Communication method and device

Abstract

This application provides a communication method and apparatus for resolving conflicts between BAP addresses in a migration process of an mIAB node in an IAB network. The method includes: when a first donor CU is different from a second donor CU, a distributed unit (DU) of a relay node determines to include a BAP address of the relay node in a first message and a first identification information of a mobile termination unit (MT) of the relay node and / or a second identification information of the mobile termination unit (MT) in the first message, where the first donor CU is a target donor CU to which the DU of the relay node will migrate, and the second donor CU is a donor CU connected to the MT, and the BAP address is used for communication of the relay node in a topology managed by the second donor CU. The DU then sends the first message to the first donor CU. According to this method, the MT's identification information in the first message can be used to distinguish between the BAP address of the relay node and the BAP address of another relay node served by the first donor CU, so that the conflict between BAP addresses in the relay node migration process is resolved and communication accuracy is guaranteed.

Description

[Technical Field]

[0001]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202310140861.9 entitled "Communication Method and Apparatus," filed with the State Intellectual Property Office of the People's Republic of China on February 16, 2023, the entire contents of which are incorporated herein by reference.

[0002]

[0002] Technical Field This application relates to the field of communications technology, and more particularly to communications methods and devices. [Background technology]

[0003]

[0003] An integrated access and backhaul (IAB) network has two types of nodes: an IAB donor (IAB-donor) and an IAB node (IAB-node). An IAB donor can provide access services to terminal devices, and the service data of the terminal devices is connected to the IAB donor by the IAB node via a wireless backhaul link. An IAB node includes a mobile termination (MT) and a distributed unit (DU). An IAB node communicates with its parent node via the MT. An IAB node communicates with its child node via the DU. A child node of an IAB node may be another IAB node or an terminal device.

[0004]

[0004] In the existing standard, the IAB-donor-CU needs to know the binding relationship between the IAB-MT and the IAB-DU in order to set up the entire topology relationship and configure BAP routing, bearer mapping, and the like for the IAB-node. In the network access process of the IAB-node, the IAB-MT first accesses the network through random access and an RRC connection, and then the IAB-donor-CU delivers the backhaul link configuration related to the IAB-node to the IAB-MT by using an RRC message. Furthermore, the IAB-donor-CU configures a BAP address for the MT, and the IAB-DU requests the IAB-donor-CU to set up an F1 connection by using an F1 SETUP REQUEST message, which contains the BAP address of the IAB-node, so that the IAB-donor-CU can determine that in this case the DU requesting to set up the F1 interface and the MT to which the BAP address was previously allocated belong to the same IAB-node.

[0005]

[0005] However, in a scenario where a DU in a network node is migrated but not a MT, the target donor CU to which the DU is migrated is not the same donor CU as the donor CU currently connected to the MT, and any two donor CUs do not pre-negotiate the assignment of a BAP address, the BAP address in the F1 SETUP REQUEST message sent by the DU to the target donor CU is the BAP address assigned to the IAB node by the donor CU currently connected to the MT. In this case, the BAP address in the F1 SETUP REQUEST message sent by the DU to the target donor CU may conflict with the BAP address of another IAB node served by the target donor CU, resulting in a communication error. Summary of the Invention

[0006]

[0006] The present application provides a communication method and apparatus for resolving conflicts between BAP addresses in a migration process of mIAB nodes in an IAB network.

[0007] According to a first aspect, there is provided a communication method, the method may be performed by a relay node (e.g., an IAB node) or a chip, chip system, or circuit located in the relay node. The method may be implemented by using the following steps: if a first donor central unit (CU) is different from a second donor CU, a distributed unit (DU) of the relay node determines to include in the first message a backhaul adaptation protocol (BAP) address of the relay node and a first identification of a mobile termination unit (MT) of the relay node and / or a second identification of the mobile termination unit (MT) of the relay node, where the first donor CU is a target donor CU to which the DU of the relay node will be migrated, and the second donor CU is a donor CU connected to the MT, the first message is for requesting the setup of an interface connection between the DU and the first donor CU, the BAP address being used for communication of the relay node in a topology managed by the second donor CU; the first identification is an identification for identifying the MT in the first donor CU, and the second identification is an identification for identifying the MT in the second donor CU. The DU then sends the first message to the first donor CU.

[0008]

[0008] According to this method, when the target donor CU to which the DU of the relay node is migrated is different from the donor CU connected to the MT, the DU decides to include the BAP address and the first identification information of the MT and / or the second identification information of the MT in the first message, thereby distinguishing between the BAP address of the relay node and the BAP address of another relay node served by the first donor CU, resolving conflicts between BAP addresses in the relay node migration process, and ensuring communication accuracy.

[0009] In a possible design, the first message further includes identification information of the DU.

[0010]

[0010] According to this design, after receiving the first message, CU1 can determine the correspondence between the DU and the MT based on the DU's identification information and the MT's first identification information and / or the MT's second identification information, so that CU1 manages the relay node.

[0011] In a possible design, before the DU sends the first message to the first donor CU, the method further includes: the relay node receiving the first identification information and / or the second identification information from the second donor CU. Alternatively, the relay node receiving the first identification information and / or the second identification information from a third donor CU, where the third donor CU is a source donor CU from which the DU is migrated, and the third donor CU and the second donor CU may be different donor CUs or the same donor CU.

[0012]

[0012] In a possible design, the relay node receiving the first identification information and / or the second identification information from the second donor CU includes: the MT of the relay node receiving an RRC message sent by the second donor CU, the RRC message including the first identification information and / or the second identification information.

[0013]

[0013] The relay node receiving the first identification information and / or the second identification information from the third donor CU means: the DU of the relay node receives an F1 message sent by the third donor CU, the F1 message including the first identification information and / or the second identification information.

[0014]

[0014] According to the above design, the relay node may obtain the first identification information of the MT and / or the second identification information of the MT in multiple manners to improve the flexibility of data transmission.

[0015] According to a second aspect, there is provided a communication method, the method being capable of being performed by a relay node (e.g., an IAB node) or a chip, chip system, or circuitry located in the relay node. The method may be implemented by using the following steps: if a first donor central unit (CU) is different from a second donor CU, a distributed unit (DU) of the relay node determines to include in the first message an identification of the DU and a first identification of a mobile termination unit (MT) of the relay node and / or a second identification of the MT, where the first donor CU is a target donor CU to which the DU of the relay node will be migrated, and the second donor CU is a donor CU connected to the MT, the first message is for requesting the setup of an interface connection between the DU and the first donor CU, and the BAP address is used for communication of the relay node in a topology managed by the second donor CU; the first identification is an identification for identifying the MT in the first donor CU, and the second identification is an identification for identifying the MT in the second donor CU. The DU sends the first message to the first donor CU.

[0016]

[0016] According to this method, the DU determines to include the DU's identification information and the MT's first identification information and / or the MT's second identification information in the first message, so that the first donor CU can determine the correspondence between the DU and the MT based on the DU's identification information and the MT's identification information, without relying on the BAP address sent by the DU for the correspondence between the DU and the MT, which is more flexible.

[0017]

[0017] In a possible design, the method further includes: the DU of the relay node determining not to include a backhaul adaptation protocol (BAP) address of the relay node in the first message.

[0018]

[0018] This design can resolve conflicts between BAP addresses and remove redundant information elements from the first message, thereby reducing transmission resource overhead.

[0019] In a possible design, before the DU sends the first message to the first donor CU, the method further includes: the relay node receiving the first identification information and / or the second identification information from the second donor CU. Alternatively, the relay node receiving the first identification information and / or the second identification information from a third donor CU, where the third donor CU is a source donor CU from which the DU is migrated, and the third donor CU and the second donor CU may be different donor CUs or the same donor CU.

[0020] According to a third aspect, a communication method is provided. The method may be performed by a relay node (e.g., an IAB node) or a chip, chip system, or circuit disposed in the relay node. The method may be implemented by using the following steps: a distributed unit (DU) of the relay node determines not to include a backhaul adaptation protocol (BAP) address of the relay node in a first message if a first donor central unit (CU) is different from a second donor CU, the first donor CU is a target donor CU to which the DU of the relay node is migrated, and the second donor CU is a donor CU connected to a mobile termination (MT) of the relay node; the first message is for requesting the setup of an interface connection between the DU and the first donor CU, and the BAP address is used for communication of the relay node in a topology managed by the second donor CU; and the DU sends the first message to the first donor CU.

[0021]

[0021] According to this method, the DU can decide not to include the BAP address in the first message to resolve the conflict between the BAP addresses and remove redundant information elements from the first message, which reduces transmission resource overhead.

[0022]

[0022] In a possible design, the method further includes: if the first donor CU is the same as the second donor CU, the DU determines to include a BAP address of the relay node in the first message.

[0023] According to this design, if the first donor CU is the same as the second donor CU, no conflict between the BAP addresses occurs. In this case, the DU can decide to include the BAP address in the first message.

[0024]

[0024] According to a fourth aspect, there is provided a communication method. The method may be performed by a relay node (e.g., an IAB node) or a chip, chip system, or circuit disposed in the relay node. The method may be implemented by using the following steps: a distributed unit (DU) of the relay node sends a second message to a first donor central unit (CU), the second message including a backhaul adaptation protocol (BAP) address of the relay node, the BAP address being used for communication of the relay node in a topology managed by the first donor central unit (CU), and an F1 interface connection exists between the DU of the relay node and the first donor central unit (CU).

[0025]

[0025] According to this method, if an F1 interface already exists between the DU and the first donor CU, after the MT is migrated to the first CU, the DU can report the BAP address to the first donor CU by using the second message, so that the first donor CU can determine the correspondence between the DU and the MT based on the second message, which helps CU1 manage the relay node.

[0026] In a possible design, the second message is a configuration upload message.

[0027]

[0027] According to a fifth aspect, there is provided a communication method. The method may be performed by a relay node (e.g., an IAB node) or a chip, chip system, or circuit disposed in the relay node. The method may be implemented by using the following steps: a first donor central unit (CU) receives a third message sent by a distributed unit (DU) of the relay node, the third message including user location information (ULI) of a mobile termination unit (MT) of the relay node, the first donor CU being a donor CU connected to the DU; the first donor CU sends a fourth message to a first core network element, the fourth message including the ULI of the UE and indication information indicating the ULI of the MT, the first core network element being a core network element serving the UE, and the UE being a UE managed by the DU.

[0028]

[0028] According to this method, the DU can send the ULI of the MT to the first donor CU, so that the first donor CU knows the ULI of the MT and can report indication information indicating the ULI of the MT to the first core network element, which ensures the accuracy of the location information of the UE.

[0029]

[0029] According to a sixth aspect, there is provided a communication method. The method may be performed by a relay node (e.g., an IAB node) or a chip, chip system, or circuit disposed in the relay node. The method may be implemented by using the following steps: a first donor central unit (CU) receives a fifth message sent by a second donor CU, the fifth message including user location information (ULI) of a mobile termination unit (MT) of the relay node, the first donor CU being a donor CU connected to a DU, and the second donor CU being a donor CU connected to the MT; the first donor CU sends a fourth message to a first core network element, the fourth message including the ULI of the UE and indication information indicating the ULI of the MT, the first core network element being a core network element serving the UE, and the UE being a UE managed by the DU.

[0030] In this way, the second donor CU may send the ULI of the MT to the first donor CU, so that the first donor CU knows the ULI of the MT and can report indication information indicating the ULI of the MT to the first core network element, which ensures the accuracy of the UE's location information.

[0031] According to a seventh aspect, there is provided a communication method. The method may be performed by a donor node (e.g., an IAB donor) or a chip, chip system, or circuit disposed in the donor node. The method may be implemented by using the following steps: a second donor central unit (CU) sends a sixth message to a first donor CU, the sixth message including identification information of a second core network element, the first donor CU being a donor CU connected to a distributed unit of a relay node, the second donor CU being a donor CU connected to a mobile termination unit (MT) of the relay node, and the second core network element being a core network element serving the MT. The second donor CU sends a seventh message to the second core network element, the seventh message including indication information indicating user location information (ULI) of the MT and identification information of a cell managed by the DU.

[0032]

[0032] According to this solution, the second donor CU sends the seventh message, including the indication information indicating the ULI of the MT and the identification information of the cell managed by the DU, only once to the second core network element, so that when the first donor CU determines that the first core network element serving the UE and the second core network element serving the MT are the same core network element, the first donor CU does not need to report the ULI of the MT or the indication information indicating the ULI of the MT to the first core network element, which reduces signaling overhead and saves communication resources.

[0033] In a possible design, before the second donor CU sends the sixth message to the first donor CU, the method further includes: the second donor CU receiving an eighth message sent by the MT, where the eighth message includes identification information of a cell managed by the DU. Alternatively, the second donor CU receiving a ninth message sent by the first donor CU, where the ninth message includes identification information of a cell managed by the DU, and the ninth message further includes first identification information of the MT and / or second identification information of the MT, where the first identification information is identification information for identifying the MT in the first donor CU and the second identification information is identification information for identifying the MT in the second donor CU.

[0034]

[0034] According to this design, the second donor CU can receive the identification information of the cell managed by the DU, which is sent by the MT or the first donor CU, and thus the second donor CU can send the identification information of the cell managed by the DU to the second core network element.

[0035]

[0035] In a possible design, the cell identification information includes a cell global identifier CGI and / or a tracking area identifier TAI.

[0036] According to an eighth aspect, there is provided a communication method. The method may be performed by a donor node (e.g., an IAB donor) or a chip, chip system, or circuit disposed in the donor node. The method may be implemented by using the following steps: a first donor central unit (CU) receives a sixth message sent by a second donor CU, the sixth message including identification information of a second core network element, the first donor CU being a donor CU connected to a distributed unit of a relay node, the second donor CU being a donor CU connected to a mobile termination unit (MT) of the relay node, and the second core network element being a core network element serving the MT. If the second core network element and the first core network element are the same core network element, the first donor CU includes the user location information ULI of the UE in the tenth message, where the first core network element is a core network element serving the UE and the UE is a UE managed by the DU; or if the second core network element and the first core network element are not the same core network element, the first donor CU includes the user location information ULI of the UE and indication information indicating the ULI of the MT in the tenth message. The first donor CU sends the tenth message to the first core network element.

[0037]

[0037] According to this solution, when the first donor CU determines that the first core network element serving the UE and the second core network element serving the MT are the same core network element, the first donor CU does not need to report the ULI of the MT or indication information indicating the ULI of the MT to the first core network element, which reduces signaling overhead and saves communication resources.

[0038]

[0038] In a possible design, before the first donor CU receives the sixth message sent by the second donor CU, the method further includes: the first donor CU sending a ninth message to the second donor CU, the ninth message including identification information of a cell managed by the DU, the ninth message further including first identification information of the MT and / or second identification information of the MT, the first identification information being identification information for identifying the MT in the first CU, and the second identification information being identification information for identifying the MT in the second CU.

[0039]

[0039] In a possible design, the cell identification information includes a cell global identifier CGI and / or a tracking area identifier TAI.

[0040] According to a ninth aspect, there is provided a communication method. The method may be performed by a donor node (e.g., an IAB donor) or a chip, chip system, or circuit disposed in the donor node. The method may be implemented by using the following steps: a second donor central unit (CU) receives an eleventh message sent by a first donor CU, the eleventh message including identification information of a first core network element, the second donor CU being a donor CU connected to a mobile termination unit (MT) of a relay node, the first donor CU being a donor CU connected to a distributed unit (DU) of the relay node, the first core network element being a core network element serving a UE, and the UE being a UE managed by the DU. The second donor CU sends a twelfth message to the first core network element based on the identification information of the first core network element, the twelfth message including indication information indicating user location information (ULI) of the MT and identification information of a cell managed by the DU.

[0041]

[0041] According to this solution, the second donor CU can send an indication information indicating the ULI of the MT and the identification information of the cell managed by the DU to the first core network element serving the UE, so that the first donor CU does not need to report the ULI of the MT or the indication information indicating the ULI of the MT again, which ensures the accuracy of the UE location information and reduces transmission resources.

[0042] In a possible design, before the second donor CU sends the twelfth message to the first core network element based on the identifier of the first core network element, the method further includes: the second donor CU receiving an eighth message sent by the MT, where the eighth message includes identification information of a cell managed by the DU. Alternatively, the second donor CU receiving a ninth message sent by the first donor CU, where the ninth message includes identification information of a cell managed by the DU, and the ninth message further includes first identification information of the MT and / or second identification information of the MT, where the first identification information is identification information for identifying the MT in the first donor CU and the second identification information is identification information for identifying the MT in the second donor CU.

[0043]

[0043] In a possible design, the cell identification information includes a cell global identifier CGI and / or a tracking area identifier TAI.

[0044] According to a tenth aspect, there is provided a communication method. The method may be performed by a donor node (e.g., an IAB donor) or a chip, chip system, or circuit disposed in the donor node. The method may be implemented by using the following steps: a first donor central unit (CU) sends an eleventh message to a second donor CU, the eleventh message including identification information of a first core network element, the second donor CU being a donor CU connected to a mobile termination unit (MT) of a relay node, the first donor CU being a donor CU connected to a distributed unit of the relay node, the first core network element being a core network element serving a UE, and the UE being a UE managed by a DU. The first donor CU sends a tenth message to the first core network element, the tenth message including user location information (ULI) of the UE.

[0045] According to an eleventh aspect, the present application provides a communication device including a processing module and a communication module, wherein the communication module is configured to receive a signal from a communication device other than the communication device and send the signal to the processing module, or to transmit a signal from the processing module to a communication device other than the communication device. The processing module is configured to: determine, when a first donor central unit CU is different from a second donor CU, to include in the first message a backhaul adaptation protocol (BAP) address of the relay node and a first identification of a mobile termination unit (MT) of the relay node and / or a second identification of the MT, where the first donor CU is a target donor CU to which a DU of the relay node is to be migrated and the second donor CU is a donor CU connected to the MT, the first message is for requesting the setting up of an interface connection between the DU and the first donor CU, the BAP address being used for communication of the relay node in a topology managed by the second donor CU; the first identification is an identification for identifying the MT in the first donor CU, and the second identification is an identification for identifying the MT in the second donor CU; and the processing module is configured to send the first message to the first donor CU via the communication module.

[0046] In a possible design, the first message further includes identification information of the DU.

[0047]

[0047] In a possible design, the processing module is: configured to, before sending the first message to the first donor CU via the communication module, further: receive the first identification information and / or the second identification information from the second donor CU via the communication module; or configured to receive the first identification information and / or the second identification information from a third donor CU via the communication module, wherein the third donor CU is the source donor CU from which the DU is migrated, and the third donor CU and the second donor CU may be different donor CUs or the same donor CU.

[0048]

[0048] In a possible design, the processing module is specifically configured to: receive, via the communication module, an RRC message sent by the second donor CU, the RRC message including the first identification information and / or the second identification information; and the processing module is specifically configured to: receive, via the communication module, an F1 message sent by the third donor CU, the F1 message including the first identification information and / or the second identification information.

[0049] According to a twelfth aspect, the present application provides a communication device including a processing module and a communication module, wherein the communication module is configured to receive a signal from a communication device other than the communication device and send the signal to the processing module, or to transmit a signal from the processing module to a communication device other than the communication device. The processing module is configured to: determine, when a first donor central unit CU is different from a second donor CU, to include in the first message an identification information of the DU and a first identification information of a mobile termination unit MT of the relay node and / or a second identification information of the MT, wherein the first donor CU is a target donor CU to which the DU of the relay node will be migrated, and the second donor CU is a donor CU connected to the MT, the first message is for requesting the setting up of an interface connection between the DU and the first donor CU, and the BAP address is used for communication of the relay node in a topology managed by the second donor CU; the first identification information is an identification information for identifying the MT in the first donor CU, and the second identification information is an identification information for identifying the MT in the second donor CU; and the processing module is configured to send the first message to the first donor CU via the communication module.

[0050]

[0050] In a possible design, the processing module is also configured to determine not to include a backhaul adaptation protocol (BAP) address of the relay node in the first message.

[0051]

[0051] In a possible design, the processing module is further configured: for the DU to receive the first identification information and / or the second identification information from the second donor CU via the communication module before sending the first message to the first donor CU; or for the DU to receive the first identification information and / or the second identification information from the third donor CU via the communication module, the third donor CU being the source donor CU from which the DU is migrated, and the third donor CU and the second donor CU may be different donor CUs or the same donor CU.

[0052] According to a thirteenth aspect, the present application provides a communication device including a processing module and a communication module. The communication module is configured to receive a signal from a communication device other than the communication device and send the signal to the processing module, or to transmit a signal from the processing module to a communication device other than the communication device. The processing module is also configured to determine not to include a backhaul adaptation protocol (BAP) address of the relay node in the first message if a first donor central unit (CU) is different from a second donor CU, the first donor CU being a target donor CU to which a DU of the relay node will be migrated, and the second donor CU being a donor CU connected to a mobile termination (MT) of the relay node, the first message being for requesting the setup of an interface connection between the DU and the first donor CU, the BAP address being used for communication of the relay node in a topology managed by the second donor CU; and the processing module is configured to transmit the first message to the first donor CU via the communication module.

[0053]

[0053] In a possible design, the processing module is further configured to: determine to include the BAP address of the relay node in the first message if the first donor CU is the same as the second donor CU.

[0054]

[0054] According to a fourteenth aspect, the present application provides a communication device including a processing module and a communication module. The communication module is configured to: receive a signal from a communication device other than the communication device, and send the signal to the processing module, or transmit a signal from the processing module to a communication device other than the communication device. The processing module is configured to: send a second message to a first donor central unit (CU) via the communication module, the second message including a backhaul adaptation protocol (BAP) address of the relay node, the BAP address being used for communication of the relay node in a topology managed by the first donor CU; and an F1 interface connection exists between the DU of the relay node and the first donor CU.

[0055] In a possible design, the second message is a configuration upload message.

[0056]

[0056] According to a fifteenth aspect, the present application provides a communication device including a processing module and a communication module. The communication module is configured to: receive a signal from a communication device other than the communication device, and send the signal to the processing module, or transmit a signal from the processing module to a communication device other than the communication device. The processing module is configured to: receive, via the communication module, a third message sent by a distributed unit (DU) of a relay node, the third message including user location information (ULI) of a mobile termination (MT) of the relay node, and a first donor CU being a donor CU connected to the DU. The first donor CU sends a fourth message to a first core network element, the fourth message including the ULI of the UE and indication information indicating the ULI of the MT, the first core network element being a core network element serving the UE, and the UE being a UE managed by the DU.

[0057]

[0057] According to a sixteenth aspect, the present application provides a communication device including a processing module and a communication module. The communication module is configured to: receive a signal from a communication device other than the communication device and send the signal to the processing module, or transmit a signal from the processing module to a communication device other than the communication device. The processing module is configured to: receive a fifth message sent by a second donor CU via the communication module, the fifth message including user location information (ULI) of a mobile termination unit (MT) of the relay node, the first donor CU being a donor CU connected to the DU, and the second donor CU being a donor CU connected to the MT; and send a fourth message to a first core network element via the communication module, the fourth message including a ULI of the UE and indication information indicating the ULI of the MT, the first core network element being a core network element serving the UE, and the UE being a UE managed by the DU.

[0058]

[0058] According to a seventeenth aspect, the present application provides a communication device including a processing module and a communication module. The communication module is configured to receive a signal from a communication device other than the communication device and send the signal to the processing module, or to transmit a signal from the processing module to a communication device other than the communication device. The processing module is configured to send a sixth message to a first donor CU via the communication module, the sixth message including identification information of a second core network element, the first donor CU being a donor CU connected to a distributed unit of a relay node, the second donor CU being a donor CU connected to a mobile termination unit (MT) of the relay node, and the second core network element being a core network element serving the MT. The second donor CU is configured to send a seventh message to the second core network element, the seventh message including indication information indicating user location information (ULI) of the MT and identification information of a cell managed by the DU.

[0059]

[0059] In a possible design, the processing module is further configured to: receive an eighth message sent by the MT via the processing module, the eighth message including identification information of a cell managed by the DU; or the processing module is configured to receive a ninth message sent by the first donor CU via the communication module, the ninth message including identification information of a cell managed by the DU, the ninth message further including first identification information of the MT and / or second identification information of the MT, the first identification information being identification information for identifying the MT in the first donor CU, and the second identification information being identification information for identifying the MT in the second donor CU.

[0060]

[0060] In a possible design, the cell identification information includes a cell global identifier CGI and / or a tracking area identifier TAI.

[0061]

[0061] According to an eighteenth aspect, the present application provides a communication device including a processing module and a communication module. The communication module is configured to: receive a signal from a communication device other than the communication device, and send the signal to the processing module, or transmit a signal from the processing module to a communication device other than the communication device. The processing module is configured to: receive, via the communication module, a sixth message sent by a second donor CU, the sixth message including identification information of a second core network element, the first donor CU being a donor CU connected to a distributed unit of a relay node, the second donor CU being a donor CU connected to a mobile termination MT of the relay node, and the second core network element being a core network element serving the MT; the processing module is configured to and the first core network element are the same core network element, the processing module is configured to include the user location information ULI of the UE in the tenth message, the first core network element is a core network element serving the UE, and the UE is a UE managed by the DU; or, if the second core network element and the first core network element are not the same core network element, the processing module is configured to include the user location information ULI of the UE and indication information indicating the ULI of the MT in the tenth message; and send the tenth message to the first core network element via the communication module.

[0062] In a possible design, the processing module is configured to send a ninth message to the second donor CU before the first donor CU receives the sixth message sent by the second donor CU, where the ninth message includes an identification of a cell managed by the DU, and the ninth message further includes a first identification of the MT and / or a second identification of the MT, where the first identification is an identification for identifying the MT in the first CU, and the second identification is an identification for identifying the MT in the second CU.

[0063]

[0063] In a possible design, the cell identification information includes a cell global identifier CGI and / or a tracking area identifier TAI.

[0064] According to a nineteenth aspect, the present application provides a communication device including a processing module and a communication module, wherein the communication module is configured to receive a signal from a communication device other than the communication device and send the signal to the processing module, or to transmit a signal from the processing module to a communication device other than the communication device. The processing module is configured to: receive, via the communication module, an eleventh message sent by the first donor CU, the eleventh message including identification information of the first core network element, the second donor CU being a donor CU connected to a mobile termination unit MT of the relay node, the first donor CU being a donor CU connected to a distributed unit DU of the relay node, the first core network element being a core network element serving the UE, and the UE being a UE managed by the DU; and the processing module is configured to send, based on the identification information of the first core network element, a twelfth message to the first core network element, the twelfth message including indication information indicating user location information ULI of the MT and identification information of a cell managed by the DU.

[0065] In a possible design, the processing module is configured to receive, via the communication module, an eighth message sent by the MT before sending the twelfth message to the first core network element based on an identifier of the first core network element, the eighth message including an identification of a cell managed by the DU. Alternatively, the second donor CU receives a ninth message sent by the first donor CU, the ninth message including an identification of a cell managed by the DU, the ninth message further including a first identification of the MT and / or a second identification of the MT, the first identification being an identification for identifying the MT in the first donor CU, and the second identification being an identification for identifying the MT in the second donor CU.

[0066]

[0066] In a possible design, the cell identification information includes a cell global identifier CGI and / or a tracking area identifier TAI.

[0067]

[0067] According to a twentieth aspect, the present application provides a communication device including a processing module and a communication module. The communication module is configured to: receive a signal from a communication device other than the communication device and send the signal to the processing module, or transmit a signal from the processing module to a communication device other than the communication device. The processing module is configured to: send an eleventh message to a second donor CU via the communication module, the eleventh message including identification information of a first core network element, the second donor CU being a donor CU connected to a mobile termination unit MT of a relay node, the first donor CU being a donor CU connected to a distributed unit of the relay node, the first core network element being a core network element serving a UE, the UE being a UE managed by a DU; and the processing module is configured to send a tenth message to the first core network element via the communication module, the tenth message including user location information ULI of the UE.

[0068] According to a twenty-first aspect, an embodiment of the present application provides a communication device including a processor coupled to a memory. The processor is configured to call a program stored in the memory to perform any of the methods according to the first to tenth aspects. The memory may be located internal to the device or external to the device. There may be one or more processors.

[0069] According to a twenty-second aspect, an embodiment of the present application provides a communication device including a processor and a memory. The memory is configured to store computer instructions. When the communication device is operated, the processor executes the computer instructions stored in the memory, such that the communication device performs any of the methods according to the first to tenth aspects.

[0070]

[0070] According to a twenty-third aspect, an embodiment of the present application further provides a computer program product, the computer program product including a computer program, which, when executed by a processor, performs any of the methods in the first to tenth aspects.

[0071]

[0071] According to a twenty-fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, the storage medium storing a computer program or instructions, which, when executed by a processor, performs any of the methods in the first to tenth aspects. [Brief explanation of the drawings]

[0072] [Figure 1] FIG. 1 is a diagram of an IAB network according to an embodiment of the present application. [Figure 2]

[0073] FIG. 2 is a diagram of a multi-hop IAB network according to an embodiment of the present application. [Figure 3]

[0074] FIG. 3 is a diagram of the architecture of an IAB network according to an embodiment of the present application. [Figure 4]

[0075] FIG. 4 is a diagram of a control plane CP protocol stack according to an embodiment of the present application. [Figure 5]

[0076] FIG. 5 is a diagram of a user plane UP protocol stack according to an embodiment of the present application. [Figure 6]

[0077] FIG. 6 is a diagram of partial migration according to an embodiment of the present application. [Figure 7]

[0078] FIG. 7 is a diagram of a complete migration according to an embodiment of the present application. [Figure 8]

[0079] FIG. 8 is a diagram of IAB node migration according to an embodiment of the present application. [Figure 9]

[0080] FIG. 9 is a diagram of an IAB node migration scenario according to an embodiment of the present application. [Figure 10]

[0081] FIG. 10 is a diagram of a mIAB node migration scenario in an IAB network according to an embodiment of the present application. [Figure 11]

[0082] FIG. 11 is a flowchart of a communication method according to an embodiment of the present application. [Figure 12]

[0083] FIG. 12 is a flowchart of a communication method according to an embodiment of the present application. [Figure 13]

[0084] FIG. 13 is a flowchart of a communication method according to an embodiment of the present application. [Figure 14]

[0085] FIG. 14 is a flowchart of a communication method according to an embodiment of the present application. [Figure 15]

[0086] FIG. 15 is a diagram of a scenario in which the mIAB-MT and mIAB-DU are connected to different donor CUs, according to an embodiment of the present application. [Figure 16]

[0087] FIG. 16 is a flowchart of a communication method according to an embodiment of the present application. [Figure 17]

[0088] FIG. 17 is a flowchart of a communication method according to an embodiment of the present application. [Figure 18]

[0089] FIG. 18 is a flowchart of a communication method according to an embodiment of the present application. [Figure 19]

[0090] FIG. 19 is a flowchart of a communication method according to an embodiment of the present application. [Figure 20]

[0091] FIG. 20 is a flowchart of a communication method according to the present application. [Figure 21]

[0092] FIG. 21 is a structural diagram of a communication device according to an embodiment of the present application. [Figure 22]

[0093] FIG. 22 is a structural diagram of a communication device according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0073]

[0094] In order to make the problems, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0074]

[0095] All node and message names in this application are merely names established for ease of explanation, and the names in the actual network may be different. The names of various nodes and messages should not be understood as being limited in this application. On the contrary, any names having the same or similar functions as the functions of the nodes or messages used in this application shall be considered as the method or equivalent substitute of this application and fall within the protection scope of this application. Details will not be described below.

[0075]

[0096] Hereinafter, some terms in the embodiments of the present application will be explained to facilitate understanding by those skilled in the art.

[0076]

[0097] (1) A terminal device is a device that provides a user with a voice and / or data connection. The terminal device in this application may be a terminal device or a hardware element within the terminal device that can perform the functions of a terminal.

[0077]

[0098] A terminal device may also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, or the like. Terminals may be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearables, smart transportation, and smart cities. A terminal may be a mobile phone, a tablet computer, a computer with wireless transceiver capabilities, a wearable device, a vehicle, an unmanned aerial vehicle, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, or the like. The specific technology and device configuration used by the terminal device are not limited to the embodiments of the present application. For ease of explanation, the following description uses an example in which a UE is used as a terminal device.

[0078]

[0099] The functionality of the terminal device may be implemented by using hardware components within the terminal device, which may be a processor and / or a programmable chip within the terminal device. Optionally, the chip may be implemented by using an application-specific integrated circuit (ASIC) or a programmable logic device (PLD). The PLD may be any one or any combination of a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), and a system on a chip (SoC).

[0079]

[0100] Regarding the various terminal device examples described above, if the terminal device is located in a vehicle (e.g., placed or installed in a vehicle), the terminal device may all be considered as an on-board terminal, e.g., an on-board unit (OBU).

[0080]

[0101] (2) A network node may also be referred to as a wireless backhaul device and may provide wireless access services to terminal devices via an access link (AL). The network node is connected to a donor node via a backhaul link (BL or BH) to transmit service data of the terminal device and to retransmit or forward the service data, thereby extending the coverage of the mobile communication system. For example, in long term evolution (LTE), a network node may be referred to as a relay node (RN), or may be called a relay device, relay transmission reception point (rTRP), transmission point (TP), or the like.

[0081]

[0102] A network node can set up wireless backhaul links to one or more higher-level nodes (parent nodes) and access the core network through the higher-level nodes. The higher-level nodes can control the network nodes (e.g., perform data scheduling, timing modulation, or power control) by using multiple types of signaling. A network node can also provide services to one or more lower-level nodes (child nodes). A higher-level node of a network node can be a donor node or another network node. A lower-level node of a network node can be a terminal device or another network node.

[0082]

[0103] In an integrated access and backhaul (IAB) network, a network node may be an IAB node (IAB-node). The IAB node includes a mobile termination (MT) and a distributed unit (DU). When facing a parent node of the IAB-node, the IAB-node may be used in the role of a terminal device, i.e., an MT, and is configured to provide data backhaul to the IAB-node's child nodes. The MT of the IAB node may be referred to as an IAB-MT. When facing a child node of the IAB node, the IAB node is used in the role of a network device, i.e., a DU, and is configured to provide access services to the IAB-node's child nodes. The DU of the IAB node may be referred to as an IAB-DU. The child node of the IAB node may be another IAB node or an terminal device.

[0083]

[0104] (3) A donor node (or simply called a donor) is a device in a relay network that has access to the core network and is configured to connect end devices to a wireless network. A donor node can be connected to the core network via a wired link (e.g., fiber optic cable). A donor node can receive data from the core network and forward the data to a network node, or can receive data from a network node and forward the data to the core network. In an IAB network, a donor node can be an IAB donor node (or IAB donor or IAB-donor).

[0084]

[0105] In one example, the donor node may include a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved Node B, or home Node B, HNB), a baseband unit (BBU), or the like; a base station in an evolved LTE system (LTE-Advanced, LTE-A) or 4G access network; an evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN), e.g., an evolved Node B (Node B, eNB, e-NodeB, or evolved Node B); or a next generation Node B (next generation Node B) in a 5th generation (5G) mobile communication technology / new radio (NR) system. This may include a NodeB, gNB, or similar.

[0085]

[0106] In another example, a donor node may include a CU and a DU. A CU of a donor node may be referred to as a donor-CU, and a DU of a donor node may be referred to as a donor-DU.

[0086]

[0107] The donor CU and donor DU are connected through an F1 interface, which may further include a control plane interface (F1-C) and a user plane interface (F1-U). The CU is connected to the core network via a next-generation (NG) interface. Alternatively, the donor CU may be in a form in which the user plane (UP) (abbreviated as CU-UP in this application) and the control plane (CP) (abbreviated as CU-CP in this application) are separated. In other words, the donor CU includes a CU-CP and a CU-UP. One donor CU may include one donor CU-CP and at least one donor CU-UP.

[0087]

[0108] The donor DU may be primarily configured to implement functions of the Layer 1 (L1) and Layer 2 (L2) protocol stacks, including functions of the physical (PHY), media access control (MAC), or radio link control (RLC) layers. The donor CU primarily implements functions of the packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), or radio resource control (RRC) layers. The F1-C interface is set up between the donor CU-CP and the IAB-DU, and the F1-U interface is set up between the donor CU-UP and the IAB-DU.

[0088]

[0109] The functionality of the donor node may be implemented by hardware components within the donor node, such as a processor and / or a programmable chip within the donor node. For example, the chip may be implemented using an ASIC or PLD. The PLD may be any one of a CPLD, FPGA, GAL, and SoC, or any combination thereof.

[0089]

[0110] In the following description of the present application, an IAB node is used as a relay node, and an IAB donor node is used as a donor node, and functions performed by the relay node and the donor node are described in the methods provided in the embodiments of the present application. However, it should be understood that the subject of the present application is not limited to an IAB node and an IAB donor node. In other words, the IAB node in the present application may alternatively be replaced by a network node, a relay node, or a wireless backhaul device. Correspondingly, the IAB donor node may alternatively be replaced by a donor node. In other words, the application scenario of the present application is not limited to an IAB network, and the present application may also be applied to other types of relay networks.

[0090]

[0111] In the embodiments of the present application, "at least one" means one or more, and "multiple" means two or more. "And / or" describes a connection relationship between related objects and indicates that three relationships may exist. For example, A and / or B may indicate three cases: A exists alone, both A and B exist, and B exists alone, where A and B may be singular or plural. The character " / " typically indicates an "or" relationship between related objects. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of a single item or multiple items. For example, at least one of a, b, or c may refer to 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.

[0091]

[0112] Unless otherwise specified, ordinal terms such as "first" and "second" referred to in the embodiments of the present application are used to distinguish between multiple objects and are not intended to limit the size, content, sequence, time sequence, priority, importance, or the like of the multiple objects. For example, "first data packet" and "second data packet" are simply used to distinguish between different data packets, but do not indicate any difference in priority, size, importance, or the like between the two data packets.

[0092]

[0113] It should be noted that in this application, terms such as "example" or "for example" are used to denote providing an example, illustration, or explanation. Any embodiment or design solution described in this application as an "example" or "for example" is not intended to be described as preferred or having more advantages than another embodiment or design solution. Rather, the use of words such as "example," "for example," or the like is intended to present relative concepts in a particular way.

[0093]

[0114] The terms "comprises," "having," and any derivatives thereof in the following description of embodiments of the present application are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include other unlisted steps or units, or may optionally further include other inherent steps or units of the process, method, product, or device.

[0094]

[0115] The above explains some terms in the embodiments of the present application. The following describes the architecture of a network system to which the method provided in the present application is applied.

[0095]

[0116] Communication systems referred to in the embodiments of the present application include, but are not limited to, narrowband internet of things (NB-IoT) systems, wireless local area network (WLAN) systems, long term evolution (LTE) systems, 5th generation mobile networks or 5th generation wireless systems (5G), or communication systems beyond 5G, such as new radio (NR) systems or device-to-device (D2D) communication systems.

[0096]

[0117] Figure 1 shows the architecture of an IAB network. An IAB node (denoted as IAB node in the figure) is configured to provide wireless access and wireless backhaul for access services to UEs. An IAB donor (denoted as IAB donor in the figure) is configured to provide wireless backhaul functionality for the IAB node and provide an interface between the UE and the core network. An IAB node is connected to the IAB donor via a wireless backhaul link, so that UEs served by the IAB node are connected to the core network.

[0097]

[0118] FIG. 2 illustrates the architecture of an IAB network in multi-hop networking. Between a UE (including UE1 and UE2 shown in FIG. 2) served by an IAB node (denoted as IAB node in the figure) and an IAB donor (denoted as IAB donor in the figure), there is at least one transmission path including multiple links. Each transmission path includes a UE, one or more IAB nodes, and the IAB donor. Each IAB node considers a nearby node that provides access and backhaul services to the IAB node as a parent node. Correspondingly, each IAB node may be considered a child node of the IAB node's parent node. For example, in FIG. 2, the parent node of IAB node 1 is the IAB donor, and IAB node 1 is the parent node of IAB node 2 and IAB node 3. Uplink data packets of a UE may be transmitted to an IAB donor via one or more IAB nodes and then transmitted by the IAB donor to a mobile gateway device, e.g., a user plane function (UPF) unit in a 5G core network. Downlink data packets are received by the IAB donor from the mobile gateway device and then delivered to the UE via an IAB node.

[0098]

[0119] FIG. 3 is an exemplary diagram of an IAB network architecture. SA networking is used as an example in FIG. 3. The IAB-DU is logically connected to an IAB donor CU (referred to as a donor CU in the subsequent description of this application) via an F1 interface. That is, the F1 connection between the IAB-DU and the donor CU may be a logical connection rather than a direct physical connection. In practice, the F1 connection between the IAB-DU and the donor CU is physically implemented via the NR Uu interface between the IAB-MT at each hop and the parent node DU of the IAB-MT, so that the IAB-DU can communicate with the donor CU. Therefore, the F1 interface may be considered to exist logically. The F1 interface supports user plane protocols (F1-U) and control plane protocols (F1-C). The user plane protocols include one or more of the following protocol layers: a General Packet Radio Service tunneling protocol user plane (GTP-U) layer, a user datagram protocol (UDP) layer, an internet protocol (IP) layer, and the like. The control plane protocols include one or more of the following protocol layers: an F1 application protocol (F1AP) layer, a stream control transmission protocol (SCTP) layer, an IP layer, and the like.

[0099]

[0120] Figures 4 and 5 show the CP and UP protocol stacks in an IAB network with a three-hop backhaul, respectively. In this architecture, a UE accesses the network via IAB node 2, IAB node 3, IAB node 1, and IAB donor 1 in that order. Below, we will explain the procedures for user plane services (F1-U traffic) and control plane services (F1-C traffic) of the F1 interface separately based on Figures 4 and 5.

[0100]

[0121] For the CP plane, as shown in Figure 4, a Uu interface is set up between the UE and the IAB 2-DU (i.e., the DU of IAB Node 2), and the peer protocol layer includes the RLC layer, MAC layer, and PHY layer. An F1-C interface is set up between the IAB 2-DU and the donor CU (i.e., the CU of IAB Donor 1), and the peer protocol layer includes the F1 application protocol (F1AP) layer and the stream control transmission protocol (SCTP) layer. The donor DU (i.e., the DU module of IAB Donor 1) and the donor CU are connected via a wired connection, and the peer protocol layer includes the Internet Protocol (IP), Layer 2, and Layer 1. Backhaul links are set up between IAB Node 2 and IAB Node 3, between IAB Node 3 and IAB Node 1, and between IAB Node 1 and the donor DU, and peer protocol layers include a backhaul adaptation protocol (BAP) layer, an RLC layer, a MAC layer, and a PHY layer. Furthermore, a peer RRC layer and a peer PDCP layer are set up between the UE and the donor CU, and a peer IP layer is set up between IAB2-DU (i.e., the DU of IAB Node 2) and the donor DU. Compared with the CP protocol stack of a single air interface, in the CP protocol stack in an IAB network, the DU module of the access IAB node implements the functions of a gNB-DU of a single air interface, specifically, the functions of setting up a peer RLC layer, a peer MAC layer, and a peer PHY layer with the UE, as well as the functions of setting up a peer F1AP layer and a peer SCTP layer with the donor CU; the donor CU implements the functions of a gNB-CU of a single air interface.

[0101]

[0122] For CP, RRC messages are encapsulated in F1AP messages between the access IAB node and the donor CU for transmission. Specifically, in the uplink direction, the UE encapsulates RRC messages into PDCP protocol data units (PDUs); processes the PDCP PDUs at the RLC, MAC, and PHY layers in order; and sends the processed PDCP PDUs to the IAB2-DU. The IAB2-DU processes the PDCP PDUs at the PHY, MAC, and RLC layers in order to obtain PDCP PDUs, encapsulates the PDCP PDUs in F1AP messages, and processes the PDCP PDUs at the SCTP and IP layers in order to obtain IP packets. The IAB2-MT (i.e., the MT of IAB Node 2) processes the IP packets individually at the BAP, RLC, MAC, and PHY layers, and then sends the processed IP packets to the IAB3-DU (i.e., the DU of IAB Node 3). The IAB3-DU sequentially performs processing at the PHY layer, MAC layer, RLC layer, and BAP layer to obtain an IP packet. Then, similar to the operation of the IAB2-MT, the IAB3-MT (i.e., the MT of IAB node 3) sends the IP packet to the IAB1-DU (i.e., the DU of IAB node 1), and then the IAB1-MT (i.e., the MT of IAB node 1) sends the IP packet to the donor DU. After obtaining the IP packet through analysis, the donor DU sends the IP packet to the donor CU. The donor CU processes the IP packet sequentially at the SCTP layer, F1AP layer, and PDCP layer to obtain an RRC message. The downlink direction is similar, and details will not be described.

[0102]

[0123] For the UP, as shown in Figure 5, a Uu interface is set up between the UE and IAB2-DU, and the peer protocol layer includes the RLC layer, MAC layer, and PHY layer. An F1-U interface is set up between the IAB2-DU and the donor-CU, and the peer protocol layer includes the general packet radio service (GPRS) tunneling protocol for the user plane (GTP-U) layer and the user datagram protocol (UDP) layer. The donor-DU and donor-CU are connected via a wired connection, and the peer protocol layer includes the IP layer, L2 layer, and L1 layer. BLs are set up between IAB node 2 and IAB node 3, between IAB node 3 and IAB node 1, and between IAB node 1 and the donor-DU, and the peer protocol layer includes the BAP layer, RLC layer, MAC layer, and PHY layer. Furthermore, a peer SDAP layer and a peer PDCP layer are set up between the UE and the donor CU, and a peer IP layer is set up between the IAB2-DU and the donor DU. Compared with the UP protocol stack of the single air interface, the DU module of the access IAB node implements some of the functions of the gNB-DU of the single air interface, specifically, the functions of setting up a peer RLC layer, a peer MAC layer, and a peer PHY layer with the terminal device, and the functions of setting up a peer GTP-U layer and a peer UDP layer with the donor CU; the donor CU implements the functions of the gNB-CU of the single air interface.

[0103]

[0124] The IAB network supports multi-hop backhaul, which is related to routing and forwarding between nodes. In the CP and UP protocol stacks of the IAB architecture, a new protocol layer, the BAP layer, is introduced for the wireless backhaul link. The protocol layer is located above the RLC layer and is used to implement functions such as data packet routing and bearer mapping in the wireless backhaul link. As shown in Figures 4 and 5, the BAP layer originates at the IAB node connected to the UE, and its termination point is at the donor DU. The donor CU allocates a unique BAP address to each IAB node and donor DU controlled by the donor CU, allowing each IAB node and donor DU in the network to be uniquely identified.

[0104]

[0125] The corresponding BAP entities in the IAB nodes implement the BAP layer protocol. Each IAB node has two BAP entities, one for each MT and one for DU, and the BAP addresses of the BAP entities in the MT and DU are the same. Each of the two BAP entities has sending and receiving capabilities.

[0105]

[0126] The function of the BAP entity includes adding a BAP header to IP data packets from upper layers, where the BAP header includes a BAP routing identifier (ID). Specifically, the BAP routing identifier may include the BAP address of the target node and an identifier of the route to the node (which may be referred to as a path in this application). The BAP routing ID reflects the identifier of the target node and the route used to reach the target node. It should be understood that in this application, the BAP address of the target node in the BAP routing identifier may be briefly referred to as the BAP address in the BAP routing identifier or the BAP address in the routing identifier. The donor CU configures a routing table for each IAB node, and the contents in the routing table are mapping relationships between the BAP routing ID and the next-hop BAP address. The routing table may indicate a specific network node to which the data packet needs to be forwarded. Each IAB node is constructed with uplink (UL) and downlink (DL) routing tables (configured by the donor CU). The DU of an IAB node uses the DL routing table, which can indicate the specific child node to which a data packet needs to be forwarded. The MT of an IAB node uses the UL routing table, which can indicate the specific parent node to which a data packet needs to be forwarded.

[0106]

[0127] In addition to the routing function, the BAP protocol is also used to perform mapping between inbound and outbound BH RLC channels, and the mapping rules are also configured by the donor CU. Its essence can be understood as finer-grained routing, in which an RLC channel is selected based on determining the next-hop target BAP address (i.e., determining the next-hop link). When the access IAB node receives a data packet, it is forwarded to upper layers and processed in the same way that a common DU processes an incoming F1-U or F1-C service data packet.

[0107]

[0128] For specific functions of the BAP layer, please refer to the 3rd Generation Partnership Project (3GPP) technical specification (TS) 38.340 standard. Details will not be repeated here.

[0108]

[0129] In the existing standard, the donor CU needs to establish a binding relationship between the IAB-MT and the IAB-DU to set up the entire topology relationship and configure the BAP routing, bearer mapping, etc. for the IAB node. In the network access process of an IAB node, the IAB-MT can first access the network through random access, RRC connection setup, or the like. The donor CU sends the backhaul link configuration related to the IAB node to the IAB-MT by using an RRC message. In this step, the donor CU also configures the IAB node's BAP address for the IAB-MT. The IAB-DU sends an F1 SETUP REQUEST message to the donor CU, where the F1 SETUP REQUEST message carries the IAB node's BAP address. After receiving the F1 SETUP REQUEST message sent by the IAB-DU, the donor CU can determine, based on the BAP address in the F1 SETUP REQUEST message, that the MT and DU to which the donor CU previously distributed the BAP address belong to the same IAB node. After the IAB node accesses the network, the connection between the IAB-MT and the donor-CU may be an RRC connection, and the connection between the IAB-DU and the donor CU may be an F1 connection.

[0109]

[0130] The following describes inter-donor-CU migration of an IAB node. Existing standards provide two implementations of inter-donor-CU migration of an IAB node: full migration and partial migration. In full migration, the IAB-MT and IAB-DU must migrate from the source donor CU to the target donor CU, respectively. In partial migration, the IAB-MT migrates from the source donor CU to the target donor CU, and the IAB-DU does not need to migrate to the target donor CU. In partial migration, inter-donor-CU migration occurs in the IAB-MT, but the IAB-DU still maintains its F1 connection to the source donor CU. In this way, the F1 interface is switched to another path for transmission, but the anchor of the F1 interface remains unchanged, achieving load-balancing migration of the IAB node. In full migration, the IAB-DU needs to set up F1 connections to the target donor CU to handle scenarios where IAB nodes move over a wide area.

[0110]

[0131] For example, Figure 6 is a diagram of partial migration. The IAB node being migrated may be referred to as a boundary node. See Figure 6. The boundary node in Figure 6 is IAB node 2. Before partial migration, there is an RRC connection between IAB-MT2 and CU1, and an F1 interface between IAB-DU2 and CU1. IAB node 2 communicates with the IAB donor via the source route (through IAB node 1, which includes IAB-MT1 and IAB-DU1). During partial migration, a donor inter-CU cell handover occurs in IAB-MT, and IAB-MT2 sets up an RRC connection to CU2. However, to avoid the introduction of an F1 interface re-setup process, IAB-DU2 still maintains an F1 interface with CU1, and an F1 interface is not set up between IAB-DU2 and CU2. Therefore, the communication path between CU1 and IAB-DU2 changes to the following inter-topology: CU1 ←→ donor DU2 ←→ IAB-MT3 ←→ IAB-DU3 ←→ IAB-MT2 ←→ IAB-DU2. In this architecture shown in Figure 6, CU1 and CU2 are referred to as the F1-terminating CU and non-F1-terminating CU, respectively. Note that after the partial migration, data does not need to pass through CU2 during data transmission on the path; CU1 and donor DU2 communicate directly with each other via the IP network. Optionally, data between CU1 and donor DU2 may alternatively be transmitted via multiple hops of some other transport network node, and CU2 may alternatively be used as an intermediate hop node.

[0111]

[0132] FIG. 7 illustrates a complete migration. In a complete migration, IAB-MT2 is migrated to CU2, and the F1 interface between IAB-DU2 and CU1 needs to be migrated to CU2. Because the coexistence of F1 interfaces between one IAB-DU and two donor CUs is not supported in the protocol, IAB-DU2 may be expanded into two logical DUs: IAB-DU2a and IAB-DU2b. IAB-DU2a always maintains the F1 interface with CU1, and IAB-DU2b is configured to set up a new F1 interface with CU2. DU2a and DU2b may be considered as two DUs, each with its own F1 interface. For ease of explanation, in the following description of the embodiments of the present application, IAB-DU migration is used to represent the aforementioned process. The UE also needs to be handed over from the cell served by IAB-DU2a to the cell served by IAB-DU2b.

[0112]

[0133] It can be seen from the above description that the essential difference between full migration and partial migration is whether IAB-DU migration needs to be performed. It should be noted that, in practice, the IAB-DU migration process involves the IAB node creating a new logical DU and the logical DU setting up an F1 interface with the target donor CU. For ease of explanation, this process will be referred to as IAB-DU migration in this application.

[0113]

[0134] In some implementations, in IAB node migration, continuous partial migration may be used as a baseline, and IAB-DU migration is performed when IAB-DU migration needs to be performed. For example, FIG. 8 is a diagram of IAB node migration. In FIG. 8, a mobile IAB (mIAB) node is used as an example for illustration. See FIG. 8. The mIAB-MT is migrated from the CU1 topology to the CU2 topology, and then from the CU2 topology to the CU3 topology. The mIAB-DU always maintains an F1 connection with CU1. FIG. 9 is a diagram of IAB node migration. See FIG. 9. When mIAB-DU migration needs to be performed, the mIAB node needs to create a new logical DU (mIAB-DU2), which sets up an F1 interface with CU3, and then the UE is handed over from the cell served by mIAB-DU1 to the cell served by mIAB-DU2.

[0114]

[0135] Optionally, in the IAB node migration scenario, IAB-MT migration can actually be separated from IAB-DU migration. For example, IAB-MT migration and IAB-DU non-migration are partial migrations, and IAB-DU migration and IAB-MT non-migration are also possible. Due to mobility, the donor CU of IAB-MT may change frequently, but the anchor donor CU of IAB-DU should not change frequently. Therefore, IAB-DU can access donor CUs with a large control range instead of selecting a donor CU of a small base station following IAB-MT. Therefore, IAB-DU migration can be separated from IAB-MT migration.

[0115]

[0136] For example, FIG. 10 is a diagram of an IAB node migration scenario according to an embodiment of the present application. See FIG. 10. It is assumed that CU3 and CU1 may be CUs of a macro base station, CU2 is a CU of a small base station located at the boundary between the control range of CU3 and the control range of CU1, and the source / donor CU of the mIAB node is CU3. When the mIAB node moves from the control range of CU3 to the control range of CU1, mIAB-MT may be migrated from CU3 to CU2. If mIAB-MT is connected to CU2, CU3 may first decide to migrate mIAB-DU to CU1, thereby avoiding an increase in transmission delay caused by an excessively long distance from CU1 after mIAB-MT continues to be migrated.

[0116]

[0137] If the target donor CU to which the mIAB-DU is to be migrated and the donor CU connected to the mIAB-MT are not the same donor CU, the mIAB-DU sends an F1 SETUP REQUEST message to the target donor CU. The F1 SETUP REQUEST message carries the BAP address of the mIAB node. The BAP address is the address used by the mIAB node for communication in the topology managed by the donor CU connected to the mIAB-MT. If any two donor CUs do not pre-negotiate the assignment of BAP addresses, the BAP address of the mIAB node may conflict with the BAP address of another IAB node served by the target donor CU, resulting in a communication error. For example, use the scenario shown in Figure 10 as an example. After mIAB-DU is migrated to CU1, if IAB node 1 and the mIAB node in CU1 have the same BAP address, when CU1 performs BAP routing configuration based on the BAP address, CU1 may send the route configuration information to the wrong IAB node because the BAP address of IAB node 1 conflicts with the BAP address of the mIAB node.

[0117]

[0138] In view of this, the embodiments of the present application provide a communication method and apparatus for resolving conflicts between BAP addresses in the migration process of mIAB nodes in an IAB network and ensuring the accuracy of data transmission in the IAB network. The method and apparatus are based on the same inventive concept. Since the method and apparatus have similar problem-solving principles, the implementation forms of the apparatus and the method can be referred to each other, and no repeated description will be given.

[0118]

[0139] Hereinafter, the communication method provided in the embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0119]

[0140] First, a scenario to which embodiments 1 to 3 are applicable will be described. FIG. 10 is a diagram of an mIAB node migration scenario in an IAB network according to an embodiment of the present application. Referring to FIG. 10, the donor CU connected to mIAB-MT is CU2. That is, an RRC connection is set up between mIAB-MT and CU2. The target donor CU to which mIAB-DU is to be migrated is CU1, and the source donor CU connected to mIAB-DU is CU3. That is, an F1 connection is set up between mIAB-DU and CU3 before the migration. It should be noted that CU3 and CU2 may be the same donor CU. That is, before the migration, mIAB-DU and mIAB-MT may be connected to the same donor CU. Of course, CU3 and CU2 may alternatively be different donor CUs.

[0120]

[0141] Furthermore, it should be noted that the connection between the IAB node and the donor DU in Figure 10 is used only as an example and not as a limitation. In implementation, there may be one or more hops of network nodes between the IAB node and the donor DU, which is not a limitation in this embodiment of the present application.

[0121]

[0142] Embodiment 1 11 is a flowchart of a communication method according to an embodiment of the present application. Please refer to FIG. 11. The method includes the following steps:

[0122]

[0143] S1101: CU1 transmits first identification information of the mIAB-MT to CU2 and / or CU3.

[0123]

[0144] The first identification information of the mIAB-MT may be identification information for identifying the mIAB-MT in CU1. For example, the first identification information of the mIAB-MT may be a User Equipment Xn Application Protocol User Identifier (UE XnAP ID) of the mIAB-MT served by CU1. The mIAB-MT has a UE XnAP ID in each donor CU.

[0124]

[0145] S1102: The mIAB node receives first identification information and / or second identification information of the mIAB-MT.

[0125]

[0146] The second identification information of the mIAB-MT may be identification information for identifying the mIAB-MT in CU2. For example, the second identification information of the mIAB-MT may be the UE XnAP ID of the mIAB-MT served by CU2.

[0126]

[0147] Optionally, S1102 may be implemented in any one of the following ways:

[0127]

[0148] S1102a: The mIAB node receives the first identification information and / or the second identification information of the mIAB-MT from CU2.

[0128]

[0149] In this way, CU2 can send an RRC message to the mIAB-MT, where the RRC message includes the first identification information and / or the second identification information of the mIAB-MT.

[0129]

[0150] S1102b: The mIAB node receives the first identification information and / or the second identification information of the mIAB-MT from CU3.

[0130]

[0151] In this way, CU3 can send an F1 message to the mIAB-DU, where the F1 message includes the first identification information and / or the second identification information of the mIAB-MT.

[0131]

[0152] It should be noted that when two donor CUs perform mIAB-MT-related interactions with each other, the identification information of the mIAB-MT served by the donor CU needs to be carried in the exchange message. The mIAB-MT-related exchange between two donor CUs may include, for example, the transfer of the mIAB-MT from one of the donor CUs to the other donor CU, or in another example, the inter-topology traffic transfer of the mIAB-MT between the two donor CUs. Based on this, after performing the mIAB-MT-related interaction with CU2, CU3 can know the second identification information of the mIAB-MT.

[0132]

[0153] In some embodiments, S1101 is an optional step, in which case CU2 or CU3 may perform S1102a or S1102b to send the second identification information of the mIAB node to the mIAB node.

[0133]

[0154] S1103: If CU1 is different from CU2, mIAB-DU decides to include the BAP address of the mIAB node in the first message and to include the first identification information of the mIAB-MT and / or the second identification information of the mIAB-MT in the first message.

[0134]

[0155] Optionally, the first message may be an F1 SETUP REQUEST message to request the setup of an F1 interface connection between the mIAB-DU and CU1.

[0135]

[0156] In an optional implementation, when CU1 is different from CU2, the BAP address of the mIAB node is the address used by the mIAB node to perform communication in the topology managed by CU2. In this case, the BAP address may conflict with the BAP address of another node served by CU1. Therefore, the mIAB-DU may decide to include the BAP address of the mIAB node and the first identification information of the mIAB-MT and / or the second identification information of the mIAB-MT in the first message, where the first identification information of the mIAB-MT and / or the second identification information of the mIAB-MT may indicate that the BAP address in the first message is the BAP address of the mIAB node to which the mIAB-MT belongs.

[0136]

[0157] Optionally, the mIAB-DU may alternatively decide to include the identification information of the mIAB-DU in the first message, so that after receiving the first message, CU1 can determine the correspondence between the mIAB-DU and the mIAB-MT based on the identification information of the mIAB-DU and the first identification information of the mIAB-MT and / or the second identification information of the mIAB-MT, so that CU1 manages the mIAB node. The identification information of the mIAB-DU may be the gNB-DU ID of the mIAB-DU.

[0137]

[0158] S1104: mIAB-DU sends a first message to CU1.

[0138]

[0159] Optionally, the first message may include the BAP address of the mIAB node, and may further include a first identification of the mIAB-MT and / or a second identification of the mIAB-MT. Below, several different combinations of information in the first message are described separately.

[0139]

[0160] 1. The first message includes the BAP address and the first identification information of the IAB-MT.

[0140]

[0161] If the first message includes first identification information of the IAB-MT, CU1 can determine the identification information of the IAB-MT based on the first identification information of the IAB-MT, and further determine that the BAP address is the address of the IAB node to which the specific IAB-MT belongs.

[0141]

[0162] 2. The first message includes the BAP address and the second identification information of the IAB-MT.

[0142]

[0163] In some implementations, when CU1 performs an IAB-MT-related interaction with CU2, CU1 receives the second identification information of the IAB-MT before receiving the first message, and thus CU1 can store a correspondence between the first identification information of the IAB-MT and the second identification information of the IAB-MT. In this case, if the first message includes the second identification information of the IAB-MT, CU1 can determine an identifier of the IAB-MT corresponding to the second identification information based on the correspondence between the first identification information of the IAB-MT and the second identification information of the IAB-MT, and further determine that the BAP address is the address of the IAB node to which the specific IAB-MT belongs.

[0143]

[0164] 3. The first message includes the BAP address, the first identification information of the IAB-MT, and the second identification information of the IAB-MT.

[0144]

[0165] In some implementations, CU1 may have performed an IAB-MT-related interaction with CU2, but CU1 may not have received the second identification information of the IAB-MT. For example, CU1 may initiate an IAB Transport Migration Management Request to CU2. After performing the corresponding configuration in the topology managed by CU2, CU2 may not send a response message to CU1 to reduce overhead. In this case, CU1 may not have received the second identification information of the IAB-MT. In this scenario, the first message may carry both the first identification information of the IAB-MT and the second identification information of the IAB-MT. CU1 may determine the identification information of IAB-MT based on the first identification information of IAB-MT and the second identification information of IAB-MT, and CU1 may store the correspondence between the first identification information of IAB-MT and the second identification information of IAB-MT, so that CU1 will again initiate IAB-MT-related interactions with CU2 in the future.

[0145]

[0166] Embodiment 2 12 is a flowchart of a communication method according to an embodiment of the present application. Please refer to FIG. 12. The method includes the following steps:

[0146]

[0167] S1201: If CU1 is different from CU2, mIAB-DU determines not to include the BAP address of the mIAB node in the first message.

[0147]

[0168] Optionally, the first message may be an F1 SETUP REQUEST message to request the setup of an F1 interface connection between the mIAB-DU and CU1.

[0148]

[0169] In an optional implementation, if it determines that the donor CU (CU2) connected to the mIAB-MT and the target donor CU (CU1) to which it is being migrated are not the same CU, the mIAB-DU may decide not to include the BAP address of the mIAB node in the first message to prevent a conflict between the BAP address of the mIAB-node and the BAP address of another relay node in CU1.

[0149]

[0170] In another optional implementation, if CU1 is the same as CU2, the BAP address of the mIAB node may be determined to be included in the first message, in which case no BAP address conflict occurs.

[0150]

[0171] S1202: mIAB-DU sends a first message to CU1. In this way, the mIAB-DU can avoid including BAP addresses in the first message, resolve conflicts between BAP addresses, and remove redundant information elements from the first message, which reduces transmission resource overhead.

[0151]

[0172] Embodiment 3 It can be seen from the above description that in the network access process of the mIAB node, the mIAB-DU includes the BAP address of the mIAB node in the F1 SETUP REQUEST message. After receiving the F1 SETUP REQUEST message, the donor CU can determine the correspondence between the mIAB-DU and the mIAB-MT based on the BAP address in the F1 SETUP REQUEST message. This embodiment of the present application provides a method for determining the correspondence between the mIAB-DU and the mIAB-MT without based on the BAP address. Figure 13 is a flowchart of a communication method according to an embodiment of the present application. Please refer to Figure 13. This method includes the following steps:

[0152]

[0173] S1301: If CU1 is different from CU2, mIAB-DU decides to include identification information of mIAB-DU in the first message and to include first identification information of mIAB-MT and / or second identification information of mIAB-MT in the first message.

[0153]

[0174] Optionally, the first message may be for requesting the setup of an F1 interface connection between the mIAB-DU and CU1. For example, the first message may be an F1 SETUP REQUEST. The first identification information of the mIAB-MT may be identification information for identifying the mIAB-MT in CU1. For example, the first identification information of the mIAB-MT may be a UE XnAP ID of the mIAB-MT served by CU1. The second identification information of the mIAB-MT may be identification information for identifying the mIAB-MT in CU2. For example, the second identification information of the mIAB-MT may be a UE XnAP ID of the mIAB-MT served by CU2. The identification information of the mIAB-DU may be a gNB-DU ID of the mIAB-DU.

[0154]

[0175] Optionally, the mIAB-DU may further decide not to include the BAP addresses of mIAB nodes in the first message, resolving conflicts between BAP addresses and removing redundant information elements from the first message, thereby reducing transmission resource overhead.

[0155]

[0176] S1302: mIAB-DU sends a first message to CU1.

[0156]

[0177] In this embodiment of the present application, after receiving the first message, CU1 can determine the correspondence between the mIAB-DU and the mIAB-MT based on the identification information of the mIAB-DU and the first identification information of the mIAB-MT and / or the second identification information of the mIAB-MT in the first message. In this way, CU1 can know the correspondence between the mIAB-DU and the mIAB-MT, and as a result, CU1 manages the IAB nodes.

[0157]

[0178] According to this solution, CU1 can receive the first message sent by mIAB-DU, which includes the identification information of mIAB-DU and the identification information of mIAB-MT, and thus CU1 can determine the correspondence between mIAB-DU and mIAB-MT based on the identification information of mIAB-DU and the identification information of mIAB-MT, and does not need to determine the correspondence between mIAB-DU and mIAB-MT depending on the BAP address sent by mIAB-DU, which is more flexible.

[0158]

[0179] Embodiment 4 It can be seen from the above description of mIAB-DU transition that mIAB-DU transition actually means that the mIAB node splits the mIAB-DU into two logical DUs, for example, mIAB-DU1 and mIAB-DU2 as shown in Figure 10. In some scenarios, when the mIAB-DU is transitioned, the UE is handed over from mIAB-DU1 to mIAB-DU2. In this case, CU1 needs to initiate an IAB transport transition management procedure associated with the MT to CU2 to request that an inter-topology user plane transmission be set up. In this case, CU1 needs to memorize the correspondence between the mIAB-DU and the mIAB-MT before initiating the procedure.

[0159]

[0180] In some implementations, CU1 may not need to initiate an IAB transport transition management procedure for CU2. For example, CU3 initiates an IAB transport transition management procedure for CU2. Alternatively, CU2 actively configures resources, and another donor CU does not need to initiate the procedure. In this case, CU1 does not need to know the correspondence between the mIAB-DU and the mIAB-MT; CU1 only needs to determine that an mIAB-DU exists within CU1's control scope, and does not need to determine that a particular mIAB-MT corresponds to the mIAB-DU. However, when an mIAB-MT is migrated from CU2 to CU1, CU1 needs to know the correspondence between the mIAB-DU and the mIAB-MT because there is no donor CU to manage the mIAB-MT.

[0160]

[0181] In view of this, an embodiment of the present application provides a communication method to solve the problem that when a mIAB-MT is transferred to a donor CU (CU1) of a mIAB-DU, CU1 cannot determine the correspondence relationship between the mIAB-DU and the mIAB-MT. Figure 14 is a flowchart of the communication method according to an embodiment of the present application. Please refer to Figure 14. The method includes the following steps:

[0161]

[0182] S1401: mIAB-DU sends a second message to CU1, where the second message includes a BAP address of the mIAB node, and the BAP address is used for communication of the mIAB node in the topology managed by CU1.

[0162]

[0183] Optionally, there is an F1 interface connection between the mIAB-DU and CU1, i.e., CU1 is a donor CU connected to the mIAB-DU.

[0163]

[0184] In this embodiment of the present application, the second message sent by the mIAB node to CU1 includes the BAP address of the mIAB node, and the BAP address of the mIAB node can be set by CU1 and distributed to the mIAB-MT. In this case, after receiving the second message, CU1 can determine the correspondence between the mIAB-DU and the mIAB-MT based on the BAP address of the mIAB-node.

[0164]

[0185] Optionally, the second message may be a configuration update message, for example, a gNB-DU configuration update message.

[0165]

[0186] Furthermore, it can be seen from the above description that the transition of the mIAB-MT may be decoupled from the transition of the mIAB-DU. In this case, the donor CU connected to the mIAB-MT may be different from the donor CU connected to the mIAB-DU. For example, FIG. 15 is a diagram of a scenario in which the mIAB-MT and the mIAB-DU are connected to different donor CUs according to an embodiment of the present application. See FIG. 15. The donor CU connected to the mIAB-DU is CU1, the donor CU connected to the mIAB-MT is CU2, UE1 is a UE managed by the mIAB-DU, the first core network element is a core network element serving the UE, and FIG. 15 illustrates an example in which the first core network element is AMF1. The second core network element is a core network element serving the MT, and FIG. 15 illustrates an example in which the second core network element is AMF2. Embodiments 5 to 8 are embodiments based on the scenario illustrated in FIG. 15. For ease of explanation, it should be noted that the connection between the IAB node and the donor-DU in Figure 15 is merely an example and not a limitation, and in implementation, there may be one or more hops of network nodes between the IAB node and the donor-DU, which is not a limitation in the embodiments of the present application.

[0166]

[0187] It can be understood that the donor CU connected to the mIAB-MT may differ from the donor CU connected to the mIAB-DU because the mIAB-MT is transferred but the mIAB-DU is not, because the mIAB-DU is transferred but the mIAB-MT is not, or because the target donor CU to which the mIAB-DU is transferred differs from the target donor CU to which the mIAB-MT is transferred, although this is not limited to this embodiment of the present application.

[0167]

[0188] If the donor CU of mIAB-MT is different from the donor CU of mIAB-DU, CU1 reports the user location information (ULI) of the UE to AMF1, and CU1 needs to further report indication information indicating the ULI of mIAB-MT to AMF1 as an additional ULI of the UE to improve the accuracy of the location information. In the scenario shown in FIG. 15, the donor CU of mIAB-MT is CU2. In this case, CU1 cannot know the ULI of mIAB-MT and cannot report indication information indicating the ULI of mIAB-MT to AMF1. Based on this problem, an embodiment of the present application provides a communication method for solving the problem that CU1 cannot report indication information indicating the ULI of mIAB-MT to AMF1. The communication methods provided in embodiments 5 to 8 of the present application are described below.

[0168]

[0189] Embodiment 5 16 is a flowchart of a communication method according to an embodiment of the present application. Please refer to FIG. 16. The method includes the following steps:

[0169]

[0190] S1601: mIAB-DU sends a third message to CU1, and the third message includes the ULI of mIAB-MT.

[0170]

[0191] In an optional implementation, the mIAB-DU may obtain the ULI of the mIAB-MT through internal interactions of the relay node.

[0171]

[0192] S1602: CU1 sends a fourth message to AMF1, where the fourth message includes the ULI of the UE and indication information indicating the ULI of the mIAB-MT.

[0172]

[0193] Optionally, the fourth message may be a message used by CU1 to send context information of the UE to AMF1. The indication information in the fourth message indicating the ULI of the mIAB-MT may be the ULI of the mIAB-MT, or may be a relationship between the ULI of the mIAB-MT and the ULI of the UE.

[0173]

[0194] In this way, the mIAB-DU may send the ULI of the mIAB-MT to the CU1, so that the CU1 knows the ULI of the mIAB-MT and can report indication information indicating the ULI of the mIAB-MT to the AMF1, which ensures the accuracy of the UE's location information.

[0174]

[0195] Embodiment 6 17 is a flowchart of a communication method according to an embodiment of the present application. Please refer to FIG. 17. The method includes the following steps:

[0175]

[0196] S1701: CU2 sends a fifth message to CU1, and the fifth message includes the ULI of mIAB-MT.

[0176]

[0197] In an optional implementation, CU2 may send a fifth message to CU1 through IP layer interaction.

[0177]

[0198] S1702: CU1 sends a fourth message to AMF1, where the fourth message includes the ULI of the UE and indication information indicating the ULI of the mIAB-MT.

[0178]

[0199] Optionally, the fourth message may be a message used by CU1 to send context information of the UE to AMF1. The indication information in the fourth message indicating the ULI of the mIAB-MT may be the ULI of the mIAB-MT, or may be a relationship between the ULI of the mIAB-MT and the ULI of the UE.

[0179]

[0200] In this way, CU2 may send the ULI of mIAB-MT to CU1, so that CU1 knows the ULI of mIAB-MT and can report indication information indicating the ULI of mIAB-MT to AMF1, which ensures the accuracy of the UE's location information.

[0180]

[0201] Embodiment 7 18 is a flowchart of a communication method according to an embodiment of the present application. Please refer to FIG. 18. The method includes the following steps:

[0181]

[0202] S1801: The mIAB-MT sends an eighth message to CU2, where the eighth message includes the identification information of the cell managed by the mIAB-DU.

[0182]

[0203] Optionally, the cell identity may include a cell global identifier (CGI) and / or a tracking area identity (TAI).

[0183]

[0204] S1802: CU1 sends a ninth message to CU2, where the ninth message includes identification information of a cell managed by the IAB-DU, and the ninth message further includes first identification information of the mIAB-MT and / or second identification information of the mIAB-MT.

[0184]

[0205] Optionally, the cell identification information may include a CGI and / or a TAI. The first identification information of the mIAB-MT is identification information for identifying the mIAB-MT in CU1. For example, the first identification information of the mIAB-MT may be the UE XnAP ID of the mIAB-MT served by CU1. The second identification information of the mIAB-MT is identification information for identifying the mIAB-MT in CU2. For example, the second identification information of the mIAB-MT may be the UE XnAP ID of the mIAB-MT served by CU2. The first identification information of the mIAB-MT and / or the second identification information of the mIAB-MT in the ninth message may indicate the IAB-MT corresponding to the IAB-DU.

[0185]

[0206] It should be noted that in some embodiments, either S1801 or S1802 may be executed. For example, in some embodiments, S1801 may be executed without executing S1802, S1802 may be executed without executing S1801, or S1801 and S1802 may be executed. Also, the execution order of S1801 and S1802 is not limited in this embodiment of the present application.

[0186]

[0207] S1803: CU2 sends a seventh message to AMF2, where the seventh message includes indication information indicating the ULI of the mIAB-MT and identification information of the cell managed by the mIAB-DU.

[0187]

[0208] Optionally, the indication information in the seventh message indicating the ULI of the mIAB-MT may be the ULI of the mIAB-MT, or may be the relationship between the ULI of the mIAB-MT and the ULI of the UE.

[0188]

[0209] In some implementations, the identity of the cell managed by the mIAB-DU may be used as the ULI of the UE managed by the mIAB-DU. In this case, after receiving the indication information indicating the ULI of the mIAB-MT and the identity of the cell managed by the DU, the AMF2 may determine the identity of the cell managed by the DU, which is associated with the indication information indicating the ULI of the mIAB-MT.

[0189]

[0210] S1804: CU2 sends a sixth message to CU1, and the sixth message includes the identification information of AMF2.

[0190]

[0211] In this step, CU1 can determine that the AMF corresponding to IAB-MT is AMF2.

[0191]

[0212] S1805: CU1 determines whether AMF1 and AMF2 are the same AMF; if AMF1 and AMF2 are the same AMF, execute S1806; or if AMF1 and AMF2 are not the same AMF, execute S1807.

[0192]

[0213] S1806: CU1 determines to include the ULI of the UE in the tenth message.

[0193]

[0214] S1807: CU1 determines to include the ULI of the UE and indication information indicating the ULI of the IAB-MT in the tenth message.

[0194]

[0215] In this embodiment of the present application, CU1 can determine whether AMF1 serving the UE and AMF2 serving the IAB-MT are the same AMF. If AMF1 and AMF2 are the same AMF, CU2 sends the seventh message to AMF2 in S1803, so that AMF2 knows the identity of the cell managed by the DU, which is associated with the indication information indicating the ULI of the mIAB-MT. In this case, CU1 may determine to include the ULI of the UE in the tenth message. After receiving the tenth message, AMF2 can determine the indication information indicating the ULI of the mIAB-MT, which corresponds to the ULI of the UE, based on the relationship between the indication information indicating the ULI of the mIAB-MT and the identity of the cell managed by the DU, and the ULI of the UE; therefore, there is no need to include the indication information indicating the ULI of the MT in the tenth message. If it is determined that AMF1 and AMF2 are not the same AMF, CU1 decides to include the ULI of the UE and indication information indicating the ULI of the MT in the 10th message and reports the ULI of the UE and indication information indicating the ULI of the MT to AMF1.

[0195]

[0216] S1808: CU1 sends the tenth message to AMF1.

[0196]

[0217] According to this solution, CU2 sends a seventh message to AMF2 once, the seventh message includes an indication indicating the ULI of mIAB-MT and the identity of the cell managed by the DU. If CU1 determines that AMF1 and AMF2 serving the UE are the same AMF, CU1 does not need to report the ULI of mIAB-MT or the indication indicating the ULI of mIAB-MT to AMF1. This reduces signaling overhead and saves communication resources.

[0197]

[0218] Embodiment 8 19 is a flowchart of a communication method according to an embodiment of the present application. Please refer to FIG. 19. The method includes the following steps:

[0198]

[0219] S1901: mIAB-MT sends an eighth message to CU2, where the eighth message includes the identification information of the cell managed by the DU.

[0199]

[0220] Optionally, the cell identity may include a cell global identifier (CGI) and / or a tracking area identity (TAI).

[0200]

[0221] S1902: CU1 sends a ninth message to CU2, where the ninth message includes identification information of a cell managed by the IAB-DU, and the ninth message further includes first identification information of the mIAB-MT and / or second identification information of the mIAB-MT.

[0201]

[0222] Optionally, the cell identification information may include a CGI and / or a TAI. The first identification information of the mIAB-MT is identification information for identifying the mIAB-MT in CU1. For example, the first identification information of the mIAB-MT may be the UE XnAP ID of the mIAB-MT served by CU1. The second identification information of the mIAB-MT is identification information for identifying the mIAB-MT in CU2. For example, the second identification information of the mIAB-MT may be the UE XnAP ID of the mIAB-MT served by CU2. The first identification information of the mIAB-MT and / or the second identification information of the mIAB-MT in the ninth message may indicate the IAB-MT corresponding to the IAB-DU.

[0202]

[0223] It should be noted that in some embodiments, either S1901 or S1902 may be executed. For example, in some embodiments, S1901 may be executed without executing S1902, S1902 may be executed without executing S1901, or S1901 and S1902 may be executed. Also, the execution order of S1901 and S1902 is not limited in this embodiment of the present application.

[0203]

[0224] S1903: CU1 sends an eleventh message to CU2, and the eleventh message includes the identification information of AMF1.

[0204]

[0225] In an optional implementation, CU1 can send the identification information of AMF1 to CU2, so that CU2 knows that the AMF serving the UE is AMF1.

[0205]

[0226] S1904: CU2 sends a 12th message to AMF1 based on the identification information of AMF1, and the 12th message includes indication information indicating the ULI of mIAB-MT and identification information of the cell managed by mIAB-DU.

[0206]

[0227] In this embodiment of the present application, CU2 may directly send to AMF1 indication information indicating the ULI of mIAB-MT and the identification information of the cell managed by mIAB-DU, so that AMF1 can store the relationship between the indication information indicating the ULI of mIAB-MT and the identification information of the cell managed by mIAB-DU.

[0207]

[0228] S1905: CU1 sends a tenth message to AMF1, where the tenth message includes the ULI of the UE.

[0208]

[0229] In this embodiment of the present application, AMF1 has received the twelfth message sent by CU2 in S1904. After receiving the tenth message sent by CU1, AMF1 can determine the indication information indicating the ULI of mIAB-MT, which corresponds to the ULI of the UE, based on the relationship between the indication information indicating the ULI of mIAB-MT and the identification information of the cell managed by the DU, and the ULI of the UE in the tenth message, so that CU1 does not need to include the indication information indicating the ULI of MT in the tenth message.

[0209]

[0230] According to this solution, CU2 can send an indication indicating the ULI of mIAB-MT and the identity of the cell managed by DU to AMF1 serving the UE, so that CU1 does not need to report the ULI of MT or the indication indicating the ULI of MT again, which ensures the accuracy of the UE location information and reduces transmission resources.

[0210]

[0231] Based on the above method, the present application further provides a communication method. The method may be performed by a relay node. Figure 20 is a flowchart of the communication method according to the present application. Please refer to Figure 20. The method includes the following steps:

[0211]

[0232] S2001: When a first donor central unit CU is different from a second donor CU, a distributed unit DU of a relay node decides to include a backhaul adaptation protocol (BAP) address of the relay node in a first message and to include a first identification of a mobile termination unit (MT) of the relay node and / or a second identification of the MT in the first message.

[0212]

[0233] The first donor CU is a target donor CU to which the DU of the relay node will be migrated, the second donor CU is a donor CU connected to the MT, the first message is to request setting up an interface connection between the DU and the first donor CU, the BAP address is used for communication of the relay node in a topology managed by the second donor CU; the first identification information is identification information for identifying the MT in the first donor CU, and the second identification information is identification information for identifying the MT in the second donor CU.

[0213]

[0234] S2002: The DU sends a first message to the first donor CU.

[0214]

[0235] It should be noted that for the specific implementation of the communication method shown in Figure 20 in the present application, please refer to Embodiment 1 of the present application, and the repeated description will not be given again.

[0215]

[0236] It will be understood that to implement the functions in the foregoing embodiments, the donor node, relay node, and terminal include corresponding hardware structures and / or software modules for performing the functions. Those skilled in the art should easily recognize that in the combination of units and method steps in the examples described in the embodiments disclosed in the present application, the present application can be implemented by hardware or a combination of hardware and computer software. Whether the functions are performed by hardware or by hardware driven by computer software depends on the specific application scenario and design constraints of the technical solution.

[0216]

[0237] 21 and 22 are respectively structural diagrams of possible communication devices according to the embodiments of the present application, which may be configured to implement the functions of the IAB node in the above-mentioned method embodiments, or may be configured to implement the functions of the donor CU in the above-mentioned method embodiments, and thus can also achieve the beneficial effects of the above-mentioned method embodiments.

[0217]

[0238] See Figure 21. The communication device 2100 may include a processing module 2101 and a communication module 2102.

[0218]

[0239] The communication module may also be referred to as a transceiver module, transceiver, transceiver device, transceiver apparatus, or the like. The processing module may also be referred to as a processor, processing board, processing unit, processing device, or the like. Optionally, the communication module is configured to perform transmitting and receiving operations at the receiving device side or the transmitting device side in the aforementioned method. A component configured to perform a receiving function within the communication module may be considered a receiving unit, and a component configured to perform a transmitting function within the communication module may be considered a transmitting unit. That is, the communication module includes a receiving unit and a transmitting unit.

[0219]

[0240] When the communication device 2100 is used in a relay device, the processing module 2101 may be configured to implement the processing functions of the mIAB node in the embodiments shown in FIGS. 11 to 14 and the embodiments shown in FIGS. 16 to 19. Optionally, when the communication device 2100 is used in a relay device, the processing module may include a first processing module and a second processing module. The first processing module may be configured to implement the processing functions of the mIAB-DU in the aforementioned embodiments, and the second processing module may implement the processing functions of the mIAB-MT in the aforementioned embodiments. The communication module 2102 may be configured to implement the receiving and transmitting functions of the mIAB node in the embodiments shown in FIGS. 11 to 14 and the embodiments shown in FIGS. 16 to 19. Alternatively, the communication device may be understood by referring to the descriptions and possible designs in the eleventh to fourteenth aspects of the Summary of the Invention.

[0220]

[0241] When the communication apparatus 2100 is used in a donor device, the processing module 2101 can be configured to perform the processing functions of any of the donor CUs in the embodiments shown in Figures 11 to 14 and the embodiments shown in Figures 16 to 19. The communication module 2102 can be configured to perform the receiving and transmitting functions of any of the donor CUs in the embodiments shown in Figures 11 to 14 and the embodiments shown in Figures 16 to 19. Alternatively, the communication apparatus can be understood with reference to the descriptions and possible designs in the fifteenth to twentieth aspects of the Summary of the Invention.

[0221]

[0242] Furthermore, it should be noted that the communication module and / or the processing module may be implemented by using virtual modules. For example, the processing module may be implemented by using a software functional unit or a virtual device, and the communication module may be implemented by using a software function or a virtual device. Alternatively, the processing module or the communication module may be implemented by using an entity device. For example, if the device is implemented by using a chip / chip circuit, the communication module may be an input / output circuit and / or a communication interface, performing input operations (corresponding to the above-mentioned receiving operations) and output operations (corresponding to the above-mentioned transmitting operations). The processing module is an integrated processor, a microprocessor, or an integrated circuit.

[0222]

[0243] The division into modules in this embodiment of the present application is merely an example, and is merely a division into logical functions, and other divisions may be used in actual implementation. Furthermore, the functional modules in the example embodiment of the present application may be integrated into one processor, and each functional module may exist physically alone, or two or more functional modules may be integrated into one module. The integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0223]

[0244] 22, the communication device 2200 may include a processor 2201 and a communication interface 2202. The processor 2201 and the communication interface 2202 are connected to each other. It will be understood that the communication interface 2202 may be a transceiver or an input / output interface. Optionally, the communication device may further include a memory 2203 configured to store instructions to be executed by the processor 2201, to store input data required for the processor 2201 to execute the instructions, or to store data generated after the processor 2201 executes the instructions.

[0224]

[0245] Optionally, see Figure 22. The processor 2201, communication interface 2202, and memory 2203 are connected to each other by using a bus 2204. The bus 2204 may be a peripheral component interconnect (PCI) bus, an extended industry standard architecture (EISA) bus, or the like. The bus may be classified as an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is used to represent a bus in Figure 22, but this does not mean that there is only one bus or only one type of bus.

[0225]

[0246] When the communication device 2200 is used in a relay device, the processor 2201 may be configured to implement the processing functions of the mIAB node in the embodiments shown in FIGS. 11 to 14 and the embodiments shown in FIGS. 16 to 19. Optionally, when the communication device 2200 is used in a relay device, the processor may include a first processor and a second processor. The first processor may be configured to implement the processing functions of the mIAB-DU in the aforementioned embodiments, and the second processor may implement the processing functions of the mIAB-MT in the aforementioned embodiments. The communication interface 2202 may be configured to implement the receiving and transmitting functions of the mIAB node in the embodiments shown in FIGS. 11 to 14 and the embodiments shown in FIGS. 16 to 19. Alternatively, the communication device may be understood with reference to the descriptions and possible designs in the eleventh to fourteenth aspects of the Summary of the Invention.

[0226]

[0247] When the communication apparatus 2200 is used in a donor device, the processor 2201 can be configured to perform the processing functions of any of the donor CUs in the embodiments shown in Figures 11 to 14 and the embodiments shown in Figures 16 to 19. The communication interface 2202 may be configured to perform the receiving and transmitting functions of any of the donor CUs in the embodiments shown in Figures 11 to 14 and the embodiments shown in Figures 16 to 19. Alternatively, the communication apparatus can be understood with reference to the descriptions and possible designs in the fifteenth to twentieth aspects of the Summary of the Invention.

[0227]

[0248] It will be understood that the processor in this embodiment of the present application may be a central processing unit (CPU), or may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or another programmable logic device, a transistor logic device, a hardware component, or any combination thereof. A general-purpose processor may be a microprocessor or any conventional processor, or the like.

[0228]

[0249] The method steps in the embodiments of the present application may be implemented in hardware or by a processor executing software instructions. The software instructions may include corresponding software modules. The software modules may be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disk, removable hard disk, CD-ROM, or any other form of storage medium known in the art. For example, the storage medium may be coupled to the processor such that the processor can read information from or write information to the storage medium. Of course, the storage medium may be a component of the processor. The processor and the storage medium may be located in an ASIC. Furthermore, the ASIC may be located in a base station or a terminal. Of course, the processor and the storage medium may reside as discrete elements in the base station or terminal.

[0229]

[0250] All or part of the above-described embodiments may be implemented by software, hardware, firmware, or any combination thereof. When software is used to implement an embodiment, all or part of the embodiment may be implemented in the form of a computer program product. A computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded into a computer and executed, the procedures or functions according to the embodiments of the present application are performed, in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a base station, a user device, or another programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer program or instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any available medium accessible by a computer, or a data storage device integrating one or more available media, such as a server or data center. The available media may be magnetic media such as floppy disks, hard disks, or magnetic tape; optical media such as digital video disks; or semiconductor media such as solid-state drives. The computer-readable storage media may be volatile or non-volatile storage media, or may include two types of storage media: volatile storage media and non-volatile storage media.

[0230]

[0251] In various embodiments of the present application, unless otherwise specified or there is no logical contradiction, the terms and / or descriptions in different embodiments are consistent and may be cross-referenced, and the technical features in different embodiments may be combined based on their internal logical relationships to form new embodiments.

[0231]

[0252] It will be understood that various numbers in the embodiments of the present application are only used for distinction to facilitate description, and are not used to limit the scope of the embodiments of the present application. The sequence numbers of the above processes do not mean the execution sequence, and the execution sequence of the processes should be determined based on the functions and internal logic of the processes.

Claims

1. 1. A method of communication comprising: a step of a distributed unit (DU) of a relay node deciding to include in a first message a backhaul adaptation protocol (BAP) address of the relay node and a first identification of a mobile termination (MT) of the relay node and / or a second identification of the MT in the first message if a first donor central unit (CU) is different from a second donor CU, the first donor CU being a target donor CU to which the DU of the relay node will be migrated, the second donor CU being a donor CU connected to the MT, the first message being for requesting the setting up of an interface connection between the DU and the first donor CU, the BAP address being used for communication of the relay node in a topology managed by the second donor CU; the first identification being an identification for identifying the MT in the first donor CU, and the second identification being an identification for identifying the MT in the second donor CU; and the DU sending the first message to the first donor CU; A method comprising:

2. The method of claim 1 , wherein the first message further includes identification information of the DU.

3. 3. The method according to claim 1, wherein before the DU sends the first message to the first donor CU, the method comprises: the relay node receiving the first identity and / or the second identity from the second donor CU; or the relay node receiving the first identification information and / or the second identification information from a third donor CU; wherein the third donor CU is a source donor CU from which the DU is migrated.

4. 1. A method of communication comprising: a step of determining, when a first donor central unit CU is different from a second donor CU, by a distributed unit DU of a relay node to include in a first message an identification of the DU and a first identification of a mobile termination MT of the relay node and / or a second identification of the MT in the first message, wherein the first donor CU is a target donor CU to which the DU of the relay node will be migrated, the second donor CU is a donor CU connected to the MT, the first message is for requesting the setting up of an interface connection between the DU and the first donor CU, and a BAP address is used for communication of the relay node in a topology managed by the second donor CU; the first identification is an identification for identifying the MT in the first donor CU, and the second identification is an identification for identifying the MT in the second donor CU; and the DU sending the first message to the first donor CU; A method comprising:

5. 5. The method of claim 4, wherein: a DU of the relay node determining not to include a backhaul adaptation protocol (BAP) address of the relay node in the first message; The method further comprises:

6. 6. The method according to claim 4 or 5, wherein before the step of the DU sending the first message to the first donor CU, the method comprises: the relay node receiving the first identity and / or the second identity from the second donor CU; or the relay node receiving the first identification information and / or the second identification information from a third donor CU; wherein the third donor CU is a source donor CU from which the DU is migrated.

7. 1. A method of communication comprising: a step of determining, by a distributed unit DU of a relay node, not to include a backhaul adaptation protocol (BAP) address of the relay node in a first message if a first donor central unit CU is different from a second donor CU, the first donor CU being a target donor CU to which the DU of the relay node will be migrated, the second donor CU being a donor CU connected to a mobile termination part MT of the relay node, the first message being for requesting setting up an interface connection between the DU and the first donor CU, the BAP address being used for communication of the relay node in a topology managed by the second donor CU; the DU sending the first message to the first donor CU; A method comprising:

8. 8. The method of claim 7, wherein: If the first donor CU is the same as a second donor CU, the DU determines to include a BAP address of the relay node in the first message; The method further comprises:

9. 1. A method of communication comprising:

1. A method comprising: a distributed unit (DU) of a relay node sending a second message to a first donor central unit (CU), the second message including a backhaul adaptation protocol (BAP) address of the relay node, the BAP address being used for communication of the relay node in a topology managed by the first donor CU, and an F1 interface connection existing between the DU of the relay node and the first donor CU.

10. 10. The method of claim 9, wherein the second message is a configuration update message.

11. 1. A method of communication comprising: receiving, by a first donor central unit CU, a third message sent by a distributed unit DU of a relay node, the third message including user location information ULI of a mobile termination MT of the relay node, the first donor CU being a donor CU connected to the DU; and a step of the first donor CU sending a fourth message to a first core network element, the fourth message including a ULI of a UE and indication information indicating a ULI of the MT, the first core network element being a core network element serving the UE, and the UE being a UE managed by the DU; A method comprising:

12. 1. A method of communication comprising: receiving, by a first donor central unit CU, a fifth message sent by a second donor CU, the fifth message including user location information ULI of a mobile termination MT of a relay node, the first donor CU being a donor CU connected to a DU, and the second donor CU being a donor CU connected to the MT; and a step of the first donor CU sending a fourth message to a first core network element, the fourth message including a ULI of a UE and indication information indicating a ULI of the MT, the first core network element being a core network element serving the UE, and the UE being a UE managed by the DU; A method comprising:

13. 1. A method of communication comprising: a second donor central unit (CU) sending a sixth message to a first donor CU, the sixth message including an identification of a second core network element, the first donor CU being a donor CU connected to a distributed unit (DU) of a relay node, the second donor CU being a donor CU connected to a mobile termination (MT) of the relay node, and the second core network element being a core network element serving the MT; and the second donor CU sending a seventh message to the second core network element, the seventh message including indication information indicating user location information (ULI) of the MT and identification information of a cell managed by the DU; A method comprising:

14. 14. The method of claim 13, wherein, prior to the second donor CU sending a sixth message to the first donor CU, the method further comprises: the second donor CU receiving an eighth message sent by the MT, the eighth message including identification information of a cell managed by the DU; or receiving, by the second donor CU, a ninth message sent by the first donor CU, the ninth message including identification information of a cell managed by the DU, and the ninth message further including first identification information of the MT and / or second identification information of the MT; wherein the first identification information is identification information for identifying the MT in the first donor CU, and the second identification information is identification information for identifying the MT in the second donor CU.

15. 15. The method of claim 13 or 14, wherein the cell identification information comprises a Cell Global Identifier CGI and / or a Tracking Area Identifier TAI.

16. 1. A method of communication comprising: receiving, by a first donor central unit CU, a sixth message sent by a second donor CU, the sixth message including identification information of a second core network element, the first donor CU being a donor CU connected to a distributed unit DU of a relay node, the second donor CU being a donor CU connected to a mobile termination MT of the relay node, and the second core network element being a core network element serving the MT; If the second core network element and the first core network element are the same core network element, the first donor CU includes user location information (ULI) of the UE in the tenth message, where the first core network element is a core network element serving the UE, and the UE is a UE managed by the DU; or When the second core network element and the first core network element are not the same core network element, the first donor CU includes, in a tenth message, user location information (ULI) of the UE and indication information indicating the ULI of the MT; and the first donor CU sending the tenth message to the first core network element; A method comprising:

17. 17. The method of claim 16, wherein, prior to the step of the first donor CU receiving a sixth message sent by a second donor CU, the method comprises: A method comprising a step in which the first donor CU sends a ninth message to the second donor CU, the ninth message including identification information of a cell managed by the DU, the ninth message further including first identification information of the MT and / or second identification information of the MT, the first identification information being identification information for identifying the MT in the first CU, and the second identification information being identification information for identifying the MT in the second CU.

18. 18. The method of claim 16 or 17, wherein the cell identification information comprises a Cell Global Identifier CGI and / or a Tracking Area Identifier TAI.

19. 1. A method of communication comprising: a step of receiving, by a second donor central unit CU, an eleventh message sent by a first donor CU, the eleventh message including identification information of a first core network element, the second donor CU being a donor CU connected to a mobile termination MT of a relay node, the first donor CU being a donor CU connected to a distributed unit DU of the relay node, the first core network element being a core network element serving a UE, and the UE being a UE managed by the DU; a step of the second donor CU sending a twelfth message to the first core network element based on the identification information of the first core network element, the twelfth message including indication information indicating user location information (ULI) of the MT and identification information of a cell managed by the DU; A method comprising:

20. 20. The method of claim 19, wherein before the second donor CU sends the twelfth message to the first core network element based on an identifier of the first core network element, the method comprises: the second donor CU receiving an eighth message sent by the MT, the eighth message including identification information of a cell managed by the DU; or receiving, by the second donor CU, a ninth message sent by the first donor CU, the ninth message including identification information of a cell managed by the DU, and the ninth message further including first identification information of the MT and / or second identification information of the MT; wherein the first identification information is identification information for identifying the MT in the first donor CU, and the second identification information is identification information for identifying the MT in the second donor CU.

21. 15. The method of claim 13 or 14, wherein the cell identification information comprises a Cell Global Identifier CGI and / or a Tracking Area Identifier TAI.

22. 1. A method of communication comprising: a step of a first donor central unit (CU) sending an eleventh message to a second donor CU, the eleventh message including identification information of a first core network element, the second donor CU being a donor CU connected to a mobile termination (MT) of a relay node, the first donor CU being a donor CU connected to a distributed unit (DU) of the relay node, the first core network element being a core network element serving a UE, and the UE being a UE managed by the DU; and the first donor CU sending a tenth message to the first core network element, the tenth message including user location information (ULI) of the UE; A method comprising:

23. 1. A communication device comprising a transceiver and a processor, the transceiver being used by the communication device to perform communications, and the processor being configured to execute a computer program stored in a memory so as to enable the communication device to perform a communication method according to any one of claims 1 to 3, a communication method according to any one of claims 4 to 6, a communication method according to claim 7 or 8, a communication method according to claim 9 or 10, a communication method according to claim 11, a communication method according to claim 12, a communication method according to any one of claims 13 to 15, a communication method according to any one of claims 16 to 18, a communication method according to any one of claims 19 to 21 or a communication method according to claim 22.

24. 10. A computer program product comprising a computer program which, when executed by a processor, causes the communication method of any one of claims 1 to 3, the communication method of any one of claims 4 to 6, the communication method of claim 7 or 8, the communication method of claim 9 or 10, the communication method of claim 11, the communication method of claim 12, the communication method of any one of claims 13 to 15, the communication method of any one of claims 16 to 18, the communication method of any one of claims 19 to 21, or the communication method of claim 22.

25. 1. A computer readable storage medium storing a computer program or instructions, which when executed by a processor causes the communication method of any one of claims 1 to 3, the communication method of any one of claims 4 to 6, the communication method of claim 7 or 8, the communication method of claim 9 or 10, the communication method of claim 11, the communication method of claim 12, the communication method of any one of claims 13 to 15, the communication method of any one of claims 16 to 18, the communication method of any one of claims 19 to 21, or the communication method of claim 22.

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