WO2023125274A1 - Communication method and related device - Google Patents

Abstract

The present application provides a communication method. The communication method comprises: a second node receives a third radio resource control (RRC) reconfiguration message from a centralized unit from a host node. The third RRC reconfiguration message comprises a new Internet protocol (IP) address of a third node. The second node acquires and starts a discard timer. When a first condition is satisfied and the discard timer times out, the second node discards the third RRC reconfiguration message. The first condition comprises that the second node does not receive a routing table reconfiguration message from the centralized unit of the host node or a second RRC reconfiguration message from a parent node. A parent node of the third node is the second node. By means of the current method, the occurrence of erroneous transmission network layer migration may be reduced, thereby ensuring the continuity of terminal service.

Description

A communication method and related equipment

This application claims the priority of a Chinese patent application filed with the Intellectual Property Office of the People's Republic of China on December 27, 2021, with application number 202111613555.X, and the title of the invention is "A communication method and related equipment", the entire content of which is incorporated by reference incorporated in this application.

technical field

The present application relates to the technical field of communication, and more specifically, to a communication method and related equipment.

Background technique

In existing relay networks, topology updates may occur on relay nodes. During the topology update process, if the transport network layer (TNL) migration of the upstream node has not been successful, then the transmission link of the upstream node on the target path has not been established yet. If the downstream node performs TNL migration in advance at this time, it may fail, thereby increasing the interruption delay of the terminal service served by the downstream node. Therefore, the migration node and its downstream nodes need to complete topology updates successively.

However, there is no technical solution on how to ensure that the migration node and its downstream nodes complete topology update successively in the prior art.

Contents of the invention

The present application provides a communication method, which can improve the efficiency of node topology update.

In the first aspect, a communication method is provided, including the second node receiving a third radio resource control RRC reconfiguration message from a centralized unit Donor-CU of the donor node, wherein the third RRC reconfiguration message includes the third node's New Internet Protocol IP address. The second node obtains the discard timer configuration. The second node starts the drop timer. If the first condition is met and the discard timer expires, the second node discards the third RRC reconfiguration message. Wherein, the first condition includes: the second node has not completed the routing table update, or the second node has not received the routing table reconfiguration message from the Donor-CU, or the second node has not received the routing table reconfiguration message from the parent CU. A second RRC reconfiguration message of the node, wherein the second RRC reconfiguration message includes the new IP address of the second node. The parent node of the third node is the second node.

Through the communication method provided in the first aspect, exemplary beneficial effects include: the situation that the third RRC reconfiguration message is always cached in the second node can be reduced, on the one hand, the storage burden of the second node is reduced, on the other hand, it can The situation that the second node mistakenly sends the third RRC reconfiguration message to the third node is reduced, causing the third node to mistakenly perform TNL relocation, thereby ensuring the continuity of terminal services served by the third node.

In a possible implementation manner, the acquiring the discard timer configuration by the second node includes: receiving, by the second node, the discard timer configuration from the Donor-CU. Or the second node determines the discard timer configuration by itself. Through this design, exemplary beneficial effects include: the Donor-CU is a centralized control node of the network, and can more accurately determine the configuration of the discarding timer.

In a possible implementation manner, the second node receiving the discard timer configuration from the Donor-CU includes: the second node receiving an F1 application protocol F1AP message from the Donor-CU, where the F1AP message includes the first Three RRC reconfiguration messages and the discard timer configuration.

Exemplarily, the timeout of the discarding timer includes that the working duration of the discarding timer exceeds a first duration.

In a possible implementation manner, the first duration is positively correlated with a first hop count, where the first hop count is a hop count between the second node and a first node, and the first node is a migration node. Through this design, exemplary beneficial effects include: by properly setting the timing length of the discard timer, the situation that the second node discards the third RRC reconfiguration message prematurely can be reduced. Because the routing table reconfiguration message and other configuration messages in the first condition are transmitted along the direction from the migrating node to the second node, the timer duration can be set for nodes with fewer hops to the migrating node The timer duration can be set shorter for the node with more transmission hops with the migration node.

Optionally, the discarding timer configuration includes the first duration.

In a possible implementation manner, when the first condition is not met and the discard timer has not expired, the second node sends the third RRC reconfiguration message to the third node.

Exemplarily, the second RRC reconfiguration message is used for the second node to perform transport network layer TNL relocation, and the third RRC reconfiguration message is used for the third node to perform TNL relocation.

In another possible implementation manner, the second node receives an F1AP message from the Donor-CU, where the F1AP message includes the third RRC reconfiguration message and a cache indication, where the cache indication is used to indicate that the second node Buffer the third RRC reconfiguration message.

Exemplarily, the first node, the second node and the third node are access and backhaul integrated IAB nodes.

In a second aspect, another communication method is provided, including the second node receiving a second radio resource control RRC reconfiguration message from a centralized unit Donor-CU of the donor node, wherein the second RRC reconfiguration message includes the second The new Internet Protocol IP address of the node. The second node obtains the discard timer configuration. The second node starts the drop timer. If the second condition is met and the discard timer expires, the second node discards the second RRC reconfiguration message. Wherein, the second condition includes: the second node has not completed the routing table update, or the second node has not received the routing table reconfiguration message from the Donor-CU, or the second node has not received the routing table reconfiguration message from the parent CU. A validation indication of the node, where the validation indication is used to instruct the second node to validate the second RRC reconfiguration message.

Through the communication method provided in the second aspect, exemplary beneficial effects include: the situation that the second RRC reconfiguration message is always cached in the second node can be reduced, on the one hand, the storage burden of the second node is reduced, on the other hand, it can The situation that the second node wrongly takes effect of the second RRC reconfiguration message and causes the second node to wrongly perform TNL relocation is reduced, thereby ensuring the continuity of the service of the terminal served by the second node.

In a possible implementation manner, the acquiring the discard timer configuration by the second node includes: receiving, by the second node, the discard timer configuration from the Donor-CU. Or the second node determines the discard timer configuration by itself.

In another possible implementation manner, receiving the discard timer configuration from the Donor-CU by the second node includes: the second RRC reconfiguration message includes the discard timer configuration.

Exemplarily, the timeout of the discarding timer includes that the working duration of the discarding timer exceeds a second duration.

Optionally, the second duration is positively correlated with the first hop number, where the first hop number is the hop number between the second node and the first node, and the first node is a migration node.

Optionally, the discarding timer configuration includes the second duration.

In another possible implementation manner, if the first condition is not met and the discard timer has not expired, the second node validates the second RRC reconfiguration message.

Exemplarily, the second RRC reconfiguration message is used for the second node to perform transport network layer TNL migration.

Optionally, the second RRC reconfiguration message includes a temporary non-validation indication, and the temporary non-validation indication is used to instruct the second node to temporarily not take effect of the second RRC reconfiguration message.

In a possible implementation manner, after the second node validates the second RRC reconfiguration message, the second node sends a validation indication to the third node, where the validation indication is used to instruct the third node to validate the third RRC reconfiguration message. A configuration message, the third RRC reconfiguration message is from the Donor-CU and is used for the third node to perform TNL relocation. Wherein, the third node is a child node of the second node.

Exemplarily, the first node, the second node and the third node are access and backhaul integrated IAB nodes.

In the third aspect, there is provided another communication method, including: the second node receives at least two third transmission network layer TNL migration related configurations from the centralized unit Donor-CU of the host node, wherein the at least two first Each third TNL migration-related configuration of the three TNL migration-related configurations includes the new Internet Protocol IP address of the third node, and the at least two third TNL migration-related configurations respectively correspond to at least two candidate target cells of the first node . The second node receives the second TNL migration-related configuration and first cell identity information from the first node, wherein the second TNL migration-related configuration includes the new IP address of the second node, and the first cell is the first cell A node determines candidate target cells for access. The second node determines the third TNL relocation related configuration to be sent from the at least two third TNL relocation related configurations according to the identification information of the first cell. The second node sends the to-be-sent third TNL migration related configuration to the third node. Wherein, the parent node of the third node is the second node, and the parent node of the second node is the first node.

Through the communication method provided in the second aspect, exemplary beneficial effects include: the first node and its downstream nodes can correctly send the pre-cached TNL migration-related configurations to their respective child nodes, so that each node can perform TNL migration correctly and efficiently .

In a possible implementation manner, the third TNL migration-related configuration corresponding to the candidate target cell of the same distributed unit Donor-DU belonging to the donor node includes the same new IP address of the third node.

In a fourth aspect, a communication method is provided, including: the first node receives a conditional handover configuration from a centralized unit Donor-CU of a donor node, the conditional handover configuration includes a handover trigger condition and information of at least two candidate target cells. The first node receives at least two second TNL migration-related configurations from the Donor-CU, wherein each of the at least two second TNL migration-related configurations includes a new Internet of the second node Protocol IP address, the at least two second TNL migration-related configurations respectively correspond to at least two candidate target cells of the first node. The first node determines to access the first cell according to the conditional handover configuration information, and the first cell is a candidate target cell that satisfies a handover triggering condition among the at least two candidate target cells. The first node determines to send the second TNL migration-related configuration corresponding to the first cell and the first cell information to the second node. Wherein, the parent node of the second node is the first node.

In a possible implementation manner, the second TNL migration-related configuration corresponding to the candidate target cell of the same Donor-DU belonging to the donor node includes the same new IP address of the second node.

In a fifth aspect, the present application provides a communication device, which includes a module for executing any method in the methods of the first aspect to the fourth aspect and any design thereof.

In a sixth aspect, the present application provides a communication device, including a processor and a memory, the processor is coupled to the memory, and the processor is used to implement any of the methods from the first aspect to the fourth aspect and any design thereof method.

In a seventh aspect, the present application provides a communication device, including at least one processor and an interface circuit, and the interface circuit is used to receive signals from other communication devices other than the communication device and transmit them to the processor or transfer signals from the processing The signal of the processor is sent to other communication devices other than the communication device, and the processor is used to implement any method in the methods of the first aspect to the fourth aspect and any design thereof through a logic circuit or executing code instructions.

In a possible design, the device may be a chip or an integrated circuit in a node in any one of the methods of the first aspect to the fourth aspect and any design thereof.

Optionally, the communication device may further include at least one memory, and the memory stores related program instructions.

In an eighth aspect, the present application provides a communication device, which has the function or operation of implementing any of the methods in the above-mentioned first to fourth aspects and methods in any design thereof, and the function or operation It can be realized by hardware, and it can also be realized by executing corresponding software by hardware. The hardware or software includes one or more units (modules) corresponding to the above functions or operations, such as a transceiver unit and a processing unit.

In a ninth aspect, the present application provides a computer-readable storage medium, in which related program instructions are stored, and when the related program instructions are executed, the communication device realizes the first aspect to the first aspect. Any of the four-way approach and any of its designs.

In a tenth aspect, the present application provides a computer program product, the computer program product includes related program instructions, when the related program instructions are executed, to realize the method of the first aspect to the fourth aspect and any design thereof any of the methods.

In an eleventh aspect, the present application further provides a chip, which is used to implement any method in the methods of the first aspect to the fourth aspect and any design thereof.

In a twelfth aspect, the present application provides a communication system, which includes at least one communication device in the fifth aspect to the eighth aspect and any design thereof.

Description of drawings

The solutions provided by the present application will be described in detail below in conjunction with the accompanying drawings. The features or contents marked with dotted lines in the accompanying drawings can be understood as optional operations or optional structures of the embodiments of the present application.

Fig. 1 is a schematic diagram of an IAB network communication system;

Fig. 2 is a schematic diagram of a control plane protocol stack in an IAB network;

Fig. 3 is a schematic diagram of a user plane protocol stack in an IAB network;

FIG. 4 is a schematic diagram of an applicable scenario provided by the embodiment of the present application;

Fig. 5 is a schematic flow chart of a method provided by the embodiment of the present application;

Fig. 6 is a schematic diagram of a communication method;

FIG. 7 is a schematic flow chart of a method provided in the embodiment of the present application;

Fig. 8 is a schematic diagram of a communication method;

FIG. 9 is a schematic diagram of an applicable scenario provided by the embodiment of the present application;

Fig. 10 is a schematic diagram of a communication method;

Fig. 11 is a schematic block diagram of a communication device provided by an embodiment of the present application;

Fig. 12 is a schematic block diagram of a device provided by an embodiment of the present application.

Detailed ways

FIG. 1 is a schematic diagram of an IAB network communication system provided by the present application. The communication system includes a terminal, an IAB node, and a host base station. In this application, "IAB network" is just an example, and may be replaced with "wireless backhaul network" or "relay network". "IAB node" is just an example, and can be replaced with "wireless backhaul device" or "relay node".

The donor base station (donor base station) can serve as the donor node of the IAB node. In this application, the host base station may include but not limited to: next generation base station (generation nodeB, gNB), evolved node B (evolved Node B, eNB), radio network controller (radio network controller, RNC), node B (Node B, NB), base station controller (base station controller, BSC), base transceiver station (base transceiver station, BTS), home base station (home evolved Node B or home Node B), transmission point (transmission and reception point or transmission point ), roadside unit (road side unit, RSU) with base station function, baseband unit (baseband unit, BBU), radio frequency remote unit (Remote Radio Unit, RRU), active antenna unit (active antenna unit, AAU), One or a group of antenna panels, or nodes with base station functions in subsequent evolution systems, etc. The host base station may be one entity, and may also include a centralized unit (centralized unit, CU) entity plus at least one distributed unit (distributed unit, DU) entity. Wherein, the interface between the CU and the DU may be referred to as an F1 interface. The two ends of the F1 interface are the CU and the DU. The opposite end of the F1 interface of the CU is the DU, and the opposite end of the F1 interface of the DU is the CU. The F1 interface may further include a control plane F1 interface (F1-C) and a user plane F1 interface (F1-U). In this application, the CU of the host base station may be referred to as Donor CU for short, and the DU of the host base station may be referred to as Donor DU for short.

In this application, a terminal is sometimes referred to as user equipment (user equipment, UE), mobile station, terminal equipment, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (Internet of Things) of things, IOT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. Terminals can be mobile phones, tablet computers, computers with wireless transceiver functions, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc. Terminals may include, but are not limited to: user equipment UE, mobile station, mobile device, terminal device, user agent, cellular phone, cordless phone, session initiation protocol (session initiation protocol, SIP) phone, wireless local loop (wireless local loop, WLL) station, personal digital assistant (PDA), handheld devices with wireless communication capabilities, computing devices, other processing devices connected to wireless modems, vehicle-mounted devices, wearable devices (such as smart watches, smart bracelets, Smart glasses, etc.), smart furniture or home appliances, vehicle equipment in vehicle to everything (V2X), terminal equipment with relay function, customer premises equipment (CPE), IAB nodes (specifically IAB The MT of the node or the IAB node as the terminal role), etc., the application does not limit the specific name and implementation form of the terminal.

In this application, the IAB node may include at least one mobile terminal (mobile terminal, MT) and at least one distributed unit DU (distributed unit, DU). An IAB node may be an entity, for example, the IAB node includes at least one MT function and at least one DU function. The IAB node may also include multiple entities, for example, the IAB node includes at least one MT entity and at least one DU entity. The MT entity and the DU entity can communicate with each other, for example, communicate with each other through a network cable. When an IAB node faces its parent node (the parent node may be a host base station or other IAB nodes), it can be used as a terminal, for example, in various scenarios where the above-mentioned terminal is applied, that is, the terminal role of the IAB node. In this case, it is the MT function or MT entity that provides the terminal role for the IAB node. When an IAB node faces its child nodes (the child nodes can be other IAB nodes or terminals), it can act as a network device, that is, the network device role of the IAB node. In this case, it is the DU function or DU entity that provides the network device role for the IAB node. In this application, the MT of the IAB node may be referred to as IAB-MT for short, and the DU of the IAB node may be referred to as IAB-DU for short. The IAB node can access the host base station, and can also connect to the host base station through other IAB nodes.

The IAB network supports multi-hop networking and multi-connection networking to ensure the reliability of service transmission. The IAB node regards the IAB node providing the backhaul service as a parent node, and accordingly, the IAB node can be regarded as a child node of its parent node. The terminal may also regard the IAB node which it accesses as a parent node, and correspondingly, the IAB node may also regard the terminal which it accesses as a child node. The IAB node may regard the host base station that it accesses as a parent node, and correspondingly, the host base station may also regard the IAB node that accesses itself as a child node. As shown in FIG. 1 , the parent node of the IAB node 1 includes a master base station. IAB node 1 is also the parent node of IAB node 2 or IAB node 3 . The parent node of terminal 1 includes IAB node 4 . The child nodes of IAB node 4 include terminal 1 or terminal 2 . The IAB node directly accessed by the terminal may be referred to as an access IAB node. The IAB node 4 in FIG. 1 is the access IAB node of the terminal 1 and the terminal 2 . The IAB node 5 is the access IAB node of the terminal 2 . The nodes on the uplink transmission path from the IAB node to the donor base station may be referred to as the upstream node (upstream node) of the IAB node. The upstream node may include a parent node, a parent node (or a grandparent node) of the parent node, and the like. For example, IAB node 1 and IAB node 2 in FIG. 1 may be referred to as upstream nodes of IAB node 5 . The nodes on the downlink transmission path from the IAB node to the terminal may be referred to as downstream nodes (downstream nodes) or descendant nodes (descendant nodes) of the IAB node. A downstream node or a descendant node may include a child node, a child node (or called a grandson node) of a child node, or a terminal. For example, terminal 1, terminal 2, IAB node 2, IAB node 3, IAB node 4 or IAB node 5 in FIG. 1 may be referred to as a downstream node or descendant node of IAB node 1. For another example, the IAB node 4 and the IAB node 5 in FIG. 1 may be referred to as downstream nodes or descendant nodes of the IAB node 2 . The terminal 1 in FIG. 1 may be referred to as a downstream node or a descendant node of the IAB node 4 . Each IAB node needs to maintain a backhaul link (BL) facing the parent node. If the child node of the IAB node is a terminal, the IAB node also needs to maintain an access link (access link, AL) with the terminal. As shown in FIG. 1, the link between the IAB node 4 and the terminal 1 or the terminal 2 includes an AL. A BL is included between IAB node 4 and IAB node 2 or IAB node 3 .

FIG. 2 and FIG. 3 are respectively a schematic diagram of a control plane protocol stack and a schematic diagram of a user plane protocol stack in an IAB network provided by an embodiment of the present application. The donor base station in Figure 2 and Figure 3 may include the functions of the host CU and the host DU (in this case, the host base station is one entity), or may include the host CU entity and the host DU entity (in this case, the host base station is divided into two entities). As shown in Figure 2 or Figure 3, the peer-to-peer protocol layers between the host DU and the host CU include the IP layer, layer 2 (layer 2, L2), and layer 1 (layer 1, L1). Wherein, L1 and L2 may refer to protocol stack layers in a wired transmission (such as optical fiber transmission) network. For example, L1 may be the physical layer, and L2 may be the data link layer. Backhaul links (BL) are established between the IAB node 4 and the IAB node 3, between the IAB node 3 and the IAB node 1, and between the IAB node 1 and the host DU. The peer-to-peer protocol stack at both ends of the BL may include a backhaul adaptation protocol (BAP) layer, a radio link control (radio link control, RLC), a medium access control (medium access control, MAC) layer, and Physical (PHY) layer.

As shown in Figure 2, there is an interface between the terminal and the host base station, which is sometimes called an air interface. For example, it can be called Uu interface. One end of the Uu interface is located at the terminal, and the other end is located at the host base station. The peer-to-peer control plane protocol stack at both ends of the Uu interface includes a radio resource control (radio resource control, RRC) layer, a packet data convergence protocol (PDCP) layer, an RLC layer, a MAC layer, and a PHY layer. The protocol layer included in the Uu interface control plane protocol stack may also be called the access stratum (AS) of the control plane. If the host base station includes a host CU entity and a host DU entity, the control plane protocol stack of the Uu interface at the host base station side can be respectively located in the host DU and the host CU. For example, the PHY layer, the MAC layer and the RLC layer are located in the host DU, and the RRC layer and the PDCP layer are located in the host CU.

There is an interface between the DU of the IAB node that the terminal accesses (that is, the IAB node 4 in FIG. 2 ) and the host base station, for example, it is called an F1 interface. One end of the F1 interface is located at the IAB node 4, and the other end is located at the host base station. The opposite end of the F1 interface of the host base station (for example, it may be the host CU) is the IAB node (specifically, it may be the DU of the IAB node), and the opposite end of the F1 interface of the IAB node (specifically, it may be the DU of the IAB node) is the host base station (specifically, it may be the DU of the IAB node). can be the host CU). The peer-to-peer control plane protocol stack at both ends of the F1 interface includes the F1 application protocol (F1application protocol, F1AP) layer, the stream control transmission protocol (stream control transmission protocol, SCTP) layer and the IP layer, optionally including the Internet security protocol (internet protocol) security, IPsec) layer. The host base station may include a host CU entity and a host DU entity. The control plane protocol stack of the F1 interface at the end of the host base station may be located in the host CU. For example, the host CU includes an F1AP layer, an SCTP layer, and an IP layer, and optionally includes an IPsec layer. The control plane protocol stack of the F1 interface at the end of the host base station can also be respectively located in the host CU and the host DU. For example, the host CU includes the F1AP layer and the SCTP layer, and optionally includes the IPsec layer, and the host DU includes the IP layer.

As shown in Figure 3, the user plane protocol stacks at both ends of the Uu interface between the terminal and the host base station are equivalent, including a service data adaptation protocol (service data adaptation protocol, SDAP) layer, a PDCP layer, an RLC layer, a MAC layer, and PHY layer. The protocol layer included in the Uu interface user plane protocol stack may also be referred to as the access layer (AS) of the user plane. If the host base station includes a host CU entity and a host DU entity, the user plane protocol stack of the Uu interface at the end of the host base station may be respectively located in the host DU and the host CU. For example, the PHY layer, the MAC layer and the RLC layer are located in the host DU, and the SDAP layer and the PDCP layer are located in the host CU.

The peer-to-peer user plane protocol layers at both ends of the F1 interface between the DU of IAB node 4 and the host base station include the general packet radio service user plane tunneling protocol (general packet radio service tunneling protocol for the user plane, GTP-U) layer. A datagram protocol (user datagram protocol, UDP) layer and an IP layer, optionally including an IPsec layer. The host base station may include a host CU entity and a host DU entity. The user plane protocol stack of the F1 interface at the end of the host base station may be located in the host CU. For example, the host CU includes a GTP-U layer, a UDP layer, and an IP layer, and optionally includes an IPsec layer. The user plane protocol stack of the F1 interface at the end of the host base station can also be respectively located in the host CU and the host DU. For example, the host CU includes the GTP-U layer and the UDP layer, and optionally includes the IPsec layer, and the host DU includes the IP layer.

In addition, in FIG. 2 and FIG. 3 , when a terminal accesses the host DU, the interface between the host DU and the host CU may also include an F1 interface. The peer-to-peer control plane protocol stacks at both ends of the F1 interface include an F1AP layer, an SCTP layer and an IP layer. The peer-to-peer user plane protocol stacks at both ends of the F1 interface include a GTP-U layer, a UDP layer, and an IP layer. When a terminal accesses the IAB node 1 or IAB node 3, an F1 interface may also be included between the IAB node 1 or IAB node 3 and the host base station, and the description of the F1 interface may refer to the above-mentioned DU of the IAB node 4 and the host base station Description of the interface between F1.

When the terminal refers to the MT function or MT entity of the IAB node, or the IAB node as the terminal role, the protocol stack of the terminal shown in Figure 2 or Figure 3 is the protocol stack of the MT function or MT entity of an IAB node , or the protocol stack when an IAB node acts as a terminal.

When an IAB node accesses the IAB network, it can act as a terminal. In this case, the MT of the IAB node has the protocol stack of the terminal. There is an air interface (Uu interface) protocol stack between the IAB node and the host base station. The protocol stack of the terminal as shown in Fig. 2 and Fig. 3 includes RRC layer or SDAP layer, PDCP layer, RLC layer, MAC layer and PHY layer. Wherein, on the control plane, the RRC message of the IAB node is encapsulated in the F1AP message by the parent node of the IAB node for transmission. On the user plane, the data packet of the IAB node is encapsulated in a PDCP protocol data unit (protocol data unit, PDU) and sent to the parent node of the IAB node, and the parent node of the IAB node encapsulates the received PDCP PDU in the parent node of the IAB node. Transmitted in the GTP-U tunnel on the F1 interface between the node and the host CU. In addition, after the IAB node is connected to the IAB network, the IAB node can still act as an ordinary terminal. For example, the IAB node can transmit its own data packets with the host base station, such as operating, managing and maintaining network elements (operation, administration and maintenance, OAM) data packets, measurement reports, etc.

It should be noted that an IAB node may have one or more roles in the IAB network. For example, the IAB node can be used as a terminal role, or as an access IAB node role (such as the protocol stack of IAB node 4 in Figure 2 and Figure 3 ) or an intermediate IAB node role (such as the IAB node role in Figure 2 and Figure 3 ). protocol stack of node 1 or IAB node 3). The IAB node can use protocol stacks corresponding to different roles for different roles. When the IAB node has multiple roles in the IAB network, it can have multiple sets of protocol stacks at the same time. Various sets of protocol stacks may share some same protocol layers, such as sharing the same RLC layer, MAC layer, and PHY layer.

As shown in Figure 4, IAB node 1 is connected to the source Donor-DU through a one-hop wireless backhaul link (or through the source parent node IAB node 4) before the topology update, and IAB node 1 is connected to the source Donor-DU through a one-hop wireless backhaul link after the topology update. The backhaul link (or through the target parent node IAB node 5) is connected to the target Donor-DU. It should be noted that the IAB node 1 whose parent node has been replaced may have other child nodes (for example, the child node connected to the IAB node 1 is IAB node 2), or the IAB node 1 whose parent node has been replaced may have other child nodes A node's secondary child nodes (for example IAB node 3 connected to the secondary child node of IAB node 2). Other IAB nodes or terminals can also be connected behind the secondary child nodes. FIG. 4 is only a schematic diagram of IAB node 1 performing topology update inside the host, and there may be other situations. For example, IAB node 1 in Figure 4 can be directly connected to the source Donor-DU before the topology update (or in other words, the source Donor-DU can be connected without going through the IAB node 4), and/or, the IAB node 1 can be connected to the source Donor-DU after the topology update It may be directly connected to the target Donor-DU (or in other words, the target Donor-DU can be connected without going through the IAB node 5).

Considering that the IP address of the IAB node is related to the Donor-DU it is connected to (for example, the IP address of the IAB node needs to belong to the same network segment or have the same network prefix as the IP address of the Donor-DU it is connected to), in Figure 4 In the topology update example shown, if the Donor-DU connected to the IAB node changes after the topology update, the IAB node needs to obtain a new IP address, and use the new IP address to communicate with the Donor-CU (specifically, it can be Donor-CU- CP) establishes a new TNL association (association), and then uses the new TNL association to transmit the control plane message of the F1 interface between the IAB node and the Donor-CU (that is, the F1AP message, such as the gNB-DU CONFIGURATION UPDATE message), in After the F1AP message can be transmitted between the IAB node and the Donor-CU through the updated new path, the Donor-CU can use the F1AP message to send a routing table reconfiguration message to the IAB node. In this application, TNL may include any of the following: SCTP, UDP, IP. In this application, the new IP address of the IAB node that needs to update the topology can be obtained from OAM, or by executing the Dynamic Host Configuration Protocol (DHCP), or obtained by the Donor IP address connected after the topology update. -DU allocation.

In this way, in the mobile scenario where the IAB node does not change the IAB host, the TNL association information of the F1-C signaling between the CU bearing the IAB host and the IAB node can be updated without re-establishing the F1 connection.

The above topology update can be applied to IAB host internal switching, or donor CU internal switching (intra-donor CU migrating) scenarios, and can also be applied to link recovery or RRC connection after radio link failure (RLF) Restore the scene. That is to say, "topology update" in this application can be replaced with "handover", "RLF recovery" or "RRC connection recovery".

A migration (migration) process of the IAB node in the topology update within the host node will be described below with reference to the schematic flowchart of the communication method provided in FIG. 5 .

The Donor-CU carries the RRC reconfiguration message 3 in the F1AP message 1 and sends it to the IAB node 2 (specifically, it may be the DU2 of the IAB node 2). The Donor-CU carries the RRC reconfiguration message 2 in the F1AP message 2 and sends it to the IAB node 1 (specifically, it may be the DU1 of the IAB node 1). The Donor-CU sends the RRC reconfiguration message 1 to the IAB node 1 (specifically, it may be the MT1 of the IAB node 1). The above F1AP message 1, F1AP message 2 and RRC reconfiguration message 1 are all sent by the Donor-CU through the source path (or through the source Donor-DU and the source parent node).

The IAB node 1 (specifically, MT1 of the IAB node 1) initiates random access to the target parent node according to the random access related configuration included in the RRC reconfiguration message 1 . After IAB node 1 successfully randomly accesses the target parent node, IAB node 1 (specifically, DU1 of IAB node 1) migrates related configurations according to the transport network layer (TNL) included in the RRC reconfiguration message 1 , perform TNL migration through the target path (or in other words, through the target Donor-DU and the target parent node). After TNL migration, IAB nodes can also perform F1 interface migration. In this way, the Donor-CU can send the F1AP message 3 carrying the routing table reconfiguration information to the IAB node 1 through the F1 interface. The IAB node 1 can use the routing table reconfiguration information to update its own routing table (routing table), so as to subsequently route data to the Donor-CU through the target path.

In this application, random access-related configurations may include any of the following: handover command, synchronous reconfiguration cell (Reconfiguration with Sync), mobility control cell (Mobility Control Information), random access channel (random access channel, RACH ) configuration, used to instruct IAB node 1 to switch to the cell served by the target Donor-DU2 (the cell may be specifically provided by the target parent node), and the IAB node 1 (specifically may be MT1 of IAB node 1) and the target parent node perform random Access needs to be configured (such as dedicated time-frequency resources, preamble, etc.), cell identification information of the target cell, and the cell radio network temporary identifier (C-RNTI) assigned by the target cell to the IAB node .

In this application, the configuration related to TNL migration may include the new IP address of the IAB node. For example, the TNL migration-related configuration included in the RRC reconfiguration message 1 may include the new IP address of the IAB node 1 . The TNL migration-related configuration included in the RRC reconfiguration message 2 may include the new IP address of the IAB node 2 . The TNL migration-related configuration included in the RRC reconfiguration message 3 may include the new IP address of the IAB node 3 .

In this application, TNL migration may include using the new IP address of the IAB node to establish a new transport network layer association (TNLA) with the Donor-CU. The TNL migration may also include using the new IP address of the IAB node to establish a new TNLA with the Donor-CU to re-negotiate IPSec security.

Migration of the F1 interface may include that the IAB node migrates the F1 interface (such as the F1-C connection or the GTP-U tunnel of the F1-U) to the target path by using the newly created TNLA. It should be noted that since the Donor-CU accessed by the IAB node does not change before and after the topology update, there is no need to re-establish the F1 interface between the IAB node (or IAB-DU) and the host node. If the IP address of the IAB node (or IAB-DU) changes before and after the topology update, it is only necessary to update the IP address or the transport network layer address of the corresponding F1-C/F1*-C and F1-U/F1*-U connections. Can.

After IAB node 1 (specifically, it can be MT1 of IAB node 1) successfully randomly accesses the target parent node and completes routing table update, IAB node 1 can send RRC reconfiguration message 2 to IAB node 2 (specifically, it can be IAB node 2 MT2).

The IAB node 2 (specifically, it may be the DU2 of the IAB node 2) can also perform TNL migration and subsequent F1 interface migration according to the TNL migration-related configuration included in the RRC reconfiguration message 2 .

The IAB node 2 may send the RRC reconfiguration message 3 to the IAB node 3 when the following conditions are met:

Condition 1: IAB node 2 finishes updating the routing table.

Condition 2: IAB node 2 receives the routing table reconfiguration message from Donor-CU.

Condition 3: IAB node 2 receives RRC reconfiguration message 2 from IAB node 1 .

The IAB node 3 (specifically, the DU3 of the IAB node 3) can also perform TNL migration and subsequent F1 interface migration according to the TNL migration-related configuration included in the RRC reconfiguration message 3 .

In FIG. 5, the IAB node 3 is directly connected to the terminal as an example. Of course, the IAB node 3 may have other IAB child nodes, and the TNL migration and F1 interface migration of the child nodes of the IAB node 3 can be understood with reference to the embodiment of the present application.

In the embodiment shown in FIG. 5 , the F1AP message 1 carrying the RRC reconfiguration message 3 includes a cache indication 1, and the cache indication 1 is used to instruct the IAB node 2 to cache the RRC reconfiguration message 3 or not send the RRC reconfiguration message 3 to the IAB temporarily. Node 3 sends the RRC reconfiguration message 3 . The F1AP message 2 carrying the RRC reconfiguration message 2 includes a cache indication 2, and the cache indication 2 is used to instruct the IAB node 1 to cache the RRC reconfiguration message 2 or not to send the RRC reconfiguration message 2 to the IAB node 2 temporarily.

In the embodiment shown in FIG. 5 , F1AP message 1 of RRC reconfiguration message 3 includes cache indication 1 . The F1AP message 2 carrying the RRC reconfiguration message 2 includes the cache indication 2 . Alternatively, in the embodiment shown in FIG. 5 , the RRC reconfiguration message 3 includes the cache indication 1 . The RRC reconfiguration message 2 includes a cache indication 2 . Wherein, the cache indication 1 is used to instruct the IAB node 2 to cache the RRC reconfiguration message 3 or not to send the RRC reconfiguration message 3 to the IAB node 3 temporarily. The cache indication 2 is used to instruct the IAB node 1 to cache the RRC reconfiguration message 2 or not to send the RRC reconfiguration message 2 to the IAB node 2 temporarily.

In the embodiment shown in FIG. 5 , the IAB node 1 may also fail to update the topology. In this application, the topology update failure may include any of the following: random access failure, TNL relocation failure, and F1 interface relocation failure. Once the IAB node 1 topology update fails, the RRC reconfiguration message 1, RRC reconfiguration message 2, and RRC reconfiguration message 3 will all be invalid. Since the IAB node 1 can determine that the topology update fails, the IAB node 1 can discard the RRC reconfiguration message 1 and the RRC reconfiguration message 2 in time. However, since the IAB node 2 cannot perceive that the topology update failure of the IAB node 1 occurs, it cannot be determined whether the RRC reconfiguration message 3 should be discarded. If the RRC reconfiguration message 3 is always cached in the IAB node 2, on the one hand, the storage burden of the IAB node 2 will be increased; on the other hand, the subsequent IAB node 2 may mistakenly send the RRC reconfiguration message 3 to the IAB node 3, further As a result, the IAB node 3 performs TNL migration by mistake, thereby affecting the continuity of services served by the IAB node 3 . Exemplarily, it is assumed that the IAB node 2 sends the RRC reconfiguration message 3 to the IAB node 3 when the condition 1 is met (the IAB node 2 finishes updating the routing table). Then, after IAB node 1 fails to update the topology, in the process of Donor-CU updating the backhaul routing configuration of IAB node 2, IAB node 2 may also update the routing table, thus satisfying condition 1. This will cause the IAB node 2 to send the RRC reconfiguration message 3 to the IAB node 3 by mistake, thus causing the IAB node 3 as a downstream node to start the TNL migration before the IAB node 1 and the IAB node 2 have completed the TNL migration. TNL migration. Since the TNL migration of the upstream node has not been successful, and the transmission link of the upstream node on the target path has not yet been established, this early TNL migration of IAB node 3 may fail, thereby increasing the terminal business served by IAB node 3 interrupt delay.

The solution provided by the present application will be further described based on the aforementioned communication architecture and communication scenarios with reference to the schematic flowchart of the communication method provided in FIG. 6 . The second node, the third node, the first Donor DU, the second Donor DU, and the Donor CU in this application can refer to IAB node 2, IAB node 3, source Donor-DU, and target in Figure 4 or Figure 5 respectively Donor-DU, Donor-CU. Wherein, the first node is a migration node. In this application, the "migration node" may refer to the node that needs to update the topology first, such as the IAB node 1 in FIG. 4 or FIG. 5 . Certainly, the parent node of the IAB node 2 in FIG. 4 or FIG. 5 happens to be a migration node, but this does not constitute a limitation to this embodiment of the present application. In this application, the parent node of the second node may or may not be the first node, that is to say, the second node may be connected to the first node through at least one node.

FIG. 6 provides a schematic flowchart of a communication method 100 .

S101: The second node receives a third RRC reconfiguration message from the Donor-CU.

The third RRC reconfiguration message includes the new IP address of the third node. Specifically, the third RRC reconfiguration message may be used for the third node to perform TNL relocation, that is, include configuration related to TNL relocation.

Exemplarily, the DU part of the second node receives the F1AP message from the Donor-CU, and the F1AP message includes the third RRC reconfiguration message.

S102: The second node acquires a discard timer (discard timer) configuration.

The method for the second node to obtain the discard timer configuration may include any of the following situations: the second node receives the discard timer configuration from the Donor-CU; or the second node determines the discard timer configuration by itself.

Specifically, the second node receives the F1AP message from the Donor-CU, where the F1AP message includes the third RRC reconfiguration message and the discard timer configuration. Optionally, the third RRC reconfiguration message includes the discard timer configuration.

S103: The second node starts the discard timer.

S104: When the first condition is met and the discard timer expires, the second node discards the third RRC reconfiguration message.

The first condition includes at least one of the following situations: the second node has not completed the routing table update; or, the second node has not received the routing table reconfiguration message from the Donor-CU; or, the second node has not received to the second RRC reconfiguration message from the parent node. The second RRC reconfiguration message may include the new IP address of the second node. Specifically, the second RRC reconfiguration message may be used for the second node to perform TNL relocation, that is, include configuration related to TNL relocation.

Exemplarily, when the first condition includes that the second node has not received the routing table reconfiguration message from the Donor-CU and the second node has not received the second RRC reconfiguration message from the parent node, once the second When the node determines that it has neither received the routing table reconfiguration message from the Donor-CU nor the second RRC reconfiguration message from the first node when the discard timer expires, the second node The third RRC reconfiguration message will be discarded.

In this application, "discard" can be replaced with "empty" or "delete".

Wherein, the discarding timer configuration includes the first duration. The timeout of the discarding timer includes that the working duration of the discarding timer exceeds the first duration. The first duration is positively correlated with the first hop number, wherein the first hop number is the hop number between the second node and the first node. For example, the first node and the second node are connected through N nodes, then the number of hops between the first node and the second node is N+1, where N is an integer. Alternatively, the first duration is positively correlated with the first number of nodes, where the first number of nodes is the number of nodes separated between the second node and the first node. For example, the first node and the second node are connected by M nodes, then the number of first nodes is M, where M is an integer.

In this application, "timer" can be replaced with "counter", and "first duration" can be replaced with "first value". That is to say, "the timer expires" can be equivalent to "the counter reaches the first value".

Optionally, the foregoing embodiment may further include operation S105.

S105: When the first condition is not satisfied and the discard timer has not expired, the second node sends the third RRC reconfiguration message to the third node.

The above S102-S105 can be replaced by S106, thus forming a new embodiment.

S106: The second node receives a first message from the Donor-CU, where the first message instructs the second node to discard the third RRC reconfiguration message.

The first message may be an F1AP message.

Since the Donor-CU can learn whether the topology update of the first node fails, it can send the first message to the second node when it is determined that the topology update of the first node fails, so that the second node can discard the failed first node in time. Three RRC reconfiguration messages.

The method provided by the above embodiment can reduce the situation that the third RRC reconfiguration message is always cached in the second node. On the one hand, it reduces the storage burden of the second node; The fact that the three nodes send the third RRC reconfiguration message causes the third node to perform TNL migration by mistake, thereby ensuring the continuity of the service of the terminal served by the third node.

The following describes another migration process of the IAB node in the topology update within the host node in conjunction with the flow diagram of the communication method provided in FIG. 7 .

The Donor-CU sends the RRC reconfiguration message 1 to the IAB node 1 (specifically, it may be the MT1 of the IAB node 1). The Donor-CU sends the RRC reconfiguration message 2 to the IAB node 2 (specifically, it may be the MT2 of the IAB node 2). The Donor-CU sends the RRC reconfiguration message 3 to the IAB node 3 (specifically, it may be the MT3 of the IAB node 3). The above RRC reconfiguration message 1, RRC reconfiguration message 2 and RRC reconfiguration message 3 are all sent by the Donor-CU through the source path (or through the source Donor-DU and the source parent node). When the RRC reconfiguration message 1 is transmitted between the source parent node and the host node, it may be encapsulated in the F1AP message between the source parent node and the host node. When the RRC reconfiguration message 2 is transmitted between the IAB node 1 and the host node, it may be encapsulated in the F1AP message between the IAB node 1 and the host node. When the RRC reconfiguration message 3 is transmitted between the IAB node 2 and the host node, it may be encapsulated in the F1AP message between the IAB node 2 and the host node.

The IAB node 1 (specifically, MT1 of the IAB node 1) initiates random access to the target parent node according to the random access related configuration included in the RRC reconfiguration message 1 . After IAB node 1 successfully randomly accesses the target parent node, IAB node 1 (specifically, DU1 of IAB node 1) migrates related configurations according to the transport network layer (TNL) included in the RRC reconfiguration message 1 , perform TNL migration through the target path (or in other words, through the target Donor-DU and the target parent node). After TNL migration, IAB nodes can also perform F1 interface migration. In this way, the Donor-CU can send the F1AP message carrying the routing table reconfiguration information to the IAB node 1 through the F1 interface. The IAB node 1 can use the routing table reconfiguration information to update its own routing table (routing table), so as to subsequently route data to the Donor-CU through the target path.

After IAB node 1 (specifically, MT1 of IAB node 1) successfully randomly accesses the target parent node and completes routing table update, IAB node 1 can send validation indication 1 to IAB node 2 (specifically, MT2 of IAB node 2) , the validation indication 1 is used to instruct the IAB node 2 to validate the RRC reconfiguration message 2 .

The IAB node 2 (specifically, it may be the DU2 of the IAB node 2) can also perform TNL migration and subsequent F1 interface migration according to the TNL migration-related configuration included in the RRC reconfiguration message 2 .

The IAB node 2 may send the validation indication 2 to the IAB node 3 when the following conditions are met, and the validation indication 2 is used to instruct the IAB node 3 to validate the RRC reconfiguration message 3:

Condition 1: IAB node 2 finishes updating the routing table.

Condition 2: IAB node 2 receives the routing table reconfiguration message from Donor-CU.

Condition 3: IAB node 2 receives validation indication 1 from IAB node 1 .

The IAB node 3 (specifically, the DU3 of the IAB node 3) can also perform TNL migration and subsequent F1 interface migration according to the TNL migration-related configuration included in the RRC reconfiguration message 3 .

In FIG. 7, the IAB node 3 is directly connected to the terminal as an example. Of course, the IAB node 3 may have other IAB child nodes, and the TNL migration and F1 interface migration of the child nodes of the IAB node 3 can be understood with reference to the embodiment of the present application.

In the embodiment shown in FIG. 7 , the RRC reconfiguration message 2 includes a temporarily invalid indication 1 . The RRC reconfiguration message 3 includes a temporarily inactive indication 2 . Alternatively, the temporary non-validation indication 1 and the temporary non-validation indication 2 are carried in a separate/other RRC reconfiguration message or F1AP message. Wherein, the temporarily not valid indication 1 is used to indicate that the RRC reconfiguration message 1 is temporarily not valid/suspend (suspend). The temporarily not valid indication 2 is used to indicate that the RRC reconfiguration message 3 is temporarily not valid/suspend (suspend). The RRC reconfiguration in the pending state, the configuration content is retained, but the packet processing rules corresponding to these configurations are in the invalid state, and the IAB node will not use any rules corresponding to the pending RRC reconfiguration to process the packets to be sent or received packets. Suspended refers to temporarily not using or not taking effect temporarily.

In the embodiment shown in FIG. 7 , the IAB node 1 may also fail to update the topology. Once the IAB node 1 topology update fails, the RRC reconfiguration message 1, RRC reconfiguration message 2, and RRC reconfiguration message 3 will all be invalid. Then also because the IAB node 3 cannot perceive that the topology update failure of the IAB node 1 occurs, it cannot determine whether the RRC reconfiguration message 3 should be discarded. If the RRC reconfiguration message 3 is always cached in the IAB node 3, on the one hand, the storage burden of the IAB node 3 will be increased. On the other hand, the follow-up IAB node 2 may mistakenly send the validation instruction 2 to the IAB node 3, resulting in the wrong effective RRC reconfiguration message 3 of the IAB node 3, which further causes the IAB node 3 to perform TNL migration by mistake, thus affecting the IAB node 3 Continuity of business served. Exemplarily, it is assumed that IAB node 2 sends validation instruction 2 to IAB node 3 when condition 1 is satisfied (IAB node 2 finishes updating the routing table). Then, after IAB node 1 fails to update the topology, in the process of Donor-CU updating the backhaul routing configuration of IAB node 2, IAB node 2 may also update the routing table, thus satisfying condition 1. This will cause IAB node 2 to incorrectly send an effective indication 2 to IAB node 3, causing IAB node 3 to incorrectly issue an effective RRC reconfiguration message 3, resulting in that when IAB node 1 and IAB node 2 have not completed the TNL migration, The IAB node 3 as the downstream node starts to perform TNL migration. Since the TNL migration of the upstream node has not been successful, and the transmission link of the upstream node on the target path has not yet been established, this early TNL migration of IAB node 3 may fail, thereby increasing the terminal business served by IAB node 3 interrupt delay.

The solution provided by the present application will be further described based on the aforementioned communication architecture and communication scenarios with reference to the schematic flowchart of the communication method 200 provided in FIG. 8 . The second node, the third node, the first Donor DU, the second Donor DU, and the Donor CU in this application can refer to IAB node 2, IAB node 3, source Donor-DU, and target in Figure 4 or Figure 7 respectively Donor-DU, Donor-CU. Wherein, the first node is a migration node. In this application, the "migration node" may refer to the node that needs to update the topology first, such as the IAB node 1 in FIG. 4 or FIG. 7 . Certainly, the parent node of the IAB node 2 in FIG. 4 or FIG. 7 happens to be a migration node, but this does not constitute a limitation to this embodiment of the present application. In this application, the parent node of the second node may or may not be the first node, that is to say, the second node may be connected to the first node through at least one node.

S201: The second node receives a second RRC reconfiguration message from the Donor-CU.

The second RRC reconfiguration message includes the new Internet Protocol IP address of the second node. Specifically, the second RRC reconfiguration message may be used for the second node to perform TNL relocation, that is, include configuration related to TNL relocation.

Exemplarily, the MT part of the second node receives the second RRC reconfiguration message from the Donor-CU.

S202: The second node acquires a discard timer (discard timer) configuration.

The method for the second node to obtain the discard timer configuration may include any of the following situations: the second node receives the discard timer configuration from the Donor-CU; or the second node determines the discard timer configuration by itself.

Specifically, the second RRC reconfiguration message includes the discard timer configuration. Optionally, the second node receives a separate or another F1AP message/RRC reconfiguration message from the Donor-CU, and the F1AP message/RRC reconfiguration message includes the discard timer configuration.

S203: The second node starts the discard timer.

S204: When the second condition is met and the discard timer expires, the second node discards the second RRC reconfiguration message.

The second condition includes at least one of the following situations: the second node has not completed the routing table update; or, the second node has not received the routing table reconfiguration message from the Donor-CU; or, the second node has not A validation indication from the parent node is received, where the validation indication is used to instruct the second node to validate the second RRC reconfiguration message.

Exemplarily, when the second condition includes that the second node has not received the routing table reconfiguration message from the Donor-CU and the second node has not received the validation instruction from the parent node, once the second node is at the discarding timing When the router times out, the second node will discard the second RRC reconfiguration when it determines that it has neither received the routing table reconfiguration message from the Donor-CU nor received the validation instruction from the first node information.

Wherein, the discarding timer configuration includes the second duration. The timeout of the discarding timer includes that the working duration of the discarding timer exceeds the second duration. The second duration is positively correlated with the first hop count, wherein the first hop count is the hop count between the second node and the first node. For example, the first node and the second node are connected through N nodes, then the number of hops between the first node and the second node is N+1, where N is an integer. Alternatively, the second duration is positively correlated with the first number of nodes, where the first number of nodes is the number of nodes separated between the second node and the first node. For example, the first node and the second node are connected by M nodes, then the number of first nodes is M, where M is an integer.

Optionally, the foregoing embodiment may further include operation S205, and/or, S206.

S205: If the first condition is not met and the discard timer has not expired, the second node validates the second RRC reconfiguration message.

S206: After the second node validates the second RRC reconfiguration message, the second node sends a validation indication to the third node. The validation indication is used to instruct the third node to validate the third RRC reconfiguration message. The third RRC reconfiguration message is from the Donor-CU and is used for the third node to perform TNL migration,

The above S202-S206 can be replaced by S207, thus forming a new embodiment.

S207: The second node receives a second message from the Donor-CU, where the second message instructs the second node to discard the second RRC reconfiguration message.

The second message may be an F1AP message.

Since the Donor-CU can know whether the topology update of the first node fails, it can send the second message to the second node when it is determined that the topology update of the first node fails, so that the second node can discard the failed first node in time. Two RRC reconfiguration messages.

The method provided by the above embodiment can reduce the situation that the second RRC reconfiguration message is always cached in the second node. On the one hand, it reduces the storage burden of the second node. The situation of the second RRC reconfiguration message causes the situation that the second node performs TNL migration by mistake, thereby ensuring the continuity of the service of the terminal served by the second node.

Referring to the schematic diagram of the conditional handover scenario shown in FIG. 9 , the host node includes one Donor-CU and multiple Donor-DUs. The IAB node 1 can switch to a cell provided by a different Donor-DU. For example, in handover 1, IAB node 1 switches from a cell provided by IAB node 4 connected to Donor-DU1 to a cell provided by IAB node 5 connected to Donor-DU2. In handover 2, IAB node 1 is handed over from the cell provided by IAB node 4 connected to Donor-DU1 to the cell provided by IAB node 6 connected to Donor-DU3.

In this application, the cell provided by the Donor-DU and the cell provided by the IAB node connected to the Donor-DU may be collectively referred to as the cell belonging to the Donor-DU.

The Donor-CU may send the conditional handover configuration to the IAB node 1, and the conditional handover configuration may include handover-related configurations for handover 1 and handover 2, and handover trigger conditions. The IAB node 1 can determine whether to perform handover 1 or handover 2 based on the handover trigger condition. In this application, handover related configuration may include random access related configuration.

In the conditional switching scenario shown in Figure 9, since Donor-CU cannot know in advance whether IAB node 1 will eventually perform switching 1 or switching 2, that is, it does not know which Donor-DU and Donor-DU IAB node 1 and its downstream nodes will pass through. -CU for TNL migration. Therefore, Donor-CU will send to IAB node 1 the configuration related to TNL migration for IAB node 1 to perform TNL migration with Donor-CU through Donor-DU2 when IAB node 1 performs handover 1, and for IAB node 1 When Node 1 executes Handover 2, IAB Node 1 performs TNL migration-related configurations for TNL migration through Donor-DU3 and Donor-CU. Donor-CU will also send to the downstream node of IAB node 1 the TNL migration-related configuration for the downstream node of IAB node 1 to perform TNL migration with Donor-CU through Donor-DU2 when IAB node 1 performs handover 1, and , when IAB node 1 executes handover 2, the downstream node of IAB node 1 performs TNL migration related configuration with Donor-CU through Donor-DU3.

The solution provided by the present application will be further described based on the aforementioned communication architecture and communication scenarios with reference to the schematic flowchart of the communication method provided in FIG. 10 .

S301: The Donor-CU may send a conditional handover (conditional handover, CHO) configuration to the first node.

In a possible implementation manner, the Donor-CU may send at least two CHO configurations to the first node. Each CHO configuration in the at least two CHO configurations includes a handover trigger condition and candidate target cell information. As shown in Table 1 below.

Table 1 CHO configuration example 1

CHO configuration 1	Handover trigger condition 1, candidate target cell 1 information
CHO configuration 2	Handover trigger condition 2, candidate target cell 2 information
...	the

In another possible implementation manner, the Donor-CU may send a CHO configuration to the first node. The CHO configuration may include handover trigger conditions and information of at least two candidate target cells. Exemplarily, the CHO configuration includes information of M candidate target cells, where M is an integer greater than 2. As shown in Table 2 below.

Table 2 CHO configuration example 2

A possible configuration of a handover trigger condition is to configure the handover trigger event as an A3 event, and configure a parameter Q for the A3 event, then when the signal quality of a certain cell among the M candidate cells is higher than the signal quality of the current serving cell of the first node When the quality is higher than Q, the cell meets the handover trigger condition. It can be seen that Q is a threshold, and its unit may be decibel (dB) or decibel milliwatt (dBm), which is not specifically limited in this embodiment of the present application.

Another possible configuration of the handover trigger condition is to configure the handover trigger event as an A5 event, and configure parameters K and L for the A5 event, then when the signal quality of a certain cell in the M candidate cells is higher than K and the first node When the signal quality of the current serving cell of is lower than L, the cell satisfies the handover trigger condition, wherein the current serving cell of the first node refers to the serving cell when the first node receives the conditional handover configuration information, that is, the first node The current serving cell of is the source cell. It can be seen that both K and L are thresholds, and their units may be decibels (dB) or decibels-milliwatts (dBm), which are not specifically limited in this embodiment of the present application.

The handover triggering conditions in this application may be in one-to-one correspondence with each of the M candidate cells, that is, the network device may be configured with M handover triggering conditions, and the M handover triggering conditions are in one-to-one correspondence with the M candidate cells. Optionally, the network device may configure the same handover trigger condition for multiple candidate cells, which is not specifically limited in this application. Exemplarily, taking the source cell as cell A and three candidate cells B, C, and D configured in the conditional handover configuration information as an example, handover trigger condition 1 can be configured for cell B, handover trigger condition 2 can be configured for cell C, and Configure handover trigger condition 3 for cell D, or configure handover trigger condition 4 for cells B and C, and configure handover trigger condition 5 for cell D; or configure the same handover trigger condition 6 for cells B, C, and D.

It should be noted that the above configuration of the triggering condition for handover and the corresponding relationship between the triggering condition for the handover and the candidate cell are only exemplary descriptions of this application, and this application does not specifically limit it in practical applications.

In this application, the cell information includes at least one of the following: cell identity information, and random access configuration corresponding to the cell. Wherein, the cell identity can include at least one of the following: physical cell identifier (physical cell identifier, PCI), cell identity (CellIdentity), NR cell identity (NR Cell Identity, NCI), NR cell global identity (NR cell Global Identity, NCGI ), Evolved Universal Terrestrial Radio Access Network (Evolved Universal Terrestrial Radio Access Network, E-UTRAN) Cell Identifier (E-UTRA Cell Identifier, ECI), and E-UTRAN Cell Global Identifier (E-UTRAN Cell Global Identifier, ECGI ), cell global identification (CGI). The cell identity is composed of a base station identity and a local cell identity. The cell global identifier consists of a public land mobile network identifier (PLMNId), a base station identifier (host node identifier) and a cell local identifier (cellLocalId). Wherein, the random access configuration corresponding to the cell is used for nodes to randomly access the cell, including at least one of the following: time-frequency resource configuration for dedicated or contention random access, dedicated or contention random access preamble, the cell is The cell radio network temporary identifier (C-RNTI) assigned by the node, etc.

S302: The Donor-CU sends at least two second TNL migration-related configurations to the first node.

The definition of the second TNL relocation-related configuration can specifically refer to other embodiments of the present application, such as the TNL relocation-related configuration included in the second RRC reconfiguration message in method 100 or 200 . Each second TNL migration-related configuration of the at least two second TNL migration-related configurations includes the new IP address of the second node.

In a possible manner 1, the at least two second TNL migration-related configurations respectively correspond to at least two candidate target cells of the first node. At this time, the number of second TNL migration-related configurations may be equal to the number of candidate target cells in the conditional handover configuration, that is, one-to-one correspondence. as shown in Table 3.

Table 3 Example 1 of the correspondence between the second TNL migration-related configuration and candidate target cell information

Configuration related to the second TNL migration 1	Candidate target cell 1 information
Second TNL migration related configuration 2	Candidate target cell 2 information
...	the

Wherein, Table 3 is just an example, and the corresponding relationship between the second TNL migration-related configuration and candidate target cell information may also be many-to-one or one-to-many. The candidate target cell information in Table 3 may include the candidate target cell identification information or the random access configuration corresponding to the candidate target cell, for example, the at least two second TNL migration-related configurations respectively correspond to the at least two candidate target cell information included The configuration index of the random access configuration. As shown in Table 4.

Table 4 Example 2 of the correspondence between the second TNL migration-related configuration and candidate target cells

Configuration related to the second TNL migration 1	Random Access Configuration Index 1
Second TNL migration related configuration 2	Random Access Configuration Index 2
...	the

Wherein, the random access configuration index 1 is used to indicate the random access configuration 1 in the candidate target cell information 1 . The random access configuration index 2 is used to indicate the random access configuration 2 in the candidate target cell information 2 . The random access configuration index in Table 4 may also be replaced by a candidate target cell information index.

In another possible manner 2, the at least two second TNL migration-related configurations respectively correspond to configuration indexes (index) of the CHO configuration. As shown in Table 5.

Table 5 An example of the corresponding relationship between the second TNL migration-related configuration and the CHO configuration index

Configuration related to the second TNL migration 1	CHO configuration index 1
Second TNL migration related configuration 2	CHO configuration index 2
...	the

Wherein, CHO configuration index 1 is used to indicate CHO configuration 1, and CHO configuration index 2 is used to indicate CHO configuration 2. Table 5 can be applied to the above CHO configuration example 1. Table 5 is just an example, and the correspondence between the second TNL migration-related configuration and the CHO configuration index may also be many-to-one or one-to-many.

In yet another possible manner 3, the at least two second TNL migration-related configurations respectively correspond to one Donor-DU. That is to say, assuming that M candidate target cells in the conditional handover configuration belong to N Donor-DUs, then the number of second TNL migration-related configurations may be equal to N, and N is an integer less than or equal to M. Since the second TNL migration-related configurations corresponding to candidate target cells belonging to the same Donor-DU include the same new IP address of the second node, mode 3 at this time is equivalent to mode 2 and can reduce signaling overhead. As shown in Table 6.

Table 6 An example of the correspondence between the second TNL migration-related configuration and Donor-DU

Configuration related to the second TNL migration 1	Donor-DU1 information
Second TNL migration related configuration 2	Donor-DU2 information
...	the

Wherein, the Donor-DU1 information and the Donor-DU2 information are used to indicate different Donor-DUs of the Donor-CU. The Donor-DU information may specifically include DU identification information. Table 6 is just an example, and the correspondence between the second TNL migration-related configuration and the Donor-DU may also be many-to-one or one-to-many.

S301 and S302 can be combined, that is to say, the CHO configuration and at least two second TNL migration-related configurations can be carried in the same message, such as an RRC reconfiguration message or an F1AP message.

S303: The Donor-CU sends at least two third TNL migration-related configurations to the second node.

The definition of the third TNL relocation-related configuration can specifically refer to other embodiments of the present application, such as the TNL relocation-related configuration included in the third RRC reconfiguration message in method 100 or 200 . Each third TNL migration-related configuration of the at least two third TNL migration-related configurations includes the new IP address of the third node.

In a possible manner 1, the at least two third TNL migration-related configurations respectively correspond to at least two candidate target cells of the first node. At this time, the number of third TNL migration-related configurations may be equal to the number of candidate target cells in the conditional handover configuration, that is, one-to-one correspondence. The corresponding relationship between the third TNL migration-related configuration and candidate target cells can also be understood with reference to Table 3 or Table 4.

In another possible manner 2, the at least two third TNL migration-related configurations respectively correspond to configuration indexes (index) of the CHO configuration. The corresponding relationship between the third TNL migration-related configuration and the CHO configuration index can also be understood with reference to Table 5.

In yet another possible manner 3, the at least two third TNL migration-related configurations respectively correspond to one Donor-DU. That is to say, assuming that the M candidate target cells in the conditional handover configuration belong to N Donor-DUs (the Donor-DUs corresponding to the at least two candidate target cells can be the same or different), then the third TNL migration-related configuration The number of can be equal to N, and N is an integer less than or equal to M. Since the third TNL migration-related configurations corresponding to the candidate target cells belonging to the same Donor-DU include the same new IP address of the third node, mode 3 at this time is equivalent to mode 2 and can reduce signaling overhead. The corresponding relationship between the configuration related to the third TNL migration and the Donor-DU can also be understood with reference to Table 6.

In a possible manner 4, the number of the at least two third TNL migration-related configurations and the number of the at least two second TNL migration-related configurations may be the same, that is, there may be a one-to-one correspondence, RRC The reconfigured configuration index may be shared. As shown in Table 7.

Table 7 An example of the corresponding relationship between the configuration related to the second TNL migration and the configuration related to the third TNL migration

configuration index 1	Configuration related to the second TNL migration 1	The third TNL migration related configuration 1
configuration index 2	Second TNL migration related configuration 2	The third TNL migration related configuration 2
...	the	the

Wherein, the configuration index 1 is used to indicate the second TNL migration-related configuration 1 in the view of the first node, and indicates the third TNL migration-related configuration 1 in the view of the second node. The configuration index 2 is used to indicate the second TNL migration-related configuration 2 in the view of the first node, and indicates the third TNL migration-related configuration 2 in the view of the second node. The second TNL migration-related configuration 1 may be used for the second node to establish a new TNL association with the Donor-CU through the Donor-DU2. The third TNL migration-related configuration 1 may be used for the third node to establish a new TNL association with the Donor-CU through the Donor-DU2. That is to say, the second TNL migration-related configuration and the third TNL migration-related configuration having a corresponding relationship are respectively used for the second node and the third node to establish a new TNL association with the Donor-CU through the same Donor-DU. Table 7 is just an example. The second TNL migration-related configuration, the third TNL migration-related configuration, and the corresponding relationship between configuration indexes may also be many-to-one or one-to-many.

S304: The first node determines to access the first cell.

The first node determines to access the first cell according to the conditional handover configuration information. The first cell is a candidate target cell that satisfies a handover trigger condition among the M candidate target cells.

S305: The first node sends the second TNL migration-related configuration corresponding to the first cell to the second node.

S305 is suitable for mode 1 in S302. The first node stores the correspondence between the at least two second TNL migration-related configurations and the at least two candidate target cell information of the first node.

For mode 2 in S302. The first node stores the correspondence between the at least two second TNL migration-related configurations and the configuration index of the CHO configuration. S305 can be replaced by S3051.

S3051: The first node determines the configuration index of the CHO configuration corresponding to the first cell, and then sends the second TNL migration-related configuration corresponding to the configuration index of the CHO configuration to the second node.

For mode 3 in S303. The first node stores the correspondence between the at least two second TNL migration-related configurations and Donor-DU information. S305 can be replaced by S3052.

S3052: The first node determines the Donor-DU to which the first cell belongs, and then sends the second TNL migration-related configuration corresponding to the Donor-DU to the second node.

S306: The first node sends the first cell information to the second node.

S307: The second node sends the third TNL migration-related configuration corresponding to the first cell to the third node.

The second node determines the third TNL migration-related configuration corresponding to the first cell according to the received first cell information. The second node sends the third TNL migration-related configuration corresponding to the first cell to the third node.

S306-S307 are suitable for mode 1 in S303. The second node stores the correspondence between the at least two third TNL migration-related configurations and the at least two candidate target cell information of the first node.

For mode 2 in S303. The second node stores the correspondence between the at least two third TNL migration-related configurations and the configuration index of the CHO configuration. S306-S307 can be replaced by S3061-S3071.

S3061: The first node sends the configuration index of the CHO configuration corresponding to the second TNL migration related configuration to the second node.

S3071: The second node sends the third TNL migration-related configuration corresponding to the CHO configuration index to the third node.

For mode 3 in S303. The second node stores the correspondence between the at least two third TNL migration-related configurations and the Donor-DU. S306-S307 can be replaced by S3062-S3072.

S3062: The first node sends Donor-DU information corresponding to the second TNL migration-related configuration to the second node.

S3072: The second node sends a third TNL migration-related configuration corresponding to the Donor-DU information to the third node.

For mode 4 in S303. The second node stores the corresponding relationship between the at least two second TNL migration-related configurations and the third TNL migration-related configuration and configuration index. S306-S307 can be replaced by S3063-S3073.

S3063: The first node sends the configuration index corresponding to the second TNL migration-related configuration to the second node.

S3073: The second node sends the third TNL migration-related configuration corresponding to the configuration index to the third node.

The above S305 and S306 can be combined in the same message.

In Fig. 10, the third node can directly serve the terminal. Optionally, when there is another relay node between the third node and the terminal, this embodiment of the present application may further include S308.

S308: The second node sends the first cell information to the third node, or the configuration index of the CHO configuration corresponding to the third TNL migration-related configuration, or the Donor-DU information corresponding to the third TNL migration-related configuration, or, the third The configuration index corresponding to the configuration related to TNL migration.

Through S308, the third node may determine the corresponding correct TNL migration related configuration from at least two TNL migration related configurations of the child nodes of the third node stored by itself, and send it to the child node.

S307 and S308 can be combined in the same message.

The embodiments of the present application may be combined with the foregoing embodiments to form new embodiments in a conditional switching scenario. For example, in this application, the Donor-CU may send at least two second TNL migration-related configurations and discard timer configurations to the first node. The Donor-CU may send at least two third TNL migration-related configurations and discard timer configurations to the second node.

Through the embodiment of the present application, the first node and its downstream nodes can correctly send the pre-cached TNL migration-related configurations to their respective child nodes, so that each node can perform TNL migration correctly and efficiently.

Based on the above-mentioned similar technical concept, the embodiment of the present application provides a communication device, which can be the first node, the second node, the third node or the host in any possible design scheme of the methods in the foregoing embodiments For a node, the communication device includes: in the communication methods provided in the foregoing embodiments, at least one corresponding unit for performing the method steps or operations or behaviors performed by the first node, the second node, the third node or the host node. Wherein, the configuration of the at least one unit may have a one-to-one correspondence with the method steps or operations or behaviors performed by the first node, the second node, the third node or the host node. These units may be realized by computer programs, hardware circuits, or a combination of computer programs and hardware circuits.

The following describes the communication device provided by the present application with reference to FIG. 11 and FIG. 12 . As shown in FIG. 11 , a communication device 1100 may be applied to a second node. The structure and functions of the communication device 1100 will be divided into different designs for a specific description below. The module name is the same between different designs, but the structure and function can be different.

The communication device 1100 may include an acquisition module 1101 and a processing module 1102 . An obtaining module 1101, configured to receive a third radio resource control RRC reconfiguration message from the centralized unit Donor-CU of the donor node, where the third RRC reconfiguration message includes a new Internet Protocol IP address of the third node, and the third The parent node of the three nodes is the second node. The acquiring module 1101 is also configured to acquire the discard timer configuration. The processing module 1102 is configured to start the discard timer. The processing module 1102 is further configured to discard the third RRC reconfiguration message when the first condition is met and the discard timer expires. Wherein, the first condition includes: the second node has not completed the routing table update, or the second node has not received the routing table reconfiguration message from the Donor-CU, or the second node has not received the routing table reconfiguration message from the parent CU. A second RRC reconfiguration message of the node, wherein the second RRC reconfiguration message includes the new IP address of the second node.

In a possible implementation manner, the obtaining module 1101 is specifically configured to receive the discard timer configuration from the Donor-CU. Or the obtaining module 1101 is specifically configured to determine the discarding timer configuration by itself.

Wherein, the obtaining module 1101 is specifically configured to receive an F1 application protocol F1AP message from the Donor-CU, and the F1AP message includes the third RRC reconfiguration message and the discard timer configuration.

Exemplarily, the timeout of the discarding timer includes that the working duration of the discarding timer exceeds a first duration.

Optionally, the first duration is positively correlated with a first hop number, wherein the first hop number is a hop number between the second node and a first node, and the first node is a migration node.

Optionally, the discarding timer configuration includes the first duration.

In another possible implementation manner, the communication device 1100 further includes a sending module 1103 . A sending module 1103, configured to send the third RRC reconfiguration message to the third node when the first condition is not satisfied and the discard timer has not expired.

Wherein, the second RRC reconfiguration message is used for the second node to perform transport network layer TNL relocation, and the third RRC reconfiguration message is used for the third node to perform TNL relocation.

Optionally, the obtaining module 1101 is further configured to receive an F1AP message from the Donor-CU, where the F1AP message includes the third RRC reconfiguration message and a cache indication, where the cache indication is used to instruct the second node to cache the A third RRC reconfiguration message.

Wherein, the first node, the second node and the third node are access and backhaul integrated IAB nodes.

As shown in FIG. 12 , a communications device 1200 includes one or more processors 1201 , and optionally, an interface 1202 . When the related program instructions are executed in the at least one processor 1201, the device 1200 may be enabled to implement the communication method provided in any of the foregoing embodiments and any possible design therein. Alternatively, the processor 1201 implements the communication method provided by any of the foregoing embodiments and any possible design thereof through a logic circuit or by executing code instructions. The interface 1202 may be used to receive program instructions and transmit them to the processor, or the interface 1202 may be used for the apparatus 1200 to communicate and interact with other communication devices, such as to exchange control signaling and/or service data. Exemplarily, the interface 1202 may be used to receive signals from other devices other than the device 1200 and transmit them to the processor 1201 or send signals from the processor 1201 to other communication devices other than the device 1200 . The interface 1202 may be a code and/or data read/write interface circuit, or the interface 1202 may be a signal transmission interface circuit between the communication processor and the transceiver, or a chip pin. Optionally, the communication device 1200 may further include at least one memory 1203, and the memory 1203 may be used to store required related program instructions and/or data. Optionally, the apparatus 1200 may further include a power supply circuit 1204, which may be used to supply power to the processor 1201, and the power supply circuit 1204 may be located in the same chip as the processor 1201, or located inside another chip outside of the chip. Optionally, the apparatus 1200 may further include a bus 1205 , and various parts in the apparatus 1200 may be interconnected via the bus 1205 .

It should be understood that the processor in this application can be a central processing unit (central processing unit, CPU), and the processor can also be other general processors, digital signal processors (digital signal processor, DSP), application specific integrated circuits (application specific integrated circuit (ASIC), off-the-shelf programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.

It should also be understood that memory in this application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. Among them, the non-volatile memory can be read-only memory (read-only memory, ROM), programmable read-only memory (programmable ROM, PROM), erasable programmable read-only memory (erasable PROM, EPROM), electrically programmable Erases programmable read-only memory (electrically EPROM, EEPROM) or flash memory. Volatile memory can be random access memory (RAM), which acts as external cache memory. By way of illustration and not limitation, many forms of random access memory (RAM) are available, such as static random access memory (static RAM, SRAM), dynamic random access memory (dynamic random access memory, DRAM) ), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), Synchronous connection dynamic random access memory (synchlink DRAM, SLDRAM), or direct memory bus random access memory (direct rambus RAM, DR RAM).

The power supply circuit described in the embodiment of the present application includes but is not limited to at least one of the following: a power supply circuit, a power supply subsystem, a power management chip, a power consumption management processor, or a power consumption management control circuit.

The transceiver device, interface, or transceiver described in the embodiments of the present application may include a separate transmitter and/or a separate receiver, or the transmitter and the receiver may be integrated. Transceiving means, interfaces, or transceivers may operate under the direction of a corresponding processor. Optionally, the transmitter may correspond to the transmitter in the physical device, and the receiver may correspond to the receiver in the physical device.

Those skilled in the art can clearly understand that for the convenience and brevity of description, only the division of the above-mentioned functional modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional modules according to needs. The internal structure of the device is divided into different functional modules to complete all or part of the functions described above. For the specific working process of the above-described system, device, and unit, reference may be made to the corresponding process in the foregoing method embodiments, and details are not repeated here.

In this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined Or it can be integrated into another system, or some features can be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

Those skilled in the art can appreciate that the units or algorithm operations of the examples described in conjunction with the embodiments disclosed herein can be implemented by hardware, or by software, or by a combination of software and hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.

In this application, "realized by software" may mean that a processor reads and executes program instructions stored in a memory to realize the functions corresponding to the above-mentioned modules or units, wherein a processor refers to a processing circuit capable of executing program instructions, Including but not limited to at least one of the following: central processing unit (central processing unit, CPU), microprocessor, digital signal processing (digital signal processing, DSP), microcontroller (microcontroller unit, MCU), or artificial intelligence processing Processors and other processing circuits capable of executing program instructions. In some other embodiments, the processor may also include circuits with other processing functions (such as hardware circuits for hardware acceleration, buses and interfaces, etc.). Processors can be presented in the form of an integrated chip, for example, in the form of an integrated chip whose processing function consists only of executing software instructions, or in the form of a system on a chip (SoC), that is, on a chip In addition to the processing circuit (usually called "core") capable of running program instructions, it also includes other hardware circuits for realizing specific functions (of course, these hardware circuits can also be implemented independently based on ASIC and FPGA), corresponding Yes, in addition to the function of executing software instructions, the processing function may also include various hardware acceleration functions (such as AI calculation, codec, compression and decompression, etc.).

In this application, "implemented by hardware" refers to realizing the functions of the above-mentioned modules or units through a hardware processing circuit that does not have the function of program instruction processing. The hardware processing circuit may be composed of discrete hardware components, or may be an integrated circuit. In order to reduce power consumption and size, it is usually implemented in the form of an integrated circuit. The hardware processing circuit may include an ASIC, or a programmable logic device (programmable logic device, PLD); wherein, the PLD may include an FPGA, a complex programmable logic device (complex programmable logic device, CPLD) and the like. These hardware processing circuits can be a semiconductor chip packaged separately (such as packaged into an ASIC); they can also be integrated with other circuits (such as CPU, DSP) and packaged into a semiconductor chip, for example, can be formed on a silicon base. A variety of hardware circuits and CPUs are packaged separately into a chip. This chip is also called SoC, or circuits and CPUs for realizing FPGA functions can also be formed on a silicon base, and separately sealed into a chip. This chip Also known as a programmable system on a chip (system on a programmable chip, SoPC).

It should be noted that when the present application is realized by means of software, hardware or a combination of software and hardware, different software and hardware may be used, and the use of only one kind of software or hardware is not limited. For example, one of the modules or units may be implemented using a CPU, and the other module or unit may be implemented using a DSP. Similarly, when implemented by hardware, one of the modules or units can be implemented using an ASIC, and the other module or unit can be implemented using an FPGA. Of course, it is not limited that part or all of the modules or units are implemented by the same software (eg, all through CPU) or the same hardware (eg, all through ASIC). In addition, for those skilled in the art, it can be known that software is usually more flexible, but its performance is not as good as that of hardware, and hardware is just the opposite. Therefore, those skilled in the art can choose software or hardware or a combination of both based on actual needs. form to achieve.

In the foregoing embodiments, the descriptions of each embodiment have their own emphases, and for parts not described in detail in a certain embodiment, reference may be made to relevant descriptions of other embodiments. The embodiments of the present application can be combined, some technical features in the embodiments can also be decoupled from the specific embodiments, and the technical problems involved in the embodiments of the present application can be solved by combining existing technologies.

In this application, a unit described as a separate component may or may not be physically separated, and a component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or may also be distributed to multiple network units superior. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment of the present application.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of software products, and the computer software products are stored in a storage The medium may include several instructions to enable a computer device, such as a personal computer, server, or network device, or a processor to perform all or part of the operations of the methods described in the various embodiments of the present application. The aforementioned storage medium can include: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disk, or optical disk, etc., which can store program codes. media or computer-readable storage media.

In the description of this application, words such as "first", "second", "S101", or "S102" are only used for the purpose of distinguishing the description and the convenience of the context, and the different sequence numbers themselves have no specific technical meaning , should not be construed as indicating or implying relative importance, nor as indicating or implying the order in which operations are performed.

The term "and/or" in this application is just an association relationship describing associated objects, which means that there may be three relationships, for example, "A and/or B" can mean: A exists alone, A and B exist simultaneously, and There are three cases of B, where A and B can be singular or plural. In addition, the character "/" in this article indicates that the contextual objects are an "or" relationship.

In this application, "transmission" may include the following three situations: sending of data, receiving of data, or sending of data and receiving of data. In this application, "data" may include service data and/or signaling data.

The terms "comprising" or "having" and any variations thereof in this application are intended to cover a non-exclusive inclusion, for example, a process/method comprising a series of steps, or a system/product/equipment comprising a series of units, without necessarily limiting Instead, other steps or elements not explicitly listed or inherent to the process/method/product/apparatus may be included.

In the description of the present application, unless otherwise specified, the number of nouns means "singular noun or plural noun", that is, "one or more". "At least one" means one or more. "Including at least one of the following: A, B, C." means that it may include A, or include B, or include C, or include A and B, or include A and C, or include B and C, or include A, B, and c. Among them, A, B, and C can be single or multiple.

The above is only a specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application. Should be covered within the protection scope of this application.

Claims (23)

1. A communication method, characterized in that, comprising:

   The second node receives a third radio resource control RRC reconfiguration message from the centralized unit Donor-CU of the donor node, wherein the third RRC reconfiguration message includes the new Internet Protocol IP address of the third node, and the third The parent node of the node is the second node;

   The second node obtains a discard timer configuration;

   the second node starts the drop timer;

   If the first condition is met and the discard timer expires, the second node discards the third RRC reconfiguration message;

   Wherein, the first condition includes:

   The second node has not completed routing table updates; or,

   The second node does not receive the routing table reconfiguration message from the Donor-CU; or,

   The second node does not receive the second RRC reconfiguration message from the parent node, wherein the second RRC reconfiguration message includes the new IP address of the second node.
2. The method according to claim 1, wherein said second node obtaining discard timer configuration comprises:

   The second node receives the discard timer configuration from the Donor-CU; or

   The second node determines the discard timer configuration by itself.
3. The method according to claim 2, wherein the second node receives the discard timer configuration from the Donor-CU, comprising:

   The second node receives an F1 application protocol F1AP message from the Donor-CU, where the F1AP message includes the third RRC reconfiguration message and the discard timer configuration.
4. The method according to any one of claims 1-3, wherein the timeout of the discarding timer includes that the working duration of the discarding timer exceeds a first duration.
5. The method according to claim 4, wherein the first duration is positively correlated with a first hop count, wherein the first hop count is the hop count between the second node and the first node, The first node is a migration node.
6. The method according to claim 4 or 5, wherein the discard timer configuration includes the first duration.
7. The method according to any one of claims 1-6, comprising:

   If the first condition is not satisfied and the discard timer has not expired, the second node sends the third RRC reconfiguration message to the third node.
8. The method according to any one of claims 1-7, wherein the second RRC reconfiguration message is used for the second node to perform transport network layer TNL migration, and the third RRC reconfiguration message is used for The third node performs TNL migration.
9. The method according to any one of claims 1-8, comprising:

   The second node receives the F1AP message from the Donor-CU, the F1AP message includes the third RRC reconfiguration message and a cache indication, where the cache indication is used to instruct the second node to cache the A third RRC reconfiguration message.
10. The method according to any one of claims 1-9, wherein the first node, the second node and the third node are access and backhaul integrated IAB nodes.
11. A communication device, characterized in that it is applied to a second node, comprising:

    An obtaining module, configured to receive a third radio resource control RRC reconfiguration message from the centralized unit Donor-CU of the donor node, wherein the third RRC reconfiguration message includes a new Internet Protocol IP address of the third node, and the The parent node of the third node is the second node;

    The obtaining module is also used to obtain the discard timer configuration;

    A processing module, configured to start the discard timer;

    The processing module is further configured to discard the third RRC reconfiguration message when the first condition is met and the discard timer expires;

    Wherein, the first condition includes: the second node has not completed the routing table update; or, the second node has not received the routing table reconfiguration message from the Donor-CU; or, the second node The second RRC reconfiguration message from the parent node is not received, wherein the second RRC reconfiguration message includes the new IP address of the second node.
12. The communication device according to claim 11, wherein the acquiring module is specifically configured to receive the discarding timer configuration from the Donor-CU; or the acquiring module is specifically configured to determine the discarding timing by itself device configuration.
13. The communication device according to claim 12, wherein the acquiring module is specifically configured to receive an F1 application protocol F1AP message from the Donor-CU, and the F1AP message includes the third RRC reconfiguration message and the The discard timer configuration described above.
14. The communication device according to any one of claims 11-13, wherein the timeout of the discarding timer includes that the working duration of the discarding timer exceeds a first duration.
15. The communication device according to claim 14, wherein the first duration is positively correlated with a first hop count, wherein the first hop count is the hop count between the second node and the first node , the first node is a migration node.
16. The communication device according to claim 14 or 15, wherein the discard timer configuration includes the first duration.
17. The communication device according to any one of claims 11-16, further comprising:

    A sending module, configured to send the third RRC reconfiguration message to the third node when the first condition is not met and the discard timer has not expired.
18. The communication device according to any one of claims 11-17, wherein the second RRC reconfiguration message is used for the second node to perform transport network layer TNL migration, and the third RRC reconfiguration message is used for Perform TNL migration on the third node.
19. The communication device according to any one of claims 11-18, comprising:

    The obtaining module is further configured to receive an F1AP message from the Donor-CU, the F1AP message includes the third RRC reconfiguration message and a cache indication, wherein the cache indication is used to indicate the second node Buffering the third RRC reconfiguration message.
20. The communication device according to any one of claims 11-19, wherein the first node, the second node and the third node are integrated access and backhaul IAB nodes.
21. A communication device, characterized in that it comprises: at least one processor and an interface, the interface is used to receive and/or send signals, the processor is configured to enable the The method described above is executed.
22. A computer-readable storage medium, characterized in that computer program instructions are stored in the computer-readable storage medium, and when the computer program instructions are executed by a processor, the The method described above is implemented.
23. A computer program product comprising program instructions which, when executed by a processor, cause the method according to any one of claims 1 to 10 to be implemented.

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