected to the first access network device leaves the first access network device, and there is no terminal associated with the first access network device in the multicast group. The inactive terminal releases the context of the multicast session of the first access network device. The multicast session is used to transmit multicast data corresponding to the multicast group. In the embodiment of the present application, there is no inactive terminal associated with the first access network device in the multicast group. It can also be replaced by other description methods, for example, the coverage area of the first access network device and the multicast group There is no intersection between the radio access network (RAN) notification area (RNA) of any terminal in the multicast group, or the coverage area of the first access network device is not included in the multicast group. The access network equipment in the RNA of any terminal in the multicast group, or the access network equipment in the RNA of any terminal in the multicast group does not include the first access network equipment, or the coverage area of the first access network equipment is not the same as that in the multicast group. The RNA of any terminal does not have a common cell or tracking area, or the cell or tracking area corresponding to the RNA of any terminal in the multicast group does not belong to the first access network device.

Based on the method provided in the first aspect, the last terminal connected to the first access network device in the multicast group leaves the first access network device, and there is no connection with the first access network device in the multicast group. In the case of an inactive terminal associated with the device, the first access network device releases the context of the multicast session corresponding to the multicast group. In this way, it can not only ensure that the terminal in the multicast group receives the multicast data, but also ensure that the terminal in the multicast group receives the multicast data. It can also enable the access network device to release the context of the multicast session corresponding to the multicast group in a timely manner to save resources.

In a possible implementation, the method further includes: sending a multicast session leave message to the second network device to trigger release of the context of the multicast session of the second network device. The second network device may be an AMF network element, an MB-SMF network element, a UPF network element or an access network device other than the first access network device.

Based on the above possible implementation manner, the second network device can be triggered to release the context of the multicast session corresponding to the multicast group.

In a possible implementation, the last terminal connected to the first access network device in the determined multicast group leaves the first access network device, and there is no connection with the first access network device in the multicast group. After the inactive terminal associated with the first access network device, The method further includes: sending a request message to the first network device, the request message being used to request the release of the multicast session; before releasing the context of the multicast session of the first access network device, the method further includes: receiving A response message from the first network device, the response message being used to respond to the request message. The second network device may be an AMF network element, an MB-SMF network element, a UPF network element or an access network device other than the first access network device.

Based on the above possible implementation manner, the first network device can be caused to release the multicast session corresponding to the multicast group.

In a possible implementation, the last terminal connected to the first access network device in the multicast group leaves the first access network device, including: the last terminal connected to the first access network device in the multicast group The last terminal connected to the network device is deleted from the context of the multicast session by the first access network device; or the last terminal connected to the first access network device in the multicast group is switched to except Access network equipment other than the first access network equipment.

Based on the above possible implementation manner, when the last terminal connected to the first access network device in the multicast group is deleted from the context of the multicast session by the first access network device, the first access network device Determine that the last terminal in the multicast group connected to the first access network device leaves the first access network device. Or, in the case where the last terminal connected to the first access network device in the multicast group switches to an access network device other than the first access network device, the first access network device determines the multicast group The last terminal in the group connected to the first access network device leaves the first access network device.

In a possible implementation, determining that the last terminal connected to the first access network device in the multicast group leaves the first access network device includes: based on the connection between the multicast group and the first access network device. The first information of connected terminals associated with the access network device determines that the last terminal in the multicast group connected to the first access network device leaves the first access network device.

Based on the above possible implementation manner, the first access network device may determine, based on the first information of the connected terminal in the multicast group associated with the first access network device, the first access network device in the multicast group. Whether the last terminal connected to the device has left the first access network device.

In a possible implementation, the first information is used to indicate the number of terminals in the multicast group that are connected to the first access network device and are in a connected state, or the first information is used to indicate Indicates the number of contexts of terminals in the multicast group stored in the first access network device, or the first information is used to indicate whether the first access network device stores the context of the terminals in the multicast group. The context of the terminal.

Based on the above possible implementation manner, the first access network device can determine the number of terminals in the multicast group that are connected to the first access network device and are in the connected state. Whether the last terminal connected to the network device has left the first access network device. Alternatively, the first access network device may determine whether the last terminal in the multicast group connected to the first access network device is based on the number of contexts of the terminals in the multicast group stored in the first access network device. Left the first access network device. Alternatively, the first access network device may determine whether the last terminal connected to the first access network device in the multicast group has left based on whether the context of the terminal in the multicast group is stored in the first access network device. The first access network equipment.

In a possible implementation, determining that there is no inactive terminal associated with the first access network device in the multicast group includes: The second information about the inactive terminal associated with the device determines that there is no inactive terminal associated with the first access network device in the multicast group.

Based on the above possible implementation manner, the first access network device may determine whether there is a connection with the first access network device in the multicast group based on the second information of the inactive terminal associated with the first access network device in the multicast group. Inactive terminals associated with access network equipment.

In a possible implementation, the inactive terminal associated with the first access network device in the multicast group includes: the first access network device switches to A terminal in an inactive state; and a terminal in an inactive state that is switched to an inactive state by an access network device other than the first access network device in the multicast group, and the radio access network notification area of the terminal includes All or part of the coverage area of the first access network device.

Based on the above possible implementation manner, when the first access network device switches the terminal in the multicast group to the inactive state, the first access network device may determine that the terminal is in the multicast group and is not connected to the first terminal in the multicast group. Inactive terminals associated with access network equipment. Or, a terminal in the multicast group is switched to an inactive state by an access network device other than the first access network device, and the radio access network notification area of the terminal includes the first access network device. In the case of all or part of the coverage area, the first access network device may determine that the terminal is an inactive terminal associated with the first access network device in the multicast group. That is, the above possible implementation manner provides a method for the first access network device to determine the inactive terminal associated with the first access network device in the multicast group.

In a possible implementation, the method further includes: receiving first notification information from the second access network device, the first notification information being used to notify a terminal in the multicast group to switch to an inactive state. , or the first notification information is used to notify There is a terminal in the multicast group that is switched to the inactive state by the second access network device, or the first notification information is used to notify the multicast group that the second access network device is switched to the inactive state. The number of activated terminals; the second information is updated according to the first notification information.

Based on the above possible implementation, the first access network device can switch the terminals in the multicast group to the inactive state, or there are terminals in the multicast group that are switched to the inactive state by the second access network device. In this case, the second information is updated. For example, if the second information indicates the number of inactive terminals associated with the first access network device in the multicast group, the first access network device adds 1 to the number indicated by the second information. Alternatively, if the second information indicates the number of times the context of the multicast session is used, the first access network device adds 1 to the number of times indicated by the second information.

In a possible implementation, the method further includes: receiving second notification information from the second access network device, the second notification information being used to notify a terminal in the multicast group to leave the inactive state. , or the second notification information is used to notify that there is no terminal in the multicast group that is switched to the inactive state by the second access network device, or the second notification information is used to notify the multicast group The number of terminals that leave the inactive state under the second access network device; and update the second information according to the second notification information.

Based on the above possible implementation, the first access network device can leave the inactive state when the terminal in the multicast group, or there is no terminal in the multicast group that is switched to the inactive state by the second access network device. In this case, the second information is updated. For example, if the second information indicates the number of inactive terminals associated with the first access network device in the multicast group, the first access network device decrements the number indicated by the second information by 1. Alternatively, if the second information indicates the number of times of use of the context of the multicast session, the first access network device decrements the number of times indicated by the second information by 1.

In a possible implementation, the second information is used to indicate the number of inactive terminals associated with the first access network device in the multicast group, or the second information is used to indicate the The number of times the multicast session's context has been used.

Based on the above possible implementation manner, the first access network device may determine whether there is a connection with the first access network device in the multicast group by calculating the number of inactive terminals associated with the first access network device in the multicast group. Inactive terminals associated with access network equipment. Alternatively, the first access network device may determine whether there is an inactive terminal associated with the first access network device in the multicast group by counting the number of times the context of the multicast session is used. In the embodiment of the present application, the number of times the context of the multicast session is used can be understood as the number of times the context of the multicast session is established. For example, if other access network devices request the first access network device to establish the context of the multicast session corresponding to the multicast group, the number of times the context of the multicast session is used increases. If the network device releases the context of the multicast session corresponding to the multicast group, the number of times the context of the multicast session is used is reduced.

In a possible implementation, it is determined based on the second information of the inactive terminal associated with the first access network device in the multicast group that there is no connection with the first access network device in the multicast group. The inactive terminals associated with the network access device include: when the number of terminals indicated by the second information is zero or the number of times indicated by the second information is zero, it is determined that there is no connection with the multicast group in the multicast group. An inactive terminal associated with the first access network device.

Based on the above possible implementation manner, when the number of terminals indicated by the second information is zero or the number of times indicated by the second information is zero, the first access network device may determine that the multicast group does not exist with An inactive terminal associated with the first access network device.

In a possible implementation, the method further includes: if the first terminal in the multicast group switches to an inactive state, sending third notification information to at least one access network device, the third notification information is used to Notify one terminal in the multicast group to switch to the inactive state, or the third notification information is used to notify that there is a terminal in the multicast group that is switched to the inactive state by the first access network device.

Based on the above possible implementation manner, when a terminal in the multicast group switches to the inactive state, or when there is a terminal in the multicast group that is switched to the inactive state by the first access network device, the first The access network device may notify at least one access network device, so that each access network device in the at least one access network device updates its associated inactive status in the multicast group it maintains based on the third notification information. The second information of the terminal.

In a possible implementation manner, the first terminal is a terminal in the multicast group that is switched to an inactive state by the first access network device.

Based on the above possible implementation manner, when the first access network device switches the first terminal in the multicast group to the inactive state, the first access network device sends a third notification to at least one access network device information, so that each access network device in at least one access network device updates the second number of inactive terminals associated with it in the multicast group it maintains based on the third notification information. information.

In a possible implementation, the method further includes: when the first terminal recovers from the inactive state to the connected state under the first access network device, sending a fourth notification to the at least one access network device. information, the fourth notification information is used to notify a terminal in the multicast group to leave the inactive state; or, when the first terminal leaves the active state from the third access network device, to the at least one access network device Access network devices other than the third access network device among the network devices send fifth notification information, where the fifth notification information is used to notify a terminal in the multicast group to leave the inactive state.

Based on the above possible implementation manner, when the first terminal recovers from the inactive state to the connected state under the first access network device, the first access network device may send the fourth notification information to at least one access network device. , so that each access network device in the at least one access network device updates the second information of the inactive terminal associated with it in the multicast group maintained by it according to the fourth notification information. Or, when the first terminal leaves the active state from the third access network device, the first access network device sends the third access network device to the at least one access network device except the third access network device. Five notification information, so that the access network device that receives the fifth notification information can update the second information of the inactive terminal associated with it in the multicast group it maintains based on the fifth notification information, and then determine whether to release itself The context of the multicast session established for the multicast group.

In a possible implementation, after the first terminal is restored from the inactive state to the connected state under the first access network device, and the multicast group is switched to the inactive state by the first access device, And if the radio access network notification area of each terminal that is currently in the inactive state does not include the coverage area of at least one access network device, the fourth notification information is sent to the at least one access network device.

Based on the above possible implementation manner, the signaling overhead of the first access network device can be reduced.

In a possible implementation, when the first terminal leaves the active state from the third access network device and is switched to the inactive state by the first access device in the multicast group, it is still in the inactive state. If the radio access network notification area of each terminal in the state does not include the coverage area of at least one access network device other than the third access network device, the at least one access network device Access network devices in the device other than the third access network device send the fifth notification information.

In a possible implementation, the method further includes: when the last terminal among the terminals in the multicast group that is switched to the inactive state by the first access network device leaves the inactive state, sending a message to the at least An access network device sends sixth notification information, the sixth notification information is used to notify that the number of terminals in the multicast group switched to the inactive state by the first access network device is 0, or the sixth notification information is The notification information is used to notify that there is no terminal in the multicast group that is switched to an inactive state by the first access network device.

Based on the above possible implementation manner, when the last terminal among the terminals switched to the inactive state by the first access network device in the multicast group leaves the inactive state, the sixth notification information is sent to at least one access network device. , so that each access network device in at least one access network device updates the second information of the inactive terminal associated with it in the multicast group it maintains according to the sixth notification information, and then determines whether to release itself as a multicast The context of the multicast session established by the broadcast group.

In the second aspect, a multicast communication method is provided. The communication device that executes the method may be a second access network device; it may also be a module applied in the second access network device, such as a chip or a chip system. The following description takes the execution subject as the second access network device as an example. The method includes: establishing a context of a multicast session of the second access network device, the multicast session being used to transmit multicast data corresponding to the multicast group; receiving a first message from the first access network device, the third A message used to indicate releasing the context of the multicast session; releasing the context of the multicast session.

Based on the method provided in the second aspect, after the second access network device establishes the context of the multicast session of the second access network device, it may receive a context from the first access network device indicating the release of the multicast session. message, and timely release the context of the multicast session according to the message.

In a possible implementation, the method further includes: receiving a second message from the first access network device, where the second message is used to request the second access network device to establish the context of the multicast session.

Based on the above possible implementation manner, the second access network device can establish the context of the multicast session of the second access network device according to the second message.

In a possible implementation, releasing the context of the multicast session includes: when the last terminal in the multicast group connected to the second access network device leaves the second access network device, and the multicast session When there is no inactive terminal associated with the second access network device in the multicast group, the context of the multicast session is released.

Based on the above possible implementation manner, the second access network device can be connected to the second access network device in the multicast group. When the latter terminal leaves the second access network device and there is no inactive terminal associated with the second access network device in the multicast group, the context of the multicast session is released. In this way, the access network device that needs to send data to the terminals in the multicast group can maintain the context of the multicast session corresponding to the multicast group to ensure that the terminals in the multicast group can receive the multicast data. , and can also cause the access network equipment that does not need to send data to the terminals in the multicast group to promptly release the context of the multicast session corresponding to the multicast group to save resources.

In a third aspect, a multicast communication method is provided. The communication device that executes the method may be a first access network device; it may also be a module applied in the first access network device, such as a chip or a chip system. The following description takes the execution subject as the first access network device as an example. The method includes: sending a second message to a second access network device, the second message being used to request the establishment of a context of a multicast session of the second access network device, the multicast session being used to transmit a multicast group corresponding multicast data; and/or, sending a first message to the second access network device, where the first message is used to indicate releasing the context of the multicast session.

Based on the method provided in the third aspect, the first access network device instructs the second access device to establish or release the context of the multicast session.

In a possible implementation, sending the first message to the second access network device includes: if the multicast group is switched to an inactive state by the first access network device and is currently inactive The wireless access network notification area of each terminal in the state does not include the coverage area of the second access network device, sending the first message to the second access network device; or, if the first access network device Receive a third message from a third access network device, the third message is used to indicate that a terminal in the multicast group that is switched to an inactive state by the first access network device is in the third access network device. Return to the connected state, or the third message is used to request the first access network device to send the context of the terminal to the third access network device, and to send the first message to the second access network device.

Based on the above possible implementation manner, the wireless access notification area of each terminal in the multicast group that is switched to the inactive state by the first access network device and is currently in the inactive state does not include the second access network. In the case of the coverage area of the device, the first access network device sends the first message to the second access network device, so as to reduce the signaling overhead of the first access network device. Or, after receiving the third message from the third access network device, send the first message to the second access network device to notify the second access network device that one terminal in the multicast group has left the inactive state. .

A fourth aspect provides a communication device for implementing the method provided in the first aspect. The communication device may be the access network equipment in the above-mentioned first aspect, or a device including the above-mentioned access network equipment. The communication device includes corresponding modules, units, or means (means) for implementing the above method. The modules, units, or means can be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

In a possible implementation, the communication device may include a processing module. Optionally, the communication device also includes a transceiver module. This processing module can be used to implement the processing functions in the above first aspect and any possible implementation manner thereof. The processing module may be, for example, a processor. The transceiver module, which may also be called a transceiver unit, is used to implement the sending and/or receiving functions in the above first aspect and any possible implementation thereof. The transceiver module can be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.

In a possible implementation, the transceiver module includes a sending module and a receiving module, respectively configured to implement the sending and receiving functions in the above-mentioned first aspect and any possible implementation thereof.

In a possible implementation, the processing module is configured to determine that the last terminal connected to the communication device in the multicast group leaves the communication device, and there is no non-stop terminal associated with the communication device in the multicast group. The activated terminal and processing module are also used to release the context of the multicast session of the communication device, and the multicast session is used to transmit multicast data corresponding to the multicast group.

In a possible implementation, the transceiver module is configured to send a request message to the first network device, where the request message is used to request the release of the multicast session; the transceiver module is also configured to receive a response from the first network device. message, the response message is used to respond to the request message.

In a possible implementation, the transceiver module is also configured to send a multicast session leave message to the second network device. The multicast session leave message is used to trigger the release of the context of the multicast session of the second network device. The multicast session of the second network device is used to transmit multicast data corresponding to the multicast group.

In a possible implementation, the last terminal connected to the communication device in the multicast group leaves the communication device, including: the last terminal connected to the communication device in the multicast group is removed by the communication device It is deleted from the context of the multicast session; or, the last terminal connected to the communication device in the multicast group is switched to an access network device other than the communication device.

In a possible implementation, the processing module is specifically configured to determine, according to the first information of the terminal in the connected state associated with the communication device in the multicast group, the communication device in the multicast group. The last terminal left the communication device.

In a possible implementation, the first information is used to indicate the number of terminals in the multicast group that are connected to the communication device and are in a connected state, or the first information is used to indicate the communication device The number of contexts of terminals in this multicast group stored in .

In a possible implementation, the processing module is specifically configured to determine, based on the second information of the inactive terminal associated with the communication device in the multicast group, that there is no connection with the communication device in the multicast group. An inactive terminal associated with a communication device.

In a possible implementation, the inactive terminals associated with the communication device in the multicast group include: terminals that are switched to the inactive state by the communication device in the multicast group; and A terminal in the multicast group that is switched to an inactive state by access network equipment other than the communication device, and the wireless access network notification area of the terminal includes all or part of the coverage area of the communication device .

In a possible implementation, the transceiver module is also configured to receive first notification information from the second access network device, where the first notification information is used to notify a terminal in the multicast group to switch to a non- Active state, or the first notification information is used to notify the multicast group that there is a terminal switched to the inactive state by the second access network device, or the first notification information is used to notify the multicast group The number of terminals in the group that are switched to the inactive state by the second access network device; the processing module is also configured to update the second information according to the first notification information.

In a possible implementation, the transceiver module is also configured to receive second notification information from the second access network device, where the second notification information is used to notify a terminal in the multicast group to leave the non-unofficial network. active state, or the second notification information is used to notify that there is no terminal in the multicast group that is switched to the inactive state by the second access network device, or the second notification information is used to notify the multicast The number of terminals in the group that leave the inactive state under the second access network device; the processing module is also configured to update the second information according to the second notification information.

In a possible implementation, the second information is used to indicate the number of inactive terminals associated with the communication device in the multicast group, or the second information is used to indicate the number of inactive terminals of the multicast session. The number of times the context has been used.

In a possible implementation, the processing module is specifically configured to determine that there are no terminals in the multicast group when the number of terminals indicated by the second information is zero or the number of times indicated by the second information is zero. There are inactive terminals associated with the communication device.

In a possible implementation, the transceiver module is also configured to send third notification information to at least one access network device if the first terminal in the multicast group switches to an inactive state. The third notification The information is used to notify a terminal in the multicast group to switch to the inactive state, or the third notification information is used to notify that there is a terminal in the multicast group that is switched to the inactive state by the communication device.

In a possible implementation, the first terminal is a terminal in the multicast group that is switched to an inactive state by the communication device.

In a possible implementation, the transceiver module is also configured to send a fourth notification to the at least one access network device when the first terminal recovers from the inactive state to the connected state under the communication device. Information, the fourth notification information is used to notify a terminal in the multicast group to leave the inactive state; or, the transceiver module is also used to when the first terminal leaves the active state from the third access network device Next, send fifth notification information to the access network equipment other than the third access network equipment in the at least one access network equipment, where the fifth notification information is used to notify a terminal in the multicast group to leave. Inactive state.

In a possible implementation, the transceiver module is also configured to send a message to the at least one interface when the last terminal among the terminals switched to the inactive state by the communication device in the multicast group leaves the inactive state. The network access device sends sixth notification information. The sixth notification information is used to notify that the number of terminals in the multicast group switched to the inactive state by the communication device is 0, or the sixth notification information is used to notify the There is no terminal in the multicast group that is switched to the inactive state by the communication device.

A fifth aspect provides a communication device for implementing the method provided in the second aspect. The communication device may be the access network equipment in the above-mentioned second aspect, or a device including the above-mentioned access network equipment. The communication device includes corresponding modules, units, or means (means) for implementing the above method. The modules, units, or means can be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

In a possible implementation, the communication device may include a processing module and a transceiver module. This processing module can be used to implement the processing functions in the above second aspect and any possible implementation manner thereof. The processing module may be, for example, a processor. The transceiver module, which may also be called a transceiver unit, is used to implement the transmission and/or transmission in the above second aspect and any possible implementation manner thereof. or receive function. The transceiver module can be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.

In a possible implementation, the transceiver module includes a sending module and a receiving module, respectively configured to implement the sending and receiving functions in the above second aspect and any possible implementation thereof.

In a possible implementation, the processing module is used to establish the context of a multicast session of the communication device, and the multicast session is used to transmit multicast data corresponding to the multicast group; the transceiver module is used to receive data from the first The first message of the access network device is used to indicate releasing the context of the multicast session; the processing module is also used to release the context of the multicast session.

In a possible implementation manner, the transceiver module is also configured to receive a second message from the first access network device, where the second message is used to request the communication device to establish the context of the multicast session.

In a possible implementation, the processing module is specifically configured to be used when the last terminal connected to the communication device in the multicast group leaves the communication device, and there is no association with the communication device in the multicast group. Releases the context of the multicast session when the terminal is inactive.

A sixth aspect provides a communication device for implementing the method provided in the third aspect. The communication device may be the access network equipment in the above third aspect, or a device including the above access network equipment. The communication device includes corresponding modules, units, or means (means) for implementing the above method. The modules, units, or means can be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

In a possible implementation, the communication device may include a transceiver module. The transceiver module, which may also be called a transceiver unit, is used to implement the sending and/or receiving functions in the above third aspect and any possible implementation thereof. The transceiver module can be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.

In a possible implementation, the transceiver module includes a sending module and a receiving module, respectively configured to implement the sending and receiving functions in the above third aspect and any possible implementation thereof.

In a possible implementation, the transceiver module is configured to send a second message to the second access network device. The second message is used to request the establishment of a context of the multicast session of the second access network device. The multicast session is used to transmit multicast data corresponding to the multicast group; and/or the transceiver module is also used to send a first message to the second access network device, the first message is used to indicate the release of the multicast group. The context of the broadcast session.

In a possible implementation, the transceiver module is specifically used to notify the wireless access network notification area of each terminal in the multicast group that is switched to the inactive state by the communication device and is currently in the inactive state. The coverage area of the second access network device is not included in the second access network device, and the first message is sent to the second access network device; or, the transceiver module is specifically used to: The third message is used to indicate that the terminal in the multicast group that was switched to the inactive state by the communication device returns to the connected state on the third access network device, or the third message is used to indicate The communication device is requested to send the context of the terminal to the third access network device and the first message to the second access network device.

A seventh aspect provides a communication device, including: a processor; the processor is configured to be coupled to a memory, and after reading instructions in the memory, execute the method as described in any of the above aspects according to the instructions. The communication device may be the first access network device in the above-mentioned first aspect, or a device including the above-mentioned first access network device; or the communication device may be the second access network device in the above-mentioned second aspect, Or a device including the above-mentioned second access network device; or the communication device may be the first access network device in the above-mentioned third aspect, or a device including the above-mentioned first access network device.

In conjunction with the seventh aspect, in a possible implementation manner, the communication device further includes a memory, and the memory is used to store necessary program instructions and data.

In conjunction with the seventh aspect, in a possible implementation, the communication device is a chip or a chip system. Optionally, when the communication device is a chip system, it may be composed of a chip, or may include a chip and other discrete devices.

In an eighth aspect, a communication device is provided, including: a processor and an interface circuit; the interface circuit is used to receive a computer program or instructions and transmit them to the processor; the processor is used to execute the computer program or instructions to enable the communication The device performs the method described in any of the above aspects.

In conjunction with the eighth aspect, in a possible implementation manner, the communication device is a chip or a chip system. Optionally, when the communication device is a chip system, it may be composed of a chip, or may include a chip and other discrete devices.

In a ninth aspect, a computer-readable storage medium is provided. Instructions are stored in the computer-readable storage medium, and when run on a computer, the computer can perform the method described in any of the above aspects.

A tenth aspect provides a computer program product containing instructions that, when run on a computer, enable the computer to To perform any of the methods described above.

Among them, the technical effects brought by any one of the possible implementation methods in the fourth to tenth aspects can be referred to the technical effects brought by any one of the above-mentioned first to third aspects or different possible implementation methods in any aspect. The technical effects will not be repeated here.

In an eleventh aspect, a communication system is provided. The communication system includes an access network device and a network device, wherein the access network device is used to perform the method described in the first aspect, and the network device is used to receive data from the access network device. Multicast session leave message for network devices.

In a possible implementation manner, the network device includes a core network device or an access network device other than the access network device.

In a twelfth aspect, a communication system is provided. The communication system includes a second access network device for performing the method described in the second aspect, and a first access network device used for performing the method described in the third aspect. Access network equipment.

It is understandable that, on the premise that the solutions are not inconsistent, the solutions in each of the above aspects can be combined.

Description of drawings

Figure 1 is a schematic diagram of a communication system architecture;

Figure 2 is a schematic diagram of the hardware structure of a communication device provided by an embodiment of the present application;

Figure 3A is a schematic flowchart 1 of the multicast communication method provided by the embodiment of the present application;

Figure 3B is a schematic flowchart 2 of the multicast communication method provided by the embodiment of the present application;

Figure 4 is a schematic flowchart three of the multicast communication method provided by the embodiment of the present application;

Figure 5 is a schematic flowchart 4 of the multicast communication method provided by the embodiment of the present application;

Figure 6 is a schematic structural diagram of a communication device provided by an embodiment of the present application;

Figure 7 is a schematic second structural diagram of a communication device provided by an embodiment of the present application.

Detailed ways

Before introducing the embodiments of the present application, the technical terms and related processes involved in the embodiments of the present application are introduced. It can be understood that these introductions are to make the embodiments of the present application easier to understand and should not be regarded as limiting the scope of protection required by the embodiments of the present application.

1. Connected state, inactive state and radio resource control idle (RRC-idle) state (hereinafter referred to as idle state)

In the connected state, there is a radio resource control (RRC) connection between the terminal and the access network device. The access network device knows that the terminal is within the coverage area of the access network device, or further, accesses The network equipment knows that the terminal is in a cell corresponding to the access network equipment, and the core network equipment knows that the terminal can be found through the access network equipment. The terminal can receive downlink data and signaling from the access network equipment, and can also send uplink data and signaling to the access network equipment. The coverage area of an access network device includes the area in which the access network device can provide access services to terminals, and may also be called the service coverage area of the access network device or the service area of the access network device.

In the inactive state, there is no RRC connection between the terminal and the access network device. The access network device may not know whether the terminal is within the coverage area of the access network device. The core network device thinks that the terminal is still in the connected state (CM -Connected state), the terminal's downlink data and signaling will be sent to the access network device in the same way as the connected state.

In the idle state, there is no RRC connection between the terminal and the access network device. The access network device does not know the existence of the terminal, and the core network device may not know through which access network device the terminal can be found.

2. Radio access network (RAN) notification area (RAN notification area, RNA)

RNA can also be called RAN-based notification area or RAN notification area, etc., without limitation. The RNA may be an area set by the access network device for the terminals in the inactive state in the multicast group. That is to say, the terminals in the inactive state in the multicast group may correspond to one RNA. The RNA may indicate multiple cells (cells) or at least one access network device. For example, the RNA includes multiple cells, or a cell list, or a tracking area (TA), or an identification of at least one access network device. The terminal can move within the cell indicated by the RNA or within the coverage area of the indicated access network device without interacting with the network. If the core network has downlink data or signaling that needs to be sent to the terminal, the access network equipment in the RNA can page the terminal so that the terminal enters the connected state to receive the downlink data or signaling.

The access network equipment in the RNA can be understood to mean that all or part of the coverage area of the access network equipment is included in the RNA, or it can be understood to mean that each cell included in the RNA belongs to (or corresponds to) Access network equipment.

For example, if RNA includes cell 1, cell 2 and cell 3, where cell 1 and cell 2 are the cells of access network device 1, and cell 3 is the cell of access network device 2, then the access network devices in RNA include Access network equipment 1 and access network equipment 2.

For another example, if RNA includes the TA of access network device 1, the TA of access network device 2, and the TA of access network device 3, then the access network devices in the RNA include access network device 1, access network device 2 and access network equipment 2.

For another example, if the RNA includes the identifier of the access network device 1 and the identifier of the access network device 2, then the access network devices in the RNA include the access network device 1 and the access network device 2.

Among them, the cell can be the New Radio Cell Identity (NR Cell Identity) or the New Radio Cell Global Identity (NR Cell Global Identity). A unified explanation is given here and will not be repeated later.

3. The process for a terminal to join a multicast group (which can also be understood as joining the multicast session corresponding to the multicast group)

S11: The terminal sends the first request to the session management function (SMF) network element.

Correspondingly, the SMF network element receives the first request from the terminal.

The first request may be used to request to join a multicast group of the multicast service, or to join a multicast session corresponding to the multicast group. The first request may include information for the multicast group or information for the multicast session.

The information about the multicast group may include an identifier of the multicast group or a protocol address related to the multicast service.

Specifically, the identification of the multicast group may be used to indicate the multicast group. Specifically, the identity of the multicast group may be a temporary identity assigned to the multicast group by the application server (AS) or the fifth generation (5th generation, 5G) core network, for example, the temporary mobile group identity ( temporary mobile group identifier (TMGI).

Specifically, the protocol address related to the multicast service may be an Internet Protocol (IP) address, for example, the IP address of the multicast data, or a user plane function (UPF) network connected to the AS. Yuan’s IP address. Optionally, the multicast group information may also include the port number of the UPF network element connected to the AS. Or the protocol address related to the multicast service can be a source specific multicast address (Source Specific Multicast address).

The multicast session information may include the identification of the multicast session corresponding to the multicast group. The identifier of the multicast session can be used to identify the multicast session. The multicast session corresponding to the multicast group is used to transmit multicast data corresponding to the multicast group.

It should be noted that in this embodiment of the present application, the multicast group can be replaced by a multicast session, and the multicast session is used to transmit multicast data corresponding to the multicast group.

In a possible implementation, the first request is included in a non-access stratum (NAS) message or a user plane join request message. The NAS message may be a protocol data unit (PDU) session modification request or a PDU session establishment request. The join request message on the user plane may be an Internet group management protocol (IGMP) join message (IGMP join message).

In one possible implementation, the terminal application triggers the terminal to send a first request to the SMF network element; or, when the terminal detects that it needs to receive or send data through multicast, it sends the first request to the SMF network element.

S12: The SMF network element sends the first message to the access network device.

Correspondingly, the access network device receives the first message from the SMF network element.

The first message includes the context of the multicast session corresponding to the multicast group.

Optionally, the first message also includes unicast quality of service (QoS flow) information corresponding to the multicast group.

One possible implementation method is that after receiving the first request, the SMF network element obtains the multicast information. For example, the SMF network element uses the multicast/broadcast-session management function (multicast/broadcast-session

management function (MB-SMF) network element or unified data repository (UDR) network element to obtain multicast information. The multicast information may include QoS information of the multicast session. The SMF network element generates the context of the above multicast session based on the multicast information.

Among them, the context of multicast sessions will be introduced in the fourth point below.

Optionally, the SMF network element also generates unicast QoS flow information corresponding to the multicast group based on the multicast information.

S13: The access network device establishes or modifies the context of the multicast session corresponding to the multicast group according to the first message.

It can be understood that after S13, the terminal successfully joins the multicast group, and the terminal can receive multicast data of the multicast group through the access network device.

It can be understood that in the embodiment of the present application, the access network device establishes the context of the multicast session corresponding to the multicast group. For: the access network equipment establishes a transmission channel for transmitting multicast data between the access network equipment and the UPF network element (for example, the multicast broadcast user plane functional network element), or the access network equipment The transmission channel allocation identifier (for example, the transmission tunnel identifier) used to transmit multicast data between the network access device and the UPF network element. Further, the access network device can send the identification to the MB-SMF network element. After receiving the identifier, the MB-SMF network element can send the identifier to the UPF network element.

It can be understood that in the embodiment of the present application, the transmission channel can be alternatively described as a transmission logical channel, a logical channel, a communication connection, a transmission path, a tunnel or a transmission tunnel, etc. Multicast can be replaced by terms such as broadcast, multicast, and multicast/broadcast.

It can be understood that after a terminal joins a multicast group or multicast session, that is, the terminal is in a connected state and can receive multicast data of the multicast group. Subsequently, the access network device may release the RRC connection with the terminal, causing the terminal to switch to an inactive state. Subsequently, the terminal receives the multicast data of the multicast group in the inactive state.

4. Context of Multicast Session

The context of a multicast session may include one or more of the following information: the identification information of the transmission channel of the multicast session, the QoS information of the multicast session, the status information of the multicast session, the area identification of the MBS, or the multicast session corresponding Terminal identification information.

The identification information of the transmission channel of the multicast session is used to identify the transmission channel of the multicast session. The transmission channel may include at least one of the following: a transmission channel corresponding to the multicast session between the access network device and the UPF network element. A channel for multicast data, or a channel between two access network devices for transmitting multicast data corresponding to a multicast session. Specifically, the identification information may include a tunnel endpoint identifier used for multicast session transmission, such as: multicast/broadcast session tunnel endpoint ID (MB session TEID).

Among them, the QoS information of the multicast session may include allocation and retention priority (ARP) information for multicast transmission, and/or 5G QoS Flow ID (5QI).

The status information of the multicast session can be used to indicate the status of the multicast session, such as activation status or deactivation status. The MBS area identifier can be used to identify the MBS Service Area.

The area identifier of the MBS may include a cell identifier or a tracking area identifier.

Among them, the identification information of the terminal corresponding to the multicast session can be used to indicate the identification of the terminal corresponding to the multicast session, such as 5G-system architecture evolution-temporary mobile subscriber identity (5G-S- TMSI) and so on.

5. The terminal in the multicast group is switched to the inactive state and the process of receiving multicast data in the inactive state

In the embodiment of the present application, switching the terminal to the inactive state can be replaced by: the terminal is released to the inactive state, or the terminal is configured to the inactive state, etc. A unified explanation is given here and will not be described again.

The following takes the context in which a terminal joins a multicast group through access network device 1, and access network device 1 successfully establishes a multicast session as an example to introduce that the terminal in the multicast group is switched to the inactive state, and in the inactive state The process of receiving multicast data in the state.

S21: Access network device 1 sends an RRC Release (RRC Release) message to the terminal.

Correspondingly, the terminal receives the RRC release message from the access network device 1.

Among them, the RRC release message may include information such as suspension indication information, configuration information, RNA information, or inactive radio network temporary identifier (I-RNTI) to be released to the inactive state. one or more items.

Wherein, the indication or configuration information of releasing to the inactive state may be used to instruct the terminal to switch to the inactive state. RNA information can be used to indicate RNA. RNA information can also be carried and sent in other messages without restriction. In this example, the RNA information includes the identifier of access network device 1 and the identifier of access network device 2.

S22: The access network device 1 sends a second request to an access network device other than the access network device 1 in the RNA (access network device 2 in this example).

Correspondingly, the access network device in the RNA other than the access network device 1 (in this example, the access network device 2) receives the second request from the access network device 1.

The second request may be used to request to establish the context of the multicast session of the access network device 2 for the multicast group, or the second request may be used to request the establishment of a transmission channel corresponding to the multicast group, or the second request may be used to request the establishment of a transmission channel corresponding to the multicast group. The request may be used to request to send multicast data corresponding to the multicast group, or the second request may be used to request to process the multicast data corresponding to the multicast group.

It can be understood that if the RNA information also includes the identification of the access network device 3, the access network device 1 will also send the access network device 3 Send a request to request to establish the context of the multicast session of the access network device 3 for the multicast group, or to request to establish a transmission channel corresponding to the multicast group, or to request to send multicast data corresponding to the multicast group, Or, request processing of multicast data corresponding to the multicast group.

S23: If the access network device 2 does not establish the context of the multicast session of the access network device 2, the access network device 2 establishes the context of the multicast session of the access network device 2.

For example, the access network device 2 can interact with the core network to establish the context of the multicast session of the access network device 2 .

After S23, the access network devices in the RNA (access network device 1 and access network device 2 in this example) all establish the context of their corresponding multicast sessions. Therefore, all access network devices within RNA can send multicast data.

It can be understood that after S23, the terminal may return to the connected state under any access network device in the RNA, such as access network device 1 or access network device 2. At this time, how the access network equipment in the RNA maintains the context of its corresponding multicast session is still a problem to be solved.

In order to solve the above problems, embodiments of the present application provide a multicast communication method. In this method, the access network device can leave the access network device when the last terminal connected to the access network device in the multicast group, and there is no connection with the access network device in the multicast group. In the case of an associated inactive terminal, release the context of the multicast session. In this way, it can not only ensure that terminals in the multicast group receive multicast data, but also enable the access network device to release the context of the multicast session corresponding to the multicast group in a timely manner to save resources. The specific process of this method will be explained in the embodiment shown in FIG. 3A, FIG. 3B or FIG. 4 below, and will not be described again here.

The methods provided by the embodiments of this application can be used in various communication systems. For example, the communication system can be a long term evolution (LTE) system, a fifth generation (5G) communication system, a Wi-Fi system, or a third generation partnership project (3GPP) related system. Communication systems, future evolved communication systems (such as sixth generation (6G) communication systems, etc.), or systems integrating multiple systems, etc., are not restricted. Among them, 5G can also be called new radio (NR). The following uses the communication system 10 shown in Figure 1 as an example to describe the method provided by the embodiment of the present application. Figure 1 is only a schematic diagram and does not constitute a limitation on the applicable scenarios of the technical solution provided by this application.

As shown in Figure 1, it is a schematic architectural diagram of a communication system 10. In Figure 1, the communication system 10 may include an access network device 101, an access network device 102, a terminal 103 that can communicate with the access network device 101, and a terminal 104 that can communicate with the access network device 102. Optionally, the communication system 10 also includes an access network device 105.

In Figure 1, access network equipment can provide wireless access services to terminals. Specifically, each access network device corresponds to a service coverage area, and terminals entering this area can communicate with the access network device to receive wireless access services provided by the access network device. Optionally, the service coverage area may include one or more cells. The terminal and the access network equipment can communicate through the Uu port link. Among them, the Uu interface link can be divided into an uplink (uplink, UL) and a downlink (downlink, DL) according to the direction of data transmitted thereon. The UL can transmit uplink data sent from the terminal to the access network device, and the DL can transmit the downlink data transmitted from the access network device to the terminal.

The access network device, such as the access network device 101, the access network device 102 or the access network device 105, may be any device with wireless transceiver functions. Including but not limited to: evolutionary base station (NodeB or eNB or e-NodeB, evolutionary Node B) in LTE, base station (gNodeB or gNB) or transceiver point (transmission receiving point/transmission reception point, TRP) in NR, 3GPP Subsequently evolved base stations, access nodes in Wi-Fi systems, wireless relay nodes, wireless backhaul nodes, etc. The base station can be: macro base station, micro base station, pico base station, small station, relay station, or balloon station, etc. Multiple base stations may support networks with the same technology mentioned above, or may support networks with different technologies mentioned above. A base station may contain one or more co-located or non-co-located TRPs. The access network device may also be a wireless controller in a cloud radio access network (cloud radio access network, CRAN) scenario. The access network device may also be a centralized unit (CU) and/or a distributed unit (DU). The access network device can also be a server, wearable device, machine communication device, or vehicle-mounted device, etc. The following description takes the access network equipment as a base station as an example. The multiple access network devices may be base stations of the same type or different types of base stations. The base station can communicate with the terminal, or it can communicate with the terminal through the relay station. The terminal can communicate with multiple base stations of different technologies. For example, the terminal can communicate with a base station that supports LTE network and a base station that supports 5G network. It can also support dual connections with base stations of LTE network and base stations of 5G network. . In the embodiment of the present application, the device used to realize the function of the access network device may be the access network device; it may also be a device that can support the access network device to realize the function, such as a chip system. The device may be installed on the access network device. In the network access device or with The access network equipment is matched and used. In the embodiments of this application, the chip system may be composed of chips, or may include chips and other discrete devices. In the method provided by the embodiment of the present application, the method provided by the embodiment of the present application is described by taking the device for realizing the function of the access network equipment as an access network equipment as an example.

A terminal, such as terminal 103 or terminal 104, is a device with wireless transceiver functions. Terminals can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water (such as ships, etc.); they can also be deployed in the air (such as aircraft, balloons, satellites, etc.). The terminal may also be called a terminal device, and the terminal device may be a user equipment (UE), where the UE includes a handheld device, a vehicle-mounted device, a wearable device or a computing device with wireless communication functions. For example, the UE may be a mobile phone, a tablet computer, or a computer with wireless transceiver functions. The terminal device can also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in driverless driving, a wireless terminal in telemedicine, or a smart terminal. Wireless terminals in the power grid, wireless terminals in smart cities, or wireless terminals in smart homes, etc. In the embodiment of the present application, the device used to implement the function of the terminal may be a terminal; it may also be a device that can support the terminal to implement the function, such as a chip system. The device may be installed in the terminal or used in conjunction with the terminal. In the method provided by the embodiment of the present application, the device for realizing the functions of the terminal is a terminal as an example for description.

As an example and not a limitation, the terminal may be a wearable device. Wearable devices can also be called wearable smart devices. It is a general term for applying wearable technology to intelligently design daily wear and develop wearable devices, such as glasses, gloves, watches, clothing and shoes, etc. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothing or accessories. For example, a wearable device is not only a hardware device, but also a device that achieves powerful functions through software support, data interaction, and cloud interaction. Broadly defined wearable smart devices include devices that are full-featured, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as devices that only focus on a certain type of application function and need to be integrated with other devices such as Devices used with smartphones, such as various smart bracelets, smart jewelry, etc. for monitoring physical signs.

The terminal can be a terminal in the Internet of things (IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing human-computer interconnection and things. Intelligent network of interconnection of things. The terminal in this application may be a terminal in machine type communication (MTC). The terminal of this application may be a vehicle-mounted module, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or vehicle-mounted unit built into the vehicle as one or more components or units. The vehicle uses the built-in vehicle-mounted module, vehicle-mounted module, vehicle-mounted component , vehicle-mounted chip or vehicle-mounted unit can implement the method of this application.

Optionally, the communication system shown in Figure 1 also includes at least one UPF network element that communicates with the access network device in Figure 1 and at least one SMF network element that communicates with the access network device in Figure 1 (in Figure 1 not shown).

The SMF network element is used for session management or session establishment, for example, for establishing a multicast session corresponding to a multicast group.

The UPF network element is used to establish the context of the multicast session corresponding to the multicast group, or to establish a transmission channel between the UPF network element and its corresponding access network device for transmitting multicast data corresponding to the multicast group. .

The communication system 10 shown in FIG. 1 is only used as an example and is not used to limit the technical solution of the present application. Those skilled in the art should understand that during specific implementation, the communication system 10 may also include other devices, and the number of access network devices and terminals may also be determined according to specific needs without limitation.

Optionally, each network element or device (for example, access network device, etc.) in Figure 1 can also be called a communication device, which can be a general device or a special device, and is not specifically limited.

Optionally, the relevant functions of each network element or device (for example, access network device, etc.) in Figure 1 can be implemented by one device, or can be implemented by multiple devices together, or can be implemented by one or more devices within one device. Multiple functional modules are implemented without specific limitations. It can be understood that the above functions can be either network elements in hardware devices, software functions running on dedicated hardware, or a combination of hardware and software, or virtualization instantiated on a platform (for example, a cloud platform) Function.

During specific implementation, each network element or device (for example, access network equipment, etc.) in Figure 1 can adopt the composition structure shown in Figure 2, or include the components shown in Figure 2. FIG. 2 shows a schematic diagram of the hardware structure of a communication device applicable to embodiments of the present application. The communication device 20 includes at least one processor 201 and at least one communication interface 204, which are used to implement the methods provided by the embodiments of this application. The communication device 20 may also include a communication line 202 and a memory 203 .

The processor 201 may be a general central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more programs for controlling the present application. integrated circuit for program execution.

Communication line 202 may include a path, such as a bus, that carries information between the above-mentioned components.

Communication interface 204 is used to communicate with other devices or communication networks. The communication interface 204 can be any device such as a transceiver, such as an Ethernet interface, a radio access network (RAN) interface, a wireless local area networks (WLAN) interface, a transceiver, and pins , bus, or transceiver circuit, etc.

The memory 203 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (random access memory (RAM)) or other type that can store information and instructions. A dynamic storage device can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), disk storage media or other magnetic storage devices, or can be used to carry or store desired program code in the form of instructions or data structures and can be used by a computer Any other medium for access, but not limited to this. The memory may exist independently and be coupled to the processor 201 through the communication line 202 . The memory 203 may also be integrated with the processor 201. Among them, the memory can usually be non-volatile.

The memory 203 is used to store computer execution instructions involved in executing solutions provided by various embodiments of the present application, and is controlled by the processor 201 for execution. The processor 201 is used to execute computer execution instructions stored in the memory 203, thereby implementing the methods provided by various embodiments of the present application. Alternatively, the processor 201 performs processing-related functions in the methods provided in the following embodiments of the present application, and the communication interface 204 is responsible for communicating with other devices or communication networks, which is not specifically limited.

Among them, the instructions executed by the computer can also be called application codes without specific limitations.

Coupling is an indirect coupling or communication connection between devices, units or modules, which may be electrical, mechanical or other forms, and is used for information interaction between devices, units or modules.

As an embodiment, the processor 201 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 2 .

As an embodiment, the communication device 20 may include multiple processors, such as the processor 201 and the processor 207 in FIG. 2 . Each of these processors may be a single-CPU processor or a multi-CPU processor. A processor here may refer to one or more devices, circuits, and/or processing cores for processing data (eg, computer program instructions).

As an embodiment, the communication device 20 may also include an output device 205 and/or an input device 206. Output device 205 is coupled to processor 201 and can display information in a variety of ways. For example, the output device 205 may be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector (projector), etc. The input device 206 is coupled to the processor 201 and can receive user input in a variety of ways. For example, the input device 206 may be a mouse, a keyboard, a touch screen device, a sensing device, or the like.

It can be understood that the composition structure shown in Figure 2 does not constitute a limitation on the communication device. In addition to the components shown in Figure 2, the communication device may include more or fewer components than shown in the figure, or a combination of certain components. components, or different component arrangements.

The method provided by the embodiment of the present application will be described below with reference to the accompanying drawings. Each network element in the following embodiments may be equipped with the components shown in Figure 2, which will not be described again.

It is understood that "transmission" may be understood as sending and/or receiving depending on the specific context. "Transfer" can be a noun or a verb. When deemphasizing the subject of the action, "transmission" is often used instead of sending and/or receiving. For example, the phrase "transmit multicast data", from the perspective of the sender, can be understood as "send multicast data", and from the perspective of the receiver, it can be understood as "receive multicast data".

It can be understood that in the following embodiments of the present application, the names of messages between network elements or the names of parameters in the messages are just examples, and other names may also be used in specific implementations without specific limitations.

Among them, "/" can mean that the related objects are in an "or" relationship, for example, A/B can mean A or B; "and/or" can be used to describe the existence of three relationships between related objects, for example, A And/or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. In addition, expressions similar to "at least one of A, B and C" or "at least one of A, B or C" are often used to mean any of the following: A alone; B alone; alone C exists; A and B exist simultaneously; A and C exist simultaneously; B and C exist simultaneously; A, B, and C exist simultaneously. The above is an example of three elements A, B and C to illustrate the optional items of this project. When there are more elements in the expression, The meaning of this expression can be obtained in accordance with the aforementioned rules.

In order to facilitate the description of the technical solutions of the embodiments of the present application, words such as "first" and "second" may be used to distinguish technical features with the same or similar functions. The words "first", "second" and other words do not limit the quantity and execution order, and the words "first" and "second" do not limit the number and execution order. In the embodiments of this application, words such as "exemplary" or "for example" are used to express examples, illustrations or illustrations, and any embodiment or design solution described as "exemplary" or "for example" shall not be interpreted. To be more preferred or advantageous than other embodiments or designs. The use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete manner that is easier to understand.

It will be understood that reference throughout this specification to "an embodiment" means that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present application. Therefore, various embodiments are not necessarily referred to the same embodiment throughout this specification. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. It can be understood that in the various embodiments of the present application, the size of the sequence numbers of each process does not mean the order of execution. The execution order of each process should be determined by its functions and internal logic, and should not be determined by the execution order of the embodiments of the present application. The implementation process constitutes no limitation.

It can be understood that in this application, "when..." or "if" all mean that corresponding processing will be made under certain objective circumstances. It does not limit the time, and it does not require that there must be a judgment action when implementing it. Nor does it imply the existence of other limitations.

“At the same time” in this application can be understood as at the same point in time, within a period of time, or within the same cycle.

It can be understood that some optional features in the embodiments of the present application, in certain scenarios, can be implemented independently without relying on other features, such as the solutions they are currently based on, to solve corresponding technical problems and achieve corresponding effects. , and can also be combined with other features according to needs in certain scenarios. Correspondingly, the devices provided in the embodiments of the present application can also implement these features or functions, which will not be described again here.

It can be understood that the same step or steps with the same function or technical features in the embodiments of the present application can be used as reference between different embodiments.

It can be understood that the access network device can perform some or all of the steps in the embodiments of the present application. These steps are only examples, and other steps or variations of various steps can also be performed. In addition, various steps may be performed in a different order than those presented in the embodiments of the present application, and it may not be necessary to perform all the steps in the embodiments of the present application.

As shown in Figure 3A, a multicast communication method is provided in an embodiment of the present application. The multicast communication method may include the following steps:

S301: The first access network device determines that the last terminal in the multicast group connected to the first access network device leaves the first access network device, and the multicast group is not associated with the first access network device. of inactive terminals.

S302: The first access network device releases the context of the multicast session.

The multicast session is used to transmit multicast data corresponding to the multicast group.

Specifically, the release in step S302 can be understood as deletion, not restriction.

The first access network device in S301 may be any access network device in the communication system 10 shown in Figure 1, for example, the access network device 101, the access network device 102 or the access network device in Figure 1. Network equipment 105.

Optionally, before S301, the first access network device establishes a multicast session context for the multicast group. The context of the multicast session may be used to transmit multicast data corresponding to the multicast group between the first access network device and its corresponding UPF network element, or the context of the multicast session may be used by the first access network Multicast data is transmitted between the device and access network devices other than the first access network device.

The context in which the first access network device establishes a multicast session for the multicast group can be replaced by the context in which the first access network device establishes a multicast session corresponding to the multicast group, or the first access network device establishes a multicast session corresponding to the multicast group, or the first access network device establishes a multicast session corresponding to the multicast group. A transmission channel for the multicast session is established for the multicast group, or the first access network device establishes a transmission channel for the multicast session corresponding to the multicast group.

It can be understood that if terminals in the multicast group join the multicast group through different access network devices, then these access network devices will establish a multicast session context for the multicast group. In the embodiment of this application, in order to distinguish the context of the multicast session established by different access network devices for the multicast group, the context of the multicast session established by each access network device for the multicast group is called the access network. The context of the device's multicast session. For example, if access network device 1 and access network device 2 both establish the context of a multicast session for a multicast group, the context of the multicast session established by access network device 1 for the multicast group is called access. The context of the multicast session of network device 1 and the context of the multicast session established by access network device 2 for the multicast group are called the multicast session of access network device 2. context. Therefore, the context of the multicast session established by the first access network device for the multicast group may also be referred to as the context of the multicast session of the first access network device. A unified explanation is provided here and will not be repeated later.

In an optional implementation, when the last terminal in the multicast group connected to the first access network device is deleted from the context of the multicast session by the first access network device; or, the multicast group When the last terminal connected to the first access network device switches to other access network devices except the first access network device (hereinafter referred to as other access network devices), the first access network determines the multicast group The last terminal in the group connected to the first access network device leaves the first access network device.

For example, taking the first access network device as a next generation radio access network (NG-RAN), in the handover preparation phase, the multicast group and the first access network device (NG-RAN) That is, when the last terminal connected to the source NG-RAN is switched to the target NG-RAN, the first access network determines that the last terminal connected to the first access network device in the multicast group leaves the first access network device. Or, the last terminal in the multicast group connected to the first access network device (i.e., the source NG-RAN) switches to the target evolved universal terrestrial radio access (network)

(network), E-UTRAN), the first access network determines that the last terminal connected to the first access network device in the multicast group leaves the first access network device.

It should be pointed out that there is no inactive terminal associated with the first access network device in the multicast group. There can also be other alternative description methods. For example, it can also be described as coverage of the first access network device. There is no intersection between the area and the RNA of any terminal in the multicast group, or the coverage area described as the first access network device is not included in the RNA of any terminal in the multicast group, or it is described as a multicast group The access network equipment in the RNA of any terminal in the group does not include the first access network equipment, or the coverage area described as the first access network equipment does not have a common cell with the RNA of any terminal in the multicast group. Or the tracking area, or the cell or tracking area described as the RNA corresponding to any terminal in the multicast group does not belong to the first access network device.

As an example, take the multicast group including terminal 1 and terminal 2, and the cell of the first access network device including cell 1 and cell 2. If the RNA of terminal 1 includes cell 3 and cell 4, the RNA of terminal 2 includes Cell 5 and Cell 6, then there is no inactive terminal associated with the first access network device in the multicast group. If the RNA of terminal 1 includes cell 1 and cell 4, and the RNA of terminal 2 includes cell 5 and cell 6, then there is an inactive terminal associated with the first access network device in the multicast group. If the RNA of terminal 1 includes the identity of the first access network device and the identity of access network device 2, and the RNA of terminal 2 includes the identity of access network device 2 and the identity of access network device 3, then the multicast group There is an inactive terminal associated with the first access network device. If the RNA of terminal 1 includes the TA of access network device 2 and the TA of access network device 3, and the RNA of terminal 2 includes the TA of access network device 2 and the TA of access network device 4, then in the multicast group There is no inactive terminal associated with the first access network device.

It should be pointed out that S301 can be replaced by: when the last terminal connected to the first access network device in the multicast group leaves the first access network device, the first access network device determines that there are no terminals in the multicast group. There is an inactive terminal associated with the first access network device. Further, when the last terminal in the multicast group connected to the first access network device leaves the first access network device, it may be replaced by: the last terminal in the multicast group connected to the first access network device is left by the first access network device. An access network device is deleted from the context of the multicast session; or, the last terminal connected to the first access network device in the multicast group is switched to another access network device other than the first access network device. .

Based on the method shown in Figure 3A, the last terminal connected to the first access network device in the multicast group leaves the first access network device, and the first terminal in the multicast group If there is no inactive terminal associated with the first access network device, release the context of the multicast session. In this way, it can not only ensure that terminals in the multicast group receive multicast data, but also enable the access network device to release the context of the multicast session corresponding to the multicast group in a timely manner to save resources.

Optionally, in an implementation scenario of the above embodiment, after S301, the above method further includes: the first access network device sending a request message to the first network device.

Correspondingly, the first network device receives the request message from the first access network device.

The request message is used to request the release of the multicast session. The first network device can be an access and mobility management function (AMF) network element, an MB-SMF network element, a UPF network element or other access network equipment, without limitation.

In a possible implementation, before S302, the above method further includes: the first access network device receiving a response message from the first network device.

Correspondingly, the first network device sends a response message to the first access network device.

The response message is used to respond to the request message. The request message may be a multicast session release request, and the response message may be a multicast session release response, without limitation.

Based on the method provided in the above implementation scenario, the first access network device may determine in S301 that the last terminal connected to the first access network device in the multicast group leaves the first access network device, and the If there is no inactive terminal associated with the first access network device, the request message is sent to the first network device, and the context of the multicast session is released after receiving the response message.

Optionally, in another implementation scenario of the above embodiment, the above method further includes: the first access network device sending a multicast session leave message to the second network device. Correspondingly, the second network device receives the multicast session leave message from the first access network device.

The second network device may be a core network device or other access network device. The core network equipment is an AMF network element, MB-SMF network element or UPF network element.

For example, when the context of the multicast session is used to transmit multicast messages corresponding to the multicast group between the first access network device and the UPF network element (the UPF network element can be replaced by the MB-UPF network element, which will not be described again). data (for example, the context includes the identification of the transmission channel between the first access network device and the UPF network element), then the second network device may be a core network device. Or, if the context of the multicast session is used to transmit multicast data between the first access network device and other access network devices (for example, the context includes the communication between the first access network device and the second access network device). identification of the transmission channel), then the second network device is another access network device.

The multicast session leave message can be used to request or trigger the release of the context of the multicast session corresponding to the multicast group. Alternatively, the multicast session leave message may be used to indicate that the multicast session corresponding to the multicast group has left the first access network device. Wherein, releasing the context of the multicast session corresponding to the multicast group may be replaced by deleting the context of the multicast session corresponding to the multicast group.

Among them, the multicast session leave message can be replaced by: transmission channel release request message, for example, DISTRIBUTION RELEASE REQUEST message. The transmission channel release request message may be used to request the release of the transmission channel of the multicast session corresponding to the multicast group. The multicast session leave message can also be replaced by: an IP packet containing leave information, such as an Internet Group Management Protocol (IGMP) leave message, etc.

Based on the method provided in the above implementation scenario, the first access network device can trigger the release of the context of the multicast session of the network device, thereby further saving network resources.

It should be pointed out that embodiments of the present application also provide a multicast communication method, including: the first access network device only leaves the first terminal connected to the first access network device in the multicast group. In the case of a network access device, release the context of the multicast session established by the first access network device for the multicast group; or, the first access network device only does not exist with the first access network in the multicast group. In the case of an inactive terminal associated with the device, release the context of the multicast session established by the first access network device for the multicast group.

For example, if there is no inactive terminal in the multicast group, when the last terminal in the multicast group connected to the first access network device leaves the first access network device, the first access network device The device releases the context of the multicast session established by the first access network device for the multicast group. If there is no terminal in the connected state in the multicast group, when there is no terminal in the inactive state associated with the first access network device in the multicast group, the first access network device releases the first access The context of the multicast session established by the network device for the multicast group.

It can be understood that the actions of the first access network device in the above-mentioned S301-S302 can be executed by the processor 201 in the communication device 20 shown in FIG. 2 by calling the application code stored in the memory 203. The embodiment of the present application is This does not impose any restrictions.

Optionally, in another implementation scenario of the above embodiment, step S301 may include S301A and S301B, specifically as follows:

S301A: The first access network device determines the last terminal connected to the first access network device in the multicast group based on the first information of the connected terminals in the multicast group associated with the first access network device. Leave the first access network device.

The first information may be any one of the following four situations: Situation A: The first information may be used to indicate the terminal in the multicast group that is connected to the first access network device and is in the connected state. The number, or case B: the first information may be used to indicate the number of contexts of the terminals in the multicast group stored in the first access network device, or case C: the first information may be used to indicate the first access network device Whether the context of the terminals in the multicast group is stored in the network access device, or, case D: first information Terminal used to indicate the connection state associated with the multicast group's identity.

Optionally, the first information is included in the context related to the multicast/broadcast service (MBS) corresponding to the multicast group stored in the first access network device.

For example, the first access network device stores MBS-related context. The MBS-related context includes first information corresponding to multicast session 1, first information corresponding to multicast session 2... first information corresponding to multicast session m. Among them, multicast session 1 to multicast session m are multicast sessions corresponding to different multicast groups, and are used to transmit multicast data of their corresponding multicast groups.

The following introduces case A, case B, case C and case D respectively.

Case A: The first information may be used to indicate the number of terminals in the multicast group that are connected to the first access network device and are in the connected state.

In one possible design, the first information includes a numerical value. Initially, the value is the initial value, such as 0, or it can be other numbers or values (such as FF, 00, -1 or 1, etc.) without limitation. When the number of terminals in the multicast group that is connected to the first access network device and is in the connected state increases, this value also increases. For example, when the number of terminals increases by 1, this value also increases by 1; When the number of terminals connected to the first access network device in the multicast group and in the connected state decreases, this value also decreases. For example, when the number of terminals decreases by one, this value also decreases by one.

In another possible design, the first information is status information, that is, the first information can correspond to multiple statuses. Initially, the state corresponding to the first information is the initial state. When the number of terminals connected to the first access network device in the multicast group and in the connected state increases, the first access network device updates the first information. For example, when the number of terminals increases by one, the first access network device updates the first information. The state corresponding to the first information changes from the current state to the next state of the current state; when the multicast group is connected to the first access network device and the number of terminals in the connected state decreases, the first access network The device updates the first information. For example, when the number of terminals decreases by one, the state corresponding to the first information changes from the current state to the state previous to the current state.

It can be understood that when the value included in the first information is an initial value or the state corresponding to the first information is an initial state, it can mean that the terminal in the multicast group is connected to the first access network device and is in the connected state. The quantity is 0 or 1, there is no limit.

It can be understood that when the multicast group is connected to the first access network device and the number of terminals in the connected state is 0, the first access network device can determine that the multicast group is connected to the first access network device. The last terminal connected to the network equipment leaves the first access network equipment.

In one possible implementation manner, when a terminal in the multicast group enters the connected state under the first access network device, the first access network device updates the first information.

For example, when a terminal joins a multicast group through the first access network device, the first access network device increases the number indicated by the first information by 1; or when the first access network device receives a multicast message from After the RRC connection recovery request of the terminal in the group, the first access network device increases the number indicated by the first information by 1; or when the first access network device receives a multicast group from other access network devices After entering the context of a terminal in the first access network device, the first access network device increases the number indicated by the first information by 1.

One possible implementation is that when a terminal in the multicast group leaves the connection state (such as entering an inactive state or an idle state) under the first access network device, the first access network device updates the first information; or , when the terminal in the multicast group leaves the connected state (such as entering the inactive state or idle state) under the first access network device and enters the connected state under other access network devices, the first access network device Update first information.

For example, when the first access network device determines to release the connection of a terminal in the multicast group, after (or before) the first access network device sends an RRC connection release message to the terminal, the first access network device The network device decrements the number indicated by the first information by one.

For another example, when the first access network device determines that it is a terminal in the multicast group that switches to the inactive state or the idle state and enters the connected state under other access network devices, such as the first access network device After the device receives information requesting the context of the terminal from other access network devices, or after the first access network device sends the context information of the terminal to other access network devices, or the first access network device After receiving information from other access network equipment indicating that the terminal enters the connected state under the other access network equipment, the first access network equipment decrements the number indicated by the first information by 1.

Case B: The first information may be used to indicate the number of contexts of terminals in the multicast group stored in the first access network device.

In one possible design, the first information includes a numerical value. Initially, the value is the initial value, such as 0, or it can be other numbers or values (such as FF, 00, -1 or 1, etc.) without limitation. When the number of contexts of terminals in the multicast group stored in the first access network device increases, the value also increases. For example, when the number of contexts of the terminal increases by 1, the value also increases by 1; when When the number of contexts of terminals in the multicast group stored in the first access network device decreases, the value also decreases. For example, when the number of contexts of the terminal decreases by one, the value also decreases by one.

In another possible design, the first information is status information, that is, the first information can correspond to multiple statuses. Initially, the state corresponding to the first information is the initial state. When the number of contexts of terminals in the multicast group stored in the first access network device increases, the first access network device updates the first information. For example, when the number of contexts of the terminal increases by one, the first access network device The state corresponding to the first information changes from the current state to the next state of the current state; when the number of contexts of terminals in the multicast group stored in the first access network device decreases, the first access network device updates the first A piece of information, for example, when the number of contexts of the terminal is reduced by one, the state corresponding to the first information changes from the current state to the state previous to the current state.

It can be understood that when the value included in the first information is an initial value or the state corresponding to the first information is an initial state, it can mean that the number of contexts of terminals in the multicast group stored in the first access network device is 0. or 1, no restriction.

It can be understood that when the number of contexts of terminals in the multicast group stored in the first access network device is 0, the first access network device may determine that the multicast group is connected to the first access network device. The last terminal leaves the first access network device.

In one possible implementation, after the first access network device receives the context of the terminal in the multicast group that is not stored in the first access network device, the first access network device updates the first information; or, Each time the first access network device receives the context of the terminal in the multicast group, the first access network device updates the first information.

For example, after receiving the context of a terminal in the multicast group that is not stored in the first access network device, the first access network device increases the number indicated by the first information by 1.

A possible implementation manner is that when the first access network device receives information from other access network devices requesting the context of terminals in the multicast group, or when the first access network device requests other access network devices to After the network device sends the context information of the terminal in the multicast group, or after the first access network device deletes the context of the terminal in the multicast group, the first access network device updates the first information. For example, after sending the context information of a terminal in the multicast group to other access network devices, the first access network device decrements the number indicated by the first information by 1.

Case C: The first information may be used to indicate whether the context of the terminal in the multicast group is stored in the first access network device.

In one possible implementation, the first access network device can search in the stored context of the terminal whether the identifier of the multicast group is stored. If the identifier of the multicast group is stored, it means that the first access network device The context of the terminal in the multicast group is stored in . If the identifier of the multicast group is not stored, it means that the context of the terminal in the multicast group is not stored in the first access network device.

It can be understood that if the context of the terminal in the multicast group is not stored in the first access network device, it can be determined that the last terminal in the multicast group connected to the first access network device leaves the first access network equipment.

Case D: The first information is used to indicate the terminal in the connected state associated with the identity of the multicast group. That is, the first information may be used to indicate the terminal in the connected state in the multicast group.

In one possible design, the first information includes the identifier of the terminal associated with the identifier of the multicast group, for example, the identifier of the terminal in the connected state corresponding to the multicast group (such as 5G-S-TMSI). Initially, the first information is empty, that is, it does not include the identity of the terminal associated with the identity of the multicast group. It can be understood that this application does not limit the form of the first information. For example, the first information may include a list as shown in Table 0 (there may also be lists in other forms), or the first information may include key-value pairs. be restricted.

Table 0

In Table 0, the terminals associated with TMGI 1 include terminal 1, terminal 2 and terminal 3. The terminals associated with TMGI 2 include terminal 2 and terminal 4. The terminals associated with TMGI 3 include terminal 3, terminal 5 and terminal 6.

For example, when a terminal joins a multicast group through the first access network device, the first access network device adds the identifier of the terminal to the first information; or when the first access network device receives a message from the multicast group, After the RRC connection recovery request of the terminal in the broadcast group, the first access network device adds the identifier of the terminal to the first information; or, when the first access network device receives a multicast from other access network devices After obtaining the context of a terminal in the group, the first access network device adds the identifier of the terminal to the first information.

One possible implementation method is that when a terminal in the multicast group leaves the connected state (such as entering inactive state) under the first access network device, state or idle state), the first access network device updates the first information; or, when the terminal in the multicast group leaves the connected state (such as entering the inactive state or idle state) under the first access network device, And when other access network equipment enters the connection state, the first access network equipment updates the first information.

For example, when the first access network device determines to release the connection of a terminal in the multicast group, after (or before) the first access network device sends an RRC connection release message to the terminal, the first access network device The network device deletes the identification of the terminal from the first information.

For another example, when the first access network device determines that it is a terminal in the multicast group that switches to the inactive state or the idle state and enters the connected state under other access network devices, such as the first access network device After the device receives information requesting the context of the terminal from other access network devices, or after the first access network device sends the context information of the terminal to other access network devices, or the first access network device After receiving information from other access network equipment indicating that the terminal enters the connected state under the other access network equipment, the first access network equipment deletes the identification of the terminal from the first information.

S301B: The first access network device determines, based on the second information of the inactive terminal associated with the first access network device in the multicast group, that there is no terminal associated with the first access network device in the multicast group. Inactive terminal.

In this embodiment of the present application, the inactive terminals associated with the first access network device in the multicast group include: terminals that are switched to the inactive state by the first access network device in the multicast group; and A terminal that is switched to an inactive state by another access network device in the multicast group, and the RNA of the terminal includes all or part of the coverage area of the first access network device.

The multicast group below includes terminal 1, terminal 2 and terminal 3. Both terminal 1 and terminal 2 have established an RRC connection with the first access network device. Terminal 3 has established an RRC connection with the access network device 2. The first access network device The cell of the access network device includes cell 1 and cell 2, and the cell of the access network device 2 includes cell 3 and cell 4. This is described as an example.

For example, if the first access network device switches terminal 1 to the inactive state, then terminal 1 is an inactive state terminal associated with the first access network device in the multicast group.

For another example, if the access network device 2 switches the terminal 3 to the inactive state, and the RNA of the terminal 3 includes cell 1 and cell 3, the terminal 3 is the inactive state associated with the first access network device in the multicast group. status terminal.

For another example, if the access network device 2 switches the terminal 3 to the inactive state, and the RNA of the terminal 3 includes cell 3, cell 4 and cell 5, the terminal 3 is not associated with the first access network device in the multicast group. of inactive terminals.

Optionally, the second information is included in the MBS-related context corresponding to the multicast group stored in the first access network device.

In a possible implementation, the second information may be any one of the following three situations: Case 1, the second information may be used to indicate the inactive state associated with the first access network device in the multicast group. The number of terminals; or, case 2, the second information is used to indicate the number of times the context of the multicast session (or the transmission channel of the multicast session) is used; or, case 3, the second information is used to indicate the number of times the multicast session context is used Identifies the associated access network device. Case 1, case 2 and case 3 are introduced below respectively.

Case 1: The second information may be used to indicate the number of inactive terminals associated with the first access network device in the multicast group.

In one possible design, the second information includes a numerical value. Initially, the value is the initial value, such as 0, or it can be other numbers or values (such as FF, 00, -1 or 1, etc.) without limitation. When the number of inactive terminals associated with the first access network device in the multicast group increases, this value also increases. For example, when the number of terminals increases by 1, this value also increases by 1; when the number of terminals in the multicast group increases by 1; When the number of inactive terminals associated with the first access network device in the broadcast group decreases, this value also decreases. For example, when the number of terminals decreases by one, this value also decreases by one.

In another possible design, the second information is status information, that is, the second information can correspond to multiple statuses. Initially, the state corresponding to the second information is the initial state. When the number of inactive terminals associated with the first access network device in the multicast group increases, the first access network device updates the second information. For example, when the number of terminals increases by one, the second The state corresponding to the information changes from the current state to the next state of the current state; when the number of inactive terminals associated with the first access network device in the multicast group decreases, the first access network device updates the second Information, for example, when the number of terminals decreases by one, the state corresponding to the second information changes from the current state to the state previous to the current state.

It can be understood that when the value included in the second information is an initial value or the state corresponding to the second information is an initial state, it can mean that the number of inactive terminals associated with the first access network device in the multicast group is 0 or 1, no limit.

It can be understood that when the number of inactive terminals associated with the first access network device in the multicast group is 0, the first access network device may determine that there is no connection with the first access device in the multicast group. An inactive terminal associated with a network device. That is to say, when the number of terminals indicated by the second information is zero, the first access network device determines that there is no association with the first access network device in the multicast group. of inactive terminals.

In one possible implementation, the first access network device receives the first notification information from the second access network device, and updates the second information according to the first notification information. The first notification information may be used to notify a terminal in the multicast group to switch to the inactive state, or the first notification information may be used to notify the second access network device in the multicast group to switch to the inactive state. the number of terminals, or the first notification information is used to notify one terminal in the multicast group to be switched to an inactive state by the second access network device.

It can be understood that when the terminal in the multicast group switches to the inactive state and the access network equipment in the RNA of the terminal includes the first access network equipment, the second access network device provides the first access network device with the first access network device. The network access device sends the first notification information. Correspondingly, after receiving the first notification information, the first access network device may determine that the terminal in the multicast group is switched to the inactive state under the second access network device, and the RNA of the terminal includes the first access All or part of the coverage area of network equipment. At this time, the first access network device updates the second information.

Optionally, in order to reduce signaling overhead, the second access network device switches the terminal in the multicast group to an inactive state, and the access network device in the RNA of the terminal includes the first access network device, and If the second access network device has not sent the first notification information before, the second access network device sends the first notification information to the first access network device.

It can be understood that if the first notification information is used to notify a terminal in the multicast group to switch to an inactive state, the first access network device increases the number indicated by the second information by 1. Alternatively, if the first notification information is used to notify that the number of terminals in the multicast group that are switched to the inactive state by the second access network device is n, the first access network device adds n to the number indicated by the second information. .

Optionally, the first notification information is included in a message requesting the establishment of a context of a multicast session, or in a message requesting the establishment of a transmission channel for transmitting multicast data, or in an MBS session transmission request.

In one possible implementation manner, the first access network device receives the second notification information from the second access network device, and updates the second information according to the second notification information. The second notification information may be used to notify a terminal in the multicast group to leave the inactive state (for example, enter the connected state, or enter the idle state), or the second notification information may be used to notify a terminal in the multicast group to leave the inactive state. The number of terminals leaving the inactive state under the second access network device. In the case where the second notification information can be used to notify a terminal in the multicast group to leave the inactive state, the terminal can leave the inactive state on the second access network device, or can also leave the inactive state on other access network devices. Leave the inactive state. The terminal can change from the inactive state to the connected state, or from the inactive state to the idle state, which is not limited here.

It can be understood that the second access network device is used when the terminal in the multicast group leaves the inactive state, and the access network device in the RNA of the terminal during the inactive state includes the first access network device. , sending the second notification information to the first access network device.

Optionally, in order to reduce signaling overhead, the terminal in the multicast group of the second access network device leaves the inactive state, and the multicast group is switched to the inactive state by the second access network device and is currently still in the inactive state. If the access network equipment in the RNA of any terminal in the inactive state does not include the first access network equipment, the second notification information is sent to the first access network equipment.

It can be understood that the second access network device receives the seventh notification information from the fourth access network device, and the seventh notification information is used to notify those in the multicast group that are switched to the inactive state by the second access network device. When the fourth access network device returns to the connected state or the seventh notification information is used to notify the second access network device to send the context of the terminal to the fourth access network device, the second access network device sends the terminal to the fourth access network device. The first access network device sends the second notification information. At this time, the second notification information is used to notify a terminal in the multicast group to leave the inactive state. It should be understood that the terminal leaves the inactive state under the fourth access network device.

It can be understood that if the second notification information is used to notify a terminal in the multicast group to leave the inactive state, the first access network device decreases the number indicated by the second information by 1. Alternatively, if the second notification information is used to notify the number of terminals in the multicast group that are in the inactive state after the second access network device leaves, the first access network device adds the number indicated by the second information. n.

Optionally, the second notification information is included in a message requesting release of the context of the multicast session, or included in a message requesting release of a transmission channel used for transmitting multicast data, or included in an MBS session update request message.

Case 2: The second information is used to indicate the number of times the context of the multicast session (or the transmission channel of the multicast session) is used.

In one possible design, the second information includes a numerical value. Initially, the value is the initial value, such as 0, or it can be other numbers or values (such as FF, 00, -1 or 1, etc.) without limitation. When the number of uses of the context of the multicast session (or the transmission channel of the multicast session) increases, this value also increases; when the number of uses of the context of the multicast session (or the transmission channel of the multicast session) decreases, this value also increases. reduce.

In another possible design, the second information is status information, that is, the second information can correspond to multiple statuses. Initially, the state corresponding to the second information is the initial state. When the number of uses of a multicast session's context (or a multicast session's transport channel) increases, The first access network device updates the second information. For example, when the number of uses is increased by 1, the state corresponding to the second information changes from the current state to the next state of the current state; when the context of the multicast session (or multicast session When the number of uses of the transmission channel) decreases, the first access network device updates the second information. For example, when the number of uses decreases by 1, the state corresponding to the second information changes from the current state to the state previous to the current state.

It can be understood that when the value included in the second information is an initial value or the state corresponding to the second information is an initial state, it can mean that the number of uses of the context of the multicast session (or the transmission channel of the multicast session) is 0 or 1, No restrictions.

It can be understood that when the context of the multicast session (or the transmission channel of the multicast session) is not used, the first access network device may determine that there is no non-user associated with the first access network device in the multicast group. Active terminal. That is to say, when the number of times indicated by the second information is zero, the first access network device determines that there is no inactive terminal associated with the first access network device in the multicast group.

In the embodiment of the present application, the number of times the context of the multicast session (or the transmission channel of the multicast session) is used can be understood as the number of times the context of the multicast session (or the transmission channel of the multicast session) is established. For example, if other access network equipment requests the first access network equipment to establish the context of the multicast session corresponding to the multicast group (or the transmission channel of the multicast session corresponding to the multicast group), then the number of times indicated by the second information Increase the number of times indicated by the second information if other access network devices request the first access network device to release the context of the multicast session corresponding to the multicast group (or the transmission channel of the multicast session corresponding to the multicast group) reduce.

For example, if the current indication number of the second information is 1 and the access network device 2 requests the first access network device to establish the context of the multicast session corresponding to the multicast group, then the number of times indicated by the second information is increased by 1 and becomes 2. Then, the access network device 3 requests the first access network device to release the context of the multicast session corresponding to the multicast group, and then the number of times indicated by the second information is reduced by 1 and becomes 1.

In one possible implementation, the first access network device receives the first notification information from the second access network device, and updates the second information according to the first notification information. The first notification information may be used to notify a terminal in the multicast group to switch to the inactive state, or the first notification information may be used to notify the second access network device in the multicast group to switch to the inactive state. The number of terminals. This process is similar to that in case 1, and you can refer to the corresponding description in case 1. The difference is that in case 2, the second information indicates the number of times the context of the multicast session (or the transmission channel of the multicast session) is used.

In one possible implementation manner, the first access network device receives the second notification information from the second access network device, and updates the second information according to the second notification information. The second notification information may be used to notify a terminal in the multicast group to leave the inactive state, or the second notification information may be used to notify the multicast group to leave the inactive state under the second access network device. The number of terminals. This process is similar to that in case 1, and you can refer to the corresponding description in case 1. The difference is that in case 2, the second information indicates the number of times the context of the multicast session (or the transmission channel of the multicast session) is used.

Case 3: The second information is used to indicate the access network device associated with the identifier of the multicast group.

In this embodiment of the present application, the access network equipment associated with the identification of the multicast group includes the access network equipment that switches the terminals in the multicast group to the inactive state, and the access network equipment in the multicast group that is in the inactive state. Access network equipment within the terminal's RNA.

In a possible design, the second information includes the identifier of the access network device associated with the identifier of the multicast group. Initially, the second information is empty, that is, the second information does not include the identifier of the access network device associated with the identifier of the multicast group. It can be understood that this application does not limit the form of the second information. For example, the second information may include a list as shown in Table 1 (there may also be lists in other forms), or the second information may include key-value pairs. be restricted.

Table 1

In Table 1, the access network equipment associated with TMGI 1 includes access network equipment 1, access network equipment 2 and access network equipment 3. The access network equipment associated with TMGI2 includes access network equipment 2 and access network equipment 4. The access network equipment associated with TMGI 3 includes access network equipment 3, access network equipment 5 and access network equipment 6.

In one possible implementation, the first access network device receives the first notification information from the second access network device, and updates the second information according to the first notification information. The first notification information may be used to notify that there is a terminal in the multicast group that is switched to an inactive state by the second access network device.

It can be understood that when the terminal in the multicast group switches to the inactive state and the access network equipment in the RNA of the terminal includes the first access network equipment, the second access network device provides the first access network device with the first access network device. The network access device sends the first notification information. Correspondingly, after receiving the first notification information, the first access network device may determine that the terminal in the multicast group is switched to the inactive state under the second access network device, and the RNA of the terminal includes the first access All or part of the coverage area of network equipment. At this time, the first access network device updates the second information. For example, the identifier of the first access network device and the identifier of the second access network device are added to the second information.

In one possible implementation manner, the first access network device receives the second notification information from the second access network device, and updates the second information according to the second notification information. The second notification information may be used to notify that there is no terminal in the multicast group that is switched to the inactive state by the second access network device.

It can be understood that the second access network device does not have a terminal in the multicast group that is switched to the inactive state by the second access network device, and the access network in the RNA of the terminal when in the inactive state If the device includes a first access network device, the second notification information is sent to the first access network device. Alternatively, the terminal in which the second access network device is switched to the inactive state in the multicast group by the second access network device leaves the inactive state, and is released to the inactive state in the multicast group by the second access network device. state, and if the access network equipment in the RNA of any terminal that is currently in the inactive state does not include the first access network equipment, the second notification information is sent to the first access network equipment. Correspondingly, after receiving the second notification information, the first access network device may determine that the terminal in the multicast group is switched to the inactive state by the second access network device. At this time, the first access network device updates the second information. For example, the identifier of the first access network device is deleted from the second information.

It can be understood that if the access network device associated with the multicast group identifier does not include the first access network device, the first access network device determines that there is no connection with the first access network device in the multicast group. The associated inactive terminal.

The embodiment of the present application does not limit the execution order of S301A and S301B. For example, S301A can be executed first and then S301B, S301B can be executed first and then S301A, or S301A and S301B can be executed simultaneously.

It can be understood that the actions of the first access network device in the above S301A-S301B can be executed by the processor 201 in the communication device 20 shown in Figure 2 by calling the application code stored in the memory 203. The embodiment of the present application is This does not impose any restrictions.

It can be understood that any notification information mentioned in the embodiments of this application (for example, the first notification information, the second notification information or the third notification information, etc.) can be replaced by update information. For example, the first notification information can be replaced by Be the first to update information.

Optionally, as shown in Figure 3B, in another implementation scenario of the above embodiment, if the first access network device determines that the terminal in the multicast group has switched to the inactive state, the above method also includes the following S300a -One or more steps in S300d, as follows:

S300a: The first access network device sends third notification information to at least one access network device.

Correspondingly, at least one access network device receives the third notification information from the first access network device.

It can be understood that if the first terminal in the multicast group switches to an inactive state, the first access network device sends the third notification information to at least one access network device.

In a possible implementation manner, the third notification information is used to notify a terminal in the multicast group to switch to an inactive state. In this case, the terminal may be switched to the inactive state by the first access network device, or may not be switched to the inactive state by the first access network device. All or part of the differences in the coverage area of at least one access network device are included in the RNA of the one terminal.

In another possible implementation manner, the third notification information is used to notify that there is a terminal in the multicast group that is switched to an inactive state by the first access network device. In this case, the terminal is switched to the inactive state by the first access network device. All or part of the differences in the coverage area of at least one access network device are included in the RNA of the terminal.

For example, the first access network device switches the first terminal in the multicast group to an inactive state, and sends the third notification information to the access network device in the RNA of the first terminal.

Optionally, in order to reduce signaling overhead, when the first access network device has not sent the third notification information to at least one access network device, the first access network device sends the third notification information to at least one access network device. Three notification messages.

The above-mentioned second access network device may be included in at least one access network device, or may not be included in at least one access network device, without limitation.

Optionally, the third communication information is included in a message requesting the establishment of a context of a multicast session, or in a message requesting the establishment of a transmission channel for transmitting multicast data, or in an MBS session transmission request.

It can be understood that after at least one access network device receives the third notification information, it may update the second information maintained by at least one access network device. The process of updating the second information by at least one access network device is similar to the process of updating the second information by the first access network device, and will not be described again.

Optionally, if the first terminal returns to the connected state from the inactive state under the first access network device, or the first terminal leaves the inactive state under the first access network device, for example, the first access network When the device receives the RRC connection recovery request from the first terminal, the method shown in Figure 3B also includes the following steps:

S300b: The first access network device sends fourth notification information to at least one access network device.

Correspondingly, at least one access network device receives the fourth notification information from the first access network device.

The fourth notification information may be used to notify a terminal in the multicast group to leave the inactive state.

In one possible implementation, all or part of the coverage area of at least one access network device is not included in the multicast group and is switched to an inactive state by the first access network device, and is currently still inactive. In the case of RNA of any terminal in the state, the first access network device sends fourth notification information to at least one access network device.

Optionally, the fourth notification information is included in a message requesting release of the context of the multicast session, or included in a message requesting release of a transmission channel used for transmitting multicast data.

It can be understood that after at least one access network device receives the fourth notification information, it may update the second information maintained by at least one access network device. The process of updating the second information by at least one access network device is similar to the process of updating the second information by the first access network device, and will not be described again.

Optionally, if the first terminal leaves the active state from the third access network device, the method shown in Figure 3B further includes the following steps:

S300c: The first access network device sends the fifth notification information to the access network device other than the third access network device among the at least one access network device.

Correspondingly, the access network devices other than the third access network device among the at least one access network device receive the fifth notification information from the first access network device.

The fifth notification information may be used to notify a terminal in the multicast group to leave the inactive state.

In one possible implementation, after receiving a message from a third access network device for requesting the context of the first terminal, the first access network device removes the third access network device from at least one access network device. The access network equipment other than the access network device sends the fifth notification information.

Optionally, in order to reduce signaling overhead, after the first access network device receives a message from the third access network device for requesting the context of the first terminal, it is accessed by the first terminal in the multicast group. When the device switches to the inactive state, and the RNA of each terminal that is currently in the inactive state does not include the coverage area of at least one access network device other than the third access network device. , sending the fifth notification information to the access network device other than the third access network device among the at least one access network device.

Optionally, the fifth notification information is included in a message requesting release of the context of the multicast session, or included in a message requesting release of a transmission channel used for transmitting multicast data.

It can be understood that after receiving the fifth notification information, the access network devices in the at least one access network device except the third access network device may update the at least one access network device except the third access network device. Second information maintained by external access network equipment. The process of updating the second information by the access network devices other than the third access network device among the at least one access network device is similar to the process of updating the second information by the first access network device, and will not be described again.

Optionally, if the last terminal among the terminals in the multicast group that was switched to the inactive state by the first access network device leaves the inactive state, the method shown in Figure 3B also includes the following steps:

S300d: The first access network device sends sixth notification information to at least one access network device. Correspondingly, at least one access network device receives the sixth notification information from the first access network device.

The sixth notification information may be used to notify the number of terminals in the multicast group that are switched to the inactive state by the first access network device. The quantity is 0, or the sixth notification information may be used to notify that there is no terminal in the multicast group that is switched to the inactive state by the first access network device.

Optionally, the sixth notification information is included in a message requesting release of the context of the multicast session, or included in a message requesting release of a transmission channel used for transmitting multicast data.

It can be understood that after at least one access network device receives the sixth notification information, it may update the second information maintained by at least one access network device. The process of updating the second information by at least one access network device is similar to the process of updating the second information by the first access network device, and will not be described again.

It can be understood that the action of any access network device in the above-mentioned S300a-S300d can be executed by the processor 201 in the communication device 20 shown in Figure 2 by calling the application code stored in the memory 203. The embodiment of the present application is This does not impose any restrictions.

In order to facilitate understanding of the method provided by the embodiment of the present application, the method provided by the embodiment of the present application will be described below with reference to the communication system 10 shown in FIG. 1 . It should be understood that the introduction of each feature and the introduction of each step in the method shown in Figures 3A and 3B are applicable to the method shown in Figure 4 below. Similarly, the introduction of each feature and each step in the method shown in Figure 4 is also applicable to the method shown in Figure 3A and Figure 3B and is not limited.

As shown in Figure 4, another multicast communication method is provided by the embodiment of the present application. The multicast communication method may include the following steps:

S401: The terminal 103 joins the multicast group through the access network device 101.

For example, the terminal 103 joins the multicast group through the process shown in S11-S13 above.

Optionally, after S401, for the above situation A (the first information can be used to indicate the number of terminals in the multicast group that are connected to the access network device 101 and are in the connected state), the access network device 101 will The number indicated by the first information in the access network device 101 is increased by one. For the above situation B (the first information can be used to indicate the number of contexts of terminals in the multicast group stored in the access network device 101), the access network device 101 indicates the first information in the access network device 101 Add 1 to the quantity. For the above situation C (the first information can be used to indicate whether the access network device 101 stores the context of the terminal in the multicast group), the access network device 101 can query that it has stored the context of the terminal 103 in the multicast group. The first information indicates that the access network device 101 stores the context of the terminal in the multicast group. For the above situation D (the first information is used to indicate the terminal in the connected state associated with the identification of the multicast group), the access network device 101 adds the identification of the terminal 103 to the first information.

S402: The access network device 101 sends an RRC connection release message to the terminal 103. Correspondingly, the terminal 103 receives the RRC connection release message from the access network device.

For example, after determining that the terminal 103 enters the inactive state according to the auxiliary information provided by the core network, the access network device 101 sends an RRC connection release message to the terminal 103. The auxiliary information may include at least one of the following: a registration area (RA) of the terminal 103, a discontinuous reception (DRX) parameter of the terminal 103, and an extended idle mode DRX parameter (extended idle mode) of the terminal 103. DRX values) or periodic registration update timer (Periodic Registration Update timer).

In one possible implementation, the RRC connection release message may include the I-RNTI of the terminal 103 and the RNA information of the terminal 103. In the method shown in Figure 4, the RNA information includes the identity of the cell of the access network device 102 and the identity of the cell of the access network device 105. That is, the RNA of the terminal 103 includes the cell and access number of the access network device 102. Network equipment 105 of the cell.

It is understandable that S402 can also be executed after S403.

Optionally, after S402, for the above situation A, the access network device 101 decrements the number of first information indications in the access network device 101 by 1. For the above situation B, the access network device 101 does not modify the first information. For the above situation C, the access network device 101 can query that it has stored the context of the terminal 103 in the multicast group. For the above situation D, the access network device 101 deletes the identification of the terminal 103 from the first information.

S403: The access network device 101 sends the first notification information to the access network device 102 and the access network device 105.

Correspondingly, the access network device 102 and the access network device 105 receive the first notification information from the access network device 101.

It can be understood that, in addition to the introduction of the first notification information in the method shown in Figure 3B, optionally, the first notification information also includes at least one of the following: an identifier of the multicast group (such as TMGI), area information , the I-RNTI of the terminal 103 or the context of the terminal 103. The context of the terminal 103 may include information about the PDU session of the terminal 103 . The information of the PDU session of the terminal 103 may include the PDU session identifier of the terminal 103, the QoS information of the PDU session of the terminal 103 (for example, 5QI, ARP wait).

One possible design is that if the terminal 103 joins a multicast group, the first notification information may include the identifier of a multicast group; if the terminal 103 joins multiple multicast groups, the first notification information may Contains the identifiers of multiple multicast groups.

In one possible design, the area information is used to indicate the RNA of the terminal 103, or to indicate the area of the access network device 102 included in the RNA of the terminal 103, or to indicate the area of the access network device 105 included in the RNA of the terminal 103. .

For example, the area information included in the first notification information sent to the access network device 102 includes RNA information, or includes the identification of the cell of the access network device 102 included in the RNA of the terminal 103. The area information included in the first notification information sent to the access network device 105 includes RNA information, or includes the identification of the cell of the access network device 105 included in the RNA of the terminal 103.

It can be understood that the first notification information may trigger the access network device 102 or the access network device 105 to establish a multicast session context for the multicast group. If the access network device 102 does not establish the context of the multicast session for the multicast group, that is, the access network device 102 does not establish the context of the multicast session of the access network device 102, the access network device 102 establishes the context of the multicast session of the access network device 102. The context of the multicast session. Similarly, if the access network device 105 does not establish the context of the multicast session for the multicast group, that is, the access network device 105 does not establish the context of the multicast session of the access network device 105, the access network device 105 establishes access. The context of the multicast session of the network device 105.

In one possible implementation, if the access network device 101 does not trigger the access network device 102 to establish the context of the multicast session of the access network device 102, the access network device 101 sends a first notification to the access network device 102. information. Similarly, if the access network device 101 does not trigger the access network device 105 to establish the context of the multicast session of the access network device 105, the access network device 101 sends the first notification information to the access network device 105.

Optionally, after S402 or S403, the access network device 101 updates the second information in the access network device 101.

For example, for the above situation 1 (the second information can be used to indicate the number of inactive terminals associated with the first access network device in the multicast group), the access network device 101 adds the number indicated by the second information. 1. For case 2 (the second information is used to indicate the number of times the context of the multicast session (or the transmission channel of the multicast session) is used), the access network device 101 adds 1 to the number of times indicated by the second information. For case 3 (the second information is used to indicate the access network device associated with the identifier of the multicast group), the access network device 101 adds its own identifier to the second information.

Optionally, after S403, the terminal 103 may receive multicast data corresponding to the multicast group in the RNA of the terminal 103.

S404: The access network device 102 updates the second information in the access network device 102 according to the first notification information, and the access network device 105 updates the second information in the access network device 105 according to the first notification information.

The following takes the access network device 102 to update the second information according to the first notification information as an example. The process of the access network device 105 updating the second information according to the first notification information is the same as the access network device 102 updating the second information according to the first notification information. The process of the second information is similar and will not be described again.

As an example, if the access network device 102 does not establish the context of the multicast session of the access network device 102, for case 1, the access network device 102 sets the second information as an initial value or an initial state, or the access network device 102 The device 102 sets the second information as an initial value or an initial state, and adds 1 to the number of terminals indicated by the second information. For case 2, the access network device 102 sets the second information as an initial value or initial state, or the access network device 102 sets the second information as an initial value or initial state, and adds 1 to the number of times indicated by the second information. For case 3, the access network device 102 adds the identification of the access network device 102 to the second information.

As another example, if the access network device 102 establishes the context of the multicast session of the access network device 102, for case 1, the access network device 102 increases the number of terminals indicated by the second information by 1. For case 2, the access network device 102 adds 1 to the number of times indicated by the second information. For case 3, the access network device 102 may determine whether the access network device associated with the multicast group includes the identification of the access network device 102. If not, the access network device 102 adds its own identification to the second information, If included, the access network device 102 may perform no operation; or, the access network device 102 directly adds its own identifier to the second information.

Optionally, the access network device 102 and/or the access network device 105 sends a response message to the access network device 101 to indicate to the access network device 101 whether the context of the multicast session is successfully established.

Optionally, if the context establishment of the multicast session fails, the response message may include the identification of the multicast session that failed to be established and its corresponding resource information (for example, QoS flow information, etc.). Optionally, after receiving the response message, the access network device 101 sends indication information to the terminal 103. The indication information includes the identification of the multicast session that failed to be established and the information of its corresponding resources. In this way, after receiving the indication information, the terminal 103 can determine that the multicast data cannot be received within the coverage area of the access network device 102 and/or the access network device 105 .

The following describes the situation in which the access network device updates the second information in two situations. In the first case, the terminal 103 restores the connection state under the access network device 101. For the specific process, please refer to S405A-S407A. In the second case, the terminal 103 restores the connection state under the access network device 102. For the specific process, please refer to S405B-S407B.

First, let’s introduce the first case:

S405A: The terminal 103 sends an RRC connection recovery request message to the access network device 101.

Correspondingly, the access network device 101 receives the RRC connection recovery request message from the terminal 103.

The RRC connection recovery request message may include the I-RNTI of the terminal 103.

It can be understood that after S405A, the terminal 103 enters the connected state.

Optionally, after S405A, for the above situation A, the access network device 101 increases the number indicated by the first information in the access network device 101 by 1. For the above situation B, the access network device 101 does not modify the first information. For the above situation C, the access network device 101 can query that it has stored the context of the terminal 103 in the multicast group. For the above situation D, the access network device 101 adds the identification of the terminal 103 to the first information.

Optionally, after S405A, for the above situation 1, the access network device 101 decrements the number of second information indications by 1. For case 2, the access network device 101 decrements the number of times indicated by the second information by 1. For case 3, the access network device 101 can delete its own identity from the second information.

S406A: The access network device 101 sends the second notification information to the access network device 102 and the access network device 105.

Correspondingly, the access network device 102 and the access network device 105 receive the second notification information from the access network device 101.

One possible implementation is that in the multicast group, the access network equipment in the RNA of any terminal that is switched to the inactive state by the access network device 101 and is currently in the inactive state does not include access network equipment. 102, the access network device 101 sends the second notification information to the access network device 102. Similarly, in the case where the access network device 101 in the multicast group is switched to the inactive state and the access network devices in the RNA of any terminal that is currently in the inactive state do not include the access network device 105 , the access network device 101 sends the second notification information to the access network device 105.

Exemplarily, the multicast group includes terminal 103 and terminal 104. Terminal 103 returns to the connected state under the access network device 101. Terminal 104 is switched to the inactive state by the access network device 101 and is currently still inactive. For example, if the access network equipment in the RNA of the terminal 104 includes the access network equipment 102 but does not include the access network equipment 105, the access network equipment 101 sends the second notification information to the access network equipment 105, but does not Send the second notification information to the access network device 102. If the access network equipment in the RNA of the terminal 104 does not include the access network equipment 102 and the access network equipment 105, the access network equipment 101 sends the second notification information to the access network equipment 102 and the access network equipment 105. If the access network equipment in the RNA of the terminal 104 includes the access network equipment 102 and the access network equipment 105, the access network equipment 101 does not send the second notification information to the access network equipment 102 and the access network equipment 105.

In one possible implementation, the access network device 101 obtains the context of the terminal 103 according to the I-RNTI value provided by the terminal 103 (for example, the context of the terminal stored locally and indexed by the I-RNTI). The context of terminal 103 includes RNA information of terminal 103 . The access network device 101 sends the second notification information to the corresponding access network device (in this example, the access network device 102 and the access network device 105) according to the RNA information of the terminal 103. Specifically, the access network device 101 sends the second notification information to the corresponding access network device (in this example, the access network device 102 and the access network device 105) according to the RNA information of the terminal 103, which may be the access network device. 101 parses out the corresponding base station according to the cell information (such as NR Cell ID) contained in the RNA information (can be parsed according to the preconfiguration, or can be parsed according to some fields of the cell identification), and sends the second notification information to the corresponding base station.

Optionally, the second notification information is included in the MBS session update request message.

S407A: The access network device 102 and the access network device 105 update the second information according to the second notification information.

It can be understood that for the above situation 1, the access network device 102 decreases the number of the second information indication of the access network device 102 by 1. For case 2, the access network device 102 decrements the number of times indicated by the second information of the access network device 102 by 1. For case 3, the access network device 102 may delete its own identity from the second information.

It can be understood that for the above situation 1, the access network device 105 decreases the number of the second information indication of the access network device 105 by 1. For case 2, the access network device 105 decrements the number of times indicated by the second information of the access network device 105 by 1. For case 3, the access network device 105 can delete its own identity from the second information.

The second case is introduced below:

S405B: The terminal 103 sends an RRC connection recovery request message to the access network device 102.

Correspondingly, the access network device 102 receives the RRC connection recovery request message from the terminal 103.

It can be understood that after S405B, the terminal 103 enters the connection state.

Optionally, after S405B, for the above situation A, the access network device 102 increases the number indicated by the first information in the access network device 102 by 1. For the above situation B, the access network device 102 does not modify the first information. For the above situation C, the access network device 102 queries that it has not stored the context of the terminal 103 in the multicast group, and the first information indicates that the access network device has not stored the context of the terminal in the multicast group. For the above situation D, the access network device 102 adds the identification of the terminal 103 to the first information.

Optionally, after S405B, for the above situation 1, the access network device 102 decrements the number of second information indications by 1. For case 2, the access network device 102 decrements the number of times indicated by the second information by 1. For case 3, the access network device 102 may delete its own identity from the second information.

S406B: The access network device 102 sends the second notification information to the access network device 101 and the access network device 105.

Correspondingly, the access network device 101 and the access network device 105 receive the second notification information from the access network device 102.

One possible implementation is that the access network device in the RNA of any terminal that is switched to the inactive state by the access network device 102 in the multicast group and is currently in the inactive state does not include the access network. In the case of device 101, the access network device 102 sends the second notification information to the access network device 101. Similarly, in the multicast group, the access network device in the RNA of any terminal in the inactive state that is switched to the inactive state by the access network device 102 and is currently in the inactive state does not include the access network device. In the case of the access network device 105, the access network device 102 sends the second notification information to the access network device 105.

In one possible implementation manner, the access network device 102 sends a context acquisition request message of the terminal 103 to the access network device 101. The context acquisition request message of the terminal 103 may include the I-RNTI of the terminal 103. Optionally, the context acquisition request message of the terminal 103 also includes the identification of the multicast group. After receiving the context acquisition request message of the terminal 103, the access network device 101 sends the context of the terminal 103 to the access network device 102. Subsequently, the access network device 101 deletes the context of the terminal 103.

Optionally, for the above situation B, after deleting the context of the terminal 103, the access network device 101 decrements the number indicated by the first information by 1. For the above situation C, after the access network device 101 deletes the context of the terminal 103, the access network device 101 cannot query the context of the terminal 103. If the access network device 101 does not store the context of other terminals in the multicast group, , then the first information indicates that the context of the terminal in the multicast group is not stored in the access network device 101.

It can be understood that in S406B, the access network device 102 may not send the second notification message to the access network device 105. Instead, after receiving the context acquisition request message of the terminal 103, the access network device 101 sends the second notification message to the access network device 103. Device 105 sends a message. This message may notify the access network device 105 that a terminal in the multicast group leaves the inactive state.

For example, this message is an MBS session update request message. The MBS session update request message may include at least one of the following: RNA information, an identification of the multicast group, or the I-RNTI of the terminal 103.

S407B: The access network device 101 and the access network device 105 update the second information according to the second notification information.

It can be understood that for the above situation 1, the access network device 101 decreases the number of the second information indication of the access network device 101 by 1. For case 2, the access network device 101 decrements the number of times indicated by the second information of the access network device 101 by 1. For case 3, the access network device 101 can delete its own identity from the second information.

S408: The access network device 101 determines whether to release the context of the multicast session of the access network device 101 based on the first information and the second information of the access network device 101.

One possible implementation is that when the last terminal connected to the access network device 101 in the multicast group leaves the access network device 101, and there is no inactive state associated with the access network device 101 in the multicast group When the terminal is terminated, the access network device 101 releases the context of the multicast session of the access network device 101; otherwise, the access network device 101 does not release the context of the multicast session.

It can be understood that if the access network device 101 releases the context of the multicast session of the access network device 101, the access network device 101 sends a multicast session leave message to the second network device, and/or the access network device 101 sends a multicast session leave message to the second network device. The first network device sends a request message.

S409: The access network device 102 determines whether to release the context of the multicast session of the access network device 102 based on the first information and the second information of the access network device 102.

S410: The access network device 105 determines whether to release the context of the multicast session of the access network device 105 based on the first information and the second information of the access network device 105.

It can be understood that the process of S409-S410 is similar to the process of S408, and reference can be made to the corresponding description in S408, which will not be described again.

Among them, the actions of the access network device 101, the access network device 102 or the access network device 105 in the above-mentioned S401-S410 can be performed by the processor 201 in the communication device 20 shown in Figure 2 to call the application program stored in the memory 203. Code is executed, and the embodiments of this application do not impose any restrictions on this.

Based on the method shown in Figure 4, the access network device 101, the access network device 102 or the access network device 103 can leave the access network device in the multicast group in which the last terminal connected to the access network device , and if there is no inactive terminal associated with the access network device in the multicast group, release the context of the multicast session. In this way, it can not only ensure that terminals in the multicast group receive multicast data, but also enable the access network device to release the context of the multicast session corresponding to the multicast group in a timely manner to save resources.

As shown in Figure 5, another multicast communication method is provided by an embodiment of the present application. The multicast communication method may include the following steps:

S501: The second access network device establishes the context of the multicast session of the second access network device.

The second access network device may be any access network device in the communication system 10 shown in Figure 1, for example, the access network device 101, the access network device 102 or the access network device 105 in Figure 1 . Multicast sessions can be used to transmit multicast data corresponding to multicast groups.

In one possible implementation manner, the second access network device establishes the context of the multicast session of the second access network device through the process shown in S11-S13. That is: the terminal joins the multicast group through the second access network device.

In another possible implementation, the first access network device sends the second message to the second access network device. The second message may be used to request the establishment of a context for a multicast session of the second access network device. After receiving the second message, the second access network device establishes the context of the multicast session of the second access network device.

The first access network device is an access network device different from the second access network device in the communication system 10 shown in FIG. 1 . For example, if the second access network device is the access network device 101 in Figure 1, then the first access network device is the access network device 102 or the access network device 105 in Figure 1.

For example, if the terminal joins the multicast group through the first access network device, enters the inactive state under the first access network device, and the access network device in the terminal's RNA includes the second access network device, Then, the first access network device sends the second message to the second access network device to trigger the second access network device to establish the context of the multicast session of the second access network device.

S502: The first access network device sends the first message to the second access network device.

Correspondingly, the second access network device receives the first message from the first access network device.

The first message may be used to indicate releasing the context of the multicast session.

One possible implementation manner is that a terminal in the multicast group leaves the inactive state under an access network device other than the second access network device, and the first access network device sends the second access network device to the second access network device. A message.

For example, if a terminal in the multicast group leaves the inactive state under the first access network device, the first access network device sends the first message to the second access network device.

For another example, if the first access network device receives the third message from the third access network device, the third message is used to indicate that the terminal in the multicast group that was switched to the inactive state by the first access network device is in the multicast group. The third access network device returns to the connected state, or the third message is used to request the first access network device to send the context of the terminal to the third access network device, then the first access network device sends the context to the second access network device. The device sends the first message.

One possible implementation is that if the RNA of each terminal in the multicast group that is switched to the inactive state by the first access network device and is still in the inactive state does not include the coverage area of the second access network device , the first access network device sends the first message to the second access network device.

S503: The second access network device releases the context of the multicast session of the second access network device.

In a possible implementation, the second access network device determines that the last terminal connected to the second access network device in the multicast group leaves the second access network device, and there is no connection with the second access network device in the multicast group. For an inactive terminal associated with the access network device, the second access network device releases the context of the multicast session of the second access network device. Specifically, reference may be made to the corresponding description in the method shown in FIG. 3A, FIG. 3B, or FIG. 4, which will not be described again here.

Among them, the actions of the first access network device or the second access network device in the above-mentioned S501-S503 can be executed by the processor 201 in the communication device 20 shown in Figure 2 by calling the application program code stored in the memory 203, The embodiments of this application do not do anything about this What restrictions.

Based on the method shown in Figure 5, after the second access network device establishes the context of the multicast session of the second access network device, it may receive a message from the first access network device indicating to release the context of the multicast session. message, according to which the context of the multicast session is promptly released.

It can be understood that in the above embodiments, the methods and/or steps implemented by the access network equipment can also be implemented by components (such as chips or circuits) that can be used in the access network equipment.

The above mainly introduces the solution provided by the embodiment of the present application from the perspective of interaction between various network elements. Correspondingly, embodiments of the present application also provide a communication device. The communication device may be the first access network device in the above method embodiment, or a device including the above first access network device, or may be used for the first access network device. A component of the network access equipment; alternatively, the communication device may be the second access network equipment in the above method embodiment, or a device including the above second access network equipment, or may be a component that can be used in the second access network equipment. . It can be understood that, in order to implement the above functions, the above-mentioned first access network device or second access network device includes hardware structures and/or software modules corresponding to each function. Persons skilled in the art should easily realize that, with the units and algorithm operations of each example described in conjunction with the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed by hardware or computer software driving the hardware depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each specific application, but such implementations should not be considered beyond the scope of this application.

It should be understood that the above only takes access network equipment as an example to describe the interaction between various network elements. In fact, the processing performed by the above access network equipment is not limited to being performed by only a single network element. For example, the processing performed by the access network device may be performed by at least one of a central unit (central unit, CU), a distributed unit (DU), and a remote unit (RU), respectively.

Embodiments of the present application can divide the first access network device or the second access network device into functional modules according to the above method examples. For example, each functional module can be divided corresponding to each function, or two or more Functions are integrated in a processing module. The above integrated modules can be implemented in the form of hardware or software function modules. It can be understood that the division of modules in the embodiment of the present application is schematic and is only a logical function division. In actual implementation, there may be other division methods.

For example, when each functional module is divided into integrated modules, FIG. 6 shows a schematic structural diagram of a communication device 60 . The communication device 60 includes a processing module 601. Optionally, the communication device also includes a transceiver module 602. The processing module 601, which may also be called a processing unit, is used to perform operations other than sending and receiving operations, and may be, for example, a processing circuit or a processor. The transceiver module 602, which may also be called a transceiver unit, is used to perform transceiver operations, and may be, for example, a transceiver circuit, transceiver, transceiver, or communication interface.

In some embodiments, the communication device 60 may also include a storage module (not shown in FIG. 6) for storing program instructions and data.

Illustratively, the communication device 60 is used to implement the functions of an access network device (such as a first access network device, the access network device 101, the access network device 102 or the access network device 105). The communication device 60 is, for example, the first access network device described in the embodiment shown in FIG. 3A or FIG. 3B, the access network device 101, the access network device 102 or the access network device described in the embodiment shown in FIG. 4. Device 105.

Among them, the processing module 601 is used to determine that the last terminal connected to the communication device 60 in the multicast group leaves the communication device 60, and there is no inactive terminal associated with the communication device 60 in the multicast group. terminal. For example, the processing module 601 may be used to perform S301.

The processing module 601 is also used to release the context of the multicast session of the communication device 60 . The multicast session is used to transmit multicast data corresponding to the multicast group. For example, the processing module 601 can also be used to perform S302.

In a possible implementation, the transceiver module 602 is configured to send a request message to the first network device. The request message is used to request the release of the multicast session; the transceiver module 602 is also configured to receive a response message from the first network device. , the response message is used to respond to the request message.

In a possible implementation, the transceiver module 602 is also configured to send a multicast session leave message to the second network device. The multicast session leave message is used to trigger the release of the context of the multicast session of the second network device. The multicast session of the network device is used to transmit multicast data corresponding to the multicast group.

In a possible implementation, the last terminal connected to the communication device 60 in the multicast group leaves the communication device 60. Setting 60 includes: the last terminal connected to the communication device 60 in the multicast group is deleted from the context of the multicast session by the communication device 60; or, the last terminal connected to the communication device 60 in the multicast group The last terminal is switched to an access network device other than the communication device 60 .

In a possible implementation, the processing module 601 is specifically configured to determine, according to the first information of the terminals in the connected state associated with the communication device 60 in the multicast group, the communication device in the multicast group. 60 The last terminal connected leaves the communication device 60 .

In a possible implementation, the first information is used to indicate the number of terminals in the multicast group that are connected to the communication device 60 and are in a connected state, or the first information is used to indicate that the communication The number of contexts of terminals in the multicast group stored in the device 60 .

In a possible implementation, the processing module 601 is specifically configured to determine, based on the second information of the inactive terminal associated with the communication device 60 in the multicast group, that there is no connection with the multicast group. The communication device 60 is associated with an inactive terminal.

In a possible implementation, the inactive terminals associated with the communication device 60 in the multicast group include: terminals switched to the inactive state by the communication device 60 in the multicast group; and a terminal in the multicast group that is switched to an inactive state by access network equipment other than the communication device 60, and the radio access network notification area of the terminal includes the terminal in the coverage area of the communication device 60 All or part of the area.

In a possible implementation, the transceiver module 602 is also configured to receive first notification information from the second access network device, where the first notification information is used to notify a terminal in the multicast group to switch to a non- Active state, or the first notification information is used to notify the multicast group that there is a terminal switched to the inactive state by the second access network device, or the first notification information is used to notify the multicast group The number of terminals in the group that are switched to the inactive state by the second access network device; the processing module 601 is also configured to update the second information according to the first notification information.

In a possible implementation, the transceiver module 602 is also configured to receive second notification information from the second access network device, where the second notification information is used to notify a terminal in the multicast group to leave the active state, or the second notification information is used to notify that there is no terminal in the multicast group that is switched to the inactive state by the second access network device, or the second notification information is used to notify the multicast The number of terminals in the group that leave the inactive state under the second access network device; the processing module 601 is also configured to update the second information according to the second notification information.

In a possible implementation, the second information is used to indicate the number of inactive terminals associated with the communication device 60 in the multicast group, or the second information is used to indicate the multicast session. The number of times the context is used.

In a possible implementation, the processing module 601 is specifically configured to determine that there are no terminals in the multicast group when the number of terminals indicated by the second information is zero or the number of times indicated by the second information is zero. There is an inactive terminal associated with the communication device 60 .

In a possible implementation, the transceiver module 602 is also configured to send third notification information to at least one access network device if the first terminal in the multicast group switches to an inactive state. The third notification The information is used to notify a terminal in the multicast group to switch to the inactive state, or the third notification information is used to notify that there is a terminal in the multicast group that is switched to the inactive state by the communication device 60 .

In a possible implementation, the first terminal is a terminal in the multicast group that is switched to an inactive state by the communication device 60 .

In a possible implementation, the transceiver module 602 is also configured to send a fourth message to the at least one access network device when the first terminal recovers from the inactive state to the connected state under the communication device 60 . Notification information, the fourth notification information is used to notify a terminal in the multicast group to leave the inactive state; or, the transceiver module 602 is also used to notify the first terminal to leave the active state from the third access network device. In this case, send fifth notification information to the access network device other than the third access network device in the at least one access network device, where the fifth notification information is used to notify a terminal in the multicast group Leave the inactive state.

In a possible implementation, the transceiver module 602 is also configured to send a message to the at least one terminal in the multicast group when the last terminal among the terminals switched to the inactive state by the communication device 60 leaves the inactive state. The access network equipment sends sixth notification information, the sixth notification information is used to notify that the number of terminals in the multicast group switched to the inactive state by the communication device 60 is 0, or the sixth notification information is used to notify It is notified that there is no terminal in the multicast group that is switched to the inactive state by the communication device 60 .

When used to implement the functions of the first access network device, the access network device 101, the access network device 102 or the access network device 105, for other functions that the communication device 60 can implement, please refer to Figure 3A or Figure 3B The embodiment shown or the method shown in Figure 4 implements The relevant introduction of the embodiment will not be described in detail.

Or, for example, the communication device 60 is used to implement the function of the second access network device. The communication device 60 is, for example, the second access network device described in the embodiment shown in FIG. 5 .

Among them, the processing module 601 is used to establish the context of the multicast session of the communication device 60 . The multicast session is used to transmit multicast data corresponding to the multicast group. For example, the processing module 601 may be used to perform S501.

The transceiver module 602 is configured to receive the first message from the first access network device. The first message is used to indicate releasing the context of the multicast session. For example, the transceiver module 602 may be used to perform S502.

The processing module 601 is also used to release the context of the multicast session. For example, the processing module 601 may be used to perform S503.

In a possible implementation, the transceiver module 602 is also configured to receive a second message from the first access network device, where the second message is used to request the communication device 60 to establish the context of the multicast session.

In a possible implementation, the processing module 601 is specifically configured to be used when the last terminal connected to the communication device 60 in the multicast group leaves the communication device 60 and there is no communication with the communication device 60 in the multicast group. When the device 60 is associated with an inactive terminal, the context of the multicast session is released.

When used to implement the functions of the second access network device, regarding other functions that the communication device 60 can implement, reference may be made to the relevant introduction of the embodiment shown in FIG. 5 and will not be described again.

In a simple embodiment, those skilled in the art can imagine that the communication device 60 can take the form shown in FIG. 2 . For example, the processor 201 in Figure 2 can cause the communication device 60 to execute the method described in the above method embodiment by calling the computer execution instructions stored in the memory 203.

For example, the functions/implementation processes of the processing module 601 and the transceiver module 602 in Figure 6 can be implemented by the processor 201 in Figure 2 calling computer execution instructions stored in the memory 203. Alternatively, the function/implementation process of the processing module 601 in Figure 6 can be implemented by the processor 201 in Figure 2 calling the computer execution instructions stored in the memory 203. The function/implementation process of the transceiver module 602 in Figure 6 can be implemented by Figure 6 It is implemented by the communication interface 204 in 2.

For example, when each functional module is divided in an integrated manner, FIG. 7 shows a schematic structural diagram of a communication device 70 . The communication device 70 includes a transceiver module 701. The transceiver module 701, which may also be called a transceiver unit, is used to perform transceiver operations. For example, it may be a transceiver circuit, a transceiver, a transceiver or a communication interface.

Illustratively, the communication device 70 is used to implement the function of the first access network device. The communication device 70 is, for example, the first access network device described in the embodiment shown in FIG. 5 .

Among them, the transceiver module 701 is used to send the second message to the second access network device. The second message is used to request the establishment of a context of a multicast session of the second access network device, and the multicast session is used to transmit multicast data corresponding to the multicast group. And/or; the transceiving module 701 is also configured to send a first message to the second access network device, where the first message is used to indicate releasing the context of the multicast session.

In a possible implementation, the transceiver module 701 is specifically used to notify the radio access network notification area of each terminal in the multicast group that is switched to the inactive state by the communication device and is currently in the inactive state. does not include the coverage area of the second access network device, and sends the first message to the second access network device; or, the transceiver module 701 is specifically used to: The third message is used to indicate that the terminal in the multicast group that was switched to the inactive state by the communication device returns to the connected state on the third access network device, or the third message is used to indicate The communication device is requested to send the context of the terminal to the third access network device and the first message to the second access network device.

When used to implement the functions of the first access network device, regarding other functions that the communication device 70 can implement, reference may be made to the relevant introduction of the embodiment shown in FIG. 5 and will not be described again.

In a simple embodiment, those skilled in the art can imagine that the communication device 70 may take the form shown in FIG. 2 . For example, the processor 201 in Figure 2 can cause the communication device 70 to execute the method described in the above method embodiment by calling the computer execution instructions stored in the memory 203.

For example, the function/implementation process of the transceiver module 701 in Figure 7 can be implemented by the processor 201 in Figure 2 calling the computer execution instructions stored in the memory 203. Alternatively, the function/implementation process of the transceiver module 701 in Figure 7 can be implemented through the communication interface 204 in Figure 2 .

It can be understood that one or more of the above modules or units can be implemented in software, hardware, or a combination of both. When any of the above modules or units is implemented in software, the software exists in the form of computer program instructions and is stored in the memory, The processor can be used to execute the program instructions and implement the above method flow. The processor can be built into an SoC (System on a Chip) or ASIC, or it can be an independent semiconductor chip. In addition to the core used to execute software instructions for calculation or processing, the processor may further include necessary hardware accelerators, such as field programmable gate array (FPGA), PLD (programmable logic device) , or a logic circuit that implements dedicated logic operations.

When the above modules or units are implemented in hardware, the hardware can be a CPU, a microprocessor, a digital signal processing (DSP) chip, a microcontroller unit (MCU), an artificial intelligence processor, an ASIC, Any one or any combination of SoC, FPGA, PLD, dedicated digital circuits, hardware accelerators or non-integrated discrete devices, which can run the necessary software or not rely on software to perform the above method flow.

Optionally, embodiments of the present application also provide a chip system, including: at least one processor and an interface. The at least one processor is coupled to the memory through the interface. When the at least one processor executes the computer program or instructions in the memory When, the method in any of the above method embodiments is executed. In a possible implementation, the chip system further includes a memory. Optionally, the chip system may be composed of chips, or may include chips and other discrete devices, which is not specifically limited in the embodiments of the present application.

Optionally, embodiments of the present application also provide a computer-readable storage medium. All or part of the processes in the above method embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in the above computer-readable storage medium. When executed, the program can include the processes of the above method embodiments. . The computer-readable storage medium may be an internal storage unit of the communication device of any of the aforementioned embodiments, such as a hard disk or memory of the communication device. The above-mentioned computer-readable storage medium may also be an external storage device of the above-mentioned communication device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card equipped on the above-mentioned communication device, Flash card, etc. Furthermore, the computer-readable storage medium may also include both an internal storage unit of the communication device and an external storage device. The above computer-readable storage medium is used to store the above computer program and other programs and data required by the above communication device. The above-mentioned computer-readable storage media can also be used to temporarily store data that has been output or is to be output.

Optionally, the embodiment of the present application also provides a computer program product. All or part of the processes in the above method embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in the above computer program product. When executed, the program can include the processes of the above method embodiments.

Optionally, the embodiment of the present application also provides a computer instruction. All or part of the processes in the above method embodiments can be completed by computer instructions to instruct related hardware (such as computers, processors, access network equipment, mobility management network elements or session management network elements, etc.). The program may be stored in the above-mentioned computer-readable storage medium or in the above-mentioned computer program product.

Optionally, this embodiment of the present application also provides a communication system, including: the first access network device in the embodiment shown in Figure 3A or Figure 3B. Optionally, the communication system also includes: the first network device and/or the second network device in the embodiment shown in Figure 3A.

Optionally, this embodiment of the present application also provides a communication system, including: the access network device 101, the access network device 102 and the access network device 105 in the embodiment shown in Figure 4. Optionally, the communication system also includes: the terminal 103 in the embodiment shown in Figure 4.

Optionally, this embodiment of the present application also provides a communication system, including: a first access network device and a second access network device in the embodiment shown in FIG. 5 .

Through the above description of the embodiments, those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above functional modules is used as an example. In practical applications, the above functions can be allocated by different modules. The functional module is completed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods, for example, multiple units or components may be The combination can either be integrated into another device, or some features can be omitted, or not implemented. On the other hand, the coupling or direct coupling or communication connection between each other shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated. The components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place, or they may be distributed to multiple different places. . Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can be It can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or software functional units.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be covered by the protection scope of the present application. . Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A multicast communication method, characterized in that it is applied to a first access network device, and the method includes:

Determining that the last terminal in the multicast group connected to the first access network device leaves the first access network device, and there is no association with the first access network device in the multicast group The inactive terminal;

Release the context of the multicast session of the first access network device, where the multicast session is used to transmit multicast data corresponding to the multicast group.
The method according to claim 1, characterized in that, in determining the multicast group, the last terminal connected to the first access network device leaves the first access network device, and the multicast group After there is no inactive terminal associated with the first access network device in the group, the method further includes:

Send a request message to the first network device, the request message being used to request release of the multicast session;

Before releasing the context of the multicast session of the first access network device, the method further includes:

Receive a response message from the first network device, the response message being used to respond to the request message.
The method according to claim 1 or 2, characterized in that, the method further includes:

Send a multicast session leave message to the second network device, the multicast session leave message is used to trigger the release of the context of the multicast session of the second network device, and the multicast session of the second network device is used to transmit the The multicast data corresponding to the multicast group.
The method according to any one of claims 1-3, characterized in that the last terminal connected to the first access network device in the multicast group leaves the first access network device, include:

The last terminal in the multicast group connected to the first access network device is deleted from the context of the multicast session by the first access network device; or, in the multicast group The last terminal connected to the first access network device is switched to an access network device other than the first access network device.
The method according to any one of claims 1 to 4, characterized in that the last terminal connected to the first access network device in the determined multicast group leaves the first access network device. ,include:

Determine the last terminal in the multicast group connected to the first access network device according to the first information of the terminals in the connected state associated with the first access network device in the multicast group Leave the first access network device.
The method according to claim 5, wherein the first information is used to indicate the number of terminals in the multicast group that are connected to the first access network device and are in a connected state, or , the first information is used to indicate the number of contexts of terminals in the multicast group stored in the first access network device.
The method according to any one of claims 1-6, wherein determining that there is no inactive terminal associated with the first access network device in the multicast group includes:

According to the second information of the inactive terminal associated with the first access network device in the multicast group, it is determined that there is no inactive terminal associated with the first access network device in the multicast group. Inactive terminal.
The method of claim 7, wherein the inactive terminal associated with the first access network device in the multicast group includes: The first access network device switches to the inactive state terminal; and other access network devices other than the first access network device in the multicast group switch to the inactive state terminal, and The radio access network notification area of the terminal includes all or part of the coverage area of the first access network device.
The method according to claim 7 or 8, characterized in that, the method further includes:

Receive first notification information from the second access network device, the first notification information is used to notify a terminal in the multicast group to switch to an inactive state, or the first notification information is used to notify There is a terminal in the multicast group that is switched to an inactive state by the second access network device, or the first notification information is used to notify the multicast group that is switched to an inactive state by the second access network device. The number of terminals whose network equipment switches to inactive state;

The second information is updated according to the first notification information.
The method of claim 9, further comprising:

Receive second notification information from the second access network device, the second notification information is used to notify a terminal in the multicast group to leave the inactive state, or the second notification information is used to Notifying that there is no terminal in the multicast group that is switched to an inactive state by the second access network device, or the second notification information is used to notify the multicast group that the second access network device has switched to an inactive state. The number of terminals leaving the inactive state under access network equipment;

The second information is updated according to the second notification information.
The method according to any one of claims 7-10, characterized in that the second information is used to indicate an inactive terminal associated with the first access network device in the multicast group. The number, or the second information is used to indicate the number of times the context of the multicast session is used.
The method according to any one of claims 7-11, characterized in that, based on the second information of inactive terminals associated with the first access network device in the multicast group, Determining that there is no inactive terminal associated with the first access network device in the multicast group includes:

When the number of terminals indicated by the second information is zero or the number of times indicated by the second information is zero, it is determined that there is no non-user associated with the first access network device in the multicast group. Active terminal.
The method according to any one of claims 1-12, characterized in that the method further includes:

If the first terminal in the multicast group switches to an inactive state, send third notification information to at least one access network device, the third notification information is used to notify one terminal in the multicast group Switch to the inactive state, or the third notification information is used to notify that there is a terminal in the multicast group that is switched to the inactive state by the first access network device.
The method according to claim 13, wherein the first terminal is a terminal in the multicast group that is switched to an inactive state by the first access network device.
The method according to claim 13 or 14, characterized in that the method further includes:

When the first terminal recovers from the inactive state to the connected state under the first access network device, the fourth notification information is sent to the at least one access network device, where the fourth notification information is To notify a terminal in the multicast group to leave the inactive state; or,

When the first terminal leaves the active state from the third access network device, send a fifth notification to the access network devices in the at least one access network device except the third access network device. information, the fifth notification information is used to notify a terminal in the multicast group to leave the inactive state.
The method of claim 15, further comprising:

When the last terminal in the multicast group that is switched to the inactive state by the first access network device leaves the inactive state, sending sixth notification information to the at least one access network device, The sixth notification information is used to notify that the number of terminals in the multicast group that is switched to the inactive state by the first access network device is 0, or the sixth notification information is used to notify the There is no terminal in the multicast group that is switched to an inactive state by the first access network device.
A communication device, characterized by comprising a unit or module for executing the method according to any one of claims 1 to 16.
A communication device, characterized in that it includes: a processor, the processor is coupled to a memory, the memory is used to store programs or instructions, and when the programs or instructions are executed by the processor, the device causes the device to A method as claimed in any one of claims 1 to 16 is performed.
A chip, characterized in that it includes: a processor, the processor is coupled to a memory, the memory is used to store programs or instructions, and when the programs or instructions are executed by the processor, the chip executes The method of any one of claims 1 to 16.
A computer-readable storage medium on which a computer program or instructions are stored, characterized in that, when executed, the computer program or instructions cause the computer to perform the method according to any one of claims 1 to 16.
A computer program product, the computer program product includes computer program code, characterized in that when the computer program code is run on a computer, it causes the computer to implement the method described in any one of claims 1 to 16.
A communication system, characterized by comprising: access network equipment, the access network equipment being configured to perform the method according to any one of claims 1 to 16.
The communication system according to claim 22, characterized in that the communication system further includes: a first network device, the first network device is configured to: receive a request message, the request message is used to request the release of the multiple broadcast session, and send a response message of the request message to the access network device.
The communication system according to claim 22 or 23, characterized in that the communication system further includes: a second network device, the second network device is configured to: receive a multicast session leave message, and according to the multicast The session leave message releases the context of the multicast session of the second network device, and the multicast session of the second network device is used to transmit multicast data corresponding to the multicast group.