Communication method and device

Abstract

The invention provides a communication method and device. The method comprises the following steps: determining first information; sending first information to the first CU; the first information requests first tracking area information, and the first CU is connected with the MT of the 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 arranged between the DU of the IAB node and the second CU; or the source CU migrated by the DU of the IAB node is the second CU, and the target CU migrated by the DU of the IAB node is the third CU. The first CU is triggered through the first information to send the updated first tracking area information to the DU of the IAB node, so that the IAB node can obtain new tracking area information in time, the tracking area information broadcasted by the DU of the IAB node can reflect the position information of the IAB node, frequent execution of tracking area updating by terminal equipment around an IAB node cell is reduced, and the system stability is improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0002] The fifth generation of mobile communications (5G) introduces 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 service data of the UE is transmitted by the IAB-node to the IAB host (IAB-donor) through a wireless backhaul link. The IAB-node includes a mobile termination (MT) part and a distributed unit (DU) part. 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).

[0003] IAB nodes can migrate, i.e., partial migration. For example, before partial migration, there is an RRC connection between IAB-MT and CU1 of IAB-donor 1, and there is an F1 interface between IAB-DU and CU1 of IAB-donor. During partial migration, IAB-MT undergoes cross-CU cell migration and establishes an RRC connection with CU2 of IAB-donor 2. However, in order to reduce the introduction of the re-establishment process of the F1 interface, IAB-DU still maintains the F1 interface with CU1 of IAB-donor 1, and does not establish an F1 interface with CU2 of IAB-donor 2.

[0004] IAB nodes may move over a large range. When an IAB-node moves far away, it may be difficult for the IAB-DU to maintain a connection with the original IAB host CU. Therefore, in order to support the large-scale movement of IAB-nodes, an important feature is currently proposed: DU migration. For example, the RRC connection of IAB-MT is always on CU2 of IAB-donor 2, and the F1 interface of IAB-DU is migrated from CU1 of IAB-donor 1 to CU3 of IAB-donor 3.

[0005] 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 by 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 update of the TAC of the IAB-DU, which makes the TAC broadcast by the IAB-DU mismatch with the position of the IAB-DU after migration. Summary of the invention

[0006] 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.

[0007] 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;

[0008] 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.

[0009] 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 time, 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.

[0010] In a possible implementation, the MT of the IAB node is not switched.

[0011] 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.

[0012] 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.

[0013] By using 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 of 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.

[0014] In a possible implementation manner, the method further includes: determining that the DU of the IAB node is migrated from the second CU to the third CU.

[0015] According to a second aspect, a communication method is provided, the method comprising: receiving first information from a first node; the first information requests first tracking area information, the first tracking area information being used to configure the 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, 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 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, the cell identifier being the identifier of the cell under the DU of the IAB node.

[0016] In one possible implementation, the first information includes second tracking area information, and the second tracking area information is the 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.

[0017] In a possible implementation manner, 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.

[0018] In a third aspect, a communication method is provided, the method comprising: determining second information; sending the second information to a first centralized unit CU;

[0019] Among them, the second information requests the 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.

[0020] 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, so that the tracking area information broadcast by the DU of the 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 the system stability.

[0021] In a possible implementation manner, the second information includes at least one of the following: an identifier of the second CU; an identifier of the third CU.

[0022] In a possible implementation manner, 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.

[0023] In a possible implementation, it also includes: receiving a service 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 service 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.

[0024] In a possible implementation manner, 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.

[0025] In a fourth aspect, a communication method is provided, the method comprising: receiving second information from a first node; the second information requests access to a service cell identifier of a mobile terminal MT of an integrated backhaul IAB node, the first node being 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; and the service cell identifier is sent according to the second information.

[0026] 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, and the IAB node can obtain the new tracking area information in time, so that the tracking area information broadcast by the DU of the 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.

[0027] In a possible implementation manner, the second information includes at least one of the following: an identifier of the second CU; an identifier of the third CU.

[0028] In a fifth aspect, a communication method is provided, the method comprising: 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.

[0029] In a sixth aspect, a communication method is provided, the method comprising: receiving a service 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; 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.

[0030] In a seventh aspect, a communication method is provided, the method comprising: 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, 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 comprising 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; a 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.

[0031] 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 time, and then the tracking area information broadcast by the DU of the IAB 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.

[0032] 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.

[0033] In an eighth aspect, the present application further provides a communication device, which can implement any of the methods provided in any of the first to seventh aspects above. The communication device can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions.

[0034] In a possible implementation, the communication device includes: a processor, the processor is configured to support the communication device to perform the corresponding functions of any of the methods shown above. The communication device may also include a memory, which may be coupled to the processor and stores the necessary program instructions and data of the communication device. Optionally, the communication device also includes an interface circuit, which is used to support communication between the communication device and other devices.

[0035] In a possible implementation, the communication device includes corresponding functional modules, which are respectively used to implement 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.

[0036] In a possible implementation, the structure of the communication device includes a processing unit and a transceiver unit, which can perform 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.

[0037] In a ninth aspect, a communication device is provided, comprising a processor and an interface circuit, wherein the interface circuit is 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, and the processor is used to implement a method in any possible implementation manner provided in any one of the first to seventh aspects through a logic circuit or by executing code instructions.

[0038] 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 a method in any possible implementation manner provided in any one of the first to seventh aspects through a logic circuit or by executing code instructions.

[0039] 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 manner provided in any one of the first to seventh aspects is implemented.

[0040] In a twelfth aspect, a computer program product storing instructions is provided, which, when executed by a processor, implements a method in any possible implementation manner provided in any one of the first to seventh aspects.

[0041] In a thirteenth aspect, a circuit is provided, the circuit being used to execute the method in any possible implementation provided in any one of the first to seventh aspects, the circuit may include a chip circuit. Optionally, the circuit may also be coupled to a memory.

[0042] In a fourteenth aspect, a chip is provided, the chip including a processor, for implementing the method in any possible implementation provided in any of the first to seventh aspects. Optionally, the chip may also include a memory, and the chip may be composed of a chip, or may include a chip and other discrete devices.

[0043] 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 manner provided in the aforementioned first aspect; the first node is used to execute the method in any possible implementation manner provided in the aforementioned second aspect.

[0044] 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 manner provided in the aforementioned third aspect; the first node is used to execute the method in any possible implementation manner provided in the aforementioned fourth aspect.

[0045] 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; the first node is used to execute the method in any possible implementation provided in the aforementioned sixth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the architecture of a communication system used in an embodiment of the present application;

[0047] Figure 2 A schematic diagram of an IAB network including multiple UEs and multiple IAB nodes is shown;

[0048] Figure 3 is a schematic diagram of an IAB network architecture;

[0049] Figure 4 A schematic diagram of a partial migration;

[0050] Figure 5 A schematic diagram of a continuous partial migration;

[0051] Figure 6 is a schematic diagram of DU migration;

[0052] Figure 7 A flow chart of a communication method provided in an embodiment of the present application;

[0053] Figure 8 A flow chart of a communication method provided in an embodiment of the present application;

[0054] Fig. 9 A flow chart of a communication method provided in an embodiment of the present application;

[0055] Fig.10 A flow chart of a communication method provided in an embodiment of the present application;

[0056] Fig.11 A flow chart of a communication method provided in an embodiment of the present application;

[0057] Fig.12 A flow chart of a communication method provided in an embodiment of the present application;

[0058] Fig.13 A flow chart of a communication method provided in an embodiment of the present application;

[0059] Fig.14 A flow chart of a communication method provided in an embodiment of the present application;

[0060] Fig.15 A flow chart of a communication method provided in an embodiment of the present application;

[0061] Fig.16 A flow chart of a communication method provided in an embodiment of the present application;

[0062] Fig.17 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0063] Fig.18 A schematic diagram of the structure of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0064] 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.

[0065] 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 digital 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 the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic.

[0066] Figure 1 Schematic diagram of the architecture of the communication system used in the embodiment of the present application. Figure 1 As shown, 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 ( Figure 1 The terminal device 140 and the terminal device 150 are used as examples in the description). 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 may 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 by wire. The core network device and the wireless access network device may be independent and different physical devices, or the functions of the core network device and the logical functions of the wireless access network device may be integrated on the same physical device, or some functions of the core network device and some functions of the wireless access network device may be integrated on one physical device, and this application does not limit this. The terminal device may be fixed in position or movable. It should be understood that, if Figure 1 The mobile communication system shown is only a schematic diagram. The communication system may also include other network devices, such as wireless relay devices or wireless backhaul devices. Figure 1 The embodiment of the present application does not limit the number of core network devices, wireless access network devices, wireless backhaul devices and terminal devices included in the mobile communication system.

[0067] Among them, the wireless access network device is an access device that the terminal device uses to access the mobile communication system wirelessly, which 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.

[0068] The terminal device may be a mobile phone, a tablet computer, a computer with wireless transceiver function, 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 in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a machine type communication (MTC) terminal, a wearable device, a vehicle-mounted terminal device, a drone, etc. The terminal device may also be referred to as a terminal, UE, a mobile station (MS), MT, etc.

[0069] Among them, the wireless backhaul device can provide backhaul services for its child nodes. Specifically, it can be a relay node in a long term evolution (LTE) system, an IAB node in a 5G system, or other equipment 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.

[0070] Wireless access network equipment and terminal equipment, as well as terminal equipment and terminal equipment, can communicate through licensed spectrum (licensed spectrum), can communicate through unlicensed spectrum (unlicensed spectrum), or can communicate through both licensed spectrum and unlicensed spectrum.

[0071] 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 business 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 of ordinary skill in the art that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

[0072] In order to facilitate understanding of the embodiments of the present application, the terms and technical features involved in the embodiments of the present application are briefly described below.

[0073] 1) IAB network: Considering the small coverage of high frequency bands, in order to ensure the coverage performance of the network and provide network coverage in some remote areas, the deployment of optical fiber is difficult and costly, and it is also necessary to design flexible and convenient access and backhaul solutions. IAB technology came into being, and its access link and backhaul link both use wireless transmission solutions, which can reduce optical fiber deployment and reduce equipment costs.

[0074] In the IAB network, the relay node, or IAB node (IAB-node), can provide wireless access services for UEs, and the service data of the UE is transmitted by the IAB-node to the IAB host node (IAB-donor) through a wireless backhaul link. The IAB node can also be called a mobile mAB (mobile IAB) node. In the following text, mIAB refers to the mAB node, mAB-MT refers to the MT of the IAB node, and mAB-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 node of an IAB node may also be referred to as its upstream node or parent node, and the lower node of the IAB node may also be referred to as its downstream node or child node.

[0075] 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.

[0076] The IAB donor node (IAB-donor) can be an access network element with complete base station functions, such as a donor base station DgNB, or an access network element with a centralized unit (CU) and DU separated. The IAB donor node is connected to the core network element (e.g., connected to the 5G core network) serving the terminal device and provides wireless backhaul functions for the IAB node. For ease of description, the centralized unit of the IAB donor node can be referred to as donor CU or IAB-donorCU, and the distributed unit of the IAB donor node can be referred to as donor DU or IAB-donor DU. The donor CU may also be in a form where the control plane (CP) and the user plane (UP) are separated. For example, the CU can be composed of a CU-CP and one (or more) CU-UPs.

[0077] 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, the wireless access link is 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, the wireless backhaul link is between the IAB-node and the child node (i.e., the other IAB-node). Figure 2 An example of an IAB network including multiple UEs and multiple IAB nodes is shown. Figure 2 Take 2 UEs and 5 IAB nodes as an example. The 2 UEs are UE1 and UE2, and the 5 IAB nodes are IAB node 1 to IAB node 5. It should be understood that Figure 2 Thick lines indicate access links, and thin lines indicate backhaul links. 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 is connected to IAB-node3 via a wireless backhaul link, IAB-node3 is connected to IAB-node1 via a wireless backhaul link, and IAB-node1 is connected to IAB-donor via a wireless backhaul link. It should be understood that Figure 2 The IAB networking scenario shown is merely exemplary. There are many other possibilities in the IAB network that supports multi-hop and multi-connection networking, which are not listed here one by one.

[0078] The IAB-node-DU (hereinafter simply expressed as mIAB-DU) is logically connected to the IAB-donorCU (hereinafter simply expressed as CU) through the F1 interface. Figure 3 A schematic diagram of an IAB network architecture. Figure 3 The F1 connection is not a physical direct connection, but a logical connection. In fact, the F1 connection between the mAB-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 mAB-DU can communicate with the CU in the end, it can be considered that there is a logical F1 interface. The F1 interface may also be referred to as 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 (5Gcore network, 5GC / 5GCN) through the NG interface. There is an Xn-C interface between the IAB-donor CU and the gNodeB.

[0079] 2) Tracking Area (TA)

[0080] Tracking area is a concept established by 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 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 the UE moves out to a cell that does not belong to the TAI List, it will actively access the network (including the core network) and perform NAS Registration Update. The core network registers the UE's location and updates the UE's UE registration area, that is, reassigns the TAI List containing the TA to which the UE's current cell belongs to the UE. The newly assigned TAI List may or may not contain some TAIs in the original TA list; except for this case, the UE will also perform Tracking Area Update (TAU) regularly to let the core network know the UE's location. NAS Registration Update and TAU are the same process. NAS Registration Update focuses on the description on the network side, while TAU focuses on the description on the UE side.

[0081] 3) Partial migration

[0082] In 3GPP Release-17 (R17), partial migration of IAB nodes is introduced. The IAB node that undergoes migration is called a boundary node. Figure 4 The schematic diagram of a partial migration is shown in the figure. In the mIAB-node (mobile IAB-node), before the partial migration, there is an RRC connection between the mIAB-MT (i.e., the MT of the mIAB node) and CU1, and there is an F1 interface between the mIAB-DU (i.e., the DU of the mIAB node) and CU1. During partial migration, the mAB-MT undergoes cross-CU cell switching 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 the F1 interface with CU2. Therefore, the communication path between CU1 and the mAB-DU becomes cross-topology: In the figure, CU1 and CU2 are respectively called F1-terminating CU and non-F1-terminating CU (or RRC terminating CU), and can also be called sourceCU and target CU. It should be noted that data does not pass through CU2 when transmitted on the cross-topology path. CU1 and Donor-DU2 communicate directly through the Internet protocol (IP) network.

[0083] 4) Continuous partial migration

[0084] Rel-18 (Release-18) further considers the large-scale mobility of IAB nodes. Therefore, based on partial migration, Rel-18 introduces continuous partial migration, such as Figure 5 As shown, the mAB-MT is switched from CU2 to CU3, and the F1 interface of the mAB-DU is always associated with CU1. Figure 5 In the figure, the mAB-node is directly connected to the donor-DU, but this is not limited. There may be other IAB nodes between the mAB-node and the donor-DU. In addition, regarding how the mAB-MT arrives at CU2, the mAB-MT may be switched from CU1 to CU2 (this is the case shown in the figure), but it may also be switched from other CUs to CU2 (which can be understood in conjunction with the DU migration scenario below).

[0085] 5) DU migration

[0086] Since Rel-18 considers the large-scale mobility of IAB nodes, when the mAB-node moves far away, the mAB-DU may find it difficult to maintain an IP connection with the original CU, or the transmission delay may be very large. Therefore, in order to support large-scale mobility, Rel-18 introduces an important feature, DU migration. Figure 6As shown, the RRC connection of mAB-MT is always on CU2, and the F1 interface of mAB-DU is migrated 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.

[0087] 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 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 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 the migration of mAB-DU is completely decoupled from the migration of mAB-MT is that the process of DU migration is relatively complicated (it is necessary to generate two logical DUs and switch the UEs to the new logical DUs one by one), and the mAB-DU should not be migrated frequently. The CU of the mAB-DU is preferably a CU with a larger control range; and the migration of the mAB-MT is the switching of the MT, which may be executed frequently. The selection of the CU of the mAB-MT is determined by the signal quality, and the CU of the mAB-MT may be different from the CU of the mAB-DU.

[0088] 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. Figure 6As shown in the figure, the CU of the mAB-MT is neither the source host nor the target host of the migration, and the mAB-MT does not know whether the TAC needs to be updated, which will result in the TAC that needs to be updated not being sent to the mAB-node in time, resulting in untimely TAC updates, and further resulting in the TAC broadcast by the mAB-DU not matching the current location. This will cause the 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 frequently execute TAU.

[0089] 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. A person of ordinary skill in the art can appreciate that with the evolution of the 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.

[0090] It can be understood that the present application does not particularly limit the specific structure of the execution subject of the method provided in the embodiment of the present application. It can 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.

[0091] In addition, in the following processes of the present application, the IAB node can be replaced by a mobile IAB node (mobile IAB or mIAB) description, or can be replaced by other types of relay node descriptions (such as layer 3 relays). 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 the present application are replaced by the gNB function part of the relay node, and the relevant expressions of CU are replaced by the host node of the relay node.

[0092] In one implementation, a source CU of a DU of an IAB node or a target CU of a DU of an IAB node or an MT of an IAB node sends a first message to a CU of an MT of an IAB node, wherein the first message requests first tracking area information. Through this method, the tracking area information of the DU of an IAB node can be updated in a timely manner, which will be described in detail below.

[0093] like Figure 7As shown, it is a flow chart of a communication method provided by an embodiment of the present application, in which 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 targetCU 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 (such as: judging that the DU migration of the IAB node is to be triggered or knowing that the DU migration of the IAB node is to be done). The method includes:

[0094] Step 701: The second CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0095] Step 701 is an optional step, and the present application can also be applied to the scenario where the DU does not migrate. If applied to the scenario where the DU does not migrate, step 701 may not be performed. If the DU does not migrate, the second CU refers to the CU connected to the DU, and there is no third CU in the scenario. The second CU directly performs step 702 according to the implementation.

[0096] 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 may 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.

[0097] 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.

[0098] If the DU of the 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 completed, the second CU releases the F1 interface with DU1.

[0099] This application Figures 7 to 14 In the example, the DU of the IAB node may include DU1 and DU2. If the DU of the IAB node does not migrate, then Figures 7 to 14 DU1 and DU2 in the protocol can be replaced by the DU of the IAB node.

[0100] Step 702: The second CU sends first information to the first CU.

[0101] 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.

[0102] 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, and the cell of the IAB node may refer to a cell under the DU of the IAB node.

[0103] If applied to the scenario of DU migration, the second CU is the source CU of the DU migration of the IAB node, and the third CU is the destination CU of the DU migration of the IAB node. If applied to the scenario of DU non-migration, the second CU is the CU to which the DU of the IAB node is currently connected, and there is an F1 interface between the second CU and the DU of the IAB node.

[0104] 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 (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.

[0105] In one implementation, the second CU sends an Xn message to the first CU, the Xn message including the first information. In the present application, the Xn message may also be replaced by an NG interface message, the NG interface message is forwarded by an access and mobility management function (AMF), and the specific process is not limited.

[0106] In one implementation, the first information or the Xn message includes at least one of the following:

[0107] 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 the present application, the cell provided by the IAB node may also be referred to as a cell of the IAB node;

[0108] The cell identifier under the DU of the IAB node is used for 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;

[0109] The identifier of the third CU is used for 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.

[0110] 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.

[0111] 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.

[0112] Step 703 is optional, and 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.

[0113] There may be multiple implementations of how the first CU sends the first tracking area information, which are described below respectively.

[0114] Implementation method 1: The first CU sends the first tracking area information to the third CU.

[0115] Step 704: The first CU sends the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information to the third CU.

[0116] If the first CU also receives the cell identifier under the DU of the IAB node, the cell identifier under the DU of the IAB node may also be sent 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] In one implementation, if the DU of the IAB node is migrated, the third CU may send the first tracking area information to the second logical DU of the IAB node.

[0121] 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.

[0122] Implementation method 2: The first CU sends the first tracking area information to the second CU.

[0123] Step 706: The first CU sends the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information to the second CU.

[0124] If the first CU also receives the cell identifier under the DU of the IAB node, the cell identifier under the DU of the IAB node may also be sent 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.

[0125] 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.

[0126] Step 707a: The second CU sends the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information, to the DU of the IAB node.

[0127] 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.

[0128] In one implementation, if the DU of the IAB node is migrated, the second CU may send the first tracking area information to the first logical DU of the IAB node.

[0129] 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. The first logical DU of the IAB node may send the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information to the second logical DU of the IAB node, and the specific process is not limited.

[0130] Step 707a may also be replaced by step 707b and step 707c.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] Implementation method three:

[0136] Step 708: The first CU sends the first tracking area information to the MT of the IAB node.

[0137] The first CU may also send a cell identity corresponding to the first tracking area information, that is, a cell identity under the DU of the IAB node, to the MT of the IAB node. When the first CU sends the cell identity, it may indicate that there is a corresponding relationship between the first tracking area information and the cell identity.

[0138] 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.

[0139] 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 the second logical DU of the IAB node through the interface between the DU of the IAB node.

[0140] 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, and this application does not limit this.

[0141] 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.

[0142] Through the method provided by 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 time, 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.

[0143] In the present application, the IAB node may also trigger the updating of the tracking area information of the DU of the IAB node, and the details may refer to the following process.

[0144] like Figure 8 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application. In the flow, step 801 and step 802 can be replaced by Figure 7 Step 701 and step 702 in Figure 7 The other steps in the method can be implemented in combination with step 801 and step 802.

[0145] Step 801: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0146] 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.

[0147] Step 801 is an optional step, and the present application can also be applied to the scenario where the DU does not migrate. If applied to the scenario where the DU does not migrate, step 801 may not be performed.

[0148] 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), and 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.

[0149] 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 may 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.

[0150] Step 802: The IAB node sends first information to the first CU.

[0151] 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 refer to the previous description.

[0152] Specifically, the MT of the IAB node may send the first information, wherein the MT of the IAB node does not switch or migrate.

[0153] In one implementation manner, the MT of the IAB node sends an RRC message to the first CU, where the RRC message includes the first information.

[0154] In one implementation, the first information includes at least one of the following:

[0155] Second tracking area information;

[0156] A cell identifier under the DU of the IAB node. If the DU of the IAB node is migrated, the cell identifier may be a cell identifier under the second logical DU of the IAB node;

[0157] an identifier of the second CU, used by the first CU to directly send the first tracking area information to the second CU, where the identifier of the second CU may include at least one of a gNB identifier and an IP address of the second CU;

[0158] The identifier of the third CU is used by the first CU to directly send the first tracking area information to the third CU.

[0159] Other processes may be included after step 802, such as steps 703 to 708, which will not be described in detail here.

[0160] In the above method, when the IAB node triggers the updating of the tracking area information of the DU of the IAB node, the Xn interface may not be used, so that the tracking area information of the DU can be updated in real time while reducing the Xn interaction.

[0161] 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, and the details may refer to the following process.

[0162] like Fig. 9 As shown, it is a flow chart of a communication method provided by an embodiment of the present application. In the flow, step 901 and step 902 can be replaced by Figure 7 Step 701 and step 702 in, or replace Figure 8 Step 801 and step 802 in Figure 7 The other steps in the process can be implemented in combination with step 901 and step 902.

[0163] Step 901: The third CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0164] 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 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.

[0165] 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, and 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.

[0166] Step 902: The third CU sends first information to the first CU.

[0167] 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 refer to the previous description.

[0168] 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 message requesting cross-topology traffic transmission.

[0169] In one implementation, the MT of the IAB node does not switch or migrate.

[0170] In one implementation, the first information includes at least one of the following:

[0171] Second tracking area information, for which the specific meaning may refer to the above description;

[0172] A cell identifier under the DU of the IAB node. If the DU of the IAB node is migrated, the cell identifier may be a cell identifier under the second logical DU of the IAB node;

[0173] The identifier of the second CU is used by the first CU to directly send the first tracking area information to the second CU;

[0174] The identifier of the third CU is used by the first CU to directly send the first tracking area information to the third CU.

[0175] Other processes may be included after step 902, such as steps 703 to 708, which will not be described in detail here.

[0176] In the present 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.

[0177] like Fig.10 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application, the method comprising:

[0178] Step 1001: Establish an Xn interface between the second CU or the third CU and the first CU.

[0179] 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 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 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).

[0180] 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. There is an F1 interface between the 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.

[0181] If the DU of the 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 completed, the second CU releases the F1 interface with DU1.

[0182] Step 1002: The second CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0183] For the specific content of step 1002, please refer to the description in step 701, which will not be repeated here.

[0184] Step 1002 is an optional step, and the present application can also be applied to the scenario where the DU does not migrate. If applied to the scenario where the DU does not migrate, step 1002 may not be performed.

[0185] In a possible implementation manner, 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.

[0186] Step 1003: The second CU sends second information to the first CU.

[0187] 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.

[0188] In the present application, the serving cell identifier refers to the cell identifier of the serving cell of the MT of the IAB node.

[0189] 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 (Application Protocol, AP) ID.

[0190] In one implementation, the second information includes at least one of the following:

[0191] 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;

[0192] 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.

[0193] The specific content of the first tracking area information can be found in Figure 7 The description of the process will not be repeated here.

[0194] 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.

[0195] Implementation method 1: The first CU sends the serving cell identifier to the second CU.

[0196] Step 1004: The first CU sends a serving cell identifier to the second CU.

[0197] In one implementation, the first CU may send an Xn message to the second CU, where the Xn message includes a serving cell identifier.

[0198] Step 1005a: The second CU sends third information to the DU of the IAB node.

[0199] The third information includes at least one of the following:

[0200] First tracking area information, the first tracking area information is determined according to the serving cell identifier;

[0201] 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 is migrated, the cell identifier may be the cell identifier under the second logical DU of the IAB node.

[0202] Since the second CU obtains at least one tracking area information included in the first CU and the cell identifier corresponding to each tracking area information 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.

[0203] 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.

[0204] 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.

[0205] 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.

[0206] The first logical DU of the IAB node may send the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information, to the second logical DU of the IAB node, and the specific process is not limited.

[0207] Step 1005a may also be replaced by step 1005b and step 1005c.

[0208] Step 1005b: The second CU sends third information or a serving cell identifier to the third CU.

[0209] 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.

[0210] Step 1005c: The third CU sends third information to the DU of the IAB node.

[0211] 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.

[0212] In one implementation, if the third CU obtains a serving cell identifier, the first tracking area information may be determined according to the serving cell identifier.

[0213] Implementation method 2: The first CU sends the serving cell identifier to the third CU.

[0214] Step 1006: The first CU sends a serving cell identifier to the third CU.

[0215] In one implementation, the first CU may send an Xn message to the third CU, where the Xn message includes a serving cell identifier.

[0216] Step 1007: The third CU sends third information to the DU of the IAB node.

[0217] The third information includes at least one of the following:

[0218] First tracking area information, the first tracking area information is determined according to the serving cell identifier;

[0219] The cell identifier corresponding to the first tracking area information is the identifier of the cell under the DU of the IAB node.

[0220] Since the third CU obtains at least one tracking area information included in the first CU and the cell identifier corresponding to each tracking area information 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.

[0221] 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.

[0222] 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.

[0223] 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, and this application does not limit this.

[0224] In the present application, the IAB node may also request the first CU to send a serving cell identifier, and specific details may refer to the following process.

[0225] like Fig.11 As shown, it is a flow chart of a communication method provided by an embodiment of the present application. In the flow, step 1101 and step 1102 can be replaced by Fig.10 Step 1002 and step 1003 in Fig.10 The other steps in the process can be implemented in combination with step 1101 and step 1102.

[0226] Step 1101: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0227] For the specific content of step 1101, please refer to the description in step 801, which will not be repeated here.

[0228] Step 1102: The IAB node sends second information to the first CU.

[0229] 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.

[0230] Specifically, the MT of the IAB node may send the second information, wherein the MT of the IAB node does not switch or migrate.

[0231] 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.

[0232] In one implementation, the second information or the RRC message includes at least one of the following:

[0233] The identifier of the second CU; the identifier of the third CU.

[0234] Step 1102 may include other processes, for details, please refer to Fig.10 The description of the process will not be repeated here.

[0235] In the present application, the third CU may also request a serving cell identifier, and specific details may refer to the following process.

[0236] like Fig.12 As shown, it is a schematic diagram of a communication method flow chart provided in an embodiment of the present application. In the flow chart, step 1201 and step 1202 can be replaced by Fig.10 Step 1002 and step 1003 in Fig.10 The other steps in the process can be implemented in combination with step 1201 and step 1202.

[0237] Step 1201: The third CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0238] The specific content of this step can be referred to the description in step 901 and will not be repeated here.

[0239] Step 1202: The third CU sends second information to the first CU.

[0240] 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.

[0241] Step 1202 may include other processes, for details, please refer to Fig.10 The description of the process will not be repeated here.

[0242] 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.

[0243] 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.

[0244] like Fig.13 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application, the method comprising:

[0245] Step 1301: Establish an Xn interface between the second CU or the third CU and the first CU.

[0246] The specific content of this step can refer to step 1001 and will not be described in detail.

[0247] Step 1302: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0248] For the specific content of step 1302, please refer to the description in step 801, which will not be repeated here.

[0249] Implementation method 1:

[0250] Step 1303: The IAB node sends a serving cell identifier to the second CU.

[0251] 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.

[0252] Step 1304a: The second CU sends third information to the DU of the IAB node, where the third information includes at least one of the following:

[0253] First tracking area information, the first tracking area information is determined according to the serving cell identifier;

[0254] The cell identifier corresponding to the first tracking area information is the identifier of the cell under the DU of the IAB node.

[0255] Since the second CU obtains at least one tracking area information included in the first CU and the cell identifier corresponding to each tracking area information 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.

[0256] 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.

[0257] The first logical DU of the IAB node may send the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information, to the second logical DU of the IAB node, and the specific process is not limited.

[0258] Step 1304a may also be replaced by step 1304b and step 1304c.

[0259] Step 1304b: The second CU sends third information or a serving cell identifier to the third CU.

[0260] Step 1304c: The third CU sends third information to the DU of the IAB node.

[0261] 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.

[0262] 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.

[0263] Implementation method 2:

[0264] Step 1305: The IAB node sends a serving cell identifier to the third CU.

[0265] 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 a serving cell identifier of the MT of the IAB node.

[0266] Step 1306: The third CU sends third information to the DU of the IAB node.

[0267] 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.

[0268] 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 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.

[0269] 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.

[0270] like Fig.14 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application, the method comprising:

[0271] Step 1401: The second CU determines to update the tracking area information of the DU of the IAB node.

[0272] Among them, before this step, the second CU, the third CU and the first CU establish an Xn interface with each other. 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.

[0273] 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. There is an F1 interface between the 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.

[0274] If the DU of the 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 completed, the second CU releases the F1 interface with DU1.

[0275] In one implementation, the second CU determines to update the tracking area information of the cell provided by the IAB node based on the identifiers 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.

[0276] 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 of 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 of 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.

[0277] Step 1402a: The second CU sends third information to the DU of the IAB node.

[0278] The third information includes at least one of the following information:

[0279] First tracking area information, where the first tracking area information is used to configure a tracking area of ​​a cell of the IAB node;

[0280] The cell identifier corresponding to the first tracking area information is the identifier of the cell under the DU of the IAB node.

[0281] 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, and the first tracking area information may be related to or match the current physical location of the IAB node.

[0282] In one implementation, the second CU sends an F1 message to the DU of the IAB node or the first logical DU, the F1 message including 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.

[0283] The first logical DU of the IAB node may send the first tracking area information, or the first tracking area information and a cell identifier corresponding to the first tracking area information, to the second logical DU of the IAB node, and the specific process is not limited.

[0284] Step 1402a may also be replaced by step 1402b and step 1402c.

[0285] Step 1402b: The second CU sends third information to the third CU.

[0286] 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.

[0287] Step 1402c: The third CU sends third information to the DU of the IAB node.

[0288] 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.

[0289] 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.

[0290] Steps 1401 to 1402a, or steps 1401 to 1402c may also be replaced by steps 1403 to 1404 in the following process:

[0291] Step 1403: The third CU determines to update the tracking area information of the DU of the IAB node.

[0292] Before this step, the second CU, the third CU and the first CU establish an Xn interface with each other. 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 ranges. The specific process of establishing the Xn interface is not limited in this application and will not be repeated here.

[0293] 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.

[0294] 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 of 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 of 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.

[0295] Step 1404: The third CU sends third information to the DU of the IAB node.

[0296] 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.

[0297] 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.

[0298] 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 time, and then the tracking area information broadcast by the DU of the IAB 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.

[0299] In the present application, in another possible implementation, since the CU to which the MT of the IAB node is connected remains unchanged in the 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, there is the following implementation:

[0300] Method 1: In DU migration, when the IAB node generates a new logical DU (i.e., DU2), the tracking area information of the cell under DU2 is made the same as the tracking area information of the cell under the original logical DU (i.e., DU1) of the IAB node (directly copy the tracking area information of the cell under DU1). For example, it can be applied to the scenario where all cells under one logical DU use the same tracking area information.

[0301] Method 2: In DU migration, when the IAB node generates a new logical DU (i.e., DU2), there is a corresponding relationship between the cells under DU2 and 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.

[0302] In the above method, in 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.

[0303] When sending downlink IP data packets, donor-CU can add differentiated services code point (DSCP) and / or flow label in the IP header to identify the QoS requirements of this IP packet. After the downlink IP packet reaches donor-DU, donor-DU will check the DSCP / Flow Label in the IP header and use it as an input parameter to send the data packet on the backhaul link and backhaul radio link control channel (RLC CH) that can meet the quality of service (QoS) requirements. In other words, DSCP / Flow Label is the information that the starting point CU of the downlink traffic needs to obtain. Before DU migration, CU1, as the source CU of the DU of the IAB node, knows the DSCP / Flow Label, and because CU1's traffic needs to pass through CU2 (the CU connected to the MT of the IAB node) topology, the DSCP / Flow Label is actually generated by CU2 and sent to CU1, and CU2 also knows the DSCP / Flow Label. After DU migration, CU3, as the target CU of DU, also needs to know DSCP / Flow Label. How CU3 obtains DSCP / Flow Label is an urgent problem to be solved. Therefore, this application provides a method that after the IAB node obtains DSCP / Flow Label from CU1 or CU2, it can inform CU3 through F1 message.

[0304] the following Fig.15 and Fig.16 In the process, the DU of the IAB node is migrated. The DU of the IAB node may include two logical DUs: DU1 (first logical DU) and DU2 (second logical DU). There is an F1 interface between the second CU and DU1, and there is an F1 interface between the third CU and DU2. When the DU migration of the IAB node is completed, the second CU releases the F1 interface with DU1.

[0305] like Fig.15 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application, the method comprising:

[0306] Step 1501: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0307] For the specific content of step 1501, please refer to the description in step 801, which will not be repeated here.

[0308] Step 1502: The IAB node sends a DU migration notification to the second CU.

[0309] The DU migration notification may include the identifier of the third CU.

[0310] Step 1501 and step 1502 may also be replaced by step 1503 .

[0311] Step 1503: The second CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0312] For the specific content of step 1501, please refer to the description in step 701, which will not be repeated here.

[0313] After step 1502 or step 1503 , the second CU may execute step 1504 .

[0314] Step 1504: The second CU sends the DSCP / Flow Label to the IAB node.

[0315] 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.

[0316] Step 1505: The IAB node sends the DSCP / Flow Label to the third CU.

[0317] In one implementation, the DU of the IAB node or the second logical DU (i.e., DU2 in the figure) sends an F1AP message to the third CU, and the F1AP message includes a DSCP / Flow Label. The IAB node may also send the IP address and / or backhaul link information index (BH Info Index) of the IAB node to the third CU to identify which IAB node IP address and / or backhaul link index the DSCP / Flow Label is associated with.

[0318] 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, and the specific process is not limited.

[0319] In another implementation, Fig.16 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application, the method comprising:

[0320] Step 1601: The IAB node determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0321] For the specific content of step 1601, please refer to the description in step 801, which will not be repeated here.

[0322] Step 1602: The IAB node sends a DU migration notification to the second CU.

[0323] The DU migration notification may include the identifier of the third CU.

[0324] Step 1601 and step 1602 may also be replaced by step 1603 and step 1604 .

[0325] Step 1603: The second CU determines that the DU of the IAB node is migrated from the second CU to the third CU.

[0326] For the specific content of step 1603, please refer to the description in step 701, which will not be repeated here.

[0327] Step 1604: The second CU sends a DU migration notification to the first CU.

[0328] The DU migration notification may include the identifier of the third CU.

[0329] After step 1602 or step 1604 , the first CU may execute step 1605 .

[0330] Step 1605: The first CU sends the DSCP / Flow Label to the IAB node.

[0331] In one implementation manner, the first CU sends an RRC message to the MT of the IAB node, where the RRC message includes DSCP / FlowLabel.

[0332] After the MT of the IAB node obtains the DSCP / Flow Label, the DSCP / Flow Label may be sent to the second logic DU (ie, DU2 in the figure) of the IAB node, and the specific process is not limited.

[0333] Step 1606: The IAB node sends the DSCP / Flow Label to the third CU.

[0334] 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.

[0335] The IAB node may also send the IP address of the IAB node and / or the backhaul link information index (BH InfoIndex) to the third CU to identify which IAB node IP address and / or which backhaul link index the DSCP / Flow Label is associated with.

[0336] pass Fig.15 or Fig.16 In the provided method, when no Xn interface is established between CUs, after the IAB node obtains the DSCP / Flow Label from the first CU or the second CU, it informs the third CU through an F1 message, so that the third CU can obtain the necessary parameters for traffic transmission while reducing Xn interaction, thereby improving system efficiency.

[0337] It is understandable 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. It should be easily appreciated by those skilled in the art that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0338] Fig.17 FIG. 1 is a schematic diagram showing the structure of a communication device provided in an embodiment of the present application. Fig.17 As shown, 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 the 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 respectively used to perform receiving and sending operations. 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 may be referred to as an input-output unit, a communication unit, etc., and the above-mentioned transceiver unit may be a transceiver; the above-mentioned processing unit may be a processor. When the communication device is a module (such as a chip) in a communication device, the above-mentioned transceiver unit may be an input-output interface, an input-output circuit or an input-output pin, etc., and may also be referred to as an interface, a communication interface or an interface circuit, etc.; the above-mentioned processing unit may be a processor, a processing circuit or a logic circuit, etc. Specifically, the communication device may be the above-mentioned first CU, second CU, third CU, IAB node, etc.

[0339] In one implementation, the communication device 1700 is used to implement the following functions:

[0340] A processing unit, configured to determine first information;

[0341] a transceiver unit, configured to send the first information to a first centralized unit CU;

[0342] 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.

[0343] In one implementation, the MT of the IAB node is not switched.

[0344] In one implementation, the transceiver unit is further used for:

[0345] 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;

[0346] 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.

[0347] 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.

[0348] In one implementation, the communication device 1700 is used to implement the following functions:

[0349] A transceiver unit, configured to receive 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; 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;

[0350] 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.

[0351] 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:

[0352] Determine, according to the second tracking area information, whether to update the tracking area information of the cell provided by the IAB node.

[0353] In one implementation, the communication device 1700 is used to implement the following functions:

[0354] a processing unit, configured to determine second information;

[0355] a transceiver unit, configured to send second information to the first centralized unit CU;

[0356] 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.

[0357] In one implementation, the communication device 1700 is used to implement the following functions:

[0358] A transceiver unit, configured to receive second information from a first node; the second information requests a service cell identifier of a mobile terminal MT accessing a backhaul integrated IAB node, the first node being 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;

[0359] A processing unit is used to send the serving cell identifier through the transceiver unit according to the second information.

[0360] In one implementation, the communication device 1700 is used to implement the following functions:

[0361] A transceiver unit, configured to send 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;

[0362] 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.

[0363] In one implementation, the communication device 1700 is used to implement the following functions:

[0364] A transceiver unit, configured to receive a service 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;

[0365] 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.

[0366] In one implementation, the communication device 1700 is used to implement the following functions:

[0367] 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;

[0368] The transceiver unit is configured to send third information, where the third information includes at least one of the following information:

[0369] first tracking area information, where the first tracking area information is used to configure a tracking area of ​​a cell of the IAB node;

[0370] 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.

[0371] A more detailed description of the processing unit 1710 and the transceiver unit 1720 can be directly obtained by referring to the relevant description in the method embodiments shown in the above processes, and will not be repeated here.

[0372] like Fig.18As shown, the communication device 1800 includes a processor 1810 and an interface circuit 1820. The processor 1810 and the interface circuit 1820 are coupled to each other. It is understood that the interface circuit 1820 can be a transceiver or an input-output interface. Optionally, the communication device 1800 may also include a memory 1830 for storing instructions executed by the processor 1810 or storing input data required by the processor 1810 to execute instructions or storing data generated after the processor 1810 executes instructions.

[0373] 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.

[0374] The present application also provides a communication system, which includes Figures 7 to 16 The first CU, the second CU, the third CU and the IAB node in any of the processes shown.

[0375] It is understandable that the processor in the embodiments of the present application may be a central processing unit (CPU), or 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.

[0376] 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 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 a component 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 be present in a base station or a terminal as discrete components.

[0377] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part 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 instruction is loaded and executed on a computer, the process or function described in the embodiment of the present application is executed 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 instruction may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer program or instruction may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired or wireless means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server, data center, etc. that integrates one or more available media. The available medium may be a magnetic medium, for example, a floppy disk, a hard disk, a tape; it may also be an optical medium, for example, a digital video disc; it may also be a semiconductor medium, for example, a solid-state hard disk. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0378] In the various embodiments of the present application, unless otherwise specified or provided for in any logical conflict, the terms and / or descriptions between the different embodiments are consistent and may be referenced to each other, and the technical features in the different embodiments may be combined to form new embodiments according to their inherent logical relationships.

[0379] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may 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 may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, optical storage, etc.) that contain computer-usable program code.

[0380] 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 process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart 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 generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0381] These computer program instructions may also be stored in a computer-readable memory capable of directing 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 an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0382] Obviously, those skilled in the art can 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 also 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; 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 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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