Communication method and apparatus

Abstract

A communication method and apparatus. The method comprises: determining first information; and sending the first information to a first CU, wherein the first information requests first tracking area information; the first CU is connected to an MT of an IAB node; the first tracking area information is used for configuring a tracking area of a cell of the IAB node; an F1 interface is provided between DUs of the IAB node and the second CU; alternatively, a source CU from which the DUs of the IAB node migrate is the second CU, and a destination CU to which the DUs of the IAB node migrate is a third CU. The first CU is triggered by means of the first information to send the updated first tracking area information to the DUs of the IAB node, so that the IAB node can obtain new tracking area information in a timely manner, and thus the tracking area information broadcasted by the DUs of the IAB node can reflect position information of the IAB node, thereby reducing the frequency of a terminal device around the cell of the IAB node executing a tracking area update, and improving the system stability.

Description

Communication method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on August 9, 2023, with application number 202311004610.4 and application name “A Communication Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0004] The fifth generation of mobile communications (5G) introduced integrated access and backhaul (IAB) technology. In an IAB network, a relay node, or IAB-node, can provide wireless access services for user equipment (UE). The UE's service data is transmitted by the IAB-node to the IAB host (IAB-donor) via a wireless backhaul link. The IAB-node includes a mobile terminal (MT) and a distributed unit (DU). The IAB-donor is an access network element with the function of a base station (such as the next generation NodeB (gNB)), including a centralized unit (CU) and a distributed unit (DU).

[0005] IAB nodes can migrate, i.e., perform partial migration. For example, before partial migration, an RRC connection exists between the IAB-MT and CU1 of IAB-donor 1, and an F1 interface exists between the IAB-DU and CU1 of IAB-donor 1. During partial migration, the IAB-MT undergoes inter-CU cell migration and establishes an RRC connection with CU2 of IAB-donor 2. However, to reduce the need for re-establishment of the F1 interface, the IAB-DU maintains an F1 interface with CU1 of IAB-donor 1 and does not establish an F1 interface with CU2 of IAB-donor 2.

[0006] IAB nodes can move extensively. When an IAB-node moves far away, it can be difficult for the IAB-DU to maintain a connection to its original IAB host CU. Therefore, to support large-scale IAB-node mobility, a key feature has been proposed: DU migration. For example, the IAB-MT's RRC connection remains on CU2 of IAB-donor 2, while the IAB-DU's F1 interface migrates from CU1 of IAB-donor 1 to CU3 of IAB-donor 3.

[0007] IAB-DU migration is decoupled from IAB-MT migration. Therefore, in the scenario where IAB-MT does not migrate but IAB-DU migrates, the CU of the IAB-donor connected to the IAB-MT is neither the source host nor the target host of the IAB-DU migration. The IAB-MT does not know whether the tracking area code (TAC) of the IAB-DU needs to be changed, resulting in untimely updates of the IAB-DU's TAC. This causes the TAC broadcast by the IAB-DU to not match the location of the IAB-DU after migration.

[0008] Summary of the Invention

[0009] The present application provides a communication method and apparatus to solve the problem of how to update the tracking area information of an IAB-DU.

[0010] In a first aspect, a communication method is provided, the method comprising: determining first information; sending the first information to a first centralized unit CU; wherein the first information requests first tracking area information, and the first CU is connected to a mobile terminal MT of an integrated access backhaul IAB node; the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU.

[0011] Through the method provided in the present application, the first information can be used to trigger the first CU to send the updated first tracking area information to the DU of the IAB node, so that the IAB node can obtain the new tracking area information in a timely manner, and then the tracking area information broadcast by the DU of the IAB node can reflect the location information of the IAB node, reduce the frequent tracking area updates of terminal devices around the IAB node cell, and improve system stability.

[0012] In a possible implementation, the MT of the IAB node is not switched.

[0013] In one possible implementation, the first information includes at least one of the following: second tracking area information, where the second tracking area information is tracking area information used by the cell provided by the IAB node before obtaining the first tracking area information; the cell identifier under the DU of the IAB node; the identifier of the second CU; and the identifier of the third CU.

[0014] In a possible implementation, it also includes: receiving the first tracking area information or the first tracking area information and the cell identifier corresponding to the first tracking area information from the first CU, where the cell identifier is the identifier of the cell under the DU of the IAB node; and sending the first tracking area information or the first tracking area information and the cell identifier to the third CU or the DU of the IAB node.

[0015] With this method, since the source CU of the DU migration of the IAB node, that is, the second CU, can independently select the second CU for the DU migration of the IAB node, the second CU sends the first tracking area information to the DU of the IAB node, which is more flexible to implement.

[0016] In a possible implementation, the method further includes: determining that the DU of the IAB node is migrated from the second CU to the third CU.

[0017] According to a second aspect, a communication method is provided, which includes: receiving first information from a first node; the first information requests first tracking area information, and the first tracking area information is used to configure the tracking area of ​​the cell of the access backhaul integrated IAB node; the first node is a second centralized unit CU, or a third CU, or a mobile terminal MT of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU; according to the first information, the first tracking area information or the first tracking area information and the cell identifier corresponding to the first tracking area information are sent, and the cell identifier is the identifier of the cell under the DU of the IAB node.

[0018] In one possible implementation, the first information includes second tracking area information, where the second tracking area information is tracking area information used by the cell provided by the IAB node before obtaining the first tracking area information; the method also includes: determining to update the tracking area information of the cell provided by the IAB node based on the second tracking area information.

[0019] In a possible implementation, the first information includes at least one of the following: a cell identifier under the DU of the IAB node; an identifier of the second CU; and an identifier of the third CU.

[0020] According to a third aspect, a communication method is provided, which includes: determining second information; sending the second information to a first centralized unit CU; wherein the second information requests a service cell identifier of the MT accessing the integrated backhaul IAB node, and the first CU is connected to the mobile terminal MT accessing the integrated backhaul IAB node; the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU.

[0021] Through the above method, the service cell identifier of the MT of the IAB node is requested through the second information, so that the first tracking area information after the DU of the IAB node is updated can be determined according to the service cell identifier, and the first tracking area information is sent to the IAB node. The IAB node can obtain the new tracking area information in time, and then the tracking area information broadcast by the IAB's DU can reflect the current location information of the IAB node, reduce the frequent execution of TAU by terminal devices around the IAB node cell, and improve system stability.

[0022] In a possible implementation, the second information includes at least one of the following: an identifier of the second CU; an identifier of the third CU.

[0023] In a possible implementation, the tracking area information broadcast by the DU of the IAB node is the same as the tracking area information broadcast by the MT of the IAB node.

[0024] In a possible implementation, it also includes: receiving a serving cell identifier; sending third information to a third CU or a DU of an IAB node; the third information includes at least one of the following: first tracking area information, the first tracking area information is determined based on the serving cell identifier, and the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node; a cell identifier corresponding to the first tracking area information, and the cell identifier is the identifier of the cell under the DU of the IAB node.

[0025] In a possible implementation, before determining the second information, the method further includes: determining that the DU of the IAB node is migrated from the second CU to the third CU.

[0026] In a fourth aspect, a communication method is provided, which includes: receiving second information from a first node; the second information requests access to the service cell identifier of a mobile terminal MT of an integrated backhaul IAB node, the first node is a second centralized unit CU, or a third CU, or a mobile terminal MT of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU; and the service cell identifier is sent according to the second information.

[0027] Through the above method, the second CU, the third CU or the IAB node triggers the first CU through the second information to send the service cell identifier of the MT of the IAB node to the second CU or the third CU, so that the second CU or the third CU can determine the first tracking area information of the DU of the AB node according to the service cell identifier, thereby sending the first tracking area information to the IAB node. The IAB node can obtain the new tracking area information in time, and then the tracking area information broadcast by the IAB's DU can reflect the current location information of the IAB node, reduce the frequent execution of TAU by terminal devices around the IAB node cell, and improve system stability.

[0028] In a possible implementation, the second information includes at least one of the following: an identifier of the second CU; an identifier of the third CU.

[0029] In a fifth aspect, a communication method is provided, which includes: sending a service cell identifier of a mobile terminal MT accessing an integrated backhaul IAB node to a second centralized unit CU or a third CU; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU; receiving first tracking area information, the first tracking area information is determined according to the service cell identifier, and the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node.

[0030] In a sixth aspect, a communication method is provided, which includes: receiving a service cell identifier of a mobile terminal MT that accesses an integrated backhaul IAB node; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the first CU, and the destination CU of the migration is the third CU; sending first tracking area information to the DU or the third CU of the IAB node, the first tracking area information is determined according to the service cell identifier, and the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node.

[0031] In the seventh aspect, a communication method is provided, which includes: when the tracking area information of the cell provided by the access backhaul integrated IAB node is different from the tracking area information of the cell under the first CU, and / or different from the tracking area information of the cell under the third CU, determining to update the tracking area information of the cell provided by the IAB node; the first CU is connected to the mobile terminal MT of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU; sending third information, the third information includes at least one of the following information: first tracking area information, the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node; the cell identifier corresponding to the first tracking area information, the cell identifier is the identifier of the cell under the DU of the IAB node.

[0032] In the above method, through the Xn interface interaction between CUs, the second CU or the second CU determines that the tracking area information of the DU of the IAB node needs to be updated based on the tracking area information of each cell obtained through the interaction. Then, new tracking area information (i.e., the first tracking area information) can be directly generated and configured to the IAB node, so that the IAB node can obtain the new tracking area information in a timely manner, and then the tracking area information broadcast by the IAB's DU can reflect the current location information of the IAB node, thereby reducing the frequent execution of TAU by terminal devices around the IAB node cell and improving system stability.

[0033] In a possible implementation manner, sending the third information includes: sending the third information to a DU or a third CU of the IAB node.

[0034] In an eighth aspect, the present application further provides a communication device capable of implementing any of the methods provided in any of the first to seventh aspects. The communication device can be implemented via hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more units or modules corresponding to the aforementioned functions.

[0035] In one possible implementation, the communication device includes a processor configured to support the communication device in performing the corresponding functions of any of the methods described above. The communication device may also include a memory, which may be coupled to the processor and stores program instructions and data necessary for the communication device. Optionally, the communication device also includes an interface circuit configured to support communication between the communication device and other devices, such as equipment.

[0036] In one possible implementation, the communication device includes corresponding functional modules for implementing the steps in the above method. The functions can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0037] In one possible implementation, the structure of the communication device includes a processing unit and a transceiver unit, which can perform the corresponding functions in the above method examples. For details, please refer to the description of the method provided in any aspect of the first aspect, which will not be repeated here.

[0038] In the ninth aspect, a communication device is provided, comprising a processor and an interface circuit, the interface circuit being used to receive signals from other communication devices outside the communication device and transmit them to the processor or to send signals from the processor to other communication devices outside the communication device, the processor being used to implement the method in any possible implementation provided in any of the first to seventh aspects through a logic circuit or executing code instructions.

[0039] In the tenth aspect, a communication device is provided, comprising a processor and an interface circuit, the interface circuit being used to receive signals from other communication devices outside the communication device and transmit them to the processor or to send signals from the processor to other communication devices outside the communication device, the processor being used to implement the method in any possible implementation provided in any of the first to seventh aspects through a logic circuit or executing code instructions.

[0040] In the eleventh aspect, a computer-readable storage medium is provided, which stores a computer program or instruction. When the computer program or instruction is executed by a processor, the method in any possible implementation provided in any one of the first to seventh aspects is implemented.

[0041] In the twelfth aspect, a computer program product storing instructions is provided, which, when executed by a processor, implements the method in any possible implementation provided in any of the first to seventh aspects.

[0042] In a thirteenth aspect, a circuit is provided for executing the method in any possible implementation manner provided in any one of the first to seventh aspects above, wherein the circuit may include a chip circuit. Optionally, the circuit may also be coupled to a memory.

[0043] In a fourteenth aspect, a chip is provided, comprising a processor configured to implement the method of any possible implementation provided in any of the first through seventh aspects. Optionally, the chip may further comprise a memory. The chip may be comprised solely of a chip or may include a chip and other discrete components.

[0044] In the fifteenth aspect, a communication system is provided, including a first node and a second node; the second node is used to execute the method in any possible implementation provided in the aforementioned first aspect; the first node is used to execute the method in any possible implementation provided in the aforementioned second aspect.

[0045] In the sixteenth aspect, a communication system is provided, comprising a first node and a second node; the second node is used to execute the method in any possible implementation provided in the aforementioned third aspect; and the first node is used to execute the method in any possible implementation provided in the aforementioned fourth aspect.

[0046] In the seventeenth aspect, a communication system is provided, comprising a first node and a second node; the second node is used to execute the method in any possible implementation provided in the aforementioned fifth aspect; and the first node is used to execute the method in any possible implementation provided in the aforementioned sixth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG1 is a schematic diagram of the architecture of a communication system used in an embodiment of the present application;

[0048] FIG2 shows a schematic diagram of an IAB network including multiple UEs and multiple IAB nodes;

[0049] FIG3 is a schematic diagram of an IAB network architecture;

[0050] FIG4 is a schematic diagram of a partial migration;

[0051] FIG5 is a schematic diagram of a continuous partial migration;

[0052] FIG6 is a schematic diagram of a DU migration;

[0053] FIG7 is a flow chart of a communication method provided in an embodiment of the present application;

[0054] FIG8 is a flow chart of a communication method provided in an embodiment of the present application;

[0055] FIG9 is a flow chart of a communication method provided in an embodiment of the present application;

[0056] FIG10 is a flow chart of a communication method provided in an embodiment of the present application;

[0057] FIG11 is a flow chart of a communication method provided in an embodiment of the present application;

[0058] FIG12 is a flow chart of a communication method provided in an embodiment of the present application;

[0059] FIG13 is a flow chart of a communication method provided in an embodiment of the present application;

[0060] FIG14 is a flow chart of a communication method provided in an embodiment of the present application;

[0061] FIG15 is a flow chart of a communication method provided in an embodiment of the present application;

[0062] FIG16 is a flow chart of a communication method provided in an embodiment of the present application;

[0063] FIG17 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0064] FIG18 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0065] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0066] The method provided in the embodiment of the present application can be applied to long term evolution (LTE), fifth generation (5G) communication systems, such as 5G new radio (NR), or to various future communication systems, such as sixth generation (6G) communication systems.

[0067] The terms "first" and "second" in the specification, claims, and drawings of this application are only used to distinguish different objects, rather than to describe a specific order. It is understood that the various numerical numbers involved in the embodiments of this application are only for the convenience of description and are not used to limit the scope of the embodiments of this application. The size of the sequence number of each process above does not mean the order of execution. The execution order of each process should be determined by its function and internal logic.

[0068] Figure 1 is a schematic diagram of the architecture of the communication system used in the embodiment of the present application. As shown in Figure 1, the communication system includes a core network device 110, a wireless access network device 120, a wireless backhaul device 130 and at least one terminal device (terminal device 140 and terminal device 150 are exemplarily described in Figure 1). The terminal device is connected to the wireless backhaul device wirelessly, and is connected to the wireless access network device through one or more wireless backhaul devices. In addition, some terminal devices can also be directly connected to the wireless access network device wirelessly). The wireless access network device is connected to the core network device wirelessly or wired. The core network device and the wireless access network device can be independent and different physical devices, or the functions of the core network device and the logical functions of the wireless access network device can be integrated into the same physical device, or the functions of some core network devices and some wireless access network devices can be integrated into one physical device. This application does not limit this. The terminal device can be fixed or movable. It should be understood that the mobile communication system shown in Figure 1 is merely a schematic diagram, and the communication system may also include other network devices, such as wireless relay devices or wireless backhaul devices, which are not shown in Figure 1. The embodiments of the present application do not limit the number of core network devices, wireless access network devices, wireless backhaul devices, and terminal devices included in the mobile communication system.

[0069] Among them, the wireless access network device is an access device that the terminal device uses to access the mobile communication system wirelessly. It can be a base station NodeB, an evolved base station eNodeB, a base station in a 5G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc. The embodiments of this application do not limit the specific technology and specific device form adopted by the wireless access network device.

[0070] A terminal device may be a mobile phone, a tablet computer, a computer with wireless transceiver capabilities, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA), a wireless terminal used in industrial control, a wireless terminal used in self-driving vehicles, a wireless terminal used in remote medical surgery, a wireless terminal used in smart grids, a wireless terminal used in transportation safety, a wireless terminal used in smart cities, a wireless terminal used in smart homes, a machine type communication (MTC) terminal, a wearable device, an in-vehicle terminal device, or an unmanned aerial vehicle (UAV). A terminal device may also be referred to as a terminal, UE, mobile station (MS), or MT.

[0071] Among them, the wireless backhaul device can provide backhaul services for its child nodes. Specifically, it can be a relay node in the long term evolution (LTE) system, an IAB node in the 5G system, or other devices that can provide wireless relay functions. Wireless access network equipment and terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on aircraft, balloons and artificial satellites in the air. The embodiments of the present application do not limit the application scenarios of wireless access network equipment and terminal equipment.

[0072] Wireless access network equipment and terminal equipment, as well as terminal equipment and terminal equipment, can communicate through licensed spectrum, through unlicensed spectrum, or through both licensed and unlicensed spectrum.

[0073] The above-mentioned network elements can be network elements implemented on dedicated hardware, software instances running on dedicated hardware, or instances of virtualized functions on appropriate platforms. In addition, the embodiments of the present application can also be applied to other future-oriented communication technologies. The network architecture and service scenarios described in this application are intended to more clearly illustrate the technical solutions of this application and do not constitute a limitation on the technical solutions provided in this application. It is known to those skilled in the art that with the evolution of network architecture and the emergence of new service scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

[0074] To facilitate understanding of the embodiments of the present application, the following is a brief description of the terms and technical features involved in the embodiments of the present application.

[0075] 1) IAB Network: Given the limited coverage of high-frequency bands, ensuring network coverage in remote areas is challenging and costly due to the difficulty of deploying fiber. This necessitates the design of flexible and convenient access and backhaul solutions. IAB technology has emerged as a key enabler of this. Its access and backhaul links utilize wireless transmission, reducing fiber deployment and equipment costs.

[0076] In an IAB network, a relay node, or IAB-node, can provide wireless access services for UEs. The UE's service data is transmitted by the IAB-node to the IAB-donor via a wireless backhaul link. The IAB node can also be called a mobile mIAB (mobile IAB) node. In the following text, mIAB refers to the mIAB node, mIAB-MT refers to the MT of the IAB node, and mIAB-DU refers to the DU of the IAB node. The IAB node can establish a wireless backhaul link with one or more upper-level nodes and access the core network through the upper-level node. The upper-level node can perform certain control on the relay node through various signaling (for example, data scheduling, timing modulation, power control, etc.). In addition, the relay node can establish an access link with one or more lower-level nodes and provide access services to one or more lower-level nodes. The upper-level node of the relay node can be a base station or another relay node. The lower-level node of the relay node can be a terminal or another relay node. In some cases, the upper-level node of an IAB node may also be referred to as its upstream node or parent node, and the lower-level node of the IAB node may also be referred to as its downstream node or child node.

[0077] Multi-hop networking may be used in the IAB network. Taking into account the need for service transmission reliability, the IAB node can support dual connectivity (DC) or multi-connectivity to cope with abnormal situations that may occur in the backhaul link (for example, interruption or blockage of the wireless link and load fluctuations, etc.) to improve the reliability of transmission. Therefore, the IAB network can support multi-hop and multi-connection networking, and there may be multiple routing paths between the terminal device and the host base station. Among them, on one path, there is a definite hierarchical relationship between the IAB nodes, and between the IAB nodes and the host base station serving the IAB nodes. Each IAB node regards the node that provides backhaul services to it as a parent node, and accordingly, each IAB node can be regarded as a child node of its parent node.

[0078] An IAB donor node (IAB-donor) can be an access network element with complete base station functionality, such as a donor base station (DgNB), or an access network element with a separate centralized unit (CU) and DU. The IAB donor node is connected to the core network element serving the terminal device (e.g., the 5G core network) and provides wireless backhaul functionality for the IAB node. For ease of presentation, the centralized unit of the IAB donor node is referred to as the donor CU or IAB-donor CU, and the distributed unit of the IAB donor node is referred to as the donor DU or IAB-donor DU. The donor CU may also be in a form with a separate control plane (CP) and user plane (UP). For example, the CU may consist of a CU-CP and one (or more) CU-UPs.

[0079] In the IAB network, one or more IAB-nodes may be included on a transmission path between the UE and the IAB-donor. Each IAB-node needs to maintain a wireless backhaul link to the parent node, and also needs to maintain a wireless link with the child node. If the child node of the IAB-node is a terminal device, there is a wireless access link between the IAB-node and the child node (i.e., the terminal device). If the child node of the IAB-node is another IAB-node, there is a wireless backhaul link between the IAB-node and the child node (i.e., the other IAB-node). Figure 2 shows an example of an IAB network including multiple UEs and multiple IAB nodes. Figure 2 takes an example including 2 UEs and 5 IAB nodes. Among them, the two UEs are UE1 and UE2, and the five IAB nodes are IAB node 1 to IAB node 5. It should be understood that the thick line in Figure 2 indicates the access link and the thin line indicates the backhaul link. Referring to Figure 2 , in the path "UE1 → IAB-node4 → IAB-node3 → IAB-node1 → IAB-donor," UE1 accesses IAB-node4 via a wireless access link, IAB-node4 connects to IAB-node3 via a wireless backhaul link, IAB-node3 connects to IAB-node1 via a wireless backhaul link, and IAB-node1 connects to the IAB-donor via a wireless backhaul link. It should be understood that the IAB networking scenario shown in Figure 2 is merely exemplary. There are many other possibilities in an IAB network that supports multi-hop and multi-connection networking, which are not listed here.

[0080] The IAB-node-DU (hereinafter simply referred to as mIAB-DU) is logically connected to the IAB-donor CU (hereinafter simply referred to as CU) through the F1 interface. Figure 3 is a schematic diagram of an IAB network architecture. The F1 connection in Figure 3 is not a physical direct connection, but a logical connection. In fact, the F1 connection between the mIAB-DU and the CU is physically realized through the NR Uu interface between the IAB-node MT and the parent node DU of each hop, but because the mIAB-DU can eventually communicate with the CU, it can be considered that there is a logical F1 interface. The F1 interface can also be called the F1* interface, and the embodiment of the present application does not limit the name of the interface. And in this article, the interface is called the F1 interface as an example. The IAB-donor CU is connected to the 5G core network (5G core network, 5GC / 5GCN) through the NG interface. There is an Xn-C interface between the IAB-donor CU and the gNodeB.

[0081] 2) Tracking Area (TA)

[0082] Tracking area is a concept established by the LTE / NR system for UE location management. TA is a cell-level configuration. Multiple cells can be configured with the same TA, but a cell can only belong to one TA. When a UE registers to the network, the core network assigns a UE Registration Area (UE Registration Area) to each UE, which contains a Tracking Area Identity List (TAI List). The Tracking Area Identity (TAI) consists of the Public Land Mobile Network (PLMN) and the Tracking Area Code (TAC), that is, TAI = PLMN + TAC. The TAI information is located in the SIB1 message broadcast by the cell under the DU. When a UE moves out of a cell that is not on the TAI List, it actively connects to the network (including the core network) and performs a NAS Registration Update. The core network registers the UE's location and updates the UE's UE registration area. This reassigns the UE a TAI List containing the TA to which the UE's current cell belongs. The newly assigned TAI List may or may not contain some TAIs in the original TA List. Besides this, the UE also periodically performs Tracking Area Updates (TAUs) to inform the core network of its location. NAS Registration Updates and TAUs are the same process, with NAS Registration Updates focusing on network-side descriptions and TAUs on UE-side descriptions.

[0083] 3) Partial migration

[0084] In 3GPP Release 17 (R17), partial migration of IAB nodes was introduced. The IAB node that undergoes migration is called a boundary node. Figure 4 is a schematic diagram of a partial migration. In the figure, before the partial migration, there is an RRC connection between the mIAB-MT (i.e., the MT of the mIAB node) and CU1, and an F1 interface between the mIAB-DU (i.e., the DU of the mIAB node) and CU1. mIAB-MT IAB host-DU1 (IAB donor-DU1) During partial migration, the mAB-MT switches cells across CUs and establishes an RRC connection with CU2. However, in Rel-17, in order to reduce the re-establishment process of the F1 interface, the mAB-DU still maintains the F1 interface with CU1 and does not establish an F1 interface with CU2. Therefore, the communication path between CU1 and mAB-DU becomes cross-topology: CU1 IAB host-DU2 (IAB donor-DU2) mIAB-MT In the figure, CU1 and CU2 are referred to as the F1-terminating CU and non-F1-terminating CU (or RRC terminating CU), respectively, and can also be referred to as the source CU and target CU. It's important to note that data transmitted across the topology path does not pass through CU2; CU1 and IAB host-DU2 communicate directly over the Internet Protocol (IP) network.

[0085] 4) Consecutive partial migration

[0086] Rel-18 (Release-18) further considers the large-scale mobility of IAB nodes. Therefore, based on partial migration, Rel-18 introduces continuous partial migration. As shown in Figure 5, the mAB-MT (i.e., the MT of the mAB node) switches from CU2 to CU3, and the F1 interface of the mAB-DU is always associated with CU1. In Figure 5, the mAB node (mIAB-node) is directly connected to the IAB host-DU, such as IAB host-DU2 or IAB host-DU3, but this is not limited. There may be other IAB nodes between the mAB node and the IAB host-DU. In addition, regarding how the mAB-MT arrived at CU2, the mAB-MT may have switched from CU1 to CU2 (this is the case shown in the figure), but it may also have switched from other CUs to CU2 (which can be understood in conjunction with the DU migration scenario below).

[0087] 5) DU migration

[0088] Because Rel-18 addresses the wide-range mobility of IAB nodes, when an mIAB-node moves far away, the mIAB-DU may struggle to maintain an IP connection with its original CU, or transmission latency may be significant. Therefore, to support wide-range mobility, Rel-18 introduces a key feature: DU migration. As shown in Figure 6, the RRC connection of the mIAB-MT remains on CU2, while the F1 interface of the mIAB-DU migrates from CU1 to CU3. The figure shows that mAB-DU includes mAB-DU1 and mAB-DU2, which are two logical DUs on a physical DU. DU migration is achieved in this way: assuming that the source DU in the DU of mAB-node is mAB-DU1, a new logical DU mIAB-DU2 is generated in the DU of mAB-node, and mAB-DU2 establishes an F1 interface with CU3. CU1 sends a UE handover request to CU3, and switches the UE from the cell under mAB-DU1 to the cell under mAB-DU2. Then CU1 releases the F1 interface between it and mAB-DU1. At this point, DU migration is completed.

[0089] In Rel-18, it is assumed that DU migration and MT migration are completely decoupled. That is, the CU of mAB-DU and the CU of mAB-MT can be different. Therefore, in a continuous partial migration, if the F1 terminating CU of mAB-DU is always CU1, mAB-MT does not necessarily switch from CU1 to CU2. In a DU migration, mAB-MT can be in CU2, and mAB-DU migrates from CU1 to CU3 (as a special case, CU2 can be the same CU as CU1 or CU3). The reason why it is assumed that mAB-DU migration is completely decoupled from mAB-MT migration is that the DU migration process is relatively complicated (it is necessary to generate two logical DUs and switch the UEs to the new logical DUs one by one), mAB-DU should not be migrated frequently, and the CU of mAB-DU should preferably be a CU with a larger control range; while mAB-MT migration is MT switching, which may be performed frequently. The selection of mAB-MT's CU is determined by signal quality, and the CU of mAB-MT may be different from that of mAB-DU.

[0090] Since DU migration is completely decoupled from MT migration, the RRC connection of mAB-MT and the F1 interface of mAB-DU can be terminated on different CUs. However, in the scenario where MT does not migrate and DU migrates (as shown in Figure 6), the CU of mAB-MT is neither the source host nor the target host of the migration. mAB-MT does not know whether the TAC needs to be updated, which will cause the TAC that needs to be updated to not be sent to mAB-node in time, resulting in untimely TAC updates, and further causing the TAC broadcast by mAB-DU to be inconsistent with the current location. This will cause terminal devices in the cells around the mAB node cell to think that the TAC broadcast by the DU of the mAB node is a new TAC, and thus TAU will be executed frequently.

[0091] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field will know that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0092] It can be understood that the present application does not specifically limit the specific structure of the execution entity of the method provided in the embodiment of the present application. It is sufficient as long as it is possible to communicate according to the method provided in the embodiment of the present application by running a program that records the code of the method provided in the embodiment of the present application.

[0093] In addition, in the following processes of the present application, the IAB node can be replaced with a mobile IAB node (mobile IAB or mIAB) description, or it can be replaced with a description of other types of relay nodes (such as layer 3 relay). When the relay node is considered to be a layer 3 relay, the relay node may include a mobile terminal function (MT) and a base station function (gNB). The relevant expressions of DU in this application are replaced with the gNB function part of the relay node, and the relevant expressions of CU are replaced with the host node of the relay node.

[0094] In one implementation, a source CU of a DU of an IAB node, a target CU of a DU of an IAB node, or a mobile station of an IAB node sends a first message to a CU of a mobile station of the IAB node, wherein the first message requests first tracking area information. This method can timely update the tracking area information of the DU of the IAB node, as described in detail below.

[0095] As shown in Figure 7, a flow chart of a communication method provided by an embodiment of the present application is provided. In this flow, the source CU of the DU of the IAB node or the IAB node triggers the CU of the MT of the IAB node to send new tracking area information to the target CU of the DU of the IAB node, the source CU of the DU of the IAB node, or the MT of the IAB node based on implementation (e.g., determining that the DU migration of the IAB node is to be triggered or learning that the DU migration of the IAB node is to be performed). The method includes:

[0096] Step 701: The second CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0097] Step 701 is optional and can also be applied to scenarios where DUs do not migrate. If this is the case, step 701 may not be performed. If the DU does not migrate, the second CU refers to the CU to which the DU is connected. There is no third CU in the scenario, and the second CU proceeds directly to step 702 based on implementation.

[0098] In one implementation, if the DU of the IAB node is migrated, the DU migration may be triggered by the source CU (ie, the second CU), so that the second CU can determine that the DU of the IAB node is to be migrated or learn that the DU of the IAB node is to be migrated.

[0099] In one implementation, if the DU of the IAB node is migrated, the DU migration may be triggered by operation administration and maintenance (OAM) configuration on the IAB node, and the DU of the IAB node may send an F1 message to the second CU, where the F1 message indicates that the DU migration is to be performed.

[0100] If the DU of an IAB node is migrated, the DU of the IAB node may include two logical DUs: DU1 (first logical DU) and DU2 (second logical DU). An F1 interface exists between the second CU and DU1, and an F1 interface exists between the third CU and DU2. When the DU migration of the IAB node is complete, the second CU releases the F1 interface with DU1.

[0101] In FIG. 7 to FIG. 14 of the present application, it is taken as an example that the DU of the IAB node may include DU1 and DU2. If the DU of the IAB node is not migrated, DU1 and DU2 in FIG. 7 to FIG. 14 may be replaced by the DU of the IAB node.

[0102] Step 702: The second CU sends first information to the first CU.

[0103] The first information requests the first tracking area information, or the first information requests the first CU to send the first tracking area information, or the first information requests the first CU to send the first tracking area information to the second CU or the third CU or the IAB node.

[0104] The first CU is connected to the MT of the IAB node; the MT of the IAB node does not switch or migrate. The first tracking area information is used to configure the tracking area of ​​the cell of the IAB node. The cell of the IAB node may refer to a cell under the DU of the IAB node.

[0105] If applied to the DU migration scenario, the second CU is the source CU of the IAB node's DU migration, and the third CU is the destination CU of the IAB node's DU migration. If applied to the scenario where the DU does not migrate, the second CU is the CU to which the DU of the IAB node is currently connected, and an F1 interface is provided between the second CU and the DU of the IAB node.

[0106] In the present application, the tracking area information may include at least one of the following: the tracking area code of the cell under the DU of the IAB node; the TAI of the cell under the DU of the IAB node; the radio access network (RAN) notification area information of the cell under the DU of the IAB node; the RAN area code (RANAC) of the cell under the DU of the IAB node.

[0107] In one implementation, the second CU sends an Xn message to the first CU, where the Xn message includes the first information. In this application, the Xn message can also be replaced by an NG interface message, which is forwarded by the access and mobility management function (AMF), and the specific process is not limited.

[0108] In one implementation, the first information or the Xn message includes at least one of the following:

[0109] Second tracking area information, where the second tracking area information is tracking area information used by a cell provided by the IAB node before obtaining the first tracking area information. The cell provided by the IAB node may refer to a cell under the DU of the IAB node. In this application, the cell provided by the IAB node may also be referred to as a cell of the IAB node;

[0110] The cell identifier under the DU of the IAB node is used by the first CU to indicate the correspondence between the first tracking area information and the cell. If the DU of the IAB node is migrated, the cell identifier may be the cell identifier under the second logical DU of the IAB node;

[0111] The identifier of the third CU is used by the first CU to directly send the first tracking area information to the third CU. The identifier of the third CU may include at least one of the gNB identifier (identity, ID) and IP address of the third CU.

[0112] Step 703: The first CU determines that the tracking area information of the cell of the DU of the IAB node needs to be updated.

[0113] In one implementation, when the first CU determines that the second tracking area information cannot reflect the current location information of the IAB node, or determines that the second tracking area information does not match the current location information of the IAB node, or determines that the second tracking area information is not in the TAC information maintained by the first CU, it determines to update the tracking area information of the cell of the DU of the IAB node.

[0114] Step 703 is optional. The first CU may not determine whether the tracking area information of the cell of the DU of the IAB node needs to be updated and directly send the first tracking area information.

[0115] There may be multiple implementations of how the first CU sends the first tracking area information, which are described below respectively.

[0116] Implementation method 1: The first CU sends the first tracking area information to the third CU.

[0117] Step 704: The first CU sends the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information, to the third CU.

[0118] If the first CU also receives the cell identifier under the DU of the IAB node, it may also send the cell identifier under the DU of the IAB node to the third CU, thereby indicating the correspondence between the first tracking area information and the cell identifier under the DU of the IAB node.

[0119] In one implementation, the first CU may send an Xn message to the third CU, where the Xn message includes the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information.

[0120] Step 705: The third CU sends the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information, to the DU of the IAB node.

[0121] If the third CU also receives the cell identifier under the DU of the IAB node, it may also send the cell identifier under the DU of the IAB node to the DU of the IAB node, thereby indicating the correspondence between the first tracking area information and the cell identifier under the DU of the IAB node.

[0122] In one implementation, if the DU of the IAB node migrates, the third CU may send the first tracking area information to the second logical DU of the IAB node.

[0123] In one implementation, the third CU may send an F1 message to the DU of the IAB node or the second logical DU, where the F1 message includes the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information.

[0124] Implementation method 2: The first CU sends the first tracking area information to the second CU.

[0125] Step 706: The first CU sends the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information, to the second CU.

[0126] If the first CU also receives the cell identifier under the DU of the IAB node, it may also send the cell identifier under the DU of the IAB node to the third CU, thereby indicating the correspondence between the first tracking area information and the cell identifier under the DU of the IAB node.

[0127] In one implementation, the first CU may send an Xn message to the second CU, where the Xn message includes the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information.

[0128] Step 707a: The second CU sends the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information, to the DU of the IAB node.

[0129] If the second CU also receives the cell identifier under the DU of the IAB node, it may also send the cell identifier under the DU of the IAB node to the DU of the IAB node, thereby indicating the correspondence between the first tracking area information and the cell identifier under the DU of the IAB node.

[0130] In one implementation, if the DU of the IAB node migrates, the second CU may send the first tracking area information to the first logical DU of the IAB node.

[0131] In one implementation, the second CU may send an F1 message to the DU or the first logical DU of the IAB node, where the F1 message includes the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information. The first logical DU of the IAB node may send the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information, to the second logical DU of the IAB node. The specific process is not limited.

[0132] Step 707a may also be replaced by step 707b and step 707c.

[0133] Step 707b: The second CU sends the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information to the third CU.

[0134] In one implementation, the second CU may send an Xn message to the third CU, where the Xn message includes the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information.

[0135] Step 707c: The third CU sends the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information, to the DU of the IAB node.

[0136] In one implementation, the third CU may send an F1 message to the DU of the IAB node or the second logical DU, where the F1 message includes the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information.

[0137] Implementation method three:

[0138] Step 708: The first CU sends the first tracking area information to the MT of the IAB node.

[0139] The first CU may also send a cell identifier corresponding to the first tracking area information, ie, the cell identifier under the DU of the IAB node, to the MT of the IAB node. When the first CU sends the cell identifier, it may indicate that there is a correspondence between the first tracking area information and the cell identifier.

[0140] In one implementation, the first CU may send an RRC message to the MT of the IAB node, where the RRC message includes the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information.

[0141] After the MT of the IAB node obtains the first tracking area information (or the first tracking area information and the cell identifier corresponding to the first tracking area information), it can send the first tracking area information (or the first tracking area information and the cell identifier corresponding to the first tracking area information) to the DU or second logical DU of the IAB node through the interface between the DU and the IAB node.

[0142] The above implementation methods 1 to 3 can be selected and executed one by one, and the specific implementation can be determined according to actual conditions. This application does not limit this.

[0143] In the present application, step 704 and subsequent steps may not depend on the existence of steps 701 to 703. The manner in which the first CU sends the first tracking area information does not depend on its triggering manner and whether it is determined that the tracking area needs to be updated.

[0144] Through the method provided in the present application, the source CU (i.e., the second CU) of the DU migration of the IAB node can trigger the first CU to send the updated first tracking area information to the DU of the IAB node through the source CU or target CU of the DU of the IAB node or the MT of the IAB node, so that the IAB node can obtain the new tracking area information in a timely manner, and then the tracking area information broadcast by the DU of the IAB node can reflect the location information of the IAB node, reduce the frequent execution of TAU by terminal devices around the IAB node cell, and improve system stability. Moreover, since the source CU of the DU migration of the IAB node can independently select the target CU of the DU migration of the IAB node, it is more flexible to implement.

[0145] In the present application, the IAB node may also trigger the updating of the tracking area information of the DU of the IAB node. For details, please refer to the following process.

[0146] As shown in Figure 8, a flow chart of a communication method provided in an embodiment of the present application is provided. In this flow, step 801 and step 802 can replace step 701 and step 702 in Figure 7, and the other steps in Figure 7 can be implemented in combination with step 801 and step 802.

[0147] Step 801: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0148] Specifically, the MT of the IAB node may determine that the DU of the IAB node is migrated from the second CU to the third CU.

[0149] Step 801 is an optional step, and the present application can also be applied to the scenario where DU does not migrate. If applied to the scenario where DU does not migrate, step 801 may not be performed.

[0150] In one implementation, if the DU of the IAB node is migrated, the DU migration may be triggered by the source CU (i.e., the second CU). The second CU may send an F1 message to the IAB node, where the F1 message indicates that the DU of the IAB node is to perform DU migration. The IAB node may thereby determine that the DU of the IAB node is to perform DU migration or learn that the DU of the IAB node is to perform DU migration.

[0151] In one implementation, if the DU of the IAB node is migrated, the DU migration may be triggered by operation administration and maintenance (OAM) configuration on the IAB node, so that the IAB node can determine that the DU of the IAB node is to be migrated or learn that the DU of the IAB node is to be migrated.

[0152] Step 802: The IAB node sends first information to the first CU.

[0153] The first information requests the first tracking area information, or the first information requests the first CU to send the first tracking area information, or the first information requests the first CU to send the first tracking area information to the second CU or the third CU or the IAB node. The specific meaning of the first tracking area information can be referred to the previous description.

[0154] Specifically, the MT of the IAB node may send the first information, wherein the MT of the IAB node does not switch or migrate.

[0155] In one implementation, the MT of the IAB node sends an RRC message to the first CU, where the RRC message includes the first information.

[0156] In one implementation, the first information includes at least one of the following:

[0157] Second tracking area information;

[0158] The cell identifier of the DU of the IAB node. If the DU of the IAB node is migrated, the cell identifier may be the cell identifier of the second logical DU of the IAB node.

[0159] An identifier of the second CU, used by the first CU to directly send the first tracking area information to the second CU. The identifier of the second CU may include at least one of a gNB identifier and an IP address of the second CU;

[0160] The identifier of the third CU is used by the first CU to directly send the first tracking area information to the third CU.

[0161] Step 802 may be followed by other processes, such as steps 703 to 708 , which will not be described in detail here.

[0162] In the above method, when the IAB node triggers the update of the tracking area information of the DU of the IAB node, the Xn interface may not be used, thereby achieving real-time update of the tracking area information of the DU while reducing Xn interaction.

[0163] In the present application, the target CU of DU migration may also trigger the updating of the tracking area information of the DU of the IAB node. For details, please refer to the following process.

[0164] As shown in Figure 9, a flow chart of a communication method provided in an embodiment of the present application is provided. In this flow, step 901 and step 902 can replace step 701 and step 702 in Figure 7, or replace step 801 and step 802 in Figure 8. The other steps in Figure 7 can be implemented in combination with step 901 and step 902.

[0165] Step 901: The third CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0166] In one implementation, if the DU of the IAB node is migrated, the source CU of the DU migration (i.e., the second CU) can send a DU migration request message to the destination CU of the DU migration (i.e., the third CU). The DU migration request message indicates that the DU of the IAB node is to be migrated to the third CU. The third CU can thereby determine that the DU of the IAB node is to be migrated or learn that the DU of the IAB node is to be migrated.

[0167] In one implementation, if the DU of the IAB node is migrated, the DU of the IAB node (for example, the second logical DU of the IAB node) sends an F1 interface establishment request message to the third CU. The F1 interface establishment request message is used to establish an F1 interface with the third CU, so that the third CU can determine that the DU of the IAB node is to be migrated or learn that the DU of the IAB node is to be migrated.

[0168] Step 902: The third CU sends first information to the first CU.

[0169] The first information requests the first tracking area information, or the first information requests the first CU to send the first tracking area information, or the first information requests the first CU to send the first tracking area information to the second CU or the third CU or the IAB node. The specific meaning of the first tracking area information can be referred to the previous description.

[0170] In one implementation, the third CU sends an Xn message to the first CU, where the Xn message includes the first information. For example, the Xn message may be an IAB transport migration management request (IAB transport migration management request) message requesting cross-topology traffic transmission.

[0171] In one implementation, the MT of the IAB node does not switch or migrate.

[0172] In one implementation, the first information includes at least one of the following:

[0173] Second tracking area information. For the specific meaning of the second tracking area information, please refer to the previous description;

[0174] The cell identifier of the DU of the IAB node. If the DU of the IAB node is migrated, the cell identifier may be the cell identifier of the second logical DU of the IAB node.

[0175] The identifier of the second CU is used by the first CU to directly send the first tracking area information to the second CU;

[0176] The identifier of the third CU is used by the first CU to directly send the first tracking area information to the third CU.

[0177] Step 902 may be followed by other processes, such as steps 703 to 708 , which will not be described in detail here.

[0178] In this application, if the TAC broadcast by the DU of the IAB node is the same as the TAC broadcast by the service cell of the MT of the IAB node, and an Xn interface is established between the source CU of the DU of the IAB node or the target CU of the IAB node and the CU of the MT of the IAB node, then the tracking area information of the DU of the IAB node can be configured based on the tracking area information of the service cell of the MT of the IAB node by requesting the service cell identifier of the MT of the IAB node, that is, the tracking area information of the DU of the IAB node is updated, which will be described in detail below.

[0179] FIG10 is a flow chart of a communication method provided in an embodiment of the present application, wherein the method includes:

[0180] Step 1001: Establish an Xn interface between the second CU or the third CU and the first CU.

[0181] Among them, during the interaction process of establishing the Xn interface, the above-mentioned CUs exchange the tracking area information of each cell within their respective management scope. The specific process of establishing the Xn interface is not limited in this application and will not be repeated here. And after the Xn interface is established, if the cell information within the management scope of a certain CU changes (such as: the tracking area information of the cell changes), the CU will also notify other CUs through the Xn interface message (NG-RAN NODE CONFIGURATION UPDATE).

[0182] The CU of the MT of the IAB node is called the first CU. The first CU is connected to the MT of the IAB node, and the MT of the IAB node does not switch or migrate. An F1 interface is provided between the DU of the IAB node and the second CU. Alternatively, the source CU of the DU migration of the IAB node is the second CU, and the destination CU is the third CU.

[0183] If the DU of an IAB node is migrated, the DU of the IAB node may include two logical DUs: DU1 (first logical DU) and DU2 (second logical DU). An F1 interface exists between the second CU and DU1, and an F1 interface exists between the third CU and DU2. When the DU migration of the IAB node is complete, the second CU releases the F1 interface with DU1.

[0184] Step 1002: The second CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0185] For the specific content of step 1002, please refer to the description of step 701 and will not be repeated here.

[0186] Step 1002 is an optional step, and the present application can also be applied to a scenario where DUs do not migrate. If applied to a scenario where DUs do not migrate, step 1002 may not be performed.

[0187] In a possible implementation, the tracking area information broadcast by the DU of the IAB node is the same as the tracking area information broadcast by the MT of the IAB node.

[0188] Step 1003: The second CU sends second information to the first CU.

[0189] The second information requests the serving cell identifier of the MT of the IAB node, or the second information requests the first CU to send the serving cell identifier of the MT of the IAB node to the second CU or the third CU, or the second information requests the first CU to send the serving cell identifier of the MT of the IAB node.

[0190] In this application, the serving cell identifier refers to the cell identifier of the serving cell of the MT of the IAB node.

[0191] In one implementation, the second CU sends an Xn message to the first CU, where the Xn message includes the second information. The Xn message may include an Xn interface identifier of the IAB-MT, where the Xn interface identifier may be a UE Xn application protocol (AP) ID.

[0192] In one implementation, the second information includes at least one of the following:

[0193] The identifier of the second CU is used by the first CU to directly send the serving cell identifier or the first tracking area information to the second CU;

[0194] The identifier of the third CU is used by the first CU to directly send the serving cell identifier or the first tracking area information to the third CU.

[0195] The specific content of the first tracking area information can be referred to the description in the process of Figure 7 and will not be repeated here.

[0196] After the first CU receives the second information, there may be multiple implementations of how to send the serving cell identifier, which are described below respectively.

[0197] Implementation method 1: The first CU sends the serving cell identifier to the second CU.

[0198] Step 1004: The first CU sends a serving cell identifier to the second CU.

[0199] In one implementation, the first CU may send an Xn message to the second CU, where the Xn message includes a serving cell identifier.

[0200] Step 1005a: The second CU sends third information to the DU of the IAB node.

[0201] The third information includes at least one of the following:

[0202] First tracking area information, where the first tracking area information is determined according to the serving cell identifier;

[0203] The cell identifier corresponding to the first tracking area information is the identifier of the cell under the DU of the IAB node. If the DU of the IAB node migrates, the cell identifier can be the cell identifier under the second logical DU of the IAB node.

[0204] Since the second CU obtains at least one tracking area information and the cell identifier corresponding to each tracking area information included in the first CU through the Xn interface, the second CU can determine the tracking area information corresponding to the serving cell identifier based on the serving cell identifier, that is, determine the first tracking area information.

[0205] Among them, in the DU migration scenario, after the third CU establishes an F1 connection with the second logical DU of the IAB node, the IAB node or the third CU can send the identifier of the cell under the second logical DU of the IAB node to the second CU, so that the second CU can determine the cell identifier under the second logical DU of the IAB node.

[0206] In one implementation, if the DU of the IAB node is migrated, the second CU may send the first tracking area information, or the first tracking area information and the cell identifier to the first logical DU of the IAB node.

[0207] In one implementation, the second CU may send an F1 message to the DU of the IAB node or the first logical DU, where the F1 message includes the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information.

[0208] The first logical DU of the IAB node may send the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information, to the second logical DU of the IAB node. The specific process is not limited.

[0209] Step 1005a may also be replaced by step 1005b and step 1005c.

[0210] Step 1005b: The second CU sends third information or a serving cell identifier to the third CU.

[0211] In one implementation, the second CU may send an Xn message to the third CU, where the Xn message includes the third information or the serving cell identifier.

[0212] Step 1005c: The third CU sends third information to the DU of the IAB node.

[0213] In one implementation, the third CU may send an F1 message to the DU of the IAB node or the second logical DU, where the F1 message includes the third information.

[0214] In one implementation, if the third CU obtains the serving cell identifier, the first tracking area information may be determined according to the serving cell identifier.

[0215] Implementation method 2: The first CU sends the serving cell identifier to the third CU.

[0216] Step 1006: The first CU sends a serving cell identifier to the third CU.

[0217] In one implementation, the first CU may send an Xn message to the third CU, where the Xn message includes a serving cell identifier.

[0218] Step 1007: The third CU sends third information to the DU of the IAB node.

[0219] The third information includes at least one of the following:

[0220] First tracking area information, where the first tracking area information is determined according to the serving cell identifier;

[0221] The cell identifier corresponding to the first tracking area information is the identifier of the cell under the DU of the IAB node.

[0222] Since the third CU obtains at least one tracking area information and the cell identifier corresponding to each tracking area information included in the first CU through the Xn interface, the third CU can determine the tracking area information corresponding to the serving cell identifier based on the serving cell identifier, that is, determine the first tracking area information.

[0223] In one implementation, if the DU of the IAB node is migrated, the third CU may send the third information to the second logical DU of the IAB node.

[0224] In one implementation, the third CU may send an F1 message to the DU of the IAB node or the second logical DU, where the F1 message includes the third information.

[0225] The above implementation methods 1 to 2 can be selected and executed one by one, and the specific implementation can be determined according to actual conditions. This application does not limit this.

[0226] In the present application, the IAB node may also request the first CU to send a serving cell identifier. For details, please refer to the following process.

[0227] As shown in Figure 11, a flow chart of a communication method provided in an embodiment of the present application is provided. In this flow, step 1101 and step 1102 can replace step 1002 and step 1003 in Figure 10, and the other steps in Figure 10 can be implemented in combination with step 1101 and step 1102.

[0228] Step 1101: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0229] For the specific content of step 1101, please refer to the description of step 801 and will not be repeated here.

[0230] Step 1102: The IAB node sends second information to the first CU.

[0231] The second information requests the serving cell identifier of the MT of the IAB node, or the second information requests the first CU to send the serving cell identifier of the MT of the IAB node to the second CU or the third CU, or the second information requests the first CU to send the serving cell identifier of the MT of the IAB node.

[0232] Specifically, the MT of the IAB node may send the second information, wherein the MT of the IAB node does not switch or migrate.

[0233] In one implementation, the MT of the IAB node sends an RRC message to the first CU, where the RRC message includes the second information. For the specific meaning of the second information, refer to the above description.

[0234] In one implementation, the second information or the RRC message includes at least one of the following:

[0235] The identifier of the second CU; the identifier of the third CU.

[0236] Other processes may be included after step 1102. For details, please refer to the description in the process of Figure 10, which will not be repeated here.

[0237] In this application, the third CU may also request the serving cell identifier, and for details, please refer to the following process.

[0238] As shown in Figure 12, a flow chart of a communication method provided in an embodiment of the present application is provided. In this flow, step 1201 and step 1202 can replace step 1002 and step 1003 in Figure 10, and the other steps in Figure 10 can be implemented in combination with step 1201 and step 1202.

[0239] Step 1201: The third CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0240] The specific content of this step can be referred to the description in step 901 and will not be repeated here.

[0241] Step 1202: The third CU sends second information to the first CU.

[0242] In one implementation, the third CU sends an Xn message to the first CU, where the Xn message includes the second information. The Xn message may also include an Xn interface identifier of the IAB-MT, such as a UE Xn AP ID.

[0243] Other processes may be included after step 1202. For details, please refer to the description in the process of Figure 10, which will not be repeated here.

[0244] Through the above method, the second CU, the third CU or the IAB node triggers the first CU to send the service cell identifier of the MT to the second CU or the third CU, so that the second CU or the third CU can determine the first tracking area information of the DU of the AB node according to the service cell identifier, thereby sending the first tracking area information to the IAB node. The IAB node can obtain the new tracking area information in time, and then the tracking area information broadcast by the IAB's DU can reflect the current location information of the IAB node, reduce the frequent execution of TAU by terminal devices around the IAB node cell, and improve system stability.

[0245] In the present application, the MT of the IAB node may also send the serving cell identifier to the source CU or target CU of the DU of the IAB node, which will be described in detail below.

[0246] FIG13 is a flow chart of a communication method provided in an embodiment of the present application, wherein the method includes:

[0247] Step 1301: Establish an Xn interface between the second CU or the third CU and the first CU.

[0248] The specific content of this step can be referred to step 1001 and will not be described in detail.

[0249] Step 1302: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0250] For the specific content of step 1302, please refer to the description in step 801 and will not be repeated here.

[0251] Implementation method 1:

[0252] Step 1303: The IAB node sends a serving cell identifier to the second CU.

[0253] Specifically, the DU of the IAB node or the first logical DU of the IAB node sends an F1 message to the second CU, where the F1 message includes a serving cell identifier of the MT of the IAB node.

[0254] Step 1304a: The second CU sends third information to the DU of the IAB node. The third information includes at least one of the following:

[0255] First tracking area information, where the first tracking area information is determined according to the serving cell identifier;

[0256] The cell identifier corresponding to the first tracking area information is the identifier of the cell under the DU of the IAB node.

[0257] Since the second CU obtains at least one tracking area information and the cell identifier corresponding to each tracking area information included in the first CU through the Xn interface, the second CU can determine the tracking area information corresponding to the serving cell identifier based on the serving cell identifier, that is, determine the first tracking area information.

[0258] In one implementation, the second CU may send an F1 message to the DU of the IAB node or the first logical DU, where the F1 message includes the third information. The F1 message may also be used to trigger the IAB node to create a new F1 interface.

[0259] The first logical DU of the IAB node may send the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information, to the second logical DU of the IAB node. The specific process is not limited.

[0260] Step 1304a may also be replaced by step 1304b and step 1304c.

[0261] Step 1304b: The second CU sends third information or a serving cell identifier to the third CU.

[0262] Step 1304c: The third CU sends third information to the DU of the IAB node.

[0263] If the third CU obtains the serving cell identifier, the third CU may determine the first tracking area information according to the serving cell identifier. For details, please refer to the previous process.

[0264] In one implementation, the third CU may send an F1 message to the DU of the IAB node or the second logical DU, where the F1 message includes the third information.

[0265] Implementation method 2:

[0266] Step 1305: The IAB node sends a serving cell identifier to the third CU.

[0267] Specifically, the DU of the IAB node or the second logical DU of the IAB node sends an F1 message to the third CU, where the F1 message includes the serving cell identifier of the MT of the IAB node.

[0268] Step 1306: The third CU sends third information to the DU of the IAB node.

[0269] In one implementation, the third CU may send an F1 message to the DU of the IAB node or the second logical DU, where the F1 message includes the third information.

[0270] Through the above method, the MT of IAB directly sends the service cell identifier of the MT of IAB to the second CU or the third CU, so that the second CU or the third CU can further send the first tracking area information to the IAB node, and the IAB node can obtain the new tracking area information in time, so that the tracking area information broadcast by the DU of IAB can reflect the current location information of the IAB node, reduce the frequent execution of TAU by terminal devices around the IAB node cell, and improve system stability.

[0271] In one scenario, the TAC broadcast by the cell of the DU of the IAB node is not necessarily the same as the TAC broadcast by the serving cell of the MT of the IAB node. The source CU of the DU of the IAB node can also directly configure the tracking area information to the IAB node, which will be described in detail below.

[0272] FIG14 is a flow chart of a communication method provided in an embodiment of the present application, wherein the method includes:

[0273] Step 1401: The second CU determines to update the tracking area information of the DU of the IAB node.

[0274] Among them, before this step, Xn interfaces are established between the second CU, the third CU and the first CU. During the interaction process of establishing the Xn interface, the above-mentioned CUs exchange the tracking area information of each cell within their respective management scopes. The specific process of establishing the Xn interface is not limited in this application and will not be repeated here. And after the Xn interface is established, if the cell information within the management scope of a certain CU changes (such as: the tracking area information of the cell changes), the CU will also notify other CUs through the Xn interface message (NG-RAN NODE CONFIGURATION UPDATE). The second CU can interact with the first CU and / or the third CU to obtain the tracking area information within the management scope of the first CU and / or the third CU, or obtain the tracking area information of the cell under the DU of the IAB node that the first CU and / or the third CU hopes to use. If the DU of the IAB node migrates, the cell under the DU can represent the cell under the second logical DU.

[0275] The CU of the MT of the IAB node is called the first CU. The first CU is connected to the MT of the IAB node, and the MT of the IAB node does not switch or migrate. An F1 interface is provided between the DU of the IAB node and the second CU. Alternatively, the source CU of the DU migration of the IAB node is the second CU, and the destination CU is the third CU.

[0276] If the DU of an IAB node is migrated, the DU of the IAB node may include two logical DUs: DU1 (first logical DU) and DU2 (second logical DU). An F1 interface exists between the second CU and DU1, and an F1 interface exists between the third CU and DU2. When the DU migration of the IAB node is complete, the second CU releases the F1 interface with DU1.

[0277] In one implementation, the second CU determines to update the tracking area information of the cell provided by the IAB node based on the identifier of the first CU and / or the third CU when the tracking area information of the cell provided by the IAB node (i.e., the cell of the DU of the IAB node) is different from the tracking area information of the cell under the first CU and / or is different from the tracking area information of the cell under the third CU.

[0278] For example, the second CU determines that the tracking area information currently broadcast by the DU of the IAB node is inconsistent with any tracking area information in the tracking area information of each cell under the first CU (for example: comparing whether the tracking area information broadcast by the DU of the IAB node is located in the cell TAC list maintained by the first CU, or comparing whether the tracking area information broadcast by the DU of the IAB node and any tracking area information in the cell TAC list maintained by the first CU represent similar geographical areas), and / or, the second CU determines that the tracking area information currently broadcast by the DU of the IAB node is inconsistent with any tracking area information in the tracking area information of each cell under the third CU (for example: comparing whether the tracking area information broadcast by the DU of the IAB node is located in the cell TAC list maintained by the third CU, or comparing whether the tracking area information broadcast by the DU of the IAB node and any tracking area information in the cell TAC list maintained by the third CU represent similar geographical areas), then determines to update the tracking area information of the cell provided by the IAB node.

[0279] Step 1402a: The second CU sends third information to the DU of the IAB node.

[0280] The third information includes at least one of the following:

[0281] First tracking area information, where the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node;

[0282] The cell identifier corresponding to the first tracking area information is the identifier of the cell under the DU of the IAB node.

[0283] In one implementation, the second CU may determine the first tracking area information from the TAC list of the first CU and / or the TAC list of the third CU, where the first tracking area information may be related to or match the current physical location of the IAB node.

[0284] In one implementation, the second CU sends an F1 message to the DU or the first logical DU of the IAB node, where the F1 message includes at least one of the first tracking area information and the cell identifier corresponding to the first tracking area information. The F1 message can also be used to trigger the IAB node to create a new F1 interface.

[0285] The first logical DU of the IAB node may send the first tracking area information, or the first tracking area information and the cell identifier corresponding to the first tracking area information, to the second logical DU of the IAB node. The specific process is not limited.

[0286] Step 1402a may also be replaced by step 1402b and step 1402c.

[0287] Step 1402b: The second CU sends third information to the third CU.

[0288] Alternatively, the second CU sends at least one of the cell identifier and the first tracking area information corresponding to the first tracking area information to the third CU.

[0289] Step 1402c: The third CU sends third information to the DU of the IAB node.

[0290] Alternatively, the third CU sends at least one of the cell identifier corresponding to the first tracking area information and the first tracking area information to the DU of the IAB node.

[0291] In one implementation, the third CU sends an F1 message to the DU of the IAB node or the second logical DU, where the F1 message includes at least one of the first tracking area information and a cell identifier corresponding to the first tracking area information.

[0292] Steps 1401 to 1402a, or steps 1401 to 1402c may also be replaced by steps 1403 to 1404 in the following process:

[0293] Step 1403: The third CU determines to update the tracking area information of the DU of the IAB node.

[0294] Prior to this step, the second CU, the third CU, and the first CU establish Xn interfaces with each other. During the interaction process of establishing the Xn interfaces, the aforementioned CUs exchange tracking area information for each cell within their respective management areas. The specific process of establishing the Xn interfaces is not limited in this application and will not be detailed here.

[0295] In one implementation, when the tracking area information of the cell provided by the IAB node (i.e., the cell of the DU of the IAB node) is different from the tracking area information of the cell under the first CU, and / or is different from the tracking area information of the cell under the third CU, it is determined to update the tracking area information of the cell provided by the IAB node.

[0296] For example, the third CU determines that the tracking area information currently broadcast by the DU of the IAB node is inconsistent with any tracking area information in the tracking area information of each cell under the first CU (for example: comparing whether the tracking area information broadcast by the DU of the IAB node is located in the cell TAC list maintained by the first CU, or comparing whether the tracking area information broadcast by the DU of the IAB node and any tracking area information in the cell TAC list maintained by the first CU represent similar geographical areas), and / or the third CU determines that the tracking area information currently broadcast by the DU of the IAB node is inconsistent with any tracking area information in the tracking area information of each cell under the third CU (for example: comparing whether the tracking area information broadcast by the DU of the IAB node is located in the cell TAC list maintained by the third CU, or comparing whether the tracking area information broadcast by the DU of the IAB node and any tracking area information in the cell TAC list maintained by the third CU represent similar geographical areas), then determines to update the tracking area information of the cell provided by the IAB node.

[0297] Step 1404: The third CU sends third information to the DU of the IAB node.

[0298] Alternatively, the third CU sends at least one of the cell identifier corresponding to the first tracking area information and the first tracking area information to the DU of the IAB node.

[0299] In one implementation, the third CU sends an F1 message to the DU of the IAB node or the second logical DU, where the F1 message includes at least one of the first tracking area information and a cell identifier corresponding to the first tracking area information.

[0300] In the above method, through the Xn interface interaction between CUs, the second CU or the second CU determines that the tracking area information of the DU of the IAB node needs to be updated based on the tracking area information of each cell obtained through the interaction. Then, new tracking area information (i.e., the first tracking area information) can be directly generated and configured to the IAB node, so that the IAB node can obtain the new tracking area information in a timely manner, and then the tracking area information broadcast by the IAB's DU can reflect the current location information of the IAB node, thereby reducing the frequent execution of TAU by terminal devices around the IAB node cell and improving system stability.

[0301] In another possible implementation of the present application, since the CU to which the MT of the IAB node is connected remains unchanged during DU migration, it can be considered that the location of the IAB node has not changed, and the tracking area information of the DU of the IAB node does not need to be updated. Therefore, the following implementation is possible:

[0302] Method 1: During DU migration, when the IAB node generates a new logical DU (i.e., DU2), the tracking area information of the cells under DU2 is made the same as the tracking area information of the cells under the original logical DU (i.e., DU1) of the IAB node (the tracking area information of the cells under DU1 is directly copied). This method is applicable to scenarios where all cells under a logical DU use the same tracking area information.

[0303] Method 2: In DU migration, when the IAB node generates a new logical DU (i.e., DU2), the cells under DU2 correspond to the cells under the original logical DU (i.e., DU1) of the IAB node. The tracking area information used by the cells under DU2 directly copies the tracking area information used by the corresponding cells under DU1. For example, it can be applicable to the case where the cells under a logical DU may use different tracking area information.

[0304] In the above method, during DU migration, the tracking area information used by the cell under the new logical DU of the IAB node is the same as the tracking area information under the original logical DU of the IAB node, so that when the IAB node does not move over a large range, the same tracking area information is used, and signaling interaction is reduced, reducing overhead.

[0305] When sending downlink IP packets, the donor-CU can add a differentiated services code point (DSCP) and / or flow label to the IP header to identify the QoS requirements for the IP packet. When the downlink IP packet reaches the donor-DU, the donor-DU checks the DSCP / Flow Label in the IP header and uses it as input parameters to route the packet over a backhaul link and radio link control channel (RLC CH) that meet the QoS requirements. In other words, the DSCP / Flow Label is information required by the CU at the origin of the downlink traffic. Before DU migration, CU1, as the source CU of the DU on the IAB node, is aware of the DSCP / Flow Label. Since CU1's traffic must traverse CU2 (the CU connected to the IAB node's mobile equipment), the DSCP / Flow Label is generated and sent to CU1 by CU2, which is also aware of the DSCP / Flow Label. After DU migration, CU3, as the target CU of the DU, also needs to know the DSCP / Flow Label. How CU3 obtains the DSCP / Flow Label is an urgent problem to be solved. Therefore, this application provides a method where the IAB node obtains the DSCP / Flow Label from CU1 or CU2 and notifies CU3 of the information through an F1 message.

[0306] In the processes of Figures 15 and 16 below, the DU migration of an IAB node includes two logical DUs: DU1 (first logical DU) and DU2 (second logical DU). An F1 interface exists between the second CU and DU1, and an F1 interface exists between the third CU and DU2. When the DU migration of the IAB node is complete, the second CU releases the F1 interface between it and DU1.

[0307] FIG15 is a flow chart of a communication method provided in an embodiment of the present application, the method including:

[0308] Step 1501: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0309] For the specific content of step 1501, please refer to the description of step 801 and will not be repeated here.

[0310] Step 1502: The IAB node sends a DU migration notification to the second CU.

[0311] The DU migration notification may include the identifier of the third CU.

[0312] Step 1501 and step 1502 may also be replaced by step 1503 .

[0313] Step 1503: The second CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0314] For the specific content of step 1501, please refer to the description of step 701 and will not be repeated here.

[0315] After step 1502 or step 1503 , the second CU may execute step 1504 .

[0316] Step 1504: The second CU sends the DSCP / flow label to the IAB node.

[0317] In one implementation, the second CU sends an F1AP message to the DU of the IAB node or the first logical DU (ie, DU1 in the figure), where the F1AP message includes a DSCP / flow label.

[0318] Step 1505: The IAB node sends the DSCP / flow label to the third CU.

[0319] In one implementation, the DU or the second logical DU (i.e., DU2 in the figure) of the IAB node sends an F1AP message to the third CU. The F1AP message includes a DSCP / flow label. The IAB node may also send the IAB node's IP address and / or a backhaul link information index (BH Info Index) to the third CU to identify the IAB node's IP address and / or backhaul link index associated with the DSCP / flow label.

[0320] After the first logical DU of the IAB node obtains the DSCP / flow label, the DSCP / flow label may be sent to the second logical DU of the IAB node. The specific process is not limited.

[0321] In another implementation, as shown in FIG16 , which is a flow chart of a communication method provided in an embodiment of the present application, the method includes:

[0322] Step 1601: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0323] For the specific content of step 1601, please refer to the description of step 801 and will not be repeated here.

[0324] Step 1602: The IAB node sends a DU migration notification to the second CU.

[0325] The DU migration notification may include the identifier of the third CU.

[0326] Step 1601 and step 1602 may also be replaced by step 1603 and step 1604 .

[0327] Step 1603: The second CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0328] For the specific content of step 1603, please refer to the description in step 701 and will not be repeated here.

[0329] Step 1604: The second CU sends a DU migration notification to the first CU.

[0330] The DU migration notification may include the identifier of the third CU.

[0331] After step 1602 or step 1604 , the first CU may execute step 1605 .

[0332] Step 1605: The first CU sends the DSCP / flow label to the IAB node.

[0333] In one implementation, the first CU sends an RRC message to the MT of the IAB node, where the RRC message includes a DSCP / flow label.

[0334] After the MT of the IAB node obtains the DSCP / flow label, it may send the DSCP / flow label to the second logic DU (ie, DU2 in the figure) of the IAB node. The specific process is not limited.

[0335] Step 1606: The IAB node sends the DSCP / flow label to the third CU.

[0336] In one implementation, the DU of the IAB node or the second logical DU (ie, DU2 in the figure) sends an F1AP message to the third CU, where the F1AP message includes a DSCP / flow label.

[0337] The IAB node may also send the IP address of the IAB node and / or the backhaul link information index (BH Info Index) to the third CU to identify which IAB node IP address and / or backhaul link index the DSCP / flow label is associated with.

[0338] Through the method provided in Figure 15 or Figure 16, when no Xn interface is established between CUs, the IAB node obtains the DSCP / flow label from the first CU or the second CU and informs the third CU through the F1 message, so that the third CU can obtain the necessary parameters for traffic transmission while reducing Xn interaction, thereby improving system efficiency.

[0339] It is understood that, in order to implement the functions in the above embodiments, the base station and the terminal include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily appreciate that, in conjunction with the units and method steps of the various examples described in the embodiments disclosed in this application, this application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in hardware or in a computer software-driven hardware manner depends on the specific application scenario and design constraints of the technical solution.

[0340] Figure 17 shows a schematic diagram of the structure of a communication device provided in an embodiment of the present application. As shown in Figure 17, the communication device 1700 may include: a processing unit 1710 and a transceiver unit 1720. The processing unit 1710 is used to control and manage the actions of the communication device 1700. The transceiver unit 1720 is used to support communication between the communication device 1700 and other devices. Optionally, the transceiver unit 1720 may include a receiving unit and / or a sending unit, which are used to perform receiving and sending operations respectively. Optionally, the communication device 1700 may also include a storage unit for storing program code and / or data of the communication device 1700. The above-mentioned transceiver unit can be called an input / output unit, a communication unit, etc., and the above-mentioned transceiver unit can be a transceiver; the above-mentioned processing unit can be a processor. When the communication device is a module (such as a chip) in a communication device, the above-mentioned transceiver unit can be an input / output interface, an input / output circuit or an input / output pin, etc., and can also be called an interface, a communication interface or an interface circuit, etc.; the above-mentioned processing unit can be a processor, a processing circuit or a logic circuit, etc. Specifically, the communication device may be the first CU, the second CU, the third CU, the IAB node, etc. mentioned above.

[0341] In one implementation, the communication device 1700 is used to implement the following functions:

[0342] a processing unit, configured to determine first information;

[0343] a transceiver unit, configured to send the first information to a first centralized unit CU;

[0344] Among them, the first information requests the first tracking area information, the first CU is connected to the mobile terminal MT of the access backhaul integrated IAB node; the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU.

[0345] In one implementation, the MT of the IAB node is not switched.

[0346] In one implementation, the transceiver unit is further configured to:

[0347] receiving the first tracking area information or the first tracking area information and a cell identifier corresponding to the first tracking area information from the first CU, where the cell identifier is an identifier of a cell under the DU of the IAB node;

[0348] Send the first tracking area information or the first tracking area information and the cell identifier to a third CU or a DU of the IAB node.

[0349] In one implementation, the processing unit is further configured to: determine that the DU of the IAB node is migrated from the second CU to the third CU.

[0350] In one implementation, the communication device 1700 is used to implement the following functions:

[0351] A transceiver unit, configured to receive first information from a first node; the first information requests first tracking area information, where the first tracking area information is used to configure a tracking area of ​​a cell accessing an integrated backhaul IAB node; the first node is a second centralized unit CU, or a third CU, or a mobile terminal MT of the IAB node; an F1 interface is provided between a distributed unit DU of the IAB node and the second CU; or the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU;

[0352] A processing unit is used to send the first tracking area information or the first tracking area information and the cell identifier corresponding to the first tracking area information through the transceiver unit according to the first information, where the cell identifier is the identifier of the cell under the DU of the IAB node.

[0353] In one implementation, the first information includes second tracking area information, where the second tracking area information is tracking area information provided by the IAB node and used by the cell before obtaining the first tracking area information; and the processing unit is further configured to:

[0354] Determine, according to the second tracking area information, whether to update the tracking area information of the cell provided by the IAB node.

[0355] In one implementation, the communication device 1700 is used to implement the following functions:

[0356] a processing unit, configured to determine second information;

[0357] a transceiver unit, configured to send second information to the first centralized unit CU;

[0358] Among them, the second information requests the service cell identifier of the mobile terminal MT accessing the integrated backhaul IAB node, and the first CU is connected to the mobile terminal MT accessing the integrated backhaul IAB node; the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU.

[0359] In one implementation, the communication device 1700 is used to implement the following functions:

[0360] A transceiver unit, configured to receive second information from a first node; the second information requests access to a serving cell identifier of a mobile terminal MT of an integrated backhaul IAB node, wherein the first node is a second centralized unit CU, or a third CU, or a mobile terminal MT of the IAB node; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU;

[0361] A processing unit is configured to send the serving cell identifier through the transceiver unit according to the second information.

[0362] In one implementation, the communication device 1700 is used to implement the following functions:

[0363] A transceiver unit, configured to send a serving cell identifier of a mobile terminal MT accessing an integrated backhaul IAB node to a second centralized unit CU or a third CU; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU and the destination CU of the migration is the third CU;

[0364] The processing unit is configured to receive first tracking area information through the transceiver unit, where the first tracking area information is determined according to the serving cell identifier, and the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node.

[0365] In one implementation, the communication device 1700 is used to implement the following functions:

[0366] A transceiver unit, configured to receive a serving cell identifier of a mobile terminal MT accessing an integrated backhaul IAB node; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or the source CU of the DU migration of the IAB node is the first CU and the destination CU of the migration is the third CU;

[0367] A processing unit is used to send first tracking area information to the DU of the IAB node or the third CU through the transceiver unit, where the first tracking area information is determined according to the serving cell identifier, and the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node.

[0368] In one implementation, the communication device 1700 is used to implement the following functions:

[0369] a processing unit, configured to determine to update the tracking area information of the cell provided by the access backhaul integrated IAB node when the tracking area information of the cell provided by the IAB node is different from the tracking area information of the cell under the first CU and / or is different from the tracking area information of the cell under the third CU; the first CU is connected to the mobile terminal MT of the IAB node; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or the source CU of the DU migration of the IAB node is the second CU and the destination CU of the migration is the third CU;

[0370] The transceiver unit is configured to send third information, where the third information includes at least one of the following:

[0371] first tracking area information, where the first tracking area information is used to configure a tracking area of ​​a cell of the IAB node;

[0372] The cell identifier corresponding to the first tracking area information is the identifier of the cell under the DU of the IAB node.

[0373] A more detailed description of the processing unit 1710 and the transceiver unit 1720 can be directly obtained by referring to the relevant descriptions in the method embodiments shown in the above processes, and will not be repeated here.

[0374] As shown in Figure 18, communication device 1800 includes a processor 1810 and an interface circuit 1820. Processor 1810 and interface circuit 1820 are coupled to each other. It will be appreciated that interface circuit 1820 may be a transceiver or an input / output interface. Optionally, communication device 1800 may also include a memory 1830 for storing instructions executed by processor 1810, input data required by processor 1810 to execute instructions, or data generated by processor 1810 after executing instructions.

[0375] When the communication device 1800 is used to implement the methods shown in the above processes, the processor 1810 is used to implement the functions of the above processing unit 1710, and the interface circuit 1820 is used to implement the functions of the above transceiver unit 1720.

[0376] An embodiment of the present application further provides a communication system, which includes the first CU, the second CU, the third CU, and the IAB node in any of the processes shown in Figures 7 to 16.

[0377] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0378] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, a CD-ROM or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. Of course, the processor and the storage medium can also exist in a base station or a terminal as discrete components.

[0379] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in 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 network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one 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 that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0380] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0381] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, optical storage, etc.) that contain computer-usable program code.

[0382] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or box in the flow chart and / or block diagram, as well as the combination of the flow chart and / or box in the flow chart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flow charts and / or one or more boxes in the block diagram.

[0383] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0384] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: include: determining first information; Sending the first information to a first centralized unit CU; Among them, the first information requests the first tracking area information, the first CU is connected to the mobile terminal MT of the access backhaul integrated IAB node; the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU.

2. The method according to claim 1, characterized in that The MT of the IAB node is not switched.

3. The method according to claim 1, characterized in that The first information includes at least one of the following: second tracking area information, where the second tracking area information is tracking area information provided by the IAB node and used by the cell before obtaining the first tracking area information; The cell identifier under the DU of the IAB node; an identifier of the second CU; The identifier of the third CU.

4. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: receiving the first tracking area information or the first tracking area information and a cell identifier corresponding to the first tracking area information from the first CU, where the cell identifier is an identifier of a cell under the DU of the IAB node; Send the first tracking area information or the first tracking area information and the cell identifier to the third CU or the DU of the IAB node.

5. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: Determine that the DU of the IAB node is migrated from the second CU to the third CU.

6. A communication method, characterized in that: include: receiving first information from a first node; The first information requests first tracking area information, where the first tracking area information is used to configure a tracking area of ​​a cell of an access backhaul integrated IAB node; The first node is a second centralized unit CU, or a third CU, or a mobile terminal MT of the IAB node; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or, a source CU of the DU migration of the IAB node is the second CU, and a destination CU of the migration is the third CU; The first tracking area information or the first tracking area information and a cell identifier corresponding to the first tracking area information are sent according to the first information, where the cell identifier is an identifier of a cell under the DU of the IAB node.

7. The method according to claim 6, characterized in that The first information includes second tracking area information, where the second tracking area information is tracking area information provided by the IAB node and used by the cell before obtaining the first tracking area information; the method further includes: Determine, according to the second tracking area information, whether to update the tracking area information of the cell provided by the IAB node.

8. The method according to claim 6 or 7, characterized in that: The first information includes at least one of the following: The cell identifier under the DU of the IAB node; an identifier of the second CU; The identifier of the third CU.

9. A communication method, characterized in that: include: determining second information; Sending second information to the first centralized unit CU; Among them, the second information requests the service cell identifier of the mobile terminal MT accessing the integrated backhaul IAB node, and the first CU is connected to the mobile terminal MT accessing the integrated backhaul IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU.

10. The method according to claim 9, characterized in that The second information includes at least one of the following: an identifier of the second CU; The identifier of the third CU.

11. The method according to claim 9 or 10, characterized in that: The method further comprises: receiving the serving cell identifier; Sending third information to the third CU or the DU of the IAB node; the third information includes at least one of the following: first tracking area information, where the first tracking area information is determined according to the serving cell identifier, and the first tracking area information is used to configure a tracking area of ​​a cell of the IAB node; The cell identifier corresponding to the first tracking area information is the identifier of the cell under the DU of the IAB node.

12. The method according to any one of claims 9 to 11, characterized in that: Before determining the second information, the method further includes: Determine that the DU of the IAB node is migrated from the second CU to the third CU.

13. A communication method, characterized in that: include: receiving second information from the first node; The second information requests a service cell identifier of a mobile terminal MT accessing the backhaul integrated IAB node, the first node is a second centralized unit CU, or a third CU, or a mobile terminal MT of the IAB node; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU; The serving cell identifier is sent according to the second information.

14. The method according to claim 13, characterized in that The second information includes at least one of the following: an identifier of the second CU; The identifier of the third CU.

15. A communication method, characterized in that: include: Sending a serving cell identifier of a mobile terminal MT accessing the backhaul integrated IAB node to the second centralized unit CU or the third CU; There is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU; Receive first tracking area information, where the first tracking area information is determined according to the serving cell identifier, and the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node.

16. A communication method, characterized in that: include: Receiving a serving cell identifier of a mobile terminal MT accessing the backhaul integrated IAB node; There is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the first CU, and the destination CU of the migration is the third CU; Send first tracking area information to the DU of the IAB node or the third CU, where the first tracking area information is determined according to the serving cell identifier, and the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node.

17. A communication method, characterized in that: include: When the tracking area information of the cell provided by the access backhaul integrated IAB node is different from the tracking area information of the cell under the first CU and / or is different from the tracking area information of the cell under the third CU, it is determined to update the tracking area information of the cell provided by the IAB node; the first CU is connected to the mobile terminal MT of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU; Sending third information, wherein the third information includes at least one of the following information: first tracking area information, where the first tracking area information is used to configure a tracking area of ​​a cell of the IAB node; A cell identifier corresponding to the first tracking area information, wherein the cell identifier is an identifier of a cell under the DU of the IAB node.

18. The method according to claim 17, characterized in that The sending of the third information comprises: The third information is sent to the DU of the IAB node or the third CU.

19. A communication device, characterized in that: include: A processing unit, configured to determine first information; a transceiver unit, configured to send the first information to a first centralized unit CU; Among them, the first information requests the first tracking area information, the first CU is connected to the mobile terminal MT of the access backhaul integrated IAB node; the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU.

20. The device according to claim 19, characterized in that The MT of the IAB node is not switched.

21. The device according to claim 19 or 20, characterized in that The transceiver unit is also used for: receiving the first tracking area information or the first tracking area information and a cell identifier corresponding to the first tracking area information from the first CU, where the cell identifier is an identifier of a cell under the DU of the IAB node; Send the first tracking area information or the first tracking area information and the cell identifier to the third CU or the DU of the IAB node.

22. The device according to any one of claims 19 to 21, characterized in that The processing unit is also used for: Determine that the DU of the IAB node is migrated from the second CU to the third CU.

23. A communication device, characterized in that: include: A transceiver unit, configured to receive first information from a first node; The first information requests first tracking area information, where the first tracking area information is used to configure a tracking area of ​​a cell of an access backhaul integrated IAB node; The first node is a second centralized unit CU, or a third CU, or a mobile terminal MT of the IAB node; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or, a source CU of the DU migration of the IAB node is the second CU, and a destination CU of the migration is the third CU; A processing unit is used to send the first tracking area information or the first tracking area information and the cell identifier corresponding to the first tracking area information through the transceiver unit according to the first information, where the cell identifier is the identifier of the cell under the DU of the IAB node.

24. The device according to claim 23, characterized in that The first information includes second tracking area information, where the second tracking area information is tracking area information provided by the IAB node and used by the cell before obtaining the first tracking area information; and the processing unit is further used to: Determine, according to the second tracking area information, whether to update the tracking area information of the cell provided by the IAB node.

25. A communication device, characterized in that: include: a processing unit, configured to determine second information; a transceiver unit, configured to send second information to the first centralized unit CU; Among them, the second information requests the service cell identifier of the mobile terminal MT accessing the integrated backhaul IAB node, and the first CU is connected to the mobile terminal MT accessing the integrated backhaul IAB node; the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU.

26. A communication device, characterized in that: include: a transceiver unit, configured to receive second information from the first node; The second information requests a service cell identifier of a mobile terminal MT accessing the backhaul integrated IAB node, the first node is a second centralized unit CU, or a third CU, or a mobile terminal MT of the IAB node; an F1 interface is provided between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU; A processing unit is used to send the serving cell identifier through the transceiver unit according to the second information.

27. A communication device, characterized in that: include: A transceiver unit, configured to send a serving cell identifier of a mobile terminal MT accessing the backhaul integrated IAB node to the second centralized unit CU or the third CU; There is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the second CU, and the destination CU of the migration is the third CU; The processing unit is used to receive first tracking area information through the transceiver unit, where the first tracking area information is determined according to the serving cell identifier, and the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node.

28. A communication device, characterized in that: include: A transceiver unit, used for receiving a serving cell identifier of a mobile terminal MT accessing the backhaul integrated IAB node; There is an F1 interface between the distributed unit DU of the IAB node and the second CU; or, the source CU of the DU migration of the IAB node is the first CU, and the destination CU of the migration is the third CU; A processing unit is used to send first tracking area information to the DU of the IAB node or the third CU through the transceiver unit, where the first tracking area information is determined according to the serving cell identifier, and the first tracking area information is used to configure the tracking area of ​​the cell of the IAB node.

29. A communication device, characterized in that: include: A processing unit, configured to determine to update the tracking area information of the cell provided by the access backhaul integrated IAB node when the tracking area information of the cell provided by the IAB node is different from the tracking area information of the cell under the first CU and / or is different from the tracking area information of the cell under the third CU; the first CU is connected to the mobile terminal MT of the IAB node; there is an F1 interface between the distributed unit DU of the IAB node and the second CU; or the source CU of the DU migration of the IAB node is the second CU, The destination CU of the migration is the third CU; The transceiver unit is configured to send third information, where the third information includes at least one of the following information: first tracking area information, where the first tracking area information is used to configure a tracking area of ​​a cell of the IAB node; A cell identifier corresponding to the first tracking area information, wherein the cell identifier is an identifier of a cell under the DU of the IAB node.

30. A communication device, characterized in that: The communication device comprises a processor and a memory, wherein the processor and the memory are coupled, and the processor executes a computer program stored in the memory, so that the communication device implements the method according to any one of claims 1 to 18.

31. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed on a computer, the communication device executes the method according to any one of claims 1 to 18.

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