Communication methods, devices, and systems

Abstract

An embodiment of the present application provides a communication method and its network node. The communication method can be applied to U2N relay communication between a UE and a network. In the communication method, a first network node gNB-CU sends first information to a second network node gNB-DU to trigger the second network node to assign a local identity to the remote UE, and the first network node receives second information from the second network node, the second information including the local identity assigned to the remote UE by the second network node. Alternatively, the first network node sends the first information to the second network node, the first information including the local identity assigned to the remote UE by the first network. The first network node or the second network node communicates with the remote UE through the relay UE. According to the method, the communication between the gNB-CU and the gNB-DU can support existing Layer-2 U2N relay communication.

Description

Technical Field

[0001] This application relates to the field of wireless communication, and in particular, to communication methods and devices, nodes, computer-readable storage media, and radio access network devices.

Background Art

[0002] The UE-to-Network relay (U2N Relay) technology between a user equipment (UE) and a network is a method in which a Relay UE provides relay communication to a Remote UE, and the Remote UE accesses a radio access network device via the Relay UE. The Relay UE communicates with the Remote UE through a PC5 interface, and the wireless communication link between the Relay UE and the Remote UE is called a sidelink (SL). The Relay UE and the network device perform wireless communication through an Un interface.

[0003] In a Layer 2 (L2) U2N relay protocol stack architecture, data packets from a remote UE are forwarded below the Packet Data Convergence Protocol (PDCP) layer of the relay UE. Specifically, the relay UE holds a relay Radio Link Control (RLC) bearer, which includes the RLC protocol layer, the Media Access Control (MAC) protocol layer, and the Physical Layer (PHY). Between the remote UE and the base station gNB, there are PDCP protocol layers, Service Data Adaptation Protocol (SDAP) protocol layers, and radio resource control (RRC) protocol layers for end-to-end communication, but there are no RLC, MAC, or PHY layers for end-to-end communication. Furthermore, in the L2 U2N relay protocol architecture, an Adaptation layer (ADAPT) is added between the RLC layer and the PDCP layer. The main functions of the adaptation layer include bearer multiplexing and demultiplexing, such as supporting multiplexing different bearers into one bearer or splitting one bearer into multiple different bearers.

[0004] In the Next Generation Radio Access Network (NG-RAN), a CU-DU separation architecture is used for base station gNBs. In other words, a base station gNB is logically divided into two parts: a Central Unit (CU) and a Distributed Unit (DU). The gNB-CU communicates with the gNB-DU via an F1 interface. However, the existing communication procedure between the gNB-CU and gNB-DU via the F1 interface cannot support L2 U2N relay communication. [Overview of the project]

[0005] Embodiments of the present invention provide a communication method and apparatus, a network node, a computer-readable storage medium, and a radio access network device to solve the problem that the F1 interface between a gNB-CU and a gNB-DU cannot support existing L2 U2N relay communication in a U2N relay scenario.

[0006] To achieve the above objectives, the following technologies are used in the embodiments of this application.

[0007] A communication method is provided according to the first aspect. The entity performing the communication method may be a first network device, or a functional module used in the first network device, a chip or chip system in a first network node, or a network entity or network device implementing the functionality of the first network node. The following explanation is provided using an example in which the implementing entity is a first network node. The communication method may include the first network node transmitting first information to a second network node, the first information being intended to trigger the second network node to assign a local identity to a remote terminal device, and the first network node receiving second information from the second network node, the second information including a local identity assigned to the remote terminal device by the second network node. Alternatively, the first network node transmits first information to the second network node, the first information including a local identity assigned to the remote terminal device by the first network node. The first or second network node communicates with the remote terminal device via a relay terminal device. Based on the communication method, the first network node can assign a local identity to a remote terminal device and notify the second network node of the local identity. Alternatively, the first network node can instruct the second network to assign a local identity to the remote terminal device. In this way, communication between the first network node (gNB-CU is used as an example) and the second network node (gNB-DU is used as an example) can support existing Layer 2 U2N relay communication.

[0008] Referring to the first aspect, in a possible implementation, the first network node receives third information transmitted by the second network node, the third information includes identity information of the remote terminal device on the first interface, which has been assigned to the remote terminal device by the second network node, or the third information includes identity information of the remote terminal device on the first interface, which has been assigned to the remote terminal device by the second network node, and identity information of the relay terminal device on the first interface, which has been assigned to the relay terminal device by the second network node, where the first interface is a communication interface between the first network node and the second network node. For example, based on the above process, the second network node (gNB-DU is used as an example) can assign identity information of the remote terminal device on the first interface to the terminal device, enabling the first network node (gNB-CU is used as an example) to know which relay terminal device is connected to the remote terminal, and to successfully transmit the configuration information necessary for relay services to the relay terminal device.

[0009] Referring to the first embodiment, possible implementations may further include the following optional actions: Operation 1: The first network node transmits the fourth information to the second network node, which includes the data radio bearer identity (DRB ID) information of the remote terminal device and the identity information of the first radio link control (RLC) bearer, with a correspondence existing between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer; the first network node receives the fifth information transmitted by the second network node, which includes the configuration information of the first RLC bearer generated by the second network node, where the first RLC bearer is the bearer between the remote terminal device and the relay terminal device, and a correspondence exists between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer; Operation 2: The first network node receives fifth information generated by the second network node, which includes the data radio bearer identity (DRB ID) information of the remote terminal device, the identity information of the first RLC bearer, and the configuration information of the first RLC bearer, where the first RLC bearer is the bearer between the remote terminal device and the relay terminal device, and a correspondence exists between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer; Operation 3: The first network node transmits the fourth information to the second network node, which includes the data radio bearer identity (DRB ID) information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer; the first network node receives the fifth information generated by the second network node, which includes the configuration information of the second RLC bearer, where the second RLC bearer is the bearer between the second network node and the relay terminal device, and a correspondence exists between the DRB ID information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer; or Operation 4: The first network node receives fifth information generated by the second network node, the fifth information including at least one of the following: data radio bearer identity (DRB ID) information of the remote terminal device, local identity of the remote terminal device, identity information of the second RLC bearer, and configuration information of the second RLC bearer, wherein the second RLC bearer is a bearer between the second network node and the relay terminal device, and a correspondence exists between the DRB ID information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer.

[0010] Referring to the first aspect, in a possible implementation, in operation 2 or operation 4, the method further includes the first network node transmitting the fourth information to the second network node, the fourth information being remote terminal Includes device identity information.

[0011] Referring to the first embodiment, in a possible implementation, the following: The fourth information further includes uplink transmission tunnel identity information, and there is a correspondence between the uplink transmission tunnel identity information and at least one of the following: remote terminal device DRB ID information, remote terminal device local identity, remote terminal device identity information, and second RLC bearer identity information, and the uplink transmission tunnel is used by the first network node to receive data from the second network node on the first interface; and / or the fifth information further includes downlink transmission tunnel identity information, and there is a correspondence between the downlink transmission tunnel identity information and at least one of the following: remote terminal device DRB ID information, remote terminal device local identity, remote terminal device identity information, and second RLC bearer identity information, and the downlink transmission tunnel is used by the first network node to transmit data to the second network node on the first interface. One of the following conditions must be satisfied.

[0012] For example, based on the process described above, a second network node (gNB-DU is used as an example) and another second network node (gNB-CU is used as an example) can configure the bearer settings for the remote terminal device and the required bearer settings for the relay terminal device, enabling the relay terminal device to provide relay services for data transmission between the relay terminal device and the network node.

[0013] Referring to the first aspect, in a possible implementation, a first network node receives first instruction information from a relay terminal device, the first instruction information includes identity information of a remote terminal device, the first instruction information is for requesting the assignment of a local identity to the remote terminal device, the local identity of the remote terminal device uniquely identifies the remote terminal device within the control of the first network node, or the local identity of the remote terminal device uniquely identifies the remote terminal device within the control of the relay terminal device.

[0014] Referring to the first aspect, in a possible implementation, the first information is a UE CONTEXT MODIFICATION REQUEST message from a relay terminal device, and the second information is a UE CONTEXT MODIFICATION RESPONSE message from a relay terminal device; the fourth information is a UE CONTEXT SETUP REQUEST message from a remote terminal device, and the fifth information is a UE CONTEXT SETUP RESPONSE message from a remote terminal device; or the third information is an Initial UL RRC Message Transfer message from a remote terminal device.

[0015] Referring to the first embodiment, in a possible implementation, the first network node includes a Radio Resource Control (RRC) protocol layer, a Service Data Adaptation Protocol (SDAP) protocol layer, and a Packet Data Convergence Protocol (PDCP) protocol layer, and the second network node includes a Radio Link Control (RLC) protocol layer, a Media Access Control (MAC) protocol layer, and a Physical PHY protocol layer, and the first and second network nodes belong to the same base station gNB.

[0016] Referring to the first aspect, in a possible implementation, a remote terminal device is switched from a third network node to a second network node, where the second network node is the target node in the switching process, the third network node is the source node in the switching process, and the first network node controls the second and third network nodes, and the following: The first piece of information is a UE CONTEXT SETUP REQUEST message from a remote terminal device, and the second piece of information is a UE CONTEXT SETUP RESPONSE message from a remote terminal device; or The fourth piece of information is the UE CONTEXT SETUP REQUEST message from the remote terminal device, and the fifth piece of information is the UE CONTEXT SETUP RESPONSE message from the remote terminal device. One of the following conditions must be satisfied.

[0017] Referring to the first embodiment, in a possible implementation, the third network node includes a radio link control RLC protocol layer, a media access control MAC protocol layer, and a physical PHY protocol layer, and the first network node, the second network node, and the third network node are included in a single base station gNB.

[0018] Referring to the first aspect, in a possible implementation, in operation 1 or operation 2, the method may further include the fourth information or fifth information further including a first identity, the first identity indicating a relay terminal device corresponding to a first RLC bearer.

[0019] The first identity is the relay terminal. device Identity, relay terminal device The serving cell identity is relayed by the first network node to the terminal. device The identity assigned to, or relay terminal by the second network node. device This is the identity assigned to it.

[0020] A communication method is provided according to a second aspect. The entity performing the communication method may be a second network device, or a functional module used in the second network device, a chip or chip system in a second network node, or a network entity or network device implementing the functionality of the second network node. The communication method may include the second network node receiving first information from the first network node, the first information being for triggering the second network node to assign a local identity to a remote terminal device, and the second network node transmitting second information to the first network node, the second information including a local identity assigned to the remote terminal device by the second network node. Alternatively, the second network node receives first information from the first network node, the first information including a local identity assigned to the remote terminal device by the first network node. The first or second network node communicates with the remote terminal device via a relay terminal device. Based on the communication method, the first network node can assign a local identity to the remote terminal device and notify the second network node of the local identity. Alternatively, the first network node can instruct the second network to assign a local identity to a remote terminal device. In this way, communication between the first network node (gNB-CU is used as an example) and the second network node (gNB-DU is used as an example) can support existing Layer 2 U2N relay communication.

[0021] Referring to the second aspect, in a possible implementation, the second network node transmits third information to the first network node, where the third information includes the identity information of the remote terminal device on the first interface assigned by the second network node to the remote terminal device, or the third information includes the identity information of the remote terminal device on the first interface assigned by the second network node to the remote terminal device and the identity information of the relay terminal device on the first interface assigned by the second network node to the relay terminal device. The first interface is the communication interface between the second network node and the first network node.

[0022] Referring to the second aspect, in a possible implementation, the method may include any one of the following operations: Any operation 1: The second network node receives the fourth information transmitted by the first network node. The fourth information includes the data radio bearer identity DRB ID information of the remote terminal device and the identity information of the first radio link control RLC bearer. There is a correspondence between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer. The second network node transmits the fifth information to the first network node. The fifth information includes the configuration information of the first RLC bearer generated by the second network node. The first RLC bearer is the bearer between the remote terminal device and the relay terminal device, and there is a correspondence between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer. Any operation 2: The second network node transmits the fifth information to the first network node. The fifth information includes the data radio bearer identity DRB ID information of the remote terminal device, the identity information of the first RLC bearer, and the configuration information of the first RLC bearer. The first RLC bearer is the bearer between the remote terminal device and the relay terminal device, and there is a correspondence between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer. Any operation 3: The second network node receives the fourth information sent by the first network node. The fourth information includes the data radio bearer identity (DRB ID) information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer. The second network node sends the fifth information to the first network node. The fifth information includes the configuration information of the second RLC bearer. The second RLC bearer is a bearer between the second network node and the relay terminal device, and there is a correspondence among the DRB ID information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer; or Any operation 4: The second network node sends the fifth information to the first network node. The fifth information includes the data radio bearer identity (DRB ID) information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer. The second RLC bearer is a bearer between the second network node and the relay terminal device, and there is a correspondence among the DRB ID information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer.

[0023] Referring to the second aspect, in a possible implementation, in operation 2 or operation 4, the method may further include the second network node receiving the fourth information sent by the first network node. The fourth information includes remote terminal device identity information.

[0024] Referring to the second aspect, in a possible implementation, the following: The fourth information further includes uplink transmission tunnel identity information, and there is a correspondence between the uplink transmission tunnel identity information and at least one of the following: remote terminal device DRB ID information, remote terminal device local identity, remote terminal device identity information, and second RLC bearer identity information, and the uplink transmission tunnel is used by the first network node to receive data from the second network node on the first interface, and / or The fifth piece of information further includes the identity information of the downlink transmission tunnel, and there is a correspondence between the identity information of the downlink transmission tunnel and at least one of the following: the DRB ID information of the remote terminal device, the local identity of the remote terminal device, the identity information of the remote terminal device, and the identity information of the second RLC bearer, and the downlink transmission tunnel is used by the first network node to transmit data to the second network node on the first interface. One of the following conditions must be satisfied.

[0025] Referring to the second aspect, in a possible implementation, the first information is a UE CONTEXT MODIFICATION REQUEST message from a relay terminal device, and the second information is a UE CONTEXT MODIFICATION RESPONSE message from a relay terminal device; the fourth information is a UE CONTEXT SETUP REQUEST message from a remote terminal device, and the fifth information is a UE CONTEXT SETUP RESPONSE message from a remote terminal device, or the third information is an Initial UL RRC Message Transfer message from a remote terminal device.

[0026] Referring to the second aspect, in a possible implementation, the first network node includes a Radio Resource Control (RRC) protocol layer, a Service Data Adaptation Protocol (SDAP) protocol layer, and a Packet Data Convergence Protocol (PDCP) protocol layer, and the second network node includes a Radio Link Control (RLC) protocol layer, a Media Access Control (MAC) protocol layer, and a Physical PHY protocol layer, and the first and second network nodes are included in a single base station gNB.

[0027] Referring to the second aspect, in a possible implementation, a remote terminal device is switched from a third network node to a second network node, where the second network node is the target node in the switching process, the third network node is the source node in the switching process, and the first network node controls the second and third network nodes, and the following: The first piece of information is a UE CONTEXT SETUP REQUEST message from a remote terminal device, and the second piece of information is a UE CONTEXT SETUP RESPONSE message from a remote terminal device, or The fourth piece of information is the UE CONTEXT SETUP REQUEST message from the remote terminal device, and the fifth piece of information is the UE CONTEXT SETUP RESPONSE message from the remote terminal device. One of the following conditions must be satisfied.

[0028] Referring to the second aspect, in a possible implementation, the third network node includes a radio link control RLC protocol layer, a media access control MAC protocol layer, and a physical PHY protocol layer, and the first network node, the second network node, and the third network node are included in a single base station.

[0029] Referring to the second aspect, in a possible implementation, in operation 1 or operation 2, the method may further include the fourth information or fifth information further including a first identity, the first identity indicating a relay terminal device corresponding to a first RLC bearer.

[0030] The first identity is the relay terminal. device Identity, relay terminal device The serving cell identity is relayed by the first network node to the terminal. device The identity assigned to, or relay terminal by the second network node. device This is the identity assigned to it.

[0031] A communication method is provided according to a third embodiment. The entity performing the communication method may be a first network device, or a functional module used in the first network device, a chip or chip system in a first network node, or a network entity or network device implementing the functions of the first network node. The following explanation will be provided using an example in which the implementing entity is a first network node. The communication method may include the first network node transmitting sixth information to a second network node, the sixth information including second instruction information, which instructs the second network node to set up a second radio link control RLC bearer between the second network node and a relay terminal device, the second RLC bearer being for carrying first data, the first data being data exchanged between a remote terminal device and the second network node or the first network node, and the first network node receiving seventh information transmitted by the second network node DU, the seventh information including configuration information for the second RLC bearer. The radio link control RLC bearer in this embodiment may also be called an RLC channel because it has the functionality of an RL channel. The details according to the method of this embodiment are as follows:

[0032] Referring to the third aspect, in a possible implementation, the second instruction information is remote terminal The second instruction information includes information about the signaling radio bearer SRB that needs to be set up for the device, or relay service authorization information for the relay terminal device.

[0033] Referring to a third aspect, in a possible embodiment, the first data is data carried by signaling radio bearers SRB0, SRB1, or SRB2 of the remote terminal device. For example, the data on SRB0, SRB1, and SRB2 of the remote terminal device may be multiplexed onto a single RLC bearer for transmission.

[0034] Referring to the third aspect, in a possible implementation, the sixth information is a UE CONTEXT SETUP REQUEST message, and the seventh information is a UE CONTEXT SETUP RESPONSE message.

[0035] Referring to the third aspect, in a possible implementation, the sixth information is the user device context. change The request is a UE CONTEXT MODIFICATION REQUEST message, and the seventh piece of information is the user device context. change This is the UE CONTEXT MODIFICATION RESPONSE message.

[0036] Referring to a third aspect, in a possible implementation, the first network node includes a Radio Resource Control (RRC) protocol layer, a Service Data Adaptation Protocol (SDAP) protocol layer, and a Packet Data Convergence Protocol (PDCP) protocol layer, the second network node includes a Radio Link Control (RLC) protocol layer, a Media Access Control (MAC) protocol layer, and a Physical PHY protocol layer, and the first and second network nodes are included in a single base station gNB.

[0037] A communication method is provided according to the fourth aspect. The entity performing the communication method may be a second network device, or a functional module used in the second network device, a chip or chip system in a second network node, or a network entity or network device implementing the functions of the second network node. The following explanation will be provided using an example in which the performing entity is a second network node. The communication method may include the second network node receiving sixth information transmitted by a first network node, the sixth information including second instruction information which instructs the second network node to set up a second radio link control RLC bearer between the second network node and a relay terminal device, the second RLC bearer being for carrying first data, the first data being data exchanged between a remote terminal device and the second network node or the first network node, and the second network node transmitting seventh information to the first network node DU, the seventh information including configuration information for the second RLC bearer.

[0038] Referring to the fourth aspect, in a possible implementation, the second instruction information is remote terminal The second instruction information includes information about the signaling radio bearer SRB that needs to be set up for the device, or the second instruction information includes relay service authorization information for the relay terminal device.

[0039] Referring to the fourth aspect, in a possible embodiment, the first data is data carried by signaling radio bearers SRB0, SRB1, or SRB2 of the remote terminal device. For example, the data on SRB0, SRB1, and SRB2 of the remote terminal device may be multiplexed onto a single RLC bearer for transmission.

[0040] Referring to the fourth aspect, in a possible implementation, the sixth information is a UE CONTEXT SETUP REQUEST message, and the seventh information is a UE CONTEXT SETUP RESPONSE message.

[0041] Referring to the fourth aspect, in a possible implementation, the sixth information is the user device context. change The request is a UE CONTEXT MODIFICATION REQUEST message, and the seventh piece of information is the user device context. change This is the UE CONTEXT MODIFICATION RESPONSE message.

[0042] Referring to the fourth aspect, in a possible implementation, the first network node includes a Radio Resource Control (RRC) protocol layer, a Service Data Adaptation Protocol (SDAP) protocol layer, and a Packet Data Convergence Protocol (PDCP) protocol layer, and the second network node includes a Radio Link Control (RLC) protocol layer, a Media Access Control (MAC) protocol layer, and a Physical PHY protocol layer, and the first and second network nodes are included in a single base station.

[0043] In accordance with a fifth aspect, the present application provides a communication device. The communication device may be a first network, or a chip or chip system within the first network, or a functional module configured to implement in a first network node a method according to either the first aspect or a possible design thereof. The communication device can implement functions performed by the first network node in the above aspects or possible designs, and the functions may be implemented by hardware running corresponding software. The hardware or software includes one or more modules corresponding to the functions.

[0044] For the technical effects of the fifth aspect, please refer to the technical sections of the first and third aspects. Further details are not provided here.

[0045] In accordance with a sixth aspect, the present application provides a communication device. The communication device may be a second network, or a chip or chip system within the second network, or a functional module configured to implement a method according to either the second aspect or a possible design thereof at a second network node. The communication device can implement functions performed by the second network node in the above aspects or possible designs, and the functions may be implemented by hardware running corresponding software. The hardware or software includes one or more modules corresponding to the functions. For example, the communication device may include a transceiver module and a processing module.

[0046] For the technical effects of the sixth aspect, please refer to the technical sections of the second and fourth aspects. Further details are not provided here.

[0047] A communication device is provided according to the seventh aspect, including a processor and memory. The memory is configured to store computer executable instructions. When the communication device is operating, the processor executes the computer executable instructions stored in memory, thereby the communication device performs a communication method according to any one of the first to fourth aspects.

[0048] A communication device is provided according to the eighth aspect, including a processor. The processor is coupled to memory and, after reading instructions from memory, is configured to execute a communication method according to any one of the first to fourth aspects according to the instructions.

[0049] In a possible implementation, the communication device further includes memory, which is configured to store computer instructions.

[0050] In possible implementations, the communication device further includes a communication interface, which is used by the communication device to communicate with other devices. For example, the communication interface may be a transceiver, an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or an associated circuit.

[0051] In possible implementations, the communication device may be a chip or a chip system. If the communication device is a chip system, it may consist of chips or include chips and other discrete devices.

[0052] In possible implementations, where the communication device is a chip or chip system, the communication interface may be an input / output interface, interface circuit, output circuit, input circuit, pin, associated circuit, etc., on the chip or chip system. The processor may be embodied as a processing circuit or logic circuit.

[0053] A computer-readable storage medium is provided according to the ninth aspect. The computer-readable storage medium stores instructions. When the instructions are executed by a computer, the computer may be able to execute a communication method according to any one of the first to fourth aspects.

[0054] A computer program product including instructions is provided according to the tenth aspect. When the computer program product is executed on a computer, the computer may be capable of executing a communication method according to any one of the first to fourth aspects.

[0055] A radio access network device is provided according to the eleventh aspect. For example, the radio access network device may be a base station gNB. The radio access network device includes at least one of the following: a first network node that performs a communication method according to either the first or third aspect, and a second network node that performs a communication method according to either the second or fourth aspect.

[0056] For the technical effects brought about by any design method in the fifth through eleventh aspects, please refer to the technical effects brought about by the various design methods in the first through fourth aspects. Further details are not provided here. [Brief explanation of the drawing]

[0057] [Figure 1(a)] This is a schematic diagram of a direct communication scenario between UEs according to an embodiment of the present invention. [Figure 1(b)] This is a control plane protocol stack architecture for communication between UE1 and UE2 on the PC5 interface, according to an embodiment of the present invention. [Figure 2] This is a schematic diagram of a communication network applicable to a U2N relay scenario according to an embodiment of the present invention. [Figure 3] A schematic diagram of the user plane protocol stack of a communication system according to an embodiment of the present invention. [Figure 4] This is a schematic diagram of the control plane protocol stack of a communication system according to an embodiment of the present invention. [Figure 5] This is a schematic diagram of a 5G communication system according to an embodiment of the present invention. [Figure 6] This is a schematic diagram of a gNB CU-DU isolation architecture according to an embodiment of the present invention. [Figure 7(a)] This is a schematic diagram of a communication system in a CU-DU isolation architecture applicable to an L2 U2N relay according to an embodiment of the present invention. [Figure 7(b)]This is a schematic diagram of a control plane protocol stack architecture in which the adaptation layer is located on the DU, according to an embodiment of the present invention. [Figure 7(c)] This is a schematic diagram of a user-plane protocol stack in which the adaptation layer is located on the DU, according to an embodiment of the present invention. [Figure 8] This is a schematic diagram of the structure of a communication device according to an embodiment of the present invention. [Figure 9(a)] This is a schematic diagram of a communication method according to an embodiment of the present invention. [Figure 9(b)] This is a schematic diagram of a communication method according to an embodiment of the present invention. [Figure 10] This is a schematic diagram of another communication method according to an embodiment of the present invention. [Figure 11] This is a schematic diagram of another communication method according to an embodiment of the present invention. [Figure 12] This is a schematic diagram of another communication method according to an embodiment of the present invention. [Figure 13] This is a schematic diagram of another communication method according to an embodiment of the present invention. [Figure 14] This is a schematic diagram of the structure of another communication device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0058] Before describing the embodiments of this application, some terms used in the embodiments are explained and described. These explanations and descriptions are intended to aid in understanding the embodiments of this application, but should not be construed as limiting the scope of protection required by the embodiments.

[0059] 1. Side Link In conventional wireless communication systems, UEs can communicate with each other via a wireless network, and data signals between UEs are relayed via access network devices. However, cellular networks centered on conventional access network devices (e.g., conventional base stations) have limitations in both data transmission quality and service range. To satisfy this requirement, proximity service (ProSe) communication emerged, allowing UEs to communicate directly with each other without using access network devices. This method can effectively reduce communication delays between UEs. Links for direct communication between UEs may be called sidelinks. The communication interface corresponding to a sidelink between UEs is the PC5 interface. Sidelinks are sometimes also called sidelink / sidelink / direct communication links, etc. The PC5 interface is sometimes also called the "sidelink interface" or "direct communication interface," etc. For example, Figures 1(a) and 1(b) are schematic diagrams of direct communication scenarios between UEs, respectively. Figure 1(a) shows that sidelink communication is performed between UE1 and UE2 via the PC5 interface. Sidelink communication can be applied to multiple scenarios, such as device-to-device (D2D), machine-to-machine (M2M), or vehicle-to-everything (V2X). Figure 1(b) shows the control plane protocol stack architecture for communication between UE1 and UE2 on the PC5 interface.It can be seen that both UE1 and UE2 have the Radio Resource Control (RRC) protocol layer, Packet Data Convergence Protocol (PDCP) protocol layer, Radio Link Control (RLC) protocol layer, Media Access Control (MAC) protocol layer, and PHY protocol layer, all for end-to-end communication.

[0060] 2. Broadcast, unicast, and groupcast communications on sidelinks Broadcast communication is similar to the broadcasting of system information by a base station. Specifically, an UE transmits broadcast service data externally without encrypting the data, and any other UE within its effective reception range can receive the broadcast service data if the UE is interested in the broadcast service.

[0061] Unicast communication is similar to data communication that takes place after an RRC connection has been set up between a UE and a base station, but the unicast connection must first be set up between the two UEs. After the unicast connection is set up, the two UEs can communicate data based on negotiated identities. The data may or may not be encrypted. Compared to broadcast communication, unicast communication is only possible between two UEs for which a unicast connection has been set up. In unicast communication, when sending data, the UE may send a source identity and a destination identity along with the data. The source identity may be the identity assigned to the unicast connection by the transmitting end UE, and the destination identity may be the identity assigned to the unicast connection by the peer end receiving UE.

[0062] Embodiments of this invention relate to a unicast communication process. Each unicast communication on a sidelink corresponds to a pair of Source Layer-2 Identifiers and Destination Layer-2 Identifiers (L2 IDs). The subheader of each sidelink Media Access Control Protocol Data Unit (MAC PDU) may include the Source L2 ID and Destination L2 ID, thereby ensuring that the data is transmitted to the correct receiving end.

[0063] Groupcast communication refers to communication between all UEs within a communication group, and any UE within the group can receive and transmit data for the Groupcast service.

[0064] 3. Radio Bearer (RB) A radio bearer is a general term for a set of protocol entities and configurations assigned to a UE by a base station, typically a service provided by Layer 2 for the communication of user data between the UE and the base station. A radio bearer includes a set of resources assigned, such as PDCP protocol entities, RLC protocol entities, MAC protocol entities, and PHY protocol entities. Radio bearers are classified into Data Radio Bearers (DRBs) and Signaling Radio Bearers (SRBs). The former is for carrying data, and the latter is for carrying signaling messages. In sidelink communication scenarios, a radio bearer is called a Sidelink Radio Bearer (SLRB), and includes Sidelink Data Radio Bearers (DRBs) and Sidelink Signaling Radio Bearers (SRBs).

[0065] 4. RLC Bearer An RLC bearer may be a protocol entity and configuration at and below the RLC layer, and may include an RLC protocol entity and a set of resources such as a logical channel. Embodiments of the present application relate to two types of RLC bearers, namely Uu RLC (Uu RLC) bearers and PC5 RLC (PC5 RLC) bearers. A Uu RLC bearer is an RLC bearer on a Uu link (or Uu interface), and a PC5 RLC bearer is an RLC bearer on a side link (or PC5 interface).

[0066] 5. U2N Relay To improve network performance, for example, to improve network coverage, a Relay UE is used to facilitate communication between a Remote UE and network devices. Figure 2 is a schematic diagram of a communication network applicable to a U2N relay scenario. The base station communicates with the Relay UE via the Uu interface, and the Relay UE communicates with the Remote UE via the PC5 interface / sidelink. The Remote UE can set up a communication connection to the base station via the Relay UE. In a U2N relay scenario, the Relay UE provides relay services to the Remote UE.

[0067] Existing U2N relay technology primarily includes two designs: Layer 2 (L2) relays and Layer 3 (L3) relays. See Figure 3. L2 relays are used as an example to describe the user plane protocol stack of the communication network shown in Figure 2. Figure 3 shows the user plane protocol stack of a communication system including remote UEs, relay UEs, base station gNBs, and 5G Core Network (5GC) devices. The remote UE's protocol stack, from top to bottom, includes the Internet Protocol (IP) layer, the Service Data Adaptation Protocol (SDAP) (or Uu-SDAP) layer for peer-to-peer communication with the gNB via the Uu interface, the Packet Data Convergence Protocol (PDCP) (or Uu-PDCP) layer for peer-to-peer communication with the gNB via the Uu interface, the Adaptation layer (ADAPT), the Radio Link Control (RLC) (or PC5-RLC) layer for peer-to-peer communication with the relay UE via the PC5 interface, the Media Access Control (MAC) (or PC5-MAC) layer for peer-to-peer communication with the relay UE via the PC5 interface, and the Physical (PHY) layer (or PC5-PHY) layer for peer-to-peer communication with the remote UE. The protocol stack for communication between a relay UE and a remote UE, from top to bottom, includes the adaptation layer, PC5-RLC layer, PC5-MAC layer, and PC5-PHY layer. The protocol stack for communication between a relay UE and a gNB, from top to bottom, includes the ADAPT layer, Uu-RLC layer, Uu-MAC layer, and Uu-PHY layer.In gNB, the protocol stack for communication with remote UEs includes, from top to bottom, the Uu-SDAP layer and the Uu-PDCP layer. In gNB, the protocol stack for communication with relay UEs includes, from top to bottom, the ADAPT layer, the Uu-RLC layer, the Uu-MAC layer, and the Uu-PHY layer. In gNB, the protocol stack for communication with 5GC via the GPRS Tunneling Protocol-User Plane (GTP-U) interface includes the N3 protocol stack. In 5GC, the protocol stack for communication with remote UEs includes the IP layer, and the protocol stack for communication with gNB via the GTP-U interface includes the N3 protocol stack.

[0068] Figure 4 shows the control plane protocol stack of a communication system including a remote UE, relay UE, gNB, and 5GC device. The protocol stack of the remote UE, from top to bottom, includes a non-access stratum (NAS) for peer-to-peer communication with the 5GC, an RRC layer (or Uu-RRC layer) for peer-to-peer communication with the gNB via the Uu interface, a PDCP layer (or Uu-PDCP layer) for peer-to-peer communication with the gNB via the Uu interface, an ADAPT layer, an RLC layer (or PC5-RLC layer) for peer-to-peer communication with the relay UE via the PC5 interface, and a MAC layer (or PC5-MAC layer) and a PHY layer (or PC5-PHY layer) for peer-to-peer communication with the relay UE via the PC5 interface. The protocol stack of the relay UE for communication with the remote UE, from top to bottom, includes the ADAPT layer, PC5-RLC layer, PC5-MAC layer, and PC5-PHY layer. The protocol stack for communication between the relay UE and the gNB, from top to bottom, includes the ADAPT layer, Uu-RLC layer, Uu-MAC layer, and Uu-PHY layer. The protocol stack for communication between the gNB and the remote UE, from top to bottom, includes the Uu-RRC layer and the Uu-PDCP layer. The protocol stack for communication between the gNB and the relay UE, from top to bottom, includes the ADAPT layer, Uu-RLC layer, Uu-MAC layer, and Uu-PHY layer. The protocol stack for communication between the gNB and the 5GC device via the N2 interface includes the N2 protocol stack. The protocol stack for communication between the 5GC device and the remote UE includes the NAS layer. The protocol stack for communication between the 5GC device and the gNB via the N2 interface includes the N2 protocol stack.

[0069] It can be seen that data packets from the remote UE are relayed below the PDCP (Packet Data Convergence Protocol) layer of the relay UE. That is, the relay UE may only have an RLC bearer containing the RLC layer, MAC layer, and PHY, which are for relaying purposes. Therefore, there are end-to-end PDCP, SDAP, and RLC layers between the remote UE and the base station, but there are no end-to-end RLC, MAC, and PHY layers between the remote UE and the base station.

[0070] Furthermore, in the protocol stack architecture shown in Figure 3 or Figure 4, there is an adaptation layer between the RLC layer and the PDCP layer. The main function of the adaptation layer is to support bearer multiplexing and demultiplexing, that is, multiplexing different bearers into one bearer or separating one bearer into different bearers. The adaptation layer in the protocol stack at both ends of the PC5 interface (i.e., sidelink) is sometimes called the PC5 adaptation layer, and the adaptation layer in the protocol stack at both ends of the Uu interface is sometimes called the Uu adaptation layer.

[0071] The downlink direction is used as an example. The gNB's adaptation layer can multiplex data from multiple bearers of one or more remote UEs into a UuRLC bearer. That is, one RLC bearer on a Uu link can carry data from multiple bearers of one or more remote UEs. On each remote UE's sidelink, data from one or more bearers of the remote UE can be mapped to a single PC5 RLC bearer. The case in the uplink direction is similar to the case in the downlink direction. The remote UE's adaptation layer can map data from multiple bearers of the remote UE to a single PC5 RLC bearer. The relay UE's adaptation layer can multiplex data from different RLC bearers of one or more remote UEs into a single RLC bearer on a Uu link, thereby implementing bearer multiplexing.

[0072] To distinguish data belonging to different remote UEs, each remote UE needs to be assigned a remote UE ID, which is a remote UE identity. This identity is sometimes called a local identity (local ID), and the local ID is carried in the data packet routing process to indicate the remote UE to which the data belongs. The local ID of a remote UE can be assigned by the gNB providing services to the relay UE. The local ID assigned by the gNB can be unique within the gNB's control or unique within the relay UE's control. In possible assignment schemes, after the remote UE sets up a unicast connection to the relay UE, the relay UE sends an RRC message, such as a SidelinkUEInformationNR (SUI) message, to the gNB requesting that the gNB assign a local ID to the remote UE using the RRC message.

[0073] 6. CU-DU Architecture Figure 5 is a schematic diagram of a 5G communication system. The Next Generation Radio Access Network (NG-RAN) consists of one or more base station gNBs connected to the 5G core network (5GC). The gNBs are connected to the 5GC via the NG interface, and the gNBs are connected to each other via the Xn interface. In short, in a CU-DU separation architecture, one gNB is divided into a Central unit (CU) and one or more Distributed Units (DU). The gNB-CU is connected to the gNB-DU via the F1 interface. Typically, one gNB-DU can be connected to only one gNB-CU.

[0074] In a CU-DU isolation architecture, the gNB-CU can be involved in the RRC protocol layer, the SDAP protocol layer, and the PDCP protocol layer. In other words, the gNB-CU has the functionality of the RRC protocol layer, the SDAP protocol layer, and the PDCP protocol layer. The gNB-DU can be involved in the RLC protocol layer, the MAC protocol layer, and the PHY protocol layer. In other words, the gNB-DU has the functionality of the RLC protocol layer, the MAC protocol layer, and the PHY protocol layer.

[0075] Referring to Figure 5, Figure 6 is a schematic diagram of the gNB CU-DU separation architecture. The gNB-CU is further divided into a user plane (UP) and a control plane (CP). That is, the gNB-CU can be divided into two parts, namely gNB-CU-CP and gNB-CU-UP. The gNB-CU-CP is connected to the gNB-CU-UP by the E1 interface. The gNB-CU-CP is connected to the AMF by the NG control plane (NG-C) interface. The gNB-CU-CP is connected to another gNB by the Xn control plane (Xn-C) interface. The gNB-CU-CP is connected to the gNB-DU by the F1 control plane (F1-C) interface. The gNB-CU-UP is connected to the gNB-DU by the F1 user plane (F1-U) interface. Typically, one gNB-CU-UP may be connected to only one gNB-CU-CP, one gNB-DU may be connected to multiple gNB-CU-UPs managed by a gNB-CU-CP, and one gNB-CU-UP may be connected to multiple gNB-DUs managed by a gNB-CU-CP.

[0076] In an architecture where gNB-CU is divided into gNB-CU-CP and gNB-CU-UP, the control plane is handled by gNB-CU-CP, which is involved with RRC and the PDCP entity corresponding to SRB (also called PDCP-C). In other words, gNB-CU-CP has the functionality of the RRC protocol layer entity and the functionality of the PDCP entity corresponding to SRB (PDCP-C). The user plane is handled by gNB-CU-UP, which is involved with SDAP and the PDCP entity corresponding to DRB (also called PDCP-U). In other words, gNB-CU-UP has the functionality of the SDAP protocol layer and the functionality of the PDCP entity corresponding to DRB (PDCP-U).

[0077] From the above, it can be seen that in the existing gNB-CU-DU separation architecture, the Uu interface adaptation layer applicable to L2 U2N relay communication is not configured in the gNB CU or gNB DU. As a result, the existing F1 interface procedure cannot support L2 U2N relay communication. For example, a UE in the background communicates directly with the gNB-DU based on the Uu interface configuration. However, in the L2 U2N relay architecture, a Uu adaptation layer is added between the base station and the relay UE, and the base station must configure the remote UE and relay UE to support remote UEs that communicate with the base station via relay UE relay. Therefore, the existing F1 interface procedure is no longer applicable to L2 U2N relay.

[0078] In light of this, embodiments of the present invention relate to a method for solving the problem that existing CU-DU isolation architectures and F1 interface procedures are not applicable to L2 U2N relays. For example, when L2 U2N relays are applied to a CU-DU architecture, one or more of the following problems must be solved: How is the local ID of a remote UE generated and communicated to the relay UE? • Is the Uu adaptation layer within gNB located in the CU or DU? How should the adaptation layer settings be generated? • Will the new UE initial access procedure be designed to support successful access to remote UEs? • Will the new InterDU (Inter gNB-DU) switch procedure be managed by the same CU designed to support the mobility of remote UEs?

[0079] Referring to the accompanying drawings in embodiments of this application, the following describes the technical solutions provided in embodiments of this application. In this application, unless otherwise specified, " / " represents a "logical OR" relationship between related objects. For example, A / B represents A or B. In this application, "and / or" describes only an association relationship between related objects and indicates that three relationships may exist. For example, A and / or B can represent the following three cases: A exists only, both A and B exist, and B exists only, where A or B may be singular or plural. Furthermore, in this application, "plural" means two or more unless otherwise specified. "At least one of the following..." or similar expressions mean any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, or c may represent a, b, c, a and b, a and c, b and c, or a, b and c, where a, b, and c may be singular or plural. Furthermore, in order to clearly describe the technical solutions in the embodiments of this application, terms such as “first” and “second” are used in the embodiments of this application to distinguish the same or similar items that perform essentially the same function or purpose. Those skilled in the art will understand that terms such as “first” and “second” do not limit the number or order of execution, and that terms such as “first” and “second” do not indicate a clear distinction. Furthermore, in the embodiments of this application, words such as “example” or “for example” are intended to indicate that an example, illustration, or description is being given. Embodiments or design schemes described as “example” or “for example” in the embodiments of this application should not be described as having more advantages than other embodiments or design schemes. Indeed, the use of words such as "example" or "for example" is intended to specifically represent related concepts in order to facilitate understanding.

[0080] Furthermore, the network architecture and service scenarios in the embodiments of this application are intended to more clearly describe the technical solutions in the embodiments of this application and do not constitute a limitation on the technical solutions provided in the embodiments of this application. Those skilled in the art will recognize that, with the evolution of network architectures and the emergence of new service scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0081] In the embodiments of the present invention, the network node is a radio access network (RAN) device or a component of an access network device within a wireless communication network. For example, the first network node in the embodiment may be a CU in a gNB, and the second network node may be a DU in a gNB.

[0082] The terminal device in the embodiments of this application, also called user equipment (UE), mobile station (MS), or mobile terminal (MT), is a device that provides voice / data connectivity to a user, such as a handheld communication device or an in-vehicle communication device with wireless connectivity. Specifically, the terminal device may be a mobile phone, tablet computer, notebook computer, palmtop computer, mobile internet device (MID), wearable device, virtual reality (VR) device, augmented reality (AR) device, wireless terminal in industrial control, wireless terminal in self-driving, wireless terminal in remote medical surgery, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, and the like. Alternatively, the terminal device may be a roadside unit (RSU) in a vehicle-to-everything communication system, or a communication device or communication chip within an RSU. This is not limited to the embodiments of the present invention.

[0083] Figure 7(a) is a schematic diagram of a communication system for an L2 U2N relay in a CU-DU separation architecture to which embodiments of the present invention are applicable. The base station gNB consists of two parts: a first network node CU and a second network node DU. The first network node CU communicates with the second network node DU via an F1 interface. The relay UE communicates with the DU in the base station via a Uu interface. The remote UE communicates with the relay UE via a sidelink, and the interface between the remote UE and the relay UE is a PC5 interface. The relay UE may be located within the cell coverage of the gNB. The remote UE may be located within the cell coverage of the gNB, or it may move outside the cell coverage of the gNB. If the remote UE moves outside the cell coverage of the gNB, data from the remote UE may be relayed via the relay UE to implement user plane interactions and signaling plane interactions between the remote UE and the base station. Figure 7(b) is a schematic diagram of a control plane protocol stack architecture in which the adaptation layer is located on the DU. The CU comprises an RRC layer and a PDCP layer, while the DU comprises an adaptation ADAPT layer, an RLC layer, a MAC layer, and a PHY layer. Schematically, two RRC+PDCP entities are configured in the CU, corresponding to different SRBs. Figure 7(c) is a schematic diagram of a control plane protocol stack architecture in which the adaptation layer is located on the DU. The CU comprises an SDAP layer and a PDCP layer, while the DU comprises an adaptation ADAPT layer, an RLC layer, a MAC layer, and a PHY layer. Schematically, two SDAP+PDCP entities are configured in the CU, corresponding to different DRBs.

[0084] Based on the communication system provided in Figure 7(a), Figure 8 is a schematic diagram of the structure of a communication device 80 according to an embodiment of the present application. When the communication device 80 has the function of a first network node in an embodiment of the present application, the communication device 80 may be a first network node, or a chip or chip system within the first network node. When the communication device 80 has the function of a second network node in an embodiment of the present application, the communication device 80 may be a second network node, or a chip or chip system within the second network node. Indeed, the first network node or the 2 The implementation of a network node is not limited to the communication device 80, or the first network node or the 1 It may also be a logical network entity that possesses the functionality of a network node.

[0085] As shown in Figure 8, the communication device 80 may include a processor 801, a communication line 802, and a communication interface 803. Optionally, the communication device 80 may further include a memory 804. The processor 801, memory 804, and communication interface 803 may be connected to each other by the communication line 802.

[0086] The processor 801 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Alternatively, the processor 801 may be another device with processing capabilities, such as a circuit, component, or software module.

[0087] Communication line 802 is for transferring information between components included in the communication device 80.

[0088] The communication interface 803 is configured to communicate with other devices or other communication networks. Other communication networks may include Ethernet, radio access networks (RAN), wireless local area networks (WLAN), etc. The communication interface 803 may be a radio frequency module or any device capable of implementing communication. In this embodiment of the application, only examples where the communication interface 803 is a radio frequency module are used for description. The radio frequency module may include an antenna, a radio frequency circuit, etc. The radio frequency circuit may include a radio frequency integrated chip, a power amplifier, etc.

[0089] Memory 804 is configured to store instructions. These instructions may be computer programs.

[0090] Memory 804 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and / or instructions, a random access memory (RAM) or other type of dynamic storage device capable of storing information and / or instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or other optical disc storage, optical disc storage, or magnetic disc storage or other magnetic storage device. Optical disc storage includes compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.

[0091] The memory 804 may exist independently of the processor 801, or it may be integrated with the processor 801. The memory 804 may be configured to store instructions, program code, some data, etc. The memory 804 may be located in the communication device 80, or it may be located outside the communication device 80. This is not limited to the memory 804. The processor 801 is configured to execute instructions stored in the memory 804 in order to implement the communication method provided in subsequent embodiments of the present application.

[0092] Alternatively, and optionally, in this embodiment of the Application, the processor 801 may implement processing-related functions in a communication method provided in subsequent embodiments of the Application, and the communication interface 803 may engage in communication with other devices or communication networks. This is not particularly limited in this embodiment of the Application.

[0093] Optionally, the computer executable instructions in this embodiment of the Application may also be called application program code. This is not particularly limited in this embodiment of the Application.

[0094] In this example, the processor 801 may include one or more CPUs, for example, CPU0 and CPU1 in Figure 8.

[0095] In any implementation, the communication device 80 may include multiple processors. For example, in Figure 8, the communication device 80 may include processor 807 in addition to processor 801.

[0096] In any implementation, the communication device 80 is an output device 805 and input devices 806 It may further include, for example, input devices 806 This refers to devices such as keyboards, mice, microphones, or joysticks, and output devices. 805 This refers to a device such as a display or speaker.

[0097] Furthermore, the configuration shown in Figure 8 does not constitute any limitation on the communication device. In addition to the components shown in Figure 8, the communication device may include more or fewer components, combinations of some components, or different component arrangements than those shown.

[0098] In this embodiment of the present application, the chip system may consist of chips, or it may include chips and other discrete components.

[0099] Referring to the communication system shown in Figure 7(a), the following describes the communication method provided in the embodiments of the present application. Network nodes in subsequent embodiments may comprise the components or structures shown in Figure 8. The operations, terminology, etc., in the embodiments of the present application may be referenced to one another, but are not limited thereto. The names of messages exchanged between devices, the names of parameters within messages, etc., in the embodiments of the present application are merely examples. Other names may be used alternatively in specific implementations, but are not limited thereto.

[0100] A novel F1 interface signaling procedure provided in an embodiment of the present invention, which supports communication of remote UEs, can enable L2 U2N relay communication in a CU-DU architecture. In an embodiment of the present invention, the adaptation layer may be configured in the CU or in the DU. An example in which the adaptation layer is configured in the DU is used in a subsequent embodiment to provide an initial access procedure, an inter-DU switch procedure, and a UE context release procedure for a remote UE in a CU-DU.

[0101] Referring to the communication system shown in Figure 7(a), Figure 9(a) shows a communication method according to an embodiment of the present invention. As shown in Figure 9(a), the method relates to a first network node (e.g., CU) and a second network node (e.g., DU). The method may include the following steps.

[0102] S901: The first network node transmits the first information to the second network node.

[0103] For example, the first piece of information is intended to trigger a second network node to assign a local identity to a remote terminal device. It can be understood that S901 is an optional step.

[0104] The first or second network node communicates with the remote terminal device via a relay terminal device.

[0105] S902: The second network node transmits second information to the first network, and the second information includes a local identity assigned to the remote terminal device by the second network node.

[0106] S903: The second network node transmits the third piece of information to the first network node.

[0107] The third information includes identity information of the remote terminal device on the first interface, which has been assigned to the remote terminal device by the second network node, or the third information includes identity information of the remote terminal device on the first interface, which has been assigned to the remote terminal device by the second network node, and identity information of the relay terminal device on the first interface, which has been assigned to the relay terminal device by the second network node, where the first interface is a communication interface between the first network node and the second network node.

[0108] S904: The first network node sends the fourth piece of information to the second network node. S904 can be understood as an optional step.

[0109] S905: The second network node transmits the fifth piece of information to the first network node.

[0110] For S904 and S905, the following optional actions exist:

[0111] Any action 1 is: The first network node transmits fourth information to the second network node, which includes the data radio bearer identity (DRB ID) information of the remote terminal device and the identity information of the first radio link control (RLC) bearer, with a correspondence existing between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer. The first network node receives fifth information transmitted by the second network node, which includes configuration information for the first RLC bearer generated by the second network node, where the first RLC bearer is a bearer between the remote terminal device and the relay terminal device, with a correspondence existing between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer. This includes the following.

[0112] Any action 2 is: The first network node receives fifth information generated by the second network node, and the fifth information includes the data radio bearer identity (DRB ID) information of the remote terminal device, the identity information of the first RLC bearer, and the configuration information of the first RLC bearer, where the first RLC bearer is a bearer between the remote terminal device and the relay terminal device, and a correspondence exists between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer. This includes the following.

[0113] Any action 3 is: The first network node transmits fourth information to the second network node, which includes the data radio bearer identity (DRB ID) information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer. The first network node receives fifth information generated by the second network node, which includes the configuration information of the second RLC bearer. The second RLC bearer is a bearer between the second network node and the relay terminal device, and a correspondence exists between the DRB ID information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer. This includes the following.

[0114] Any action 4 is: The first network node receives fifth information generated by the second network node, and the fifth information includes at least one of the following: data radio bearer identity (DRB ID information) of the remote terminal device, the local identity of the remote terminal device, the identity information of the second RLC bearer, and the configuration information of the second RLC bearer, wherein the second RLC bearer is a bearer between the second network node and the relay terminal device, and a correspondence exists between the DRB ID information of the remote terminal device, the local identity of the remote terminal device, and the identity information of the second RLC bearer. This includes the following.

[0115] In operation 2 or operation 4, the method may further include the step of the first network node transmitting fourth information to the second network node, the fourth information being remote terminal It can be understood that this includes the device's identity information.

[0116] In any design, the fourth information further includes identity information for the uplink transmission tunnel, and there is a correspondence between the identity information for the uplink transmission tunnel and at least one of the following: DRB ID information for the remote terminal device, local identity information for the remote terminal device, identity information for the remote terminal device, and identity information for the second RLC bearer, and the uplink transmission tunnel is used by the first network node to receive data from the second network node on the first interface, and / or the fifth information further includes identity information for the downlink transmission tunnel, and there is a correspondence between the identity information for the downlink transmission tunnel and at least one of the following: DRB ID information for the remote terminal device, local identity information for the remote terminal device, identity information for the remote terminal device, and identity information for the second RLC bearer, and the downlink transmission tunnel is used by the first network node to transmit data to the second network node on the first interface.

[0117] In any design, the first network node further comprises receiving first instruction information from a relay terminal device, the first instruction information comprising identity information of a remote terminal device, the first instruction information requesting the assignment of a local identity to the remote terminal device, the local identity of the remote terminal device uniquely identifying the remote terminal device within the control range of the first network node, or the local identity of the remote terminal device uniquely identifying the remote terminal device within the control range of the relay terminal device.

[0118] In any design, the fourth information further includes the first identity information, and the first identity information This indicates the relay terminal device corresponding to the first RLC bearer. For example, the first identity information is the relay terminal device This may be a Layer 2 identifier, and the first RLC bearer is a remote terminal deviceAnd the relay terminal indicated by the Layer 2 identifier. device This indicates that it is an RLC bearer between the remote terminal. device multiple relay terminals device When communicating with a second network node via this, the instruction information may be for distinguishing the relay terminal device corresponding to the first RLC bearer.

[0119] Optionally, for example, multiple relay terminals device In a scenario where there is a constraint that the first identity must be placed in a different serving cell, information is a relay terminal device The serving cell identity may be further shown. Furthermore, the first identity information Alternatively, the relay terminal is handled by the first network node. device This may be identity information assigned to a remote terminal. device three relay terminals device When connected, the first network node connects to three relay terminals device Identity 0, 1, and 2 can be assigned to each, respectively. Furthermore, Identity 0, 1, and 2, along with the identity information of the first RLC bearer, indicate the second network node by using the fourth information.

[0120] In any design, the fifth information further includes the first identity information, and the first identity information This indicates the relay terminal device corresponding to the first RLC bearer. For example, the first identity information is the relay terminal device This may be a Layer 2 identifier, and the first RLC bearer is a remote terminal device And the relay terminal indicated by the Layer 2 identifier. device This indicates that it is an RLC bearer between the remote terminal. device multiple relay terminals deviceWhen communicating with a second network node via this, the instruction information may be for distinguishing the relay terminal device corresponding to the first RLC bearer.

[0121] Optionally, for example, multiple relay terminals device In a scenario where there is a constraint that the first identity must be placed in a different serving cell, information is a relay terminal device The serving cell identity may be further shown. Furthermore, the first identity information Alternatively, the relay terminal is handled by the second network node. device This may be identity information assigned to a remote terminal. device three relay terminals device When connected, the second network node connects to three relay terminals. device Identity 0, 1, and 2 can be assigned to each, respectively. Furthermore, Identity 0, 1, and 2, along with the identity information of the first RLC bearer, indicate the first network node by using the fifth piece of information.

[0122] In this embodiment, as described above, the first information may be a UE CONTEXT MODIFICATION REQUEST message from the relay terminal device, and the second information may be a UE CONTEXT MODIFICATION RESPONSE message from the relay terminal device; the first information may be the user device context of the relay terminal device set up The request may be a UE CONTEXT SETUP REQUEST message, and the second piece of information may be the user device context of the relay terminal device. set upThe fourth piece of information may be a UE CONTEXT SETUP RESPONSE message; the fourth piece of information may be a UE CONTEXT SETUP REQUEST message from the remote terminal device; the fifth piece of information may be a UE CONTEXT SETUP RESPONSE message from the remote terminal device; or the third piece of information may be an Initial UL RRC Message Transfer message from the remote terminal device.

[0123] In this embodiment, the first network node may include a Radio Resource Control (RRC) protocol layer, a Service Data Adaptation Protocol (SDAP) protocol layer, and a Packet Data Convergence Protocol (PDCP) protocol layer, and the second network node may include a Radio Link Control (RLC) protocol layer, a Media Access Control (MAC) protocol layer, and a Physical PHY protocol layer, and the first and second network nodes may be included in a single base station.

[0124] In a switching scenario, a remote terminal device is switched from a third network node to a second network node, the second network node is the target node in the switching process, the third network node is the source node in the switching process, the first network node controls the second and third network nodes, the third network node includes the Radio Link Control (RLC) protocol layer, the Media Access Control (MAC) protocol layer, and the Physical PHY protocol layer, and the first, second, and third network nodes are contained within a single base station. Furthermore, one of the following is satisfied: the first information is a User Device Context Setup Request (UE CONTEXT SETUP REQUEST) message from the remote terminal device, and the second information is a User Device Context Setup Response (UE CONTEXT SETUP RESPONSE) message from the remote terminal device, or the fourth information is a User Device Context Setup Request (UE CONTEXT SETUP REQUEST) message from the remote terminal device, and the fifth information is a User Device Context Setup Response (UE CONTEXT SETUP RESPONSE) message from the remote terminal device.

[0125] Figure 9(b) shows another communication method according to an embodiment of the present invention. The method relates to a first network node (e.g., CU) and a second network node (e.g., DU). The method may include the following steps.

[0126] S901': The first network node sends the sixth piece of information to the second network node.

[0127] The sixth piece of information includes the second instruction information, which instructs the second network node to set up a second radio link control RLC bearer between the second network node and a relay terminal device, the second RLC bearer being for carrying the first data, the first data being data exchanged between the remote terminal device and the second network node or the first network. The second RLC bearer may also be called an RLC channel.

[0128] For example, the second instruction information is remote terminal The second instruction information includes information about the signaling radio bearer SRB that needs to be set up for the device, or it includes relay service authorization information for the relay terminal device.

[0129] For example, the first data is data carried by the signaling radio bearer SRB0, signaling radio bearer SRB1, or signaling radio bearer SRB2 of the remote terminal device. Note that the data carried by the signaling radio bearer SRB0, signaling radio bearer SRB1, or signaling radio bearer SRB2 of the remote terminal device may be multiplexed on the same Uu RLC bearer.

[0130] S902': The second network node sends the seventh piece of information to the first network node.

[0131] The sixth piece of information is the UE CONTEXT SETUP REQUEST message, and the seventh piece of information is the UE CONTEXT SETUP RESPONSE message.

[0132] In S901' and S902', it can be understood that it is not limited whether the second RLC bearer is set up before or during the random access process of the remote UE.

[0133] For example, the first network node includes a Radio Resource Control (RRC) protocol layer, a Service Data Adaptation (SDAP) protocol layer, and a Packet Data Convergence (PDCP) protocol layer, while the second network node includes a Radio Resource Control (RRC) protocol layer, a Media Access Control (MAC) protocol layer, and a Physical PHY protocol layer. The first and second network nodes may be included in a single radio access network device, such as a base station (gNB).

[0134] Refer to the communication system shown in Figure 7(a) and the communication method shown in Figures 9(a) and 9(b). An example is used in which the Uu adaptation layer is located on the DU. Embodiments of the present application provide an initial UE access procedure for a remote UE. Specifically, compared to a scenario in the prior art where the UE communicates directly with the base station via a Uu link, the relay UE needs to perform further preparations in the following two aspects before the remote UE can perform initial access: • An RLC bearer carrying SRB signaling from a remote UE is set up between the relay UE and the DU (i.e., over the Uu link). For ease of description, the RLC bearer between the relay UE and the DU will be collectively referred to as the UuRLC bearer below. The base station assigns a local identity (local ID) to the remote UE and notifies the relay UE of the local identity. In the subsequent data exchange process, after receiving the remote UE's SRB0 signaling, the relay UE must add the local ID before forwarding the SRB0 signaling, so that the base station can identify the remote UE to which the received SRB0 signaling belongs.

[0135] Therefore, the base station may pre-set up a UuRLC bearer (or RLC channel) between the DU and the relay UE during the initial context setup process of the relay UE in order to carry SRB signaling from the remote UE.

[0136] Figure 10 shows a schematic diagram of another communication method according to an embodiment of the present invention, relating to the process of setting up a UuRLC bearer for carrying SRB signaling from a remote UE. The method may include the following steps:

[0137] S1001: CU sends a User Device Context Setup Request (UE CONTEXT SETUP REQUEST) message to DU.

[0138] The UE CONTEXT SETUP REQUEST message is a request to the DU to set up a UuRLC bearer, which is used to carry SRB0 / 1 / 2 for the remote UE.

[0139] S1002: The DU sends a User Device Context Setup Response (UE CONTEXT SETUP RESPONSE) message to the CU. The UE CONTEXT SETUP RESPONSE message carries the configuration information of the UuRLC bearer set up by the DU. In any possible manner, the CU instructs the DU to set up the UuRLC bearer and establish the correspondence between the UuRLC bearer and the remote UE's SRB0 / 1 / 2. Alternatively, the CU instructs the DU to set up the UuRLC bearer and provides the DU with the correspondence between the UuRLC bearer and the remote UE's SRB0 / 1 / 2.

[0140] In any other manner, the initial context setup process for the relay UE remains unchanged. The base station may set up a UuRLC bearer to carry the SRB signaling of the remote UE by using a context update procedure. The procedure may be initiated by the CU (e.g., steps S1001a and S1002a) or by the DU (e.g., steps S1001b and S1002b). Specifically, the method may include the following steps:

[0141] S1001a: The CU sends a UE CONTEXT MODIFICATION REQUEST message to the DU. The UE CONTEXT MODIFICATION REQUEST message may instruct the DU to set up a UuRLC bearer to carry the SRB0 / 1 / 2 of the remote UE.

[0142] S1002a: The DU sends a UE CONTEXT MODIFICATION RESPONSE message to the CU, which carries the UuRLC bearer configuration information generated by the DU.

[0143] In any possible manner, the CU instructs the DU to set up the UuRLC bearer and establish the correspondence between the UuRLC bearer and the remote UE's SRB0 / 1 / 2. Alternatively, the SU instructs the DU to set up the UuRLC bearer and also to generate the correspondence between the UuRLC bearer and the remote UE's SRB0 / 1 / 2.

[0144] Alternatively, and optionally, the method may include the following steps.

[0145] S1001b: The DU sends a UE CONTEXT MODIFICATION REQUIRED message to the CU. The UuRLC bearer configuration information generated by the DU is sent to the CU via the UE CONTEXT MODIFICATION REQUIRED message. It can be understood that the UuRLC bearer configured by the DU may further indicate the correspondence between the UuRLC bearer and the remote UE's SRB0 / 1 / 2.

[0146] S1002b: The CU sends a User Device Context Modification Confirmation (UE CONTEXT MODIFICATION CONFIRM) message to the DU. The CU uses the UE CONTEXT MODIFICATION CONFIRM message to the DU to confirm that the RLC bearer was successfully set up by the DU.

[0147] Optionally, the user equipment context update procedures in S1001, S1002, S1001a, S1002a, S1001b, and S1002B may be initiated based on capability and authorization. For example, F1 interface signaling sent by the CU to the DU (e.g., a UE CONTEXT SETUP REQUEST message or a UE CONTEXT MODIFICATION REQUEST message) may carry relay service authorization information for the relay UE. In this case, the CU or DU may trigger the context update procedure based on the authorization information. Alternatively, in the UE capability inquiry process, after receiving a UECapabilityEnquiry message sent by the base station, the relay UE may notify the base station of its UE capability information by using a UECapabilityInformation message. If the UE capability information includes information indicating that the UE can support relay communication, the base station may trigger the context update procedure accordingly.

[0148] It may be understood that the user device context update procedure described above may, alternatively, be initiated when the first remote UE performs access. As described below, after the remote UE accesses the relay UE, the relay UE sends SUI information to the base station to inform the base station that sidelink communication should take place between the remote UE and the relay UE and to request the base station to allocate the corresponding transmission resources. After receiving the SUI information, the base station triggers the context update procedure to pre-set up the UuRLC bearer for the remote UE's subsequent SRB signaling.

[0149] Regarding the process of assigning a local identity (local ID) to a remote UE, Figure 11 is a schematic diagram of another communication method according to an embodiment of the present invention. The method may include the following steps:

[0150] S1101: The remote UE sets up a unicast connection to the relay UE.

[0151] S1102: Relay UE sends SUI message to DU.

[0152] For example, after a remote UE sets up a unicast connection to a relay UE, the relay UE is triggered to send Sidelink User Equipment Information (SUI) to the base station (via the gNB-DU). The SUI message is intended to request that a local ID be assigned to the remote UE.

[0153] Optional action S1101a: After the remote UE sends an SRB0 signaling message (e.g., an MSG3 message or an RRCSetupRequest message) to the relay UE, the relay UE is triggered to send an SUI message to the base station.

[0154] S1103: The DU sends the uplink RRC message transfer UL RRC MESSAGE TRANSFER message to the CU.

[0155] The UR RRC MESSAGE TRANSFER message contains the SUI message sent by the relay UE to the gNB-DU. That is, the DU transparently transmits the SUI message to the CU. The SUI message can then be parsed at the CU's RRC layer.

[0156] A UE attempting to set up a unicast connection to a relay UE and perform sidelink communication with the relay UE typically comprises two parts: a remote UE that obtains relay services from the relay UE, and a UE that communicates directly with the relay UE via sidelink. When a UE accesses the relay UE and attempts to communicate with it via sidelink, the relay UE may be triggered to send a SUI message to the base station, in which case the SUI message indicates the destination L2 ID of the remote UE and requests sidelink transmission resources. For example, the SUI message may carry the destination L2 ID of the remote UE. After receiving the destination L2 ID of the remote UE, the base station may allocate sidelink transmission resources to the remote UE. In this embodiment of the present application, the base station must further assign a local ID to the remote UE. Therefore, the base station must be able to distinguish whether the destination L2 ID reported in the SUI identifies the remote UE. Specifically, several arbitrary modes may be included: A new uplink RRC message has been defined, which differs from the existing SUI message in that it is used to request the local ID of a remote UE. By using the newly defined uplink RRC message, the base station can determine that a local ID needs to be assigned to the remote UE. • In existing SUI messages, a new IE is introduced to indicate the L2 ID of the remote UE, thereby allowing the base station to determine that a local ID needs to be assigned to the remote UE based on the indicated L2 ID of the remote UE. • In existing SUI messages, a 1-bit indicator is introduced to indicate whether a UE is a remote UE. For example, the reserved bit spare 1 in the IE sl-casttype in existing SUI messages identifies whether a UE is a remote UE. For example, if the bit value is 1, it indicates that the UE is a remote UE. Alternatively, if the bit value is 0, it may also indicate that the UE is a remote UE.

[0157] S1104: The CU sends a user device context change request (UE CONTEXT MODIFICATION REQUEST) message to the DU.

[0158] The UE CONTEXT MODIFICATION REQUEST message instructs the DU to assign a local ID to a remote UE. For example, an SUI message may be forwarded directly to the DU, or dedicated instruction information may be defined and carried in a UE CONTEXT MODIFICATION REQUEST message. Alternatively, the CU may send the local ID of the remote UE assigned by the CU to the DU via a UE CONTEXT MODIFICATION REQUEST message.

[0159] In the steps described above, the gNB-CU may receive the L2 ID of the remote UE from the SUI message. Thus, the base station can generate a corresponding local ID for each L2 ID of the remote UE, and the base station can maintain a correspondence between the L2 ID of the remote UE and the local ID of the remote UE. In any other manner, the relay UE may carry the system architecture evolution temporary mobile station identifier (S-TMSI) of the remote UE in the SUI message to be transmitted. The relay UE can obtain the S-TMSI from the remote UE during the unicast connection setup process, thereby allowing the base station to assign a corresponding local ID to each S-TMSI and maintain a correspondence between the S-TMSI and the local ID.

[0160] S1105: The DU sends a User Device Context Change Response (UE CONTEXT MODIFICATION RESPONSE) message to the CU.

[0161] The DU sends the assigned local ID of the remote UE to the CU via the UE CONTEXT MODIFICATION RESPONSE message. Alternatively, if the CU sends the assigned local ID of the remote UE to the DU via the UE CONTEXT MODIFICATION REQUEST message, the DU can use the UE CONTEXT MODIFICATION RESPONSE message to verify the local ID of the remote UE sent to the DU by the CU.

[0162] S1106: The CU sends a Downlink RRC Transfer DL RRC TRANSFER message to the DU, in which the Downlink RRC Transfer message carries the local ID of the remote UE.

[0163] The CU can carry the local ID of the assigned remote UE in an RRC message, such as an RRCReconfiguration message, and send the local ID of the remote UE to the DU via a DL RRC TRANSFER message, which can carry the RRCReconfiguration message.

[0164] S1107: The DU sends an RRCReconfiguration message generated by the CU to the relay UE, and at this time, the RRCReconfiguration message carries the local ID assigned to the remote UE.

[0165] Please refer to the embodiments of the present invention shown in Figures 7(a) to 11. Figure 12 is a schematic diagram of another communication method according to an embodiment of the present invention. A communication method is provided in which initial access is provided for a remote UE. The method includes the following steps.

[0166] S1201: The remote UE sends an RRC setup request message, RRCSetupRequest, to the DU.

[0167] The remote UE may send an RRCSetupRequest message to the DU by using the relay function of the relay UE to request the setup of an RRC connection between the remote UE and the gNB. In the process of the relay UE forwarding the RRCSetupRequest message, the relay UE may add the remote UE's local ID to the header of the remote UE's SRB0 data packet (e.g., the Adaptation Layer PDU). Optionally, the relay UE may forward the SRB0 data based on the UuRLC bearer configuration configured in the various configuration methods shown in the embodiment in Figure 10.

[0168] S1202: The DU sends the Initial Uplink RRC Message Transfer message to the CU.

[0169] DU, remote UE local I D After receiving the SRB0 data packet from the remote UE, the DU may assign the UE F1 AP ID on the user equipment F1 interface to the remote UE and associate the remote UE's local ID with the DU UE F1AP ID of the remote UE. The DU then sends an INITIAL UL RRC MESSAGE TRANSFER message to the CU, in which the message carries the DU UE F1AP ID of the remote UE that was assigned by the DU.

[0170] It can be understood that the CU needs to detect the relay UE to which the remote UE is connected. Therefore, the UNITIAL UL RRC MESSAGE TRANSFER message may carry the DU UE F1AP ID of the relay UE, which was assigned to the relay UE by the DU.

[0171] In any other implementation, if the local ID assigned by the gNB is unique within the gNB's control, the INITIAL UL RRC MESSAGE TRANSFER can carry the local ID of the remote UE, and the CU can determine the relay UE to which the remote UE is connected based on the local ID.

[0172] S1203: CU sends a Downlink RRC Message Transfer (DL) message to DU.

[0173] The CU assigns the CU UE F1AP ID of the remote UE on the FI interface to the remote UE, generates an RRC Setup message to be sent to the remote UE, and sends the RRCSetup message to the DU via a DL RRC MESSAGE TRANSFER message.

[0174] S1204: The DU sends an RRCSetup message to the remote UE.

[0175] A DU can send an RRCSetup message to a remote UE by using the relay information of the relay UE. When the Adaptation Layer PDU is configured to allow the relay UE to know which remote UE the RRC message belongs to, the Adaptation Layer carries the local ID of the remote UE in the Adaptation Layer header.

[0176] S1205: The remote UE sends an RRCSetupComplete message to the DU, indicating that RRC setup is complete.

[0177] A remote UE can send an RRCSetupComplete message to the DU by using the relay function of a relay UE.

[0178] S1206: The DU sends the uplink RRC message transfer UL RRC MESSAGE TRANSFER message to the CU.

[0179] The DU can carry the RRCSetupComplete message in the UL RRC MESSAGE TRANSFER message and forward the RRCSetupComplete message sent by the remote UE to the CU.

[0180] S1207: The CU sends a User Device Context Setup Request (UE CONTEXT SETUP REQUEST) message to the DU.

[0181] The CU sends a UE CONTEXT SETUP REQUEST for the remote UE to the DU to instruct it to set up the UE context for the remote UE.

[0182] S1208 and S1210: The relay UE and DU exchange Security Mode Command (SMC) messages. The process of exchanging SMC messages between the relay UE and DU may be for activating security mode on the access stratum (AS) side.

[0183] S1209: The DU responds to the CU with the User Device Context Setup Response (UE CONTEXT SETUP REQUEST) message to indicate that the UE context of the remote UE was successfully set up in the DU.

[0184] In implementation, steps S1207 and S1209 allow the gNB to separately configure the adaptation layer configuration information for the relay UE and the remote UE, in addition to the context content of the remote UE, such as cell settings, remote UE ID information, remote UE SRB / DRB bearer configuration information, and RRC messages sent to the remote UE by the gNB (e.g., SMC messages in S1208). The adaptation layer configuration information for the relay UE and the remote UE can be configured by the gNB-DU or gNB-CU. The following describes different optional configuration methods.

[0185] 1. The adaptation layer settings for the remote UE are determined by the CU.

[0186] The remote UE's adaptation layer configuration content may include the remote UE's DRB ID information and PC5 RLC bearer information, and there is a mapping relationship between the remote UE's DRB ID information and the PC5 RLC bearer information. After configuring the above adaptation layer information, the CU may, in step S1207, send the above adaptation layer configuration content of the remote UE to the DU via the UE CONTEXT SETUP REQUEST message. Furthermore, the DU sets up the corresponding configuration of the PC5 RLC bearer based on the CU's instructions, and then... S In step 1209, configuration information for the PC5 RLC bearer can be sent to the CU via the UE CONTEXT SETUP RESPONSE message.

[0187] Furthermore, the remote UE's adaptation layer configuration content may include relay UE identity information to indicate that the PC5 RLC bearer is the PC5 RLC bearer between the remote UE and the designated relay UE. The relay UE identity information may be the relay UE's Layer 2 identifier, identity information assigned to the relay UE by the CU, or the relay UE's serving cell identity.

[0188] 2. The adaptation layer settings for the remote UE are determined by the DU.

[0189] The CU may instruct the DU to configure adaptation layer configuration information for the remote UE by using the UE CONTEXT SETUP REQUEST message in step S1207. The DU then sends the remote UE's adaptation layer configuration content and the corresponding PC5 RLC bearer configuration information configured by the DU to the CU via the UE CONTEXT SETUP RESPONSE message. The remote UE's adaptation layer configuration content may include the remote UE's DRB ID information and PC5 RLC bearer information, with a mapping relationship between the remote UE's DRB ID information and the PC5 RLC bearer information. Optionally, the CU may not need to carry additional instruction information in the UE CONTEXT SETUP REQUEST message in step S1207. Since the DU can determine from the uploaded RRC message that this is a remote UE, the remote UE's adaptation layer configuration content and the corresponding PC5 RLC bearer configuration information may be determined by the DU's internal implementation.

[0190] Furthermore, the remote UE's adaptation layer configuration content may include relay UE identity information to indicate that the PC5 RLC bearer is the PC5 RLC bearer between the remote UE and the designated relay UE. The relay UE identity information may be the relay UE's Layer 2 identifier, identity information assigned to the relay UE by the CU, or the relay UE's serving cell identity.

[0191] 3. The adaptation layer settings for the relay UE are determined by the CU.

[0192] The CU may decide to either create a UuRLC bearer for the relay UE or reuse an existing UuRLC bearer for the relay UE to carry data from the remote UE. The UuRLC bearer here may be an RLC bearer on the Uu link between the DU and the relay UE.

[0193] In step S1207, the UE CONTEXT SETUP REQUEST message sent by the CU to the DU may carry the ID information of the UuRLC bearer being requested to be generated or modified, further may carry the DRB ID information of the remote UE corresponding to the UuRLC bearer, and further may carry the QoS requirements of the UuRLC bearer. The mapping relationship between the UuRLC bearer and the remote UE's DRB ID must be set up for the relay UE's adaptation layer, and the RLC bearer's QoS requirements information may be used as a reference for the DU to generate the RLC bearer configuration. Furthermore, the UE CONTEXT SETUP REQUEST message may further include uplink tunnel information. An uplink tunnel is a tunnel required by the DU to send data to the CU. Each tunnel corresponds to one remote UE DRB ID, and one tunnel address may be assigned to the uplink tunnel to identify it. As shown in Figure 7(c), uplink data is delivered from the adaptation layer to the tunnel (e.g., an F1-U GTP tunnel) over the F1 interface, and the adaptation layer needs to deliver the multiplexed data on the UuRLC bearer to the corresponding tunnel. Therefore, the CU further needs to establish a mapping relationship between the remote UE ID, the DRB ID, and the tunnel address, and notify the DU of the remote UE ID, DRB ID, and tunnel address (including the mapping relationship between the remote UE ID, DRB ID, and tunnel address).

[0194] After receiving the content configured by the CU (remote UE ID, DRB ID, and tunnel address), the DU may generate the UuRLC bearer configuration information that needs to be generated or modified based on the CU's instructions, and send this information to the CU in step S1209 via the UE CONTEXT SETUP RESPONSE message. For example, the UuRLC bearer configuration information may be sent in the form of a separate RRC container in the UE CONTEXT SETUP RESPONSE message. Furthermore, the UE CONTEXT SETUP RESPONSE message may also include downlink tunnel configuration information (i.e., the direction to be sent by the CU to the DU). Each downlink tunnel can correspond to one remote UE DRB ID, and one tunnel address may be further assigned to the downlink tunnel to identify it. On the DU side, it may be understood that multiple tunnels may correspond to one adaptation layer or one UuRLC bearer. Thus, the same tunnel address may be assigned to different remote UE DRB IDs. Either a single address is assigned to all tunnels, or addresses are assigned based on the granularity of the UuRLC bearer. That is, the same address is assigned to tunnels corresponding to DRBs multiplexed on the UuRLC bearer.

[0195] In the tunnel reception and transmission processes, different tunnels can be distinguished by using the address on the CU side, assuming they have the same address on the DU side.

[0196] 4. The adaptation layer setting for the relay UE is determined by the DU.

[0197] In step S1207, the UE CONTEXT SETUP REQUEST message sent by the CU to the DU may request the DU to configure the relay UE's adaptation layer settings for the remote UE. The UE CONTEXT SETUP REQUEST message may carry the remote UE bearer's QoS information and uplink tunnel information. In this case, the DU may decide whether to generate a UuRLC bearer to carry the remote UE's data and configure the remote UE DRB ID and downlink tunnel information corresponding to different UuRLC bearers. A correspondence exists between the UuRLC bearer information, the remote UE's DRB ID information, and the downlink tunnel information. The assignment method is the same as described above. In step S1209, the DU sends the configuration to the CU via the UE CONTEXT SETUP RESPONSE message.

[0198] In the method described above, both the remote UE and relay UE adaptation layer settings are generated during the remote UE context setup process. In any other implementation, only the remote UE adaptation layer settings are generated during the remote UE context setup process, while the relay UE adaptation layer settings are generated during the relay UE context modification process. Similarly, in this process, the relay UE adaptation layer settings may be initiated by the DU or CU. This is similar to steps S1207 and S1209. The difference is that signaling between the DU and CU is performed by using F1 interface signaling associated with the relay UE. The following illustrates this using an example where the CU sets the adaptation layer setting information.

[0199] As shown in Figure 12, the details are as follows:

[0200] Step Sb1: The CU sends a User Device Context Change Request (UE CONTEXT MODIFICATION REQUEST) message to the DU.

[0201] The CU may decide to set up a new UuRLC bearer for data from a remote UE. Therefore, the CU sends a UE CONTEXT MODIFICATION REQUEST message to the DU, using the information elements within the message to indicate the ID of the generated UuRLC bearer and the DRB ID information of the remote UE corresponding to each UuRLC bearer. The UE CONTEXT MODIFICATION REQUEST message may include QoS information and DRB IDs for the UuRLC bearers to be generated, and may also include uplink tunnel information.

[0202] Step Sb2: The DU sends a User Device Context Change Response (UE CONTEXT MODIFICATION RESPONSE) message to the CU.

[0203] Based on the CU's instructions, the DU may determine the configuration information for the UuRLC bearer and send the UuRLC bearer configuration information between the relay UE and the DU to the CU via the UE CONTEXT MODIFICATION RESPONSE message.

[0204] S1211: The DU sends the uplink RRC message transfer UL RRC MESSAGE TRANSFER message to the CU.

[0205] Specifically, the DU can carry the SMC message returned by the relay UE in the UL RRC MESSAGE TRANSFER message and forward the SMC message returned by the relay UE to the CU.

[0206] S1212: CU sends a Downlink RRC Message Transfer (DL) message to DU.

[0207] Specifically, the CU may generate an RRCReconfiguration message. The RRCReconfiguration message includes mapping relationship configuration information for the remote UE. For example, the mapping relationship configuration information for the remote UE may include one or more of the following pieces of information and the mapping relationships between them: remote UE ID information, remote UE DRB ID information, tunnel address information, UuRLC bearer identity information, PC5 RLC bearer identity information, and identity information corresponding to the relay terminal, which is also sent to the DU via a DL RRC MESSAGE TRANSFER message. The identity corresponding to the relay terminal may include one or more of the following: the relay terminal's Layer 2 Identifier / C-RNTI / F1AP ID, the temporary identity assigned to the relay terminal device by the CU, and the identity of the serving cell where the relay terminal is located.

[0208] S1213: The DU sends an RRCReconfiguration message to the remote UE.

[0209] For example, the RRCReconfiguration message may include a mapping relationship between the remote UE ID and the PC5 RLC bearer.

[0210] S1214: The remote UE sends an RRCReconfigurationComplete message to the DU to indicate that the RRC connection setup is complete.

[0211] S1215: The DU sends a UL RRC MESSAGE TRANSFER message to the CU, and the UL RRC MESSAGE TRANSFER message carries the RRCReconfigurationComplete message sent by the remote UE to the DU in order to transfer the RRC message sent by the remote UE to the CU.

[0212] Furthermore, the CU may further distribute the adaptation layer settings to the relay UE. The following steps are included.

[0213] Step Sa1: CU sends the DL RRC MESSAGE TRANSFER message to DU.

[0214] The CU can generate an RRCReconfiguration message, which contains the relay UE's adaptation layer configuration information and is sent to the DU via a DL RRC MESSAGE TRANSFER message.

[0215] Step Sa2: The DU sends an RRCReconfiguration message to the relay UE, which may contain one or more pieces of information such as the remote UE's local ID information, the remote UE's DRB ID information, the UuRLC bearer, the PC5 RLC bearer, and identity information corresponding to the relay terminal, with mapping relationships existing between the pieces of information.

[0216] Step Sa3: The remote UE sends an RRCReconfigurationComplete message to the DU to indicate that the RRC connection setup is complete.

[0217] Step Sa4: The DU forwards the RRC message sent by the relay UE to the CU via the UL RRC MESSAGE TRANSFER message.

[0218] In steps S1207 and S1209 (or steps Sb1 and Sb2), if the gNB configures a new UuRLC bearer for data from the remote UE or modifies the original UuRLC bearer, the gNB-CU may carry the UuRLC bearer configuration information in the RRC message to be sent to the relay UE.

[0219] To support L2 U2N relay in a CU-DU isolation architecture, compared to prior art, the adaptation layer is introduced in the gNB-DU to support the L2 U2N relay protocol architecture. Before the remote UE performs initial access, the following procedures are further introduced: the relay UE sets up a UuRLC bearer for SRB signaling of the remote UE; the base station assigns a local ID to the remote UE; and the DU or CU determines the adaptation layer configuration. Furthermore, in the present embodiment, when the adaptation layer is placed in the gNB-DU, the remote UE initial access procedure is designed to enable the remote UE to successfully access the base station and set up the UE context.

[0220] Referring to the embodiments described above, Figure 12 is a schematic diagram of another communication method according to an embodiment of the present invention. In this method, when the Uu adaptation layer is located on the gNB-DU, an inter-DU switching procedure for the remote UE is proposed. Specifically, the remote UE is switched from the Source DU to the Target DU relay UE, with the same CU controlling both the Source DU and the Target DU. Specifically, the method shown in Figure 13 includes the following steps.

[0221] S1301: The remote UE sends a MeasurementReport to the source DU.

[0222] The remote UE performs the measurement report and sends a MeasurementReport message to the source DU. The measurement report content includes the relay UE ID and cell ID information.

[0223] S1302-1: Source DU sends the UL RRC MESSAGE TRANSFER message to CU.

[0224] The source DU sends the MeasurementReport message to the CU via the F1 interface signaling UL RRC MESSAGE TRANSFER.

[0225] S1302-2: Decide to switch.

[0226] Based on the remote UE's location, the CU decides to switch the remote UE to the relay UE connected to the target DU.

[0227] S1303:CU sends a UE CONTEXT SETUP REQUEST message to target DU.

[0228] The CU sends a UE CONTEXT SETUP REQUEST message to the target DU to instruct it to set up the UE context for the remote UE.

[0229] S1304: The target DU responds to the CU with a UE CONTEXT SETUP RESPONSE message, which may indicate that the UE context has been successfully set up in the gNB-DU.

[0230] Steps S1303 and S1304 relate to F1 interface signaling related to the remote UE. Thus, in the process in which the gNB-CU and gNB-DU transmit signaling, the gNB-CU and gNB-DU assign the CU F1AP ID and DU F1AP ID to the remote UE, respectively, and carry the assigned F1AP ID of the remote UE in the signaling. Furthermore, in this process, the DU or CU may assign a local ID to the remote UE and associate the local ID with the F1AP ID. If the CU assigns a local ID, the CU sends the local ID assigned by the CU to the DU in step S1303 via the UE CONTEXT SETUP REQUEST message. If the DU assigns a local ID, the CU requests the DU to assign a local ID by using the UE CONTEXT SETUP REQUEST message in step S1303, and the DU then sends the assigned local ID to the CU in step S1304 via the UE CONTEXT SETUP RESPONSE message. Alternatively, the DU may automatically decide to assign a local ID based on internal information and send the assigned local ID to the CU via the UE CONTEXT SETUP RESPONSE message in step S1304. That is, the UE CONTEXT SETUP RESPONSE message in step S1304 is used to assign a local ID. DU There is no need to carry instruction information for making requests.

[0231] In steps S1303 and S1304, the adaptation layer settings for the remote UE and the relay UE may be generated further, and there are two solutions: the DU generates the settings, and the CU generates the settings. For specific, different configuration processes, see the embodiments shown in Figure 12 (for example, the various configuration methods proposed in S1209). In other possible implementations, in steps S1303 and S1304, only the adaptation layer settings for the remote UE may be generated, and the adaptation layer settings for the relay UE are generated by using the relay UE UE context change process shown in step S1307-2. This is similar to steps Sb1 and Sb2 in the embodiments shown in Figure 12. Further details are not described here again.

[0232] S1305: The CU sends a UE CONTEXT MODIFICATION REQUEST message to the source DU, in which case the UE CONTEXT MODIFICATION REQUEST message includes the RRCReconfiguration message sent by the CU to the remote UE. For example, in addition to the configuration information included in the prior art, the RRCReconfiguration message may further include the remote UE's adaptation layer configuration information (e.g., the remote UE's DRB ID information, RLC bearer information, and the mapping relationship between the remote UE's DRB ID information and the PC5 RLC bearer information) and the local ID assigned to the remote UE.

[0233] S1306: Source DU responds to CU with the UE CONTEXT MODIFICATION RESPONSE message.

[0234] S1307-1: The source DU delivers the RRCReconfiguration message generated by the CU to the remote UE.

[0235] S1307-2: Optionally, the CU and target DU may generate the relay UE's UuRLC configuration by using the relay UE's UE context change procedure, in which case the UuRLC configuration includes the relay UE's adaptation layer configuration (i.e., the mapping relationship between the remote UE's local ID, DRB ID, UuRLC, and PC5 RLC bearer) and the required RLC bearer configuration.

[0236] S1308: CU sends the DL RRC MESSAGE TRANSFER message to the target DU.

[0237] The CU generates a DL RRC MESSAGE TRANSFER message that carries the configuration information for the relay UE, and sends an RRCReconfiguration message to the target DU via the DL RRC MESSAGE TRANSFER message.

[0238] S1309: The target DU sends an RRCReconfiguration message to the relay UE.

[0239] S1310: The relay UE responds to the target DU with the RRCReconfigurationComplete message.

[0240] S1311: The target DU forwards the relay UE's RRC message to the CU via the UL RRC MESSAGE TRANSFER message.

[0241] S1312: Set up a unicast connection.

[0242] If a unicast connection has not previously existed between the remote UE and the relay UE, the remote UE must first set up a unicast connection to the relay UE, which then matches the connected remote UE against the configuration distributed by the base station by using its local ID.

[0243] S1313: The remote UE relays the RRCReconfigurationComplete message to the target DU via the relay UE.

[0244] The remote UE sends the RRCReconfigurationComplete message on a unicast connection via the relay UE. The relay UE identifies the remote UE and, in the transfer process, adds the local ID to the adaptation layer PDU carrying the RRCReconfigurationComplete message, so that the adaptation layer of the target DU can identify that the message belongs to the remote UE and transfer the message accurately.

[0245] S1314: The target DU sends the UL RRC MESSAGE TRANSFER message to the CU.

[0246] The target DU sends the RRCReconfigurationComplete message of the remote UE to the CU via the UL RRC MESSAGE TRANSFER message.

[0247] S1315: The CU instructs the source DU to release the UE context of the remote UE. [[ID=,19]]

[0248] According to the method of this embodiment, an inter-DU switching procedure for a remote UE is proposed when the adaptation layer is placed in the DU in a CU-DU isolation architecture, thereby enabling the remote UE to successfully access the relay UE connected to the target DU. Compared to existing inter-DU switching procedures performed by the remote UE, this embodiment requires the setup of the remote UE's UE context and further execution of the relevant configuration of the relay UE. Furthermore, the base station must assign a local ID during the UE context setup process and associate the local ID with the remote UE's F1AP ID, so that the remote UE forwarding RRC messages via the relay UE can be identified in subsequent procedures.

[0249] Embodiments of the present invention further provide a communication method. A procedure for releasing the UE context of a remote UE is provided. The base station needs to release the UE context of the remote UE when the remote UE enters an RRC idle / inactive state or when the remote UE leaves the relay UE. Furthermore, the UE context of the connected relay UE may need to be further updated / released. The following steps are specifically included.

[0250] Step 1: The CU sends UE CONTEXT RELEASE COMMAND information to the DU to instruct it to release the UE context information of the remote UE. The message also carries the RRCRease message delivered to the UE.

[0251] Step 2: The DU sends an RRCRelease message, generated by the CU, to the remote UE to instruct it to release the RRC connection.

[0252] Step 3: The DU responds to the CU with UE CONTEXT RELEASE COMPLETE information to confirm that the UE context of the remote UE was successfully released.

[0253] Unlike conventional technologies, when a remote UE is released, further consideration must be given to releasing or modifying the UE context of the relay UE. After the remote UE context is released, the DU should further determine whether the relay UE's UuRLC bearer needs to be released, or whether the relay UE needs to be released. For example, when a remote UE is released, the UuRLC bearer no longer needs to carry data, and the corresponding UuRLC bearer can be released. Alternatively, after the remote UE is released, the relay UE can be released because it no longer holds relay data or relay UE data.

[0254] If the DU decides to release the UuRLC bearer, the procedures in steps 4a through 6a are executed. If the DU decides to release the relay UE, the procedures in steps 4b through 6b are executed.

[0255] Step 4a: After determining that the UuRLC bearer can be released, the DU sends a UE CONTEXT MODIFICATION REQUIRED message to the CU to indicate the ID information of the UuRLC bearer to be released.

[0256] Step 5a: The CU responds to the DU with a UE CONTEXT MODIFICATION CONFIRM message carrying the generated RRCReconfiguration message, which contains the updated relay UE configuration information.

[0257] Step 6a: The DU sends an RRCReconfiguration message to the relay UE.

[0258] Step 4b: After determining that the relay UE can be released, the DU sends a UE CONTEXT RELEASE REQUEST message to the CU to instruct it to release the relay UE.

[0259] Step 5b: The CU generates an RRCRelease message for the relay UE and sends the RRCRelease message to the DU via a DL RRC MESSAGE TRANSFER message.

[0260] Step 6b: The DU sends an RRCRelease message to the relay UE to instruct it to release the RRC connection to the base station.

[0261] In summary, compared to existing UE context release procedures, the method provided in this embodiment requires the DU to further determine whether the relay UE context needs to be updated or released after the remote UE context has been released. Following the DU's determination, the relay UE context update or release procedure is executed accordingly.

[0262] Embodiments of the present invention further provide a communication method. An initial access procedure for a remote UE is provided when the Uu adaptation layer is placed in the CU. Similarly, when the Uu adaptation layer is placed in the CU, the following is further required before the initial access procedure begins: 1. An RLC bearer carrying the remote UE's SRB signaling is set up between the relay UE and the DU. 2. The base station assigns a local ID to the remote UE and notifies the relay UE of the local ID. The method includes the following steps:

[0263] Step 1: The signaling exchanged between the DU and CU is the F1 interface signaling related to the relay UE. In other words, the remote UE's signaling is carried in the relay UE's signaling in the form of a container. Since the DU does not have an adaptation layer, the DU cannot identify whether the data / signaling uploaded by the relay UE is the remote UE's data / signaling. The base station only receives the local I on the adaptation layer header if the data / signaling is delivered to the CU's adaptation layer. DBased on this, it is possible to identify that the data / signaling belongs to a remote UE and deliver the data / signaling to the higher protocol layer of the remote UE.

[0264] Step 2: The CU generates the adaptation layer configuration. The adaptation layer resides in the CU. Therefore, it is natural for the CU to determine the mapping relationship configuration of the adaptation layer and request the DU to set up the corresponding UuRLC bearer.

[0265] Step 3: In the data plane, data from different bearers can be multiplexed over the F1 interface tunnel. The F1 interface connects the CU's adaptation layer and the DU's RLC layer. The adaptation layer is for multiplexing data from different bearers. In the uplink direction, the RLC layer delivers the data multiplexed on the UuRLC bearer directly to the adaptation layer through the tunnel. The same applies to the downlink direction. In particular, the tunnel should be an F1-U GTP tunnel configured by the CU and DU for the relay UE. Therefore, in the context setup process, when configuring the uplink tunnel, the CU needs to configure the mapping relationship between the adaptation layer entity and the tunnel address, and when configuring the downlink tunnel, the DU needs to configure the correspondence between the UuRLC bearer ID and the tunnel address.

[0266] In the method, in order to support the L2 U2N relay in the CU-DU separation architecture, an adaptation layer is introduced into the CU to support the L2 U2N relay protocol architecture. Compared with the embodiment shown in FIG. 12, in this solution, since the DU cannot identify the data of the remote UE: 1. The signaling of the remote UE is exchanged between the DU and the CU via the F1 interface signaling of the relay UE. 2. The data of the remote UE is exchanged between the DU and the CU through the F1 interface tunnel of the relay UE. Data or signaling can be identified as belonging to the remote UE only when it is delivered to the adaptation layer of the CU. Further, in the prior art, the data on one bearer corresponds to one F1 interface tunnel. In this solution, different bearer information data can be multiplexed on the F1 interface tunnel.

[0267] In the embodiment of the above method, the processor 801 in the communication device 80 shown in FIG. 8 may call the application program code stored in the memory to instruct the first terminal device to execute the operations of the first network node CU or the second network node DU. This is not limited to the embodiment. 804 In the above embodiment, it can be understood that the method and / or steps implemented by the first network node CU may alternatively be implemented by components (such as chips or circuits) that can be used in the first network node CU. The method and / or steps implemented by the second network node DU may alternatively be implemented by components that can be used in the second network node DU.

[0268]

[0269] ​From the perspective of device-to-device interaction, the above primarily describes the solution provided in embodiments of the present application. Correspondingly, embodiments of the present application further provide a communication device, which is configured to implement the various methods described above. The communication device may be a first network node CU in embodiments of the above methods, a device including the first network node CU, or a component or computer program that can be used in the first network node CU. Alternatively, the communication device may be a second network node DU in embodiments of the above methods, a device including the second network node DU, or a component or computer program that can be used in the second network node DU. To implement the above functions, it can be understood that the communication device includes corresponding hardware structures and / or software modules for performing the functions. Those skilled in the art will readily recognize, in combination with the example units and algorithmic steps described in embodiments disclosed herein, that the present application can be implemented in hardware or in combination of hardware and computer software. Whether the functions are performed in hardware or by hardware driven by computer software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use various methods to implement the functions for each specific application, but it should not be conceivable that the implementation would exceed the scope of the present application.

[0270] In embodiments of the present invention, the communication device may be divided into functional modules according to the embodiments of the method described above. For example, each functional module may be obtained by division based on its respective corresponding function, or two or more functions may be integrated into a single processing module. The integrated module may be implemented in hardware form or in the form of a software functional module. In embodiments of the present invention, the division into modules is merely an example and represents only a logical functional division. Other division methods may be used in actual implementation.

[0271] Figure 14 is a schematic diagram of the structure of the communication device 140. The communication device 140 includes a transceiver module 1401 and a processing module 1402. The transceiver module 1401 may also be called a transceiver unit and is configured to implement transceiver functions. For example, the transceiver module 1401 may be a transceiver circuit, a transceiver, or a communication interface. All relevant details of the steps in the embodiment of the above method can be referenced in the description of the functions of the corresponding functional modules. Details are not described again here.

[0272] In this embodiment, the communication device 140 is provided in a form that integrates the functional modules obtained by the division. Here, “module” may be one or more software or firmware programs, integrated logic circuits, and / or other components that can provide the above functions, such as a specific ASIC, circuit, processor, and memory. In a simple embodiment, those skilled in the art can conceive that the communication device 140 may take the form of the communication device 80 shown in Figure 8.

[0273] For example, the processor 801 in the communication device 80 shown in Figure 8 is memory 804 The communication device 80 can execute the communication method in the embodiment of the above method by calling computer executable instructions stored in it.

[0274] Specifically, the functions / implementation processes of the transceiver module 1401 and processing module 1402 in Figure 14 are as follows: 804 This can be performed by the processor 801 in the communication device 80 shown in Figure 8 by calling computer executable instructions stored in memory. Alternatively, the function / implementation process of the processing module 1402 in Figure 14 is performed in memory 804The functions / implementation processes of the transceiver module 1401 in Figure 14 can be performed by the processor 801 in the communication device 80 shown in Figure 8 by calling computer executable instructions stored therein, and the functions / implementation processes of the transceiver module 1401 in Figure 14 can be performed by the communication interface in the communication device 80 shown in Figure 8. 803 This can be implemented by [method].

[0275] The communication device 140 provided in this application can perform the above communication method. Therefore, for the technical effects that can be obtained by the communication device 140, please refer to the embodiments of the method described above. Further details are not described here.

[0276] It should be understood that in the various embodiments of the present application, the sequential numbering of the processes described above does not indicate the order of execution. The order of execution of the processes should be determined based on the function and internal logic of the processes and should not constitute any limitation on the implementation processes of the embodiments of the present application.

[0277] Those skilled in the art will recognize, in combination with the examples described in the embodiments disclosed herein, that the units and algorithmic steps can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use various methods to implement the functions for each specific application, but it should not be conceivable that the implementation would exceed the scope of this application.

[0278] For convenience and brevity, as will be readily apparent to those skilled in the art, the detailed operating processes of the above systems, apparatuses, and units should be referenced to the corresponding processes in the embodiments of the above methods. Further details are not described here.

[0279] It should be understood that in some embodiments provided herein, the disclosed systems, devices, and methods may be implemented in other ways. For example, the embodiments of the devices described above are merely illustrative. For example, the division into units is merely a logical functional division. Other division methods may be used in actual implementation. For example, multiple units or components may be coupled or integrated into other systems, or some functions may be ignored or not performed. Furthermore, the mutual coupling, direct coupling, or communication connection shown or discussed may be implemented through some interfaces. Indirect coupling or communication connection between devices or units may be implemented in electrical, mechanical, or other forms.

[0280] Units described as separate parts may or may not be physically separate, and parts shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected based on the actual requirements to achieve the objectives of the solution in the embodiment.

[0281] Furthermore, the functional units in the embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically independently, or two or more units may be integrated into a single unit.

[0282] All or part of the embodiments described above may be implemented using software, hardware, firmware, or any combination thereof. When a software program is used to implement an embodiment, the embodiment may be implemented in whole or in part in the form of a computer program product. A computer program product includes one or more computer instructions. When a computer program product is loaded into a computer and executed, all or part of the procedures or functions according to the embodiments of this application are generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or other programmable device. Computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (e.g., coaxial cable, optical fiber, or Digital Subscriber Line (DSL)) or wirelessly (e.g., infrared, radio waves, or microwaves). A computer-readable storage medium may be any useful medium accessible to a computer, or a data storage device such as a server or data center that incorporates one or more useful media. Useful media may include magnetic media (e.g., floppy disks, hard disks, or magnetic tapes), optical media (e.g., DVDs), and semiconductor media (e.g., solid-state drives (SSDs)).

[0283] The terms “component,” “module,” and “system” as used in this application refer to computer-related entities. Computer-related entities may be hardware, firmware, combinations of hardware and software, software, or running software. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable file, a thread of execution, a program, and / or a computer. In the example, both a computing device and an application running on a computing device can be components. One or more components may reside in a process and / or a thread of execution, and components may be located on one computer and / or distributed between two or more computers. Furthermore, these components may be executed from various computer-readable media having various data structures. These components may communicate, for example, by using local and / or remote processes, based on signals having one or more data packets (e.g., data from one component, which interacts with other components in a local or distributed system and / or interacts with other systems over a network such as the Internet by using signals).

[0284] This application presents aspects, embodiments, or features of systems that may include multiple devices, components, modules, etc. It should be recognized and understood that each system may include other devices, components, modules, etc., and / or may not include all of the devices, components, modules, etc. described with reference to the accompanying drawings. Furthermore, combinations of solutions may be used.

[0285] Furthermore, the term “example” in the embodiments of this application is intended to indicate an example, a practical example, or a description. No embodiment or design scheme described as “example” in this application should be described as being preferable or having more advantages than other embodiments or design schemes. Indeed, the term “example” is used to concretely present a concept.

[0286] In embodiments of this application, information, signal, message, and channel are sometimes used synonymously. The meanings expressed by the terms are consistent when the differences between them are not emphasized. "of," "corresponding, relevant," and "corresponding" are sometimes used synonymously. The meanings expressed by the terms are consistent when the differences between them are not emphasized. "System" and "network" are sometimes used synonymously. The meanings expressed by the terms are consistent when the differences between them are not emphasized. For example, "communication network" also refers to "communication system."

[0287] The network architectures and service scenarios in the embodiments of this application are intended to more clearly describe the technical solutions in the embodiments of this application and do not constitute a limitation on the technical solutions provided in the embodiments of this application. Those skilled in the art will recognize that, with the evolution of network architectures and the emergence of new service scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0288] The above description is merely a specific implementation of the present application, and the scope of protection of the present application is not limited thereto. Any modification or substitution that a person skilled in the art can easily conceive within the technical scope disclosed in the present application should fall within the scope of protection of the present application. Accordingly, the scope of protection of the present application should be subject to the scope of protection of the claims.

Claims

1. A communication method performed by a first network node, The first information is transmitted to a second network node, the first information includes a local identity assigned to a remote terminal device by the first network node, and the second network node communicates with the remote terminal device via a relay terminal device. Receiving the third information transmitted by the second network node It has, The third information includes identity information of the remote terminal device on the first interface, which has been assigned to the remote terminal device by the second network node, and identity information of the relay terminal device on the first interface, which has been assigned to the relay terminal device by the second network node. The first interface is a communication interface between the first network node and the second network node. method.

2. The aforementioned method, The fourth information is transmitted to the second network node, wherein the fourth information includes the data radio bearer identity (DRB ID) information of the remote terminal device and the identity information of the first radio link control (RLC) bearer, and a correspondence exists between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer. The process involves receiving fifth information transmitted by the second network node, wherein the fifth information includes configuration information for the first RLC bearer generated by the second network node. The first RLC bearer is a bearer between the remote terminal device and the relay terminal device. The method according to claim 1.

3. The fourth information further includes identity information of an uplink transmission tunnel, and there is a correspondence between the identity information of the uplink transmission tunnel and at least one of the following: the DRB ID information of the remote terminal device, the local identity of the remote terminal device, the identity information of the remote terminal device, or the identity information of a second RLC bearer, the uplink transmission tunnel is used by the first network node to receive data from the second network node on the first interface, and the second RLC bearer is a bearer between the second network node and the relay terminal device. The method according to claim 2.

4. The aforementioned method, The system further comprises receiving first instruction information from the relay terminal device, wherein the first instruction information includes identity information of the remote terminal device, and the first instruction information is for requesting the assignment of the local identity to the remote terminal device, wherein the local identity of the remote terminal device uniquely identifies the remote terminal device within the control range of the first network node, or the local identity of the remote terminal device uniquely identifies the remote terminal device within the control range of the relay terminal device. The method according to claim 1.

5. Next, The fourth piece of information is a user device context setup request (UE CONTEXT SETUP REQUEST) message from the remote terminal device, and the fifth piece of information is a user device context setup response (UE CONTEXT SETUP RESPONSE) message from the remote terminal device, or The third piece of information is that the remote terminal device's initial uplink RRC message transfer message is an Initial UL RRC Message Transfer message. Any one of the following conditions is satisfied: The method according to claim 2.

6. In a switching process in which the remote terminal device is switched from the third network node to the second network node, the second network node is the target node in the switching process, the third network node is the source node in the switching process, and the first network node controls the second network node and the third network node, and then The fourth piece of information is a user device context setup request (UE CONTEXT SETUP REQUEST) message from the remote terminal device, and the fifth piece of information is a user device context setup response (UE CONTEXT SETUP RESPONSE) message from the remote terminal device. that is satisfied, The method according to claim 2.

7. A communication method performed by a second network node, The process involves receiving first information from a first network node, the first information including a local identity assigned to a remote terminal device by the first network node, and the remote terminal device communicating with the second network node via a relay terminal device. The third information is transmitted to the first network node. It has, The third information includes identity information of the remote terminal device on the first interface, which has been assigned to the remote terminal device by the second network node, and identity information of the relay terminal device on the first interface, which has been assigned to the relay terminal device by the second network node. The first interface is a communication interface between the second network node and the first network node. method.

8. The aforementioned method, The process involves receiving fourth information transmitted by the first network node, wherein the fourth information includes data radio bearer identity (DRB ID) information of the remote terminal device and identity information of the first radio link control (RLC) bearer, and a correspondence exists between the DRB ID information of the remote terminal device and the identity information of the first RLC bearer. The fifth information is transmitted to the first network node, wherein the fifth information includes configuration information for the first RLC bearer generated by the second network node. The first RLC bearer is a bearer between the remote terminal device and the relay terminal device. The method according to claim 7.

9. The fourth information further includes identity information of an uplink transmission tunnel, and there is a correspondence between the identity information of the uplink transmission tunnel and at least one of the following: the DRB ID information of the remote terminal device, the local identity of the remote terminal device, the identity information of the remote terminal device, or the identity information of a second RLC bearer, the uplink transmission tunnel is used by the first network node to receive data from the second network node on the first interface, and the second RLC bearer is a bearer between the second network node and the relay terminal device. The method according to claim 8.

10. Next, The fourth piece of information is a user device context setup request (UE CONTEXT SETUP REQUEST) message from the remote terminal device, and the fifth piece of information is a user device context setup response (UE CONTEXT SETUP RESPONSE) message from the remote terminal device, or The third piece of information is that the remote terminal device's initial uplink RRC message transfer message is an Initial UL RRC Message Transfer message. Any one of the following conditions is satisfied: The method according to claim 8.

11. In a switching process in which the remote terminal device is switched from the third network node to the second network node, the second network node is the target node in the switching process, the third network node is the source node in the switching process, and the first network node controls the second network node and the third network node, and then The fourth piece of information is a user device context setup request (UE CONTEXT SETUP REQUEST) message from the remote terminal device, and the fifth piece of information is a user device context setup response (UE CONTEXT SETUP RESPONSE) message from the remote terminal device. that is satisfied, The method according to claim 8.

12. An apparatus configured to perform the method described in any one of claims 1 to 6.

13. A computer-readable storage medium having, when executed by a computer device, an instruction that causes the computer device to perform the method according to any one of claims 1 to 6.

14. A computer program that, when executed by a computer device, includes an instruction causing the computer device to perform the method according to any one of claims 1 to 6.

15. An apparatus configured to perform the method described in any one of claims 7 to 11.

16. A computer-readable storage medium having, when executed by a computer device, an instruction that causes the computer device to perform the method according to any one of claims 7 to 11.

17. A computer program that, when executed by a computer device, includes an instruction causing the computer device to perform the method according to any one of claims 7 to 11.

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