CN113873580A - Communication method and device - Google Patents

Communication method and device Download PDF

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Publication number
CN113873580A
CN113873580A CN202010612136.3A CN202010612136A CN113873580A CN 113873580 A CN113873580 A CN 113873580A CN 202010612136 A CN202010612136 A CN 202010612136A CN 113873580 A CN113873580 A CN 113873580A
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CN
China
Prior art keywords
terminal device
sidelink
indication information
remote
relay
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Pending
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CN202010612136.3A
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Chinese (zh)
Inventor
王君
史玉龙
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Priority to CN202010612136.3A priority Critical patent/CN113873580A/en
Priority to PCT/CN2021/102658 priority patent/WO2022001928A1/en
Publication of CN113873580A publication Critical patent/CN113873580A/en
Pending legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
    • H04W36/0033—Control or signalling for completing the hand-off for data sessions of end-to-end connection with transfer of context information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link
    • H04W36/0079—Transmission or use of information for re-establishing the radio link in case of hand-off failure or rejection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/70—Services for machine-to-machine communication [M2M] or machine type communication [MTC]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W40/00—Communication routing or communication path finding
    • H04W40/24—Connectivity information management, e.g. connectivity discovery or connectivity update
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W40/00—Communication routing or communication path finding
    • H04W40/24—Connectivity information management, e.g. connectivity discovery or connectivity update
    • H04W40/248—Connectivity information update
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/23—Manipulation of direct-mode connections

Abstract

The application provides a communication method and device, which can effectively recover a local identifier localid. The method comprises the following steps that a second terminal device forwards data of a first terminal device to communicate with a first network device, the second terminal device communicates with the first terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network, and comprises the following steps: the second terminal equipment determines that the sidelink is disconnected; the second terminal device deletes the association relationship between a first identifier and the first terminal device, where the first identifier is used to identify the first terminal device, and the first identifier is allocated to the first terminal device by the second terminal device or the first network device.

Description

Communication method and device
Technical Field
The present application relates to the field of communications, and more particularly, to a method and apparatus for communication.
Background
In a relay-network relay application scenario from a Long Term Evolution (LTE) User Equipment (UE) to a network, a remote UE and a relay UE communicate with each other through a Sidelink (SL), and the relay UE and a network device communicate with each other through a wireless network.
After receiving data sent by a certain remote UE, a relay UE determines that the data needs to be forwarded to the network device, but in order to enable the network device to know which remote UE sends the data, the relay UE needs to carry an identifier of the remote UE, and if a cell-radio network temporary identifier (C-RNTI) of the remote UE or an identifier of layer2 is used, since the two identifiers have longer lengths, overhead to an air interface is larger. Therefore, the relay UE or the network device allocates a shorter local identifier (local id) to the remote UE, and the local id is used to identify the remote UE in the process of forwarding the data of the remote UE to the network device by the relay UE.
At present, only how to allocate local id is considered, and no recovery or deletion mechanism of local id is considered, if local id allocated by relay UE cannot be recovered all the time, local id will be used up, and when new remote UE accesses relay UE, terminal-to-network (U2N) forwarding service cannot be provided.
Disclosure of Invention
The application provides a communication method and device, which can effectively recover local id and/or delete corresponding routing information.
In a first aspect, a method for communication, which may be executed by a second terminal device, or may be executed by a component of the second terminal device, such as a processor, a chip, or a system-on-chip, is described as an example of the method performed by the second terminal device, where the second terminal device forwards data of a first terminal device to communicate with a first network device, the second terminal device communicates with the first terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network, and the method includes: the second terminal equipment determines that the sidelink is disconnected; the second terminal device deletes the association relationship between a first identifier and the first terminal device, where the first identifier is used to identify the first terminal device, and the first identifier is allocated to the first terminal device by the second terminal device or the first network device.
Based on the above technical solution, after the second terminal device determines that the sidelink between the second terminal device and the first terminal device is disconnected, the second terminal device deletes the association relationship between the first identifier and the first terminal device, so that the first identifier can be used to identify other terminal devices, thereby avoiding that the other terminal devices cannot establish a connection with the second terminal device when the identifiers are used up.
In a possible implementation manner, the deleting, by the second terminal device, the association relationship between the first identifier and the first terminal device includes one or more of the following: and the second terminal equipment releases the first identifier and/or the corresponding routing information, and the second terminal equipment releases the context of the first terminal equipment.
In one possible implementation manner, the determining, by the second terminal device, that the sidelink is disconnected includes: the second terminal device starts a first timer after receiving the data sent by the first terminal device to the network device and/or after receiving the data sent by the first network device to the first terminal device; and if the second terminal device does not receive the data sent by the first terminal device before the first timer is overtime, and/or the second terminal device does not receive the data sent to the first terminal device by the first network device before the first timer is overtime, determining that the sidelink is disconnected.
In one possible implementation, the method further includes: and the second terminal equipment sends first indication information to the first network equipment, wherein the first indication information indicates that the sidelink is disconnected.
In one possible implementation, the method further includes: the first indication information is side link terminal information, the side link terminal information does not carry a first target identifier, and the first target identifier corresponds to the first identifier of the first terminal device.
In one possible implementation manner, the determining, by the second terminal device, that the sidelink is disconnected includes: and the second terminal equipment receives second indication information sent by the first terminal equipment, wherein the second indication information indicates that the sidelink is disconnected.
In one possible implementation manner, the determining, by the second terminal device, that the sidelink is disconnected includes: and the second terminal equipment receives third indication information sent by the first network equipment, wherein the third indication information indicates that the sidelink is disconnected.
In one possible implementation, the method further includes: the second terminal device determines the sidelink disconnection according to a logical channel configuration, the logical channel configuration being associated with the first terminal device.
In one possible implementation, the first identifier is a local identifier id.
In a second aspect, a method for communication is provided, where a first terminal device forwards data through a second terminal device to communicate with a first network device, the first terminal device communicates with the second terminal device through a sidelink, and the first network device communicates with the second terminal device through a wireless network, and the method may be performed by the first network device, or may be performed by a component of the first network device, such as a processor, a chip, or a system-on-chip, and the method is described as an example performed by the first network device, and the method includes: the first network device determining that the sidelink is disconnected; the first network device deletes an association relation between a first identifier and the first terminal device, the first identifier has an association relation with an identifier of the second terminal device, the first identifier is used for identifying the first terminal device, and the first identifier is allocated to the second terminal device or the first network device.
In a possible implementation manner, the deleting, by the first network device, the association relationship between the first identifier and the first terminal device includes one or more of the following: and the first network equipment releases the first identifier and releases the context of the first terminal equipment.
In one possible implementation, the determining, by the first network device, that the sidelink is disconnected includes: after the first network device receives the data of the first terminal device sent by the second terminal device, and/or after the first network device sends the data of the first terminal device to the second terminal device, starting a second timer; and if the first network device does not receive the data of the first terminal device before the second timer is overtime, and/or the first network device does not send the data of the first terminal device to the second terminal device before the second timer is overtime, determining that the sidelink is disconnected.
In one possible implementation, the determining, by the first network device, that the sidelink is disconnected includes: the first network device receives fourth indication information sent by a second network device, where the fourth indication information includes at least one of the following information: requesting to acquire the context of the first terminal equipment, releasing the context of the first terminal equipment and allowing switching.
In one possible implementation, the method further includes: and the first network equipment sends third indication information to the second terminal equipment, wherein the third indication information indicates that the sidelink is disconnected.
In one possible implementation, the method further includes: the second terminal device determines the sidelink disconnection according to a logical channel configuration, the logical channel configuration being associated with the first terminal device.
In one possible implementation, the determining, by the first network device, that the sidelink is disconnected includes: and the first network equipment receives first indication information sent by the second terminal equipment, wherein the first indication information indicates that the sidelink is disconnected.
In a possible implementation manner, the first indication information is side link terminal information, the side link terminal information does not carry a first target identifier, and the first target identifier corresponds to the first identifier of the first terminal device.
In one possible implementation, the determining, by the first network device, that the sidelink is disconnected includes: and the first network equipment receives second indication information sent by the first terminal equipment, wherein the second indication information indicates that the sidelink is disconnected.
In a third aspect, a communication method is provided, where a first terminal device forwards data through a second terminal device to communicate with a first network device, the first terminal device communicates with the second terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network, and the method may be executed by the first terminal device, or may be executed by a component of the first terminal device, such as a processor, a chip, or a system-on-chip, and the method is described as an example executed by the first terminal device, and the method includes: the first terminal equipment determines to disconnect the side link connection; and the first terminal equipment sends second indication information, wherein the second indication information is used for indicating the disconnection of the sidelink.
In one possible implementation manner, the determining, by the first terminal device, to disconnect the sidelink connection includes: the first terminal device determines to disconnect the sidelink connection based on one or more of: radio connection failure, handover failure, and a third timer.
In one possible implementation manner, the determining, by the first terminal device, to disconnect the sidelink connection includes: and the first terminal equipment receives fifth indication information, wherein the fifth indication information is used for indicating to disconnect the connection of the sidelink.
In a possible implementation manner, the fifth indication information includes at least one of the following information sent by the first network device: radio Resource Control (RRC) release, RRC rejection and switching command.
In a possible implementation manner, the fifth indication information includes a radio resource control RRC reestablishment notification sent by the second network device.
In a possible implementation manner, the sending, by the first terminal device, the second indication information includes: and the first terminal equipment sends the second indication information to the second terminal equipment.
In a possible implementation manner, the sending, by the first terminal device, the second indication information includes: and the first terminal equipment sends the second indication information to the first network equipment.
In a fourth aspect, a communication method is provided, where a second terminal device forwards data of at least one first terminal device to communicate with a first network device, the second terminal device communicates with the at least one first terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network, and the method may be executed by the second terminal device, or may be executed by a component of the second terminal device, such as a processor, a chip, or a system of chips, and the method is described as an example executed by the second terminal device, and the method includes:
the second terminal device sends a Radio Resource Control (RRC) reestablishment request or an RRC recovery request message to a second network device, wherein the RRC reestablishment request message or the RRC recovery request message includes sixth indication information, and the sixth indication information is used for indicating the second network device to acquire the context of the first terminal device from the first network device.
In a possible implementation manner, the sixth indication information includes an identifier of the at least one first terminal device.
In a possible implementation manner, before the second terminal device sends a radio resource control RRC reestablishment request message to the second network device, the method further includes: and the second terminal equipment disconnects the wireless network communication connection with the first network equipment.
In a fifth aspect, a method of communication is provided, including: a first terminal device sends a Radio Resource Control (RRC) establishment request message to a second terminal device by using a first logical channel, wherein the first logical channel is used for sending the RRC establishment request message, the RRC establishment message and switching permission;
the second terminal equipment forwards the RRC establishment request message to first network equipment by using a second logical channel, wherein the second logical channel is allocated to the second terminal equipment by the first network equipment;
the first network equipment receives the RRC establishment request message;
the first network equipment sends the RRC establishment message to the second terminal equipment by utilizing the second logical channel according to the RRC establishment request message;
and the second terminal equipment sends the RRC establishment message to the first terminal equipment by utilizing the first logical channel.
In a sixth aspect, a communication method is provided, where a first terminal device forwards data through a second terminal device to communicate with a first network device, the first terminal device communicates with the second terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network, where the method may be executed by the first terminal device, or may be executed by a component of the first terminal device, such as a processor, a chip, or a system of chips, and the method is described as an example executed by the first terminal device, and the method includes:
the first terminal equipment acquires a radio access network area code RANAC of a service cell where the second terminal equipment is located and all pieces of radio network temporary identification indication information;
and the first terminal equipment sends a Radio Resource Control (RRC) establishment request message to the first network equipment according to the RANAC and the all-radio network temporary identification indication information.
In a possible implementation manner, the acquiring, by the first terminal device, a radio access network area code RANAC and all radio network temporary identity indication information of a serving cell where the second terminal device is located includes: the first terminal equipment sends a request message for acquiring the RANAC to the second terminal equipment; and the first terminal equipment receives the RANAC sent by the second terminal equipment.
In a possible implementation manner, the acquiring, by the first terminal device, a radio access network area code RANAC and all radio network temporary identity indication information of a serving cell where the second terminal device is located includes: the first terminal equipment receives a system broadcast message periodically sent by the second terminal equipment; and the first terminal equipment acquires the RANAC and all the wireless network temporary identification indication information according to the system broadcast message.
In a seventh aspect, a communication method is provided, where a first terminal device forwards data through a second terminal device to communicate with a first network device, the first terminal device communicates with the second terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network, and the method may be executed by the first terminal device, or may be executed by a component of the first terminal device, such as a processor, a chip, or a system-on-chip, and the method is described as an example executed by the first terminal device, and the method includes:
the first terminal equipment acquires a Physical Cell Identity (PCI) of a service cell where the second terminal equipment is located;
and the first terminal equipment sends the PCI to second network equipment, so that the second network equipment acquires the context of the first terminal equipment from the first network equipment.
In a possible implementation manner, the acquiring, by the first terminal device, the physical cell identity PCI of the second terminal device includes: the first terminal equipment sends a request message for acquiring the PCI to the second terminal equipment; and the first terminal equipment receives the PCI sent by the second terminal equipment.
In a possible implementation manner, the acquiring, by the first terminal device, the physical cell identity PCI of the second terminal device includes: the first terminal equipment receives a system broadcast message periodically sent by the second terminal equipment; and the first terminal equipment acquires the PCI according to the system broadcast message.
In an eighth aspect, there is provided a communication device comprising means for implementing the functionality of the method as in the first aspect or any possible implementation manner of the first aspect.
In a ninth aspect, there is provided a communication device comprising means for implementing the functionality of the method as in the second aspect or any possible implementation manner of the second aspect.
A tenth aspect provides a communication apparatus comprising means for implementing the functions of the method as in the third aspect or any possible implementation manner of the third aspect.
In an eleventh aspect, there is provided a communication apparatus comprising: a processor and a transceiver for receiving computer code or instructions and transmitting the computer code or instructions to the processor, the processor executing the computer code or instructions, such as the first aspect or the method in any possible implementation manner of the first aspect.
In a twelfth aspect, a communication apparatus is provided, including: a processor and a transceiver for receiving computer code or instructions and transmitting the computer code or instructions to the processor, the processor executing the computer code or instructions, such as the second aspect or the method in any possible implementation of the second aspect.
In a thirteenth aspect, a communication apparatus is provided, including: a processor and a transceiver for receiving computer code or instructions and transmitting the computer code or instructions to the processor, the processor executing the computer code or instructions, such as the method of the third aspect or any possible implementation of the third aspect.
In a fourteenth aspect, a communication system is provided, which includes the first terminal device and the second terminal device in the method of the first aspect, the second aspect or the third aspect.
In one possible implementation, the communication system further includes: the first network device in the method of the first aspect, the second aspect, or the third aspect.
In a fifteenth aspect, there is provided a computer readable storage medium having a computer program stored thereon; the computer program, when run on a computer, causes the computer to perform the method of the first aspect or any possible implementation of the first aspect.
In a sixteenth aspect, there is provided a computer readable storage medium having a computer program stored thereon; the computer program, when run on a computer, causes the computer to perform the method of the second aspect or any possible implementation of the second aspect.
In a seventeenth aspect, there is provided a computer readable storage medium having a computer program stored thereon; the computer program, when run on a computer, causes the computer to perform the method of the third aspect or any possible implementation of the third aspect.
Drawings
Fig. 1 is a schematic diagram of a UE and a UE communicating through a PC5 interface according to an embodiment of the present application.
Fig. 2 is a schematic flow chart of a communication method according to an embodiment of the present application.
Fig. 3 is a schematic view illustrating interaction of a process in which relay UE determines that a sidelink is disconnected and then sends first indication information to a base station according to an embodiment of the present application.
Fig. 4 is a schematic diagram of a 1:1 mapping relationship between the SL LCH and the Uu LCH according to an embodiment of the present application.
Fig. 5 is a schematic diagram of an N:1 mapping relationship between SL LCH and Uu LCH according to an embodiment of the present application.
Fig. 6 is a schematic flow chart of another communication method according to an embodiment of the present application.
Fig. 7 is a schematic view illustrating interaction of a handover permission procedure that a source base station receives a handover permission sent by a target base station in an HO process according to an embodiment of the present application.
Fig. 8 is a schematic view of a process interaction in which the first network device sends the third indication information to the relay UE after receiving the handover permission message sent by the target base station according to the embodiment of the present application.
Fig. 9 is a schematic view illustrating interaction of a process in which a source base station receives context of a first terminal device and releases the context of the first terminal device in an RRC reestablishment process according to the embodiment of the present application.
Fig. 10 is a schematic view illustrating interaction of a process in which the first network device sends the third indication information to the relay UE after receiving the context message for acquiring/releasing the context message of the first terminal device sent by the target base station in the embodiment of the application.
Fig. 11 is a schematic flow chart of another communication method according to an embodiment of the present application.
Fig. 12 is a schematic view illustrating interaction of a process in which a remote UE receives a handover command sent by a source base station in an HO process according to an embodiment of the present application.
Fig. 13 is a schematic view illustrating interaction of a process in which a remote UE sends second indication information to a relay UE after receiving an HO CMD according to an embodiment of the present application.
Fig. 14 is a schematic view illustrating interaction of a process in which a remote UE sends second indication information to a relay UE after receiving an RRC release/RRC reject message sent by a base station according to an embodiment of the present application.
Fig. 15 is a schematic flow chart of another communication method according to an embodiment of the present application.
Fig. 16 is a schematic view illustrating a process of acquiring, by a target base station, a context of relay UE and a remote UE therebelow according to an RRC reestablishment request message sent by the relay UE in an RRC reestablishment process according to an embodiment of the present application.
Fig. 17 is a block diagram illustrating an internal implementation of multiplexing multiple SL LCHs of a remote UE on a Uu LCH according to an embodiment of the present application.
Fig. 18 is a schematic block diagram of a communication device according to an embodiment of the present application.
Fig. 19 is a schematic block diagram of another communication device according to an embodiment of the present application.
Fig. 20 is a schematic block diagram of another communication apparatus according to an embodiment of the present application.
Fig. 21 is a schematic block diagram of another communication device according to an embodiment of the present application.
Fig. 22 is a schematic block diagram of a communication system according to an embodiment of the present application.
Detailed Description
The technical solution in the present application will be described below with reference to the accompanying drawings.
The embodiments of the present application may be applied to various communication systems, such as Wireless Local Area Network (WLAN), narrowband band-internet of things (NB-IoT), global system for mobile communications (GSM), enhanced data rate GSM evolution (EDGE), Wideband Code Division Multiple Access (WCDMA), code division multiple access (code division multiple access, CDMA2000), time division synchronous code division multiple access (TD-SCDMA), long term evolution (long term evolution, LTE), satellite communication, fifth generation (5G), or new communication systems.
The terminal devices referred to in the embodiments of the present application may include various handheld devices, vehicle mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem with wireless communication capability. The terminal may be a Mobile Station (MS), a subscriber unit (subscriber unit), a User Equipment (UE), a cellular phone (cellular phone), a smart phone (smart phone), a wireless data card, a Personal Digital Assistant (PDA) computer, a tablet computer, a wireless modem (modem), a handheld device (handset), a laptop computer (laptop computer), a Machine Type Communication (MTC) terminal, or the like.
In a wireless communication system, the UE and the UE may communicate with each other through a network or directly without a network device, as shown in fig. 1, a direct communication interface between the UE1 and the UE2 is referred to as a PC5 interface, similar to a Uu interface between the UE and the network. The link between the UE and the UE is called Sidelink (SL). The PC5 interface is currently used for device-to-device (D2D) communication and vehicle-to-vehicle (V2X) communication. In the car networking, each car is a UE, and data transmission can be directly performed between the UEs through the Sidelink without passing through the network, so that communication delay can be effectively reduced.
Broadcast, unicast, and multicast are supported on Sidelink.
The broadcast communication is similar to the base station broadcast system information, i.e. the UE does not encrypt and send the broadcast service data to the outside, and other UEs in any effective range can receive the broadcast service data if interested in the broadcast service.
Unicast communication is similar to data communication performed after a Radio Resource Control (RRC) connection is established between a UE and a base station, and requires a unicast connection to be established between two UEs. After establishing the unicast connection, the two UEs may communicate data, which may or may not be encrypted, based on the negotiated identity. In unicast communication, compared to broadcast communication, unicast communication can be performed only between two UEs after a unicast connection is established.
The multicast communication refers to communication between all UEs in a communication group, and any UE in the group can receive and transmit data of the multicast service.
In order to expand network coverage and reduce power consumption of UE, relay (relay) UE is introduced between the UE and a network (network), and remote (remote) UE is located at the edge of network coverage or has no network coverage, and can transmit data through the relay UE so as to communicate with the network, wherein the remote UE and the relay UE communicate through a PC5 interface, and the relay UE and the network communicate through a Uu interface.
In a Long Term Evolution (LTE) SL UE-Network relay, for a layer 2(layer2, L2) relay mode, a plurality of remote UEs may be connected to the back of one relay UE, so that an Adaptation Layer (AL) is added to a protocol stack between the relay UE and the gNB. For example, in the above data transmission, after receiving SL data of a certain remote UE, a relay UE knows that the data is finally continuously sent to the network, but in order to enable the network to know which remote UE sends the data, it needs to carry an identifier of the remote UE in the AL layer, where the identifier may directly use a cell-radio network temporary identifier (C-RNTI) of the remote UE or an SL L2id, but the length of both identifiers is longer, for example, C-RNTI is 16 bits in the prior art, SL L2id is 24 bits, and if the overhead of the mobile UE on the air interface is directly used, it needs to carry a shorter local identifier (local id), such as 1 byte, and can support 256 remote UEs at most, and the identifier is used to identify different remote UEs under the relay UE and is used to inform the network of which remote UE sends the data, the remote UE identity is only active between the remote UE and the network device and is not active between the remote UE and the remote UE. The data of which remote UE is can be distinguished on the SL by different SL L2 ids between remote and relay UEs.
In the current technical scheme, only how to allocate the local id is considered, and a recovery or deletion mechanism of the local id is not considered, if the local id allocated by relay UE cannot be recovered all the time, the local id is used up, and when a new remote UE accesses the relay UE, a terminal-to-network (U2N) forwarding service cannot be provided. Therefore, the embodiment of the application provides a communication method, which can effectively recover the local id.
In order to facilitate understanding of the technical solution of the present application, a Handover (HO) procedure, a Radio Resource Control (RRC) reestablishment procedure, and an RRC release/RRC reject involved in the technical solution of the present application are briefly described.
The HO process comprises the following steps:
1) UE reports a measurement report to a source base station;
2) the source base station makes a switching decision;
3) a source base station sends a handover request (ho request) message to a target base station;
4) the target base station performs admission control to see whether the UE is allowed to switch into the local cell;
5) if the message is allowed, the target base station replies a handover allowance message, namely an Acknowledgement (ACK) message, to the source base station.
6) The source base station sends a handover command (HO CMD) to the UE;
7) a source base station sends a Sequence Number (SN) state transfer message to a target base station, and tells which packet data convergence layer protocol (PDCP) Service Data Unit (SDU) data packets are received and which are not received;
8) after receiving the HO CMD, the UE immediately breaks the connection with the source base station and tries to access to the target base station, and if the access is successful, an HO complete message is sent to the target base station;
9) after the UE is successfully accessed to the target base station, the target base station sends a path switching request message to an access and mobility management unit (AMF) to request to replace a forwarding address of downlink data, so that the AMF subsequently sends a downlink data packet of the UE to the target base station instead of a source base station;
10) after receiving the path switching request message, the AMF notifies a user plane Unit (UPF) to perform path switching;
11) if the path switching is successful, the AMF replies a path switching affirmation message to the target base station;
12) after the UE successfully accesses the target base station, the target base station sends a context notification message for releasing the UE to the source base station, so that the source base station releases the context of the UE.
Secondly, the RRC reestablishment process comprises the following steps:
1) after Radio Link Failure (RLF) or handover failure (HOF) occurs to the UE, performing an RRC reestablishment process, wherein the UE firstly selects a cell meeting connection conditions and then sends an RRC reestablishment request message on the cell;
2) after receiving the RRC reestablishment request message, the target base station searches the original serving cell of the UE according to the information carried in the message and sends a context request message for acquiring the UE;
3) after receiving the request message in the context of the UE, the source base station replies a response message for acquiring the context of the UE, wherein the response message comprises the context of the UE;
4) if the target base station successfully acquires the context of the UE, sending an RRC reestablishment notification message to the UE; it should be understood that if the target base station fails to acquire the context of the UE, an RRC reconfiguration message may be sent to the UE;
5) if the UE receives the RRC reestablishment notification message, the UE considers that the RRC reestablishment is successful and sends an RRC reestablishment completion message to the target base station; if the UE receives the RRC reconfiguration message, sending an RRC reconfiguration completion message to the target base station;
6) after the UE is successfully rebuilt, the target base station provides an XN-U address for the source base station;
7) after obtaining the XN-U address, the source base station forwards a cache data packet of the UE at the source base station to the target base station; and send SN state transfer message to the target base station, in order to notify which data packet receive, which have not received;
8) the target base station sends a path switching request message to the AMF to request to replace a downlink data packet forwarding address, so that the AMF subsequently sends the downlink data packet of the UE to the target base station instead of the source base station;
9) after receiving the path switching request message, the AMF notifies a user plane Unit (UPF) to perform path switching;
10) if the path switching is successful, the AMF replies a path switching affirmation message to the target base station;
11) and after receiving the path switching positive confirmation message, the target base station sends a context notification message for releasing the UE to the source base station, so that the source base station releases the context of the UE.
And thirdly, the UE enters an idle state/inactive state after receiving the RRC release/RRC reject message sent by the network equipment.
In the state that the UE supports inactive, the base station still maintains the context of the UE, but the UE in the idle state does not maintain the context of the UE on the network side; the benefit of maintaining the UE context is that when the UE enters the connected state next time, since the network already has the UE context, part of the procedures can be omitted, such as: safety negotiation, bearer configuration, UE capability negotiation and the like, so that the connection state can be quickly entered, and data transmission can be quickly carried out.
The RRC release issued by the base station to the UE carries a suspend configuration (suspend configuration), for example: a full radio network temporary identity (full-RNTI), a partial radio network temporary identity (short-RNTI), a continuous paging cycle (ran-paging cycle), and a timer t 380.
1. Enter inactive state flow 1
1) UE initiates an RRC reestablishment request;
2) the target base station successfully asks the source base station for the UE context;
3) the target base station determines to make the UE still remain in an inactive state;
4) the target base station informs the AMF to carry out path switching;
5) the target base station generates and sends an RRC release message to the UE;
6) the target base station informs the source base station to release the UE context.
2. Enter inactive state process 2
1) UE initiates an RRC reestablishment request;
2) the target base station fails to ask the source base station for the UE context, and the source base station has the UE context but does not want to provide the UE context to the target base station;
3) the source base station generates an RRC release message and transmits the RRC release message to the UE through the target base station;
4) the UE remains in inactive state.
It should be understood that the context of the UE in flow 1 is migrated from the source base station to the target base station, while the context of the UE in flow 2 is not migrated.
3. Flow into idle state
1) UE initiates an RRC reestablishment request;
2) the target base station fails to ask the source base station for the UE context, and the source base station has the UE context but does not want to provide the UE context to the target base station;
3) the source base station generates an RRC release message and transmits the RRC release message to the UE through the target base station;
4) after receiving the RRC release message, the UE enters an idle state; it should be understood that when the UE changes from inactive state to idle state, the AMF is notified;
5) the source base station releases the UE context.
An embodiment of the present application provides a communication method, which is applicable to a UE-Network relay application scenario, and as shown in fig. 2, a schematic flow chart of a communication method 200 according to an embodiment of the present application is shown.
The second terminal device forwards the data of the first terminal device to communicate with the first network device, the second terminal device communicates with the first terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network. The first terminal device is called remote UE, the second terminal device is called relay UE, and the first network device may be a base station. The method may be executed by the second terminal device, or may be executed by a component of the second terminal device, such as a processor, a chip, or a system of chips, and the method is described as an example executed by the second terminal device.
210. The second terminal device determines a sidelink disconnection between the first terminal device and the second terminal device.
220. The second terminal device deletes the association relation between the first identifier and the first terminal device, wherein the first identifier is allocated to the first terminal device by the second terminal device or the first network device and is used for identifying the first terminal device. Specifically, the deleting, by the second terminal device, the association relationship between the first identifier and the first terminal device includes one or more of the following: and the second terminal equipment releases the first identifier, and the second terminal equipment releases the context of the first terminal equipment.
Specifically, optionally, the second terminal device may determine the sidelink disconnection by itself through detection.
In a New Radio (NR) R16 protocol, for a scenario where two UEs perform direct communication through a sidelink, a keep-alive (keep-alive) message is defined in a PC5 signaling (PC5 signaling, PC5-S) layer, and a transmit (Tx) UE or a receive (Rx) UE can implement or periodically initiate the keep-alive message by itself, and if a response message replied by an opposite UE is not received within a specified time, the sidelink connection is considered to be abnormally released, and an Access Stratum (AS) is notified to release a corresponding SL connection (SL link). For an application scenario of UE-Network relay, the mechanism can be reused for relay UE, the relay UE periodically sends a keep-alive message to the relay UE to detect whether the relay UE leaves the relay UE, and if the PC5-S layer of the relay UE detects and informs the AS layer to release the SL link, the relay UE determines that the SL between the relay UE and the relay UE is disconnected.
The NR R16 protocol supports hybrid automatic repeat request (HARQ) to find that RLF occurs in PC5 link based on RLF, that is, Tx UE transmits data to Rx UE, and if continuous Negative Acknowledgement (NACK) or Discontinuous Transmission (DTX) is received or no ACK/NACK feedback is received, SL is considered to have RLF, and SL link can be released by itself at the AS layer. For an application scenario of UE-Network relay, the mechanism can be reused for relay UE, the relay UE is used as a sending end to send data to the remote UE, and if continuous NACK or DTX is detected or no ACK/NACK feedback is received, the relay UE determines that the SL disconnection between the relay UE and the relay UE is realized.
In addition to the above, optionally, after receiving the data sent by the remote UE to the first network device, the relay UE starts a first timer, and if the relay UE does not receive the data sent by the remote UE to the first network device before the first timer times out, the relay UE determines that the SL between the relay UE and the remote UE is disconnected. Or, after receiving the data sent by the first network device to the remote UE, the relay UE starts or restarts the first timer, and if the relay UE does not receive the data sent by the first network device to the remote UE before the first timer times out, the relay UE determines that the SL between the relay UE and the remote UE is disconnected. It should be understood that the duration of the first timer is adjustable, and may be configured on the network side, preset, or configured by other terminal devices. The relay UE starts or restarts the first timer each time it receives or sends new and/or retransmitted data.
After the second terminal device determines that the sidelink is disconnected through detection, optionally, first indication information indicating that the sidelink between the second terminal device and the first terminal device is disconnected may be sent to the first network device, where the first indication information is used for the first network device to delete an association relationship between the first identifier and the first terminal device and/or routing information corresponding to the first terminal device, and the first identifier is allocated to the first terminal device by the second terminal device or the first network device and is used for identifying the first terminal device. Optionally, the first identifier is a local id.
As shown in fig. 3, a schematic view of the interaction of the process that the relay UE determines that the sidelink is disconnected and then sends the first indication information to the base station is shown. The specific process is as follows:
301, relay UE determines that its sidelink with remote UE is disconnected;
302, the relay UE sends the first indication information to the source base station.
The first indication information may be sidelink terminal information, where the sidelink terminal information does not carry a first target identifier and a local id corresponding to the first target identifier, and the first target identifier corresponds to the first identifier of the first terminal device. The correspondence may be pre-configured, or the second terminal device may inform the first network device. The sidelink terminal information may include the identities (e.g., dest l2 id) of all remote UEs to which the relay UE is connected and the local ids of all remote UEs to which the relay UE is connected.
Optionally, the first indication information sent by the second terminal device to the first network device may be sent only after all uplink/downlink data of the remote UE are forwarded, so as to inform the first network device that data transmission of the first terminal device is completed at this time, thereby further triggering the first network device to release the local id of the first terminal device. Or the first indication information may be sent first, and then after all data of the remote is forwarded, another indication for indicating that the data has been sent is sent, so as to further trigger the first network device to release the local id of the first terminal device. Specifically, optionally, the second terminal device receives second indication information sent by the first terminal device, where the second indication information indicates that a sidelink between the second terminal device and the first terminal device is disconnected. It should be appreciated that in many scenarios, a remote UE first perceives a sidelink disconnection, for example: in the RRC reestablishment process, the remote UE receives RRC release and RRC rejection sent by the network equipment; in the HO process, the remote UE receives a handover command sent by the first network equipment. The RRC release/reject message and the HO CMD message are encrypted and are transparently transmitted to the relay UE, and the relay UE cannot know the messages. Therefore, sending the second indication information to the relay UE before the relay UE leaves the relay UE may enable the relay UE to determine that the sidelink between the relay UE and the relay UE is disconnected.
Specifically, optionally, the second terminal device receives third indication information sent by the first network device, where the third indication information indicates that the sidelink between the second terminal device and the first terminal device is disconnected. In some application scenarios, a first network device first senses that a sidelink is disconnected, for example, in an RRC reestablishment process, the first network device receives a request sent by a second network device to acquire at least one of a context of the first terminal device and release the context of the first terminal device; it should be understood that the second network device is a target base station and the first network device is a source base station. For another example, the first network device receives a handover grant sent by the second network device during the HO procedure. The first network device first senses that a sidelink between the relay UE and the remote UE is about to be disconnected or is disconnected, and may send third indication information to the relay UE, and the relay UE determines that the sidelink between the relay UE and the remote UE is disconnected according to the third indication information.
Optionally, the second terminal device may determine that the sidelink between the second terminal device and the first terminal device is disconnected according to the logical channel configuration information, where the logical channel configuration information is related to the first terminal device. If the SL Logical Channels (LCHs) between the remote UE and the relay UE are all deleted, or the Uu LCH corresponding to the remote UE is deleted, the sidelink between the remote UE and the relay UE is considered to be disconnected.
The logical channel configuration is typically configured by the network side. The mapping relationship for SL LCH and Uu LCH may be 1:1 mapping, or N:1 mapping.
The 1:1 mapping relationship includes: the SL LCH between a remote UE and a relay UE is uniquely mapped to a Uu LCH between the relay UE and the base station, and the SL LCHs corresponding to different remote UEs are not multiplexed on the same Uu LCH, as shown in fig. 4. Therefore, the relay UE knows which Uu LCHs are associated with local ids, and the relay UE can determine which remote UE the sidelink is disconnected from according to the deletion of SL LCH or the deletion of Uu LCH.
N:1 the mapping relation comprises: SL LCHs between multiple remote UEs and a relay UE may be mapped to one Uu LCH between the relay UE and a base station, and SL LCHs corresponding to different remote UEs are multiplexed on the same Uu LCH, as shown in fig. 5. At this time, the relay UE cannot determine which remote UE the sidelink is disconnected with according to the deletion of the Uu LCH, because the relay UE does not know which Uu LCH is configured for the remote UE.
Therefore, regardless of the mapping relationship, the relay UE can determine which remote UE the sidelink is disconnected with only by deleting the configuration of the SL LCH, for example, if all SL LCHs corresponding to a certain remote UE are deleted, the relay UE is considered to be disconnected with the sidelink. If the 1:1 mapping relationship is adopted, the relay UE can also judge which remote UE the sidelink between the relay UE and the relay UE is disconnected according to the deletion of the Uu LCH.
In the technical scheme provided by the embodiment of the application, the relay UE can timely determine that the sidelink between the relay UE and the remote UE is disconnected, and delete the association relationship between the first identifier and the remote UE, so that the first identifier can be used for identifying other terminal devices, thereby avoiding that the other terminal devices cannot establish connection with the second terminal device when the identifier is used up.
An embodiment of the present application provides a communication method, which is applicable to a UE-Network relay application scenario, and as shown in fig. 6, a schematic flow chart of a communication method 600 according to an embodiment of the present application is shown.
The first terminal device forwards data through the second terminal device to communicate with the first network device, the first terminal device communicates with the second terminal device through a sidelink, and the first network device communicates with the second terminal device through a wireless network, wherein the first terminal device is called a remote UE, the second terminal device is called a relay UE, and the first network device may be a base station. The method may be performed by the first network device, or may be performed by a component of the first network device, such as a processor, a chip, or a system-on-a-chip, and is described as an example of the first network device.
The first network device determines 610 that the sidelink between the first terminal device and the second terminal device is disconnected.
And 620, the first network device deletes the association relationship between the first identifier and the first terminal device, the association relationship exists between the first identifier and the identifier of the second terminal device, the first identifier is used for identifying the first terminal device, and the first identifier is allocated to the second terminal device or the first network device for the first terminal device. Specifically, optionally, the first network device deletes the association relationship between the first identifier and the first terminal device, where the association relationship includes one or more of the following: and the first network equipment releases the first identifier and releases the context of the first terminal equipment.
Specifically, optionally, the first network device may determine the sidelink disconnection by itself through detection. And after the first network equipment receives the data of the first terminal equipment sent by the second terminal equipment, starting a second timer, and if the first network equipment does not receive the data of the first terminal equipment before the second timer is overtime, determining that the sidelink is disconnected. Or after the first network device sends the data of the first terminal device to the second terminal device, starting or restarting the second timer, and if the first network device does not send the data of the first terminal device to the second terminal device before the second timer times out, determining that the sidelink is disconnected. Optionally, the second timer may be configured by the network side (e.g., CN/RAN/gNB-CU/gNB-DU, etc.) to the UE or configured by the peer UE.
Specifically, optionally, the first network device may determine that the sidelink is disconnected according to the received fourth indication information sent by the second network device. The fourth indication information includes at least one of the following information: requesting to acquire the context of the first terminal device, releasing the context of the first terminal device, switching permission, and the like. And in the HO process, the first network equipment receives the switching permission sent by the second network equipment, acquires the context of the first terminal equipment or releases the context of the first terminal equipment, and then determines that the sidelink is disconnected. When the remote UE generates SL RLF, RRC is successfully rebuilt to other cells, the first network equipment receives at least one of a request sent by the second network equipment to acquire the context of the first terminal equipment and release the context of the first terminal equipment, and then the side link is determined to be disconnected; it should be understood that the second network device is a target base station and the first network device is a source base station.
Fig. 7 shows a schematic view of interaction of a handover permission procedure that a source base station receives a target base station during HO. The specific process is as follows:
701, reporting a measurement report to a source base station by remote UE;
702, the source base station makes a switching decision;
703, the source base station sends a switching request message to the target base station;
the target base station performs admission control to see whether the remote UE is allowed to switch into the local cell, and if so, sends a handover permission message, such as an ACK message, to the source base station.
705, after receiving the handover permission message sent by the target base station, the source base station sends a handover command to the remote UE.
In the HO process, after receiving a switching permission message sent by a target base station, a source base station determines that a sidelink between remote UE and relay UE is disconnected; or after the source base station sends the handover command to the remote UE, the source base station (the first network device) determines that the sidelink between the remote UE and the relay UE is disconnected.
706, after determining that the sidelink between the remote UE and the relay UE is disconnected, the first network device releases the local id, the routing information, and the UE context of the corresponding remote UE maintained by the first network device, and may send third indication information to the relay UE, where the third indication information is used to indicate that the sidelink is disconnected, so that the relay UE deletes the association between the first identifier and the first terminal device, and releases the first identifier.
Fig. 8 shows a schematic view of a flow of interaction in which the first network device sends the third indication information to the relay UE after receiving the handover permission message sent by the target base station. The specific process is as follows:
801, a source base station receives a switching permission message sent by a target base station;
802, the source base station sends a switching command to the remote UE;
803, the source base station sends the third indication information to the relay UE.
As shown in fig. 9, a schematic view of a process interaction is shown in which a source base station receives a request sent by a target base station to acquire a context of a first terminal device and release the context of the first terminal device in an RRC reestablishment process. The specific process is as follows:
901, remote UE sends RRC reestablishment request message to target base station;
902, after receiving the reestablishment request message, the target base station searches for the source base station of the remote UE according to the information carried in the reestablishment request message, and sends a request message requesting to acquire the context of the remote UE to the source base station; if the source base station receives the request message, the source base station determines that the sidelink between the remote UE and the relay UE is disconnected, and releases the local id, the routing information and the UE context of the corresponding remote UE maintained by the first network equipment.
903, after the RRC reestablishment is successful, the target base station receives a path switch request response (path switch request response) message sent by the AMF, and may send a notification message releasing the context of the remote UE to the source base station, and if the source base station receives the notification message releasing the context of the remote UE, it determines that the sidelink between the remote UE and the relay UE is disconnected. In the RRC reestablishment process, if the source base station receives a message sent by the target base station to acquire the context of the first terminal device or a message sent by the target base station to release the context of the first terminal device, it is determined that the sidelink is disconnected. Optionally, the source base station may send third indication information to the relay UE, where the third indication information is used to indicate that the sidelink is disconnected, so that the relay UE deletes the association relationship between the first identifier and the first terminal device, and releases the first identifier.
As shown in fig. 10, a schematic view of a process interaction is shown in which the first network device sends the third indication information to the relay UE after receiving the context message for acquiring/releasing the context message of the first terminal device sent by the target base station. The specific process is as follows:
1001, a source base station receives a context message for acquiring/releasing a first terminal device sent by a target base station;
1002, the source base station sends third indication information to the relay UE.
The first network device first senses that a sidelink between the relay UE and the remote UE is about to be disconnected or is disconnected, and may send third indication information to the relay UE, so that the relay UE deletes the association relationship between the first identifier and the first terminal device, and releases the first identifier.
Optionally, the first network device may perform logical channel configuration, and if the mapping relationship between the SL LCH and the Uu LCH is 1:1 mapping, the first network device may determine that the sidelink between the remote UE and the relay UE is disconnected according to deletion of the Uu LCH corresponding to the remote UE.
Specifically, optionally, when the second terminal device determines that the sidelink is disconnected by detecting itself, the second terminal device may send first indication information to the first network device, and the first network device receives the first indication information and determines that the sidelink is disconnected according to the first indication information.
Optionally, the first indication information may be side link terminal information, where the side link terminal information does not carry a first target identifier and a local id corresponding to the first target identifier, and the first target identifier corresponds to the first identifier of the first terminal device. The correspondence may be pre-configured, or the second terminal device may inform the first network device. The sidelink terminal information may be the identities of all remote UEs connected under the relay UE (e.g. dest l2 Id) and the local ids of all remote UEs connected under the relay UE.
Specifically, optionally, the first network device may receive second indication information sent by the first terminal device, and determine that the sidelink is disconnected according to the second indication information. For example, a remote UE that is handed off from the relay UE1 to the relay UE2, but is still in communication with the first network device, may send an indication to the first network device that its sidelink with the relay UE1 is broken after the remote UE establishes a communication connection with the relay UE 2.
The second indication information may also be a handover success message, and after the remote UE is successfully handed over from the relay UE1 to the relay UE2, the handover success message may be sent to the first network device, so that the first network device determines that the sidelink between the remote UE and the sidelink relay UE1 is disconnected.
In a UE-Network relay application scenario, when a Remote UE first senses disconnection of a sidelink between the Remote UE and the relay UE, before the sidelink is disconnected, the Remote UE may send a notification message, for example, a Remote release message, to the relay UE to notify the relay UE that the sidelink is disconnected. Since in many cases the messages received by the remote UE through the relay UE are encrypted and pass-through to the relay UE, e.g. radio resource control, RRC, release, radio resource control, RRC reject, handover command, etc. The relay UE releases the local id of the relay UE after receiving the notification message sent by the relay UE, and when a new relay UE wants to access the relay UE, the relay UE may allocate the local id to the new relay UE, so as to avoid that the local id is used up and the new relay UE cannot provide a terminal-to-network (U2N) forwarding service when accessing the relay UE.
An embodiment of the present application provides a communication method, which is applicable to a UE-Network relay application scenario, and as shown in fig. 11, a schematic flowchart of a communication method 1100 according to an embodiment of the present application is shown.
The first terminal device communicates with the first network device through the second terminal device forwarding data, the first terminal device communicates with the second terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network. The first terminal device is called remote UE, the second terminal device is called relay UE, and the first network device may be a base station. The method may be executed by the first terminal device, or may be executed by a component of the first terminal device, such as a processor, a chip, or a system of chips, and the method is described as an example executed by the first terminal device.
1110, the first terminal device determines to disconnect its sidelink connection with the second terminal device. Optionally, the first terminal device may sense the disconnection of the sidelink between the first terminal device and the second terminal device through self-detection, or may determine the disconnection of the sidelink between the first terminal device and the second terminal device according to the received indication information.
1120, before the first terminal device first senses and determines to disconnect the sidelink, the first terminal device may send second indication information to the second terminal device, or may send the second indication information to the first network device, where the second indication information is used to indicate disconnection of the sidelink.
Specifically, optionally, the first terminal device determines to disconnect the sidelink with the second terminal device according to one or more of the following: radio connection failure, handover failure.
Specifically, optionally, after the first terminal device sends data to the first network device through the second terminal device, starting a third timer, and if the first terminal device does not send data to the first network device through the second terminal device before the third timer times out, determining that the sidelink is disconnected; or, after receiving the data sent by the first network device through the second terminal device, the first terminal device starts or restarts the third timer, and if the first terminal device does not receive the data sent by the first network device before the third timer times out, it is determined that the sidelink is disconnected. Optionally, the third timer may be configured by the network side (e.g., CN/RAN/gNB-CU/gNB-DU, etc.) to the UE or configured by the peer UE.
Specifically, optionally, the first terminal device receives fifth indication information, where the fifth indication information indicates that the sidelink is disconnected. The fifth indication information includes at least one of the following information sent by the first network device: radio Resource Control (RRC) release, RRC rejection and switching command. In the HO process, if the first terminal equipment receives a switching command sent by the first network equipment, the first terminal equipment determines to disconnect the sidelink between the first terminal equipment and the second terminal equipment. In the RRC Reestablishment process, the first terminal device receives a radio resource control RRC Reestablishment (RRC request) notification sent by the second network device, where the RRC Reestablishment notification is sent to the first terminal device after the second network device successfully acquires the context of the first terminal device from the first network device, and then determines that the sidelink between the first terminal device and the second terminal device is disconnected. Or the first terminal equipment determines that the sidelink between the first terminal equipment and the second terminal equipment is disconnected after receiving the RRC release/RRC reject message sent by the first network equipment; for example, when the load of the first network device is high and the RRC connection of the first terminal device is to be disconnected, an RRC release/RRC reject message is sent to the first terminal device.
In addition, if the remote UE and the first network device successfully establish a connection through the Uu interface, it is determined that the sidelink between the remote UE and the second terminal device is disconnected.
Fig. 12 shows a schematic view of the interaction of the flow when the remote UE receives the handover command sent by the source base station during HO. The specific process is as follows:
1201, the remote UE reports a measurement report to the source base station;
1202, the source base station makes a switching decision;
1203, the source base station sends a switching request message to the target base station;
1204, the target base station performs admission control, and checks whether to allow the remote UE to switch into the local cell, and if so, sends a handover permission message, such as an ACK message, to the source base station;
1205, the source base station sends a handover command (HO CMD) message to the remote UE after receiving the handover permission message sent by the target base station, and releases the local id, routing information and UE context of the corresponding remote UE maintained by the first network device. In the HO process, if the remote UE receives the HO CMD, the UE determines to break a sidelink with the relay UE.
As shown in fig. 13, a schematic view of the interaction of the process of sending the second indication information to the relay UE after the remote UE receives the HO CMD is shown. The specific process is as follows:
1301, the source base station sends a switching request message to the target base station;
1302, the source base station sends a handover command to the remote UE after receiving the handover permission message sent by the target base station;
1303, after receiving the handover command, the remote UE determines to disconnect the sidelink from the relay UE, and may send second indication information to the relay UE, where the second indication information is used to indicate the sidelink to be disconnected, so that the relay UE releases the local id of the remote UE. Alternatively, the second indication information may be "Remote release".
As shown in fig. 14, a schematic view of the flow interaction that the remote UE sends the second indication information to the relay UE after receiving the RRC release/RRC reject message sent by the base station is shown. The specific process is as follows:
1401, when a remote UE receives an RRC release/RRC reject message sent by a base station, the remote UE determines to disconnect a sidelink between the remote UE and the remote UE;
1402, before disconnecting the side link between the relay UE and the remote UE, the remote UE sends second indication information to the remote UE, wherein the second indication information is used for indicating the side link to be disconnected, and the remote UE releases the local id of the remote UE. Optionally, the second indication information may also be "Remote release".
The embodiment of the application provides a communication method 1500, which is applied to a scene in which relay UE generates RLF and then performs RRC reconstruction. In this scenario, when a relay UE generates RLF and reestablishes to other cells, the underlying remote UE still assumes that the relay UE can access the network through the relay UE, i.e. the remote UE does not change the relay UE. It should be understood that there may be multiple remote UEs establishing communication connection with one relay UE, that is, one relay UE may forward data of multiple remote UEs.
Currently, a relay UE generates RLF, reselects a new cell, and initiates an RRC reestablishment request message, after which a reestablishment cell requests the original serving cell for the context of the relay UE, and if the request is successful, the relay UE receives an RRC reestablishment notification message from the network side, which means that the network side can reestablish the relay UE. However, in the existing technical solution, the second network device in the re-established cell cannot obtain the context of the remote UE in the relay UE from the first network device in the original serving cell. Therefore, the embodiment of the present application provides a communication method 700, which can obtain the contexts of relay UE and its lower remote UE at the same time.
As shown in fig. 15, a schematic flow chart diagram of a communication method 1500 of an embodiment of the present application is shown.
The second terminal device forwards data of at least one first terminal device to communicate with the first network device, the second terminal device communicates with the at least one first terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network. The first terminal device is called remote UE, the second terminal device is called relay UE, and the first network device may be a base station. The method may be executed by the second terminal device, or may be executed by a component of the second terminal device, such as a processor, a chip, or a system of chips, and the method is described as an example executed by the second terminal device. The communication method 1500 includes:
1510, the second terminal device sends a radio resource control, RRC, reestablishment request message or an RRC recovery request message to the second network device, where the RRC reestablishment request message or the RRC recovery request message includes sixth indication information, where the sixth indication information is used to indicate the second network device to obtain the context of the first terminal device from the first network device, the sixth indication information may also indicate the second network device to obtain the context of the second terminal device, and the sixth indication information may include some information indicating that the second terminal device is a relay UE.
Before the second terminal device sends a radio resource control, RRC, reestablishment request message to the second terminal device, the method further includes: RLF occurs at the second terminal equipment, and the wireless network communication connection between the second terminal equipment and the first network equipment is disconnected.
Optionally, the sixth indication information may be used to indicate that the second network device acquires the contexts of all the first terminal devices in the second terminal device from the first network device, and may also be used to indicate that the second network device acquires the contexts of the first terminal devices in the second terminal device from the first network device. Specifically, the sixth indication information includes an identifier of at least one first terminal device, and may further include an identifier of a second terminal device. The identifier of the first terminal device may be a C-RNTI, an inactive network temporary identifier (I-RNTI), and the like of the first terminal device. It should be understood that the sixth indication information may be explicit indication information or implicit indication information.
For example, remote UEs connected to the relay UE through the sidelink include remote UE1, remote UE2, remote UE3, or all remote UEs, the sixth indication information may include identities of remote UE1, remote UE2, and remote UE3, and the second network device may obtain contexts of remote UE1, remote UE2, and remote UE3 from the first network device according to the sixth indication information. The sixth indication may also include only the identity of the remote UE1, and the second network device may obtain only the context of the remote UE1 from the first network device according to the sixth indication, in which case only the remote UE1 may need to access the re-established cell or not change the relay UE.
Optionally, the sixth indication information may be included in the RRC reestablishment request message, or may be sent independently, which is not limited in this embodiment of the application.
As shown in fig. 16, a schematic flow interaction diagram is shown, in which a target base station acquires contexts of a relay UE and a remote UE thereunder according to an RRC reestablishment request message sent by the relay UE in an RRC reestablishment process. The specific process is as follows:
1601, relay UE has RLF;
1602, the relay UE sends an RRC reestablishment request message or an RRC recovery request message to the target base station of the reestablished cell, where the RRC reestablishment request message or the RRC recovery request message includes sixth indication information used for indicating the target base station to obtain a context of the relay UE under the relay UE from the source base station, and the sixth indication information may include an identifier of the relay UE under the relay UE;
1603, the target base station acquires the context of the remote UE under the relay UE from the source base station according to the sixth indication information.
In some possible implementation manners, the second terminal device does not need to send, to the second network device, sixth indication information indicating that the context of the first terminal device is acquired. After receiving a Radio Resource Control (RRC) reestablishment request message sent by a second terminal device, a second network device sends a context fetch message to a first network device, where the context fetch message only carries an identifier of the second terminal device, and if the first network device finds that many first terminal devices exist under the second terminal device, the first network device sends a context of all first terminal devices under the second terminal device and a context of the second terminal device to the second network device.
The second network device obtains the context of the second terminal device and the first terminal device therebelow, so that the second terminal device and the first terminal device therebelow can be accessed to the network together.
In addition, the second network device may obtain the local id corresponding to the first terminal device from the first network device according to the sixth indication information in the RRC reestablishment request message sent by the second terminal device, so as to facilitate data transmission of U2N.
To facilitate understanding of the technical solution, the assignment of the local id is briefly described.
The local id can be allocated by the relay UE and informs the network, or allocated by the network and informs the relay UE, and both schemes are possible.
Take the local id allocated by relay UE as an example. The remote UE sends a message, confirms that the message is the first message and confirms that the message needs to be forwarded to the base station according to SL L2id after receiving the message, receives SL 2id corresponding to the remote UE at the same time, distributes local id by the remote UE, associates C-RNTI and local id with SL L2id, generates corresponding routing information for subsequent data forwarding, and forwards the routing information to the network side. After receiving the first message forwarded by the relay UE, the network side associates the C-RNTI and the local id of the relay UE with the C-RNTI/S-TMSI of the remote UE or the context of the remote UE.
The following description will take the remote UE entering the connected (connected) state from the idle state as an example.
After discovering the relay UE, the remote UE establishes SL unicast connection with the relay UE, and sends an RRC establishment request message, which may be carried on one or more dedicated SL LCHs or multiplexed on an existing shared SL LCH for RRC establishment. It should be understood that the shared SL LCH is native to the R16 standard, allocated after establishing a PC5-S connection between two UEs. For example, for the Uu SRB0/1/2 messages, the protocol predefines carry the corresponding SRB messages over SL LCH4,5,6, respectively (since 4 LCHs have been defined in R16 for SL SRB, corresponding to unencrypted PC5-S signaling, secured but unencrypted PC5-S signaling, secured and encrypted PC5-S signaling, and SL RRC signaling, respectively); or after the UE establishes the RRC connection (mapping between Uu SRB0 and SL LCH is still predefined by the protocol), the base station configures mapping relationship between Uu SRB1/2 of a certain remote UE or all remote UEs and SL LCH or SL LCH id, respectively.
If the RRC establishment request message is carried on one/more specific SL LCHs, for example, SL LCH ═ 5 is the SL LCH dedicated to forwarding Uu RRC messages, all messages received by the relay UE from the specific SL LCH are considered not to be sent to itself and forwarded to the base station.
If the RRC setup request message is carried on the shared SL LCH, then an additional indication is needed to inform the relay UE that the message needs to be further forwarded to the base station, instead of the remote UE sending to and parsing by the relay UE. For example, a "0" indicates forwarding is required and a "1" indicates forwarding is not required, as indicated by a 1 bit.
If the relay UE receives the message from the SL LCH, and determines that the message needs to be further forwarded to the base station, and the relay UE determines that a local id has not been previously allocated to the relay UE through a remote UE layer2 identifier carried in a Media Access Control (MAC) header in the received SL data packet, the relay UE allocates an unused local id to the remote UE, and configures a default/default backhaul logical channel (default BH LCH) to the relay UE through the base station, and forwards the message through the default BH LCH.
The default BH LCH may be one or more configured by the base station for the relay UE.
If the default BH LCH is one, all Uu RRC messages which are finally sent to the base station of all remote UEs or RRC messages which are sent to all the remote UEs by the base station are multiplexed on the shared default BH LCH for transmission; in the process, an AL needs to carry a local id allocated by the relay UE to the remote UE between the relay UE and the base station. It should be understood that Relay UE maintains an association of SL L2Id (identity of remote UE) with local Id, and gNB maintains an association of identity of remote UE with C-RNTI and local Id of Relay UE.
If the default BH LCH is multiple, the relay UE can select an unoccupied default BH LCH from multiple default BH LCHs configured in advance aiming at the first message to be forwarded of the remote UE, and only transmits the RRC message corresponding to the remote UE by using the default BH LCH all the time; the downlink RRC message sent by the base station to the remote UE also always uses the dedicated SL default LCH of the remote UE; in this case, no AL is needed between the relay UE and the base station, and no local id is needed to be carried.
Still taking shared default BH LCH as an example, the base station replies RRC establishment message to the remote UE, and the RRC establishment message is also sent on default BH LCH configured for the remote UE in advance and carries the local id corresponding to the remote UE.
Any message received by relay UE from shared default BH LCH is not considered to be sent to the relay UE, and the message needs to be further forwarded to the remote UE, and the remote UE which is forwarded needs to find out the L2Id of the corresponding remote UE according to the local Id carried by the base station in the AL; and forwarded out on the dedicated SL LCH.
After receiving the RRC establishment message sent by the base station, the remote UE replies an RRC reestablishment completion message to the base station, bears the RRC on the dedicated SL LCH or the shared SL RRC and sends the RRC to the relay UE.
The relay UE receives the message from the exclusive SL LCH, judges that the local id is allocated to the remote UE before, and encapsulates the message and forwards the message to the base station without subdivision by using the allocated local id; meanwhile, the local id allocated to the remote UE before the AL layer carries the local id, which is sent to the base station on the dedicated default BH LCH.
If the base station receives the message from the special default BH LCH, the base station considers that the message is definitely sent to the base station by the remote UE and has an AL layer, so the base station analyzes the message according to the scheme with the AL and reads out the local id, and the base station knows that the subsequent RRC message is actually sent to the base station by the corresponding remote UE according to the association relation between the identity of the remote UE maintained by the base station and the C-RNTI and the local id of the relay UE, so that the corresponding remote UE is operated.
It should be understood that, for the same remote UE, the RRC establishment request message sent by the remote UE to the base station, the RRC establishment message replied by the base station, and the handover permission sent by the base station to the remote UE in the HO handover process all use the SL LCH and default BH LCH corresponding to the remote UE.
Multiple SL LCHs for a remote UE may be multiplexed on one Uu LCH, or LCHs for multiple remote UEs may be multiplexed on one Uu LCH.
Taking the uplink transmission of multiplexing multiple SL LCHs of a remote UE on a Uu LCH as an example, after receiving a data packet, the base station side needs to obtain local id in the AL layer to know which remote UE sent the data packet, and knows which Uu PDCP/SDAP entity corresponding to which SL LCH sent the data packet through the Uu/SL LCH/DRB identifier.
Taking a radio bearer (SRB) for uplink signaling as an example, as shown in fig. 17, if 3 SRBs (e.g., SRBs 0/1/2) of a remote UE1 are all mapped to the same Uu LCH, 2 PDCP entities, e.g., PDCP1 and PDCP2, of the remote UE1 and 3 RRC entities, e.g., RRC0, RRC1, and RRC2, of the remote UE1 are associated on one RLC entity on the base station side, and the RRC0 entity has no corresponding PDCP entity; the base station sends the local id and SL LCH identification carried in the AL layer to a corresponding PDCP/RRC entity of remote UE 1; wherein, the local id in AL received by the base station is filled by relay UE according to the association relationship between the identity of remote UE and the maintained local id, the LCH identity is filled by SL LCH identity information carried in a data packet received on SL LCH, or when RRC0/1/2 is multiplexed on a SL LCH, the SL LCH identity carried in the MAC header of the data packet is indistinguishable; therefore, it is necessary to add an indication RRC0/1/2 in the SL RLC layer, so that the relay UE knows which SL LCH identified data after receiving the uplink packet and parsing the uplink packet to the SL RLC, and fills the data in the uual.
The downlink SRB is similar, relay UE further analyzes and obtains local id and SL LCH identification on an AL layer which receives a data packet sent by a base station on a Uu LCH, the relay UE identifies which SL LCH of which remote UE is sent and handed to the corresponding remote UE and the RLC entity corresponding to the SL LCH through the two identifications, and finally the remote UE is sent to the corresponding remote UE; after receiving the data packet forwarded by the relay UE, the remote UE further forwards the data packet to the RLC entity corresponding to the corresponding SL LCH and further forwards the data packet to an upper layer (PDCP/RRC or SDAP, etc.) by analyzing the MAC header if the data packet is the own data packet.
In addition, there is a problem when transmitting uplink data to a remote UE: since the SL MAC of remote UE needs to fill the destination L2Id in the SL MAC header when transmitting SL data, the destination L2Id is also the L2Id of relay UE. In NR V2X R16, the L2Id is provided to the AS layer by an upper layer (e.g., APP layer or V2X layer), but since the upper layer of the SL AS layer of a remote UE is Uu upper layer, there is no V2X layer, and Uu APP layer does not provide the SL AS layer with the destination L2Id according to the prior art, the remote UE can only obtain the destination L2Id in the AS layer itself.
The scheme that can realize includes: the RRC/PDCP/SDAP/RLC entity binds with the destination L2Id and tells the remote UE about the destination L2Id of the relay UE packet by packet through an interlayer primitive when delivering data packets to the SL MAC. Or, the MAC obtains the binding relationship between the RLC entity and the destination L2Id in advance, and the destination L2Id does not need to be indicated packet by packet when the SL RLC subsequently loses packets to the SL MAC; the MAC searches for the binding relationship between the RLC entity obtained in advance and the destination L2Id according to which RLC entity the packet is coming from, so as to obtain the destination L2Id, without filling the destination L2Id in the SL MAC header and sending out.
How the MAC obtains the binding relationship of the RLC entity in advance may be that a network side (e.g., a base station) configures the remote UE through Uu RRC/SDAP/PDCP/NAS and other messages, and after receiving the configuration, the remote UE further forwards a corresponding configuration receiving layer to the SL MAC entity of the remote UE. Or the configuration from the relay UE to the remote UE, for example, the configuration is performed through SL PC5-S/RRC/SDAP/PDCP/RLC/MAC signaling, and the configuration receiving layer of the remote UE also parses and forwards the configuration to the SL MAC entity of the remote UE after receiving the configuration. For example, after receiving the binding relationship between the Uu PDCP and SL LCH from the base station, the remote UE knows that the destination L2Id associated with the Uu SDAP/RRC/PDCP entity corresponding to the bearer is the L2Id of the relay UE, and in this case, the L2Id of the relay UE has been obtained before. Or after establishing a SL link/connection for relay with the relay UE, the remote UE binds the corresponding SL RLC/MAC entity with the L2Id of the relay UE, so that the remote UE subsequently sends Uu RRC or Uu PDCP data to the corresponding SL RLC entity, and the RLC entity records the binding relationship between itself and the target L2Id, and may carry the L2Id of the relay UE when being delivered to the SL MAC entity, and the SL MAC entity may subsequently continue to be packetized and sent out, and the carried target L2Id is also the correct L2Id of the relay UE.
In a U2N scenario, it is assumed that a remote UE can support an inactive state, RRC reestablishment is performed after RLF or HOF occurs, after the remote UE selects or resides in a new remote UE, it needs to determine whether to initiate an event radio access network notification area update (RNAU), if a RAN in which the remote UE is located is the same as a radio access network code (RANAC) of a cell in which the new remote UE is located, the RNAU does not need to be triggered, and if the RANAC in which the remote UE is located is different from the RAN of the cell in which the new remote UE is located, the RNAU needs to be triggered. Therefore, the remote UE needs to obtain a source of system broadcast information related to the cell where the relay UE is located, such as RAN area identity, cell identity, or RANAC of the cell where the relay UE is located.
In addition, the remote UE needs to determine which type of RRC reestablishment request message to send according to all radio network temporary identity (full-RNTI) indication information provided in the system broadcast information of the cell where the relay UE is located, and whether the full-RNTI or the short radio network temporary identity (short-RNTI) is carried in the RRC reestablishment request message. Therefore, the remote UE also needs to obtain full-RNTI indication information provided in the system broadcast information of the cell where the relay UE is located.
Therefore, after a remote UE resides in a new relay UE, the remote UE may send indication information for acquiring RANAC to the relay UE, the relay UE replies RANAC to the remote UE after receiving the indication information, and after receiving the RANAC, the remote UE may determine whether to initiate an RNAU.
Optionally, the remote UE may also receive a system broadcast message periodically sent by the relay UE, and acquire the RANAC and the full-RNTI according to the received system broadcast message.
In a U2N scenario, if a remote radio resource control (RLF) occurs to a remote Radio Resource Control (RRC) UE and RRC reestablishment is performed, a Physical Cell Identity (PCI) of an original serving cell needs to be carried, so that a reestablishment base station finds the original serving base station corresponding to the remote UE according to the PCI to further obtain a context of the remote UE; or, when a remote UE is handed over, for example, before the remote UE is handed over to a target remote UE, the remote UE needs to report the PCI of the serving cell where the target remote UE is located, and reports the measurement report message or other messages to the original serving base station, so that the original serving base station finds the target serving base station corresponding to the remote UE according to the PCI, thereby performing handover preparation in advance. However, the acquisition of the PCI in the above two scenarios is not supported in the current protocol, and therefore, in order to support RRC reestablishment, the remote UE needs to obtain the PCI information of the serving cell of the original relay UE, and in order to support HO, the remote UE needs to obtain the PCI information of the serving cell of the target relay UE.
Optionally, the remote UE may send a request message for obtaining the PCI to the remote UE of the original serving cell, and the remote UE replies the PCI, and then the remote UE may send the obtained PCI to the target base station, and the target base station finds the original serving base station of the remote UE according to the PCI and obtains the context of the remote UE. The remote UE may also send a request message for obtaining the PCI to the relay UE of the target serving cell, where the relay UE replies to the PCI, and the remote UE may report the obtained PCI to the original serving base station, so that the original serving base station finds the target serving base station corresponding to the remote UE according to the PCI, thereby performing handover preparation in advance.
Optionally, the remote UE may receive a system broadcast message periodically sent by relay UE of the original serving cell/the target serving cell, and obtain PCI information of the original serving cell/the target serving cell according to the received system broadcast message.
The embodiment of the application is also suitable for the CU-DU framework and the CP-UP separation framework; for the CU-DU architecture, the gNB notifies the relay UE to release local id and remote UE context, which may specifically be:
the CU informs the relay UE directly, or,
the CU informs the relay UE via the DU, or,
the DU informs the relay UE directly, or,
the DU informs the relay UE via the CU.
Also, the relay UE informs the gNB to release the local id and the context of the remote UE, and may also be subdivided similarly: if the CU receives the message of relay UE, the CU releases or informs the DU to release the local id; or after the DU receives the message, the DU releases or informs the CU to release the local id;
remote UE local id release, and optionally Remote UE context release.
The release message may be sent by way of SL/Uu RRC/SIB/SDAP/PDCP/RLC/MAC CE/PHY (DCI/UCI/SCI), etc.; it may also be sent over SL PC5-S or Uu NAS.
An embodiment of the present application provides a communication apparatus 1800, and as shown in fig. 18, a schematic block diagram of the communication apparatus 1800 according to the embodiment of the present application is shown. The apparatus may be applied in a second terminal device.
The apparatus 1800 includes: a judging unit 1810 and a processing unit 1820, where the judging unit 1810 is configured to determine that the sidelink is disconnected; the processing unit 1820 is configured to delete an association relationship between a first identifier and the first terminal device, where the first identifier is used to identify the first terminal device, and the first identifier is allocated to the first terminal device by the second terminal device or the first network device.
Optionally, the processing unit 1820 is specifically configured to release the first identifier, and/or release the context of the first terminal device.
Optionally, the apparatus 1800 further includes a transceiver 1830, where the transceiver 1830 is configured to start a first timer after receiving the data sent by the first terminal device to the network device and/or after receiving the data sent by the first network device to the first terminal device;
the determining unit 1810 is specifically configured to determine that the sidelink is disconnected if the transceiving unit 1830 does not receive the data sent by the first terminal device before the first timer times out, and/or does not receive the data sent by the first network device to the first terminal device before the first timer times out.
Optionally, the transceiving unit 1830 is further configured to send first indication information to the first network device, where the first indication information indicates that the sidelink is disconnected.
Specifically, optionally, the first indication information may be sidelink terminal information, where the sidelink terminal information does not carry the first target identifier, and the first target identifier corresponds to the first identifier of the first terminal device.
Optionally, the determining unit 1810 is specifically configured to determine that the sidelink is disconnected if the transceiving unit 1830 receives second indication information sent by the first terminal device, where the second indication information indicates that the sidelink is disconnected.
Optionally, the determining unit 1810 is specifically configured to determine that the sidelink is disconnected if the transceiving unit 1830 receives third indication information sent by the first network device, where the third indication information indicates that the sidelink is disconnected.
Optionally, the determining unit 1810 is further configured to determine that the sidelink is disconnected according to a logical channel configuration, where the logical channel configuration is related to the first terminal device.
In an embodiment of the present application, a communication apparatus 1900 is provided, and as shown in fig. 19, a schematic block diagram of the communication apparatus 1900 according to the embodiment of the present application is shown. The apparatus may be applied in a first network device.
The apparatus 1900 includes: a judging unit 1910 and a processing unit 1920, wherein the judging unit 1910 is used for determining that the side link is disconnected; the processing unit 1920 is configured to delete an association relationship between a first identifier and a first terminal device, where the first identifier has an association relationship with an identifier of a second terminal device, the first identifier is used to identify the first terminal device, and the first identifier is allocated to the first terminal device by the second terminal device or the first network device.
Optionally, the processing unit 1920 is specifically configured to release the first identifier, and/or release the context of the first terminal device.
Optionally, the apparatus 1900 further includes a transceiver 1930, where the transceiver 1930 is configured to start a second timer after receiving the data of the first terminal device sent by the second terminal device and/or after sending the data of the first terminal device to the second terminal device;
the determining unit 1910 is specifically configured to, if the transceiving unit 1930 does not receive the data of the first terminal device before the second timer times out, and/or does not send the data of the first terminal device to the second terminal device before the second timer times out, determine that the sidelink is disconnected by the determining unit 1910.
Optionally, the determining unit 1910 is specifically configured to, if the transceiving unit 1930 receives fourth indication information sent by the second network device, where the fourth indication information includes at least one of the following information: requesting to acquire the context of the first terminal device, release the context of the first terminal device, and allow handover, the determining unit 1910 determines that the sidelink is disconnected.
Optionally, the transceiver 1930 is further configured to send third indication information to the second terminal device, where the third indication information indicates that the sidelink is disconnected.
Optionally, the determining unit 1910 is specifically configured to, if the transceiving unit 1930 receives first indication information sent by the second terminal device, where the first indication information indicates that the sidelink is disconnected, determine that the sidelink is disconnected by the determining unit 1910.
Optionally, the determining unit 1910 is specifically configured to, if the transceiver unit 1930 receives second indication information sent by the first terminal device, where the second indication information indicates that a sidelink is disconnected, the determining unit 1910 determines that the sidelink is disconnected.
An embodiment of the present application provides a communication apparatus 2000, and as shown in fig. 20, a schematic block diagram of the communication apparatus 2000 according to the embodiment of the present application is shown. The apparatus may be applied in a first terminal device.
The apparatus 2000 comprises: a judging unit 2010 and a transceiving unit 2020, the judging unit 2010 being configured to determine a sidelink disconnection; the transceiver 2020 is configured to transmit second indication information indicating the sidelink disconnection.
Optionally, the determining unit 2010 is specifically configured to determine to disconnect the sidelink connection according to one or more of the following: radio connection failure, handover failure, and a third timer.
Optionally, the determining unit 2010 is specifically configured to determine that the sidelink is disconnected, if the transceiver 2020 receives fifth instruction information, where the fifth instruction information is used to instruct disconnection of the sidelink.
Specifically, optionally, the fifth indication information includes at least one of the following information sent by the first network device: radio Resource Control (RRC) release, RRC rejection and switching command.
Specifically, optionally, the fifth indication information includes a radio resource control RRC reestablishment notification sent by the second network device.
Optionally, the transceiver 2020 is specifically configured to send the second indication information to the second terminal device.
Optionally, the transceiver 2020 is specifically configured to send the second indication information to the first network device. An embodiment of the present application provides a communication apparatus 2100, and as shown in fig. 21, a schematic block diagram of a communication apparatus 2100 according to an embodiment of the present application is shown.
The apparatus 2100 includes: a processor 2110 and a transceiver 2120, wherein the transceiver 2120 is configured to receive computer code or instructions and transmit the computer code or instructions to the processor 2110, and the processor 2110 executes the computer code or instructions, such as a method in any possible implementation manner in the embodiments of the present application.
The embodiment of the present application provides a communication system 2200, which includes a first terminal device 2210 and a second terminal device 2220 described in the communication method of the embodiment of the present application.
Optionally, the communication system 2200 may further include: the first network device 2230 in the communication method in the embodiment of the present application.
The embodiment of the present application also provides a computer-readable storage medium on which a computer program for implementing the method in the above method embodiment is stored. When the computer program runs on a computer, the computer is enabled to implement the method in the above-described method embodiments.
In the embodiments of the present application, unless otherwise specified or conflicting with respect to logic, the terms and/or descriptions in different embodiments have consistency and may be mutually cited, and technical features in different embodiments may be combined to form a new embodiment according to their inherent logic relationship.
In addition, the term "and/or" in the present application is only one kind of association relationship describing the associated object, and means that three kinds of relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship; the term "at least one", as used herein, may mean "one" and "two or more", e.g., at least one of A, B and C, may mean: a exists alone, B exists alone, C exists alone, A and B exist together, A and C exist together, C and B exist together, A and B exist together, and A, B and C exist together, which are seven cases.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (32)

1. A communication method is characterized in that a second terminal device forwards data of a first terminal device to communicate with a first network device, the second terminal device communicates with the first terminal device through a sidelink, and the second terminal device communicates with the first network device through a wireless network, and the method comprises the following steps:
determining that the sidelink is disconnected;
deleting the association relation between a first identifier and the first terminal device, wherein the first identifier is used for identifying the first terminal device, and the first identifier is allocated to the first terminal device by the second terminal device or the first network device.
2. The method of claim 1, wherein deleting the association relationship between the first identifier and the first terminal device comprises:
and releasing the first identifier and/or releasing the context of the first terminal equipment.
3. The method of claim 1 or 2, wherein the determining that the sidelink is disconnected comprises:
after receiving data sent by the first terminal device to the network device, and/or after receiving data sent by the first network device to the first terminal device, starting a first timer;
and if the data sent by the first terminal device is not received before the first timer is overtime, and/or the data sent by the first network device to the first terminal device is not received before the first timer is overtime, determining that the sidelink is disconnected.
4. The method of claim 3, further comprising:
and sending first indication information to the first network equipment, wherein the first indication information indicates that the sidelink is disconnected.
5. The method of claim 4, further comprising:
the first indication information is side link terminal information, the side link terminal information does not carry a first target identifier, and the first target identifier corresponds to the first identifier of the first terminal device.
6. The method of claim 1 or 2, wherein the determining that the sidelink is disconnected comprises:
and receiving second indication information sent by the first terminal equipment, wherein the second indication information indicates that the sidelink is disconnected.
7. The method of claim 1 or 2, wherein the determining that the sidelink is disconnected comprises:
and receiving third indication information sent by the first network equipment, wherein the third indication information indicates that the sidelink is disconnected.
8. The method of claim 7, further comprising:
determining the sidelink disconnection based on a logical channel configuration, the logical channel configuration being associated with the first terminal device.
9. Method according to any of claims 1 to 8, wherein said first identity is a local identity id.
10. A communication method is characterized in that a first terminal device communicates with a first network device by forwarding data through a second terminal device, the first terminal device and the second terminal device communicate through a sidelink, and the first network device and the second terminal device communicate through a wireless network, and the method comprises the following steps:
determining that the sidelink is disconnected;
deleting the association relation between a first identifier and the first terminal device, wherein the association relation exists between the first identifier and the identifier of the second terminal device, the first identifier is used for identifying the first terminal device, and the first identifier is allocated to the first terminal device by the second terminal device or the first network device.
11. The method of claim 10, wherein deleting the association relationship between the first identifier and the first terminal device comprises:
and releasing the first identifier and/or releasing the context of the first terminal equipment.
12. The method of claim 10 or 11, wherein the determining that the sidelink is disconnected comprises:
after receiving the data of the first terminal device sent by the second terminal device and/or after sending the data of the first terminal device to the second terminal device, starting a second timer;
and if the data of the first terminal device is not received before the second timer is overtime, and/or the data of the first terminal device is not sent to the second terminal device before the second timer is overtime, determining that the sidelink is disconnected.
13. The method of claim 10 or 11, wherein the determining that the sidelink is disconnected comprises:
receiving fourth indication information sent by a second network device, where the fourth indication information includes at least one of the following information:
requesting to acquire the context of the first terminal equipment, releasing the context of the first terminal equipment and allowing switching.
14. The method according to claim 12 or 13, characterized in that the method further comprises:
and sending third indication information to the second terminal equipment, wherein the third indication information indicates that the sidelink is disconnected.
15. The method of claim 10 or 11, wherein the determining that the sidelink is disconnected comprises:
and receiving first indication information sent by the second terminal equipment, wherein the first indication information indicates that the sidelink is disconnected.
16. The method of claim 10 or 11, wherein the determining that the sidelink is disconnected comprises:
and receiving second indication information sent by the first terminal equipment, wherein the second indication information indicates that the sidelink is disconnected.
17. A communication method is characterized in that a first terminal device communicates with a first network device by forwarding data through a second terminal device, the first terminal device and the second terminal device communicate through a sidelink, and the second terminal device and the first network device communicate through a wireless network, and the method comprises the following steps:
determining to disconnect the sidelink connection;
and sending second indication information, wherein the second indication information is used for indicating the side link to be disconnected.
18. The method of claim 17, wherein the determining to disconnect the sidelink connection comprises:
disconnecting the sidelink connection based on one or more of:
radio connection failure, handover failure, and a third timer.
19. The method of claim 17, wherein the determining to disconnect the sidelink connection comprises:
and receiving fifth indication information, wherein the fifth indication information is used for indicating to disconnect the connection of the sidelink.
20. The method of claim 19, wherein the fifth indication information comprises at least one of the following information sent by the first network device:
radio Resource Control (RRC) release, RRC rejection and switching command.
21. The method of claim 19, wherein the fifth indication information comprises a Radio Resource Control (RRC) reestablishment notification sent by the second network device.
22. The method according to any one of claims 17 to 21, wherein said sending second indication information comprises:
and sending the second indication information to the second terminal equipment.
23. The method according to any one of claims 17 to 21, wherein said sending second indication information comprises:
and sending the second indication information to the first network equipment.
24. A communication apparatus, characterized by comprising means for implementing the functionality of the method according to any of claims 1 to 9.
25. A communication apparatus, characterized by comprising means for implementing the functions of the method of any of claims 10 to 16.
26. A communication apparatus, characterized in that it comprises means for implementing the functions of the method according to any of claims 17 to 23.
27. A communications apparatus, comprising: a processor and a transceiver for receiving computer code or instructions and transmitting the computer code or instructions to the processor, the processor executing the computer code or instructions, the method of any of claims 1 to 9.
28. A communications apparatus, comprising: a processor and a transceiver for receiving computer code or instructions and transmitting the computer code or instructions to the processor, the processor executing the computer code or instructions, the method of any of claims 10 to 16.
29. A communications apparatus, comprising: a processor and a transceiver for receiving computer code or instructions and transmitting the computer code or instructions to the processor, the processor executing the computer code or instructions, the method of any of claims 17 to 23.
30. A communication system, comprising:
a first terminal device and a second terminal device in the method of any one of claims 1 to 23.
31. The communication system of claim 30, further comprising:
a first network device in the method of any one of claims 1 to 23.
32. A computer-readable storage medium, comprising:
the computer readable medium stores a computer program;
the computer program, when run on a computer, causes the computer to perform the method of any one of claims 1 to 23.
CN202010612136.3A 2020-06-30 2020-06-30 Communication method and device Pending CN113873580A (en)

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