Method, device and communication system for transmitting and receiving signals

Abstract

In an embodiment of the present invention, a method, an apparatus and a communication system for transmitting and receiving a signal are provided, the apparatus for transmitting and receiving a signal is applied to an IAB node (IAB) node, and the apparatus includes: a first processing unit for performing a routing change on unsuccessfully transmitted data of a first route or received data of a first route when a destination BAP address of a first route of the IAB-node is unreachable; and a first transceiver unit for transmitting the unsuccessfully transmitted data of the first route or received data of the first route according to the changed routing.

Description

[Technical field]

[0001] The present invention relates to the technical field of communications. [Background technology]

[0002] IAB (Integrated access and backhaul) can realize the function of wireless relay in next generation radio access network (NG-RAN). IAB-node supports New Radio (NR) access and backhaul. The end point on the network side of NR backhaul is called IAB-donor, which represents a network device (e.g., gNB) that can support IAB function.

[0003] An IAB-node can be connected to one IAB-donor by single-hop or multi-hop. These multi-hops are connected to form a Directed Acyclic Graph (DAG) topology structure with the IAB-donor as the root node. The IAB-donor is responsible for performing centralized resource management, topology management, and routing management in the IAB network topology.

[0004] The IAB-node supports the function of gNB-DU (distributed unit), and the IAB-node DU is also called IAB-DU. The IAB-DU is the termination point of the radio access (NR access) interface to the terminal equipment (UE) and the next hop IAB-node, and is also the termination point of the F1 protocol to the gNB-CU (central unit) on the IAB-donor. The IAB-DU can serve normal UE and IAB child nodes. The IAB-DU realizes the function of a network side device, is connected to the downstream child IAB-node, provides NR air interface access for the UE and the downstream child IAB-node, and establishes an F1 connection with the IAB donor-CU.

[0005] In addition to the gNB-DU functions, the IAB-node also supports some UE functions and is called an IAB-MT (Mobile Termination), which includes, for example, physical layer, layer 2, RRC and NAS functions, and is thereby connected to a gNB-DU of another IAB-node or IAB-donor, connected to a gNB-CU on the IAB-donor, and connected to the core network. The IAB-MT can support, for example, UE physical layer, access stratum (AS), radio resource control (RRC) layer and non-access stratum (NAS) layer functions, and can be connected to an IAB parent node.

[0006] Figure 1 is a diagram showing an IAB topology structure. As shown in Figure 1, in the IAB topology structure 10, an IAB-node 100 includes an IAB-MT functional unit 101 and an IAB-DU functional unit 102, an adjacent node on the interface of the IAB-DU functional unit 102 is called a child node, as shown in the child nodes 201, 202, and 203 in Figure 1, communication can be performed between the IAB-DU functional unit 102 and the child nodes 201, 202, and 203 via an air interface (Uu), an adjacent node on the interface of the IAB-MT functional unit 101 is called a parent node, as shown in the parent nodes 301 and 302 in Figure 1, communication can be performed between the IAB-MT functional unit 101 and the parent nodes 301 and 302 via an air interface (Uu).

[0007] 1, the direction from the IAB-node 100 to the child nodes 201, 202, 203 is referred to as the downstream direction, and the direction from the IAB-node 100 to the parent nodes 301, 302 is referred to as the upstream direction. An IAB-donor (not shown) performs centralized resource, topology, and routing management for the IAB topology structure 10.

[0008] It should be noted that the introduction of the above background art is intended to clearly and completely explain the technical solutions of the present invention, and to facilitate understanding thereof by those skilled in the art, and these technical solutions are described in the background art of the present invention, and therefore should not be construed as being known to those skilled in the art. Summary of the Invention [Problem to be solved by the invention]

[0009] The inventors have discovered the following:

[0010] When an IAB-node disconnects from its original parent IAB-node and connects to a new parent IAB-node during migration, or when an IAB-node transfers its F1-U transmission path from one CG side to another CG side while maintaining dual connections, it can cause a change in the network topology, thus resulting in a change in the routing of the IAB-node and its downstream child nodes. Each uplink data packet carries a destination BAP address ID, and the Backhaul Adaptation Protocol (ADAP) sent by the IAB-node and child nodes after the path transfer is used to determine the destination BAP address ID. The BAP address of the destination DU carried in the BAP (Broadcast Admission Control Protocol) data packet header is the address of the target Donor-DU after switching, and the path indicator carried in the packet header corresponds to the new path indicator. However, when the IAB-node switches or transfers the F1-U transmission path, there may be some unsuccessfully transmitted data in the IAB-node and its child nodes, i.e., data packets carrying the BAP address of the original Donor-DU and the original path indicator. When a change occurs in the Donor-DU after the IAB-node switches or transfers the F1-U path, the uplink data of the original path cannot reach the original Donor-DU. When these uplink data of the original path are transmitted by the new path, they may be discarded by the target Donor-DU, because the destination BAP address carried does not match the BAP address of the new Donor-DU.

[0011] For example, Figure 2 is a diagram showing discarding uplink data. As shown in Figure 2, when IAB-node 3 disconnects from parent node IAB-node 1 and connects to IAB-node 2, IAB-nodes 3, 4, and 5 have uplink data (target BAP address in BAP packet header is 1) on the original path that has not been successfully transmitted. When a change occurs in Donor-DU of IAB-node (i.e., Donor-DU 1 becomes Donor-DU 2), if IAB-node 3 transmits these uplink data along the new path that has not been successfully transmitted, the uplink data may be discarded by the new Donor-DU (BAP address is 2), and therefore cannot reach Donor-CU.

[0012] In view of the above problems, an embodiment of the present invention provides a method, an apparatus and a communication system for transmitting and receiving signals, which performs a routing change on the data of the first route that has not been successfully transmitted or the data of the first route that has been received when the destination BAP address of the first route of the IAB-node is unreachable, so that the data can be transmitted based on the changed routing, thereby avoiding data loss. [Means for solving the problem]

[0013] According to one aspect of an embodiment of the present invention, there is provided an apparatus for transmitting and receiving a signal, the apparatus being applied to an IAB node, the apparatus comprising: a first processing unit for performing a routing change on the unsuccessfully transmitted first-path data or the received first-path data when the destination BAP address of the first-path of the IAB-node is unreachable; and A first transceiver unit is included for transmitting the unsuccessfully transmitted first path data or the received first path data based on the changed routing.

[0014] According to another aspect of an embodiment of the present invention, there is provided an apparatus for transmitting and receiving a signal, the apparatus being applied to a child node of an IAB-node, the apparatus comprising: A second processing unit for performing a routing change on the unsuccessfully transmitted data of the first path or the received data of the first path when the destination BAP address of the first path of the IAB-node is unreachable; and A second transceiver unit is included for transmitting the unsuccessfully transmitted first path data or the received first path data based on the changed routing.

[0015] According to another aspect of an embodiment of the present invention, there is provided an apparatus for transmitting and receiving a signal, the apparatus being applied to a Donor Central Unit (Donor-CU), the apparatus comprising: The third transceiver unit includes a third transceiver unit for transmitting route reconfiguration parameters to an IAB-node or a child node of the IAB-node when a destination BAP address of a first route of the IAB-node is unreachable, wherein the route reconfiguration parameters are used by the IAB-node or the child node to make a routing change to data of the first route that has not been successfully transmitted or data of the first route that has been received.

[0016] According to another aspect of an embodiment of the present invention, there is provided a method for transmitting and receiving a signal, the method being applied to an IAB node, the method comprising: When the destination BAP address of the first route of the IAB-node is unreachable, performing a routing change on the data of the first route that has not been successfully transmitted or the data of the first route that has been received; and Transmitting the unsuccessfully transmitted first path data or the received first path data based on the changed routing.

[0017] According to another aspect of an embodiment of the present invention, there is provided a method for transmitting and receiving a signal, the method being applied to a child node of an IAB node, the method comprising: When the destination BAP address of the first route of the IAB-node is unreachable, performing a routing change on the data of the first route that has not been successfully transmitted or the data of the first route that has been received; and Transmitting the unsuccessfully transmitted first path data or the received first path data based on the changed routing.

[0018] According to another aspect of an embodiment of the present invention, there is provided a method for transmitting and receiving signals, the method being applied to a Donor Central Unit (Donor-CU), the method comprising: sending a route reconfiguration parameter to the IAB-node or a child node of the IAB-node when a destination BAP address of a first route of the IAB-node is unreachable; The route reconfiguration parameters are used by the IAB-node or the child node to change the routing of the data of the first route that has not been successfully transmitted or that has been received. Effect of the Invention

[0019] One of the advantageous effects of the embodiment of the present invention is as follows: when the destination BAP address of the first route of the IAB-node is unreachable, a routing change is made to the data of the first route that has not been successfully transmitted or the data of the first route that has been received, so that the data can be transmitted based on the changed routing, thereby avoiding data loss.

[0020] Specific embodiments of the present invention will be disclosed in detail with reference to the following description and drawings, which show the manner in which the principles of the present invention may be employed. However, the scope of the present invention is not limited thereto. The embodiments of the present invention may include various changes, modifications, and alternatives within the scope of the appended claims.

[0021] Additionally, features described and / or illustrated in one embodiment may be used in the same or similar manner in one or more other embodiments, may be combined with features in the other embodiments, or may be substituted for features in the other embodiments.

[0022] It should be noted that terms such as "comprise / have" when used in this specification refer to the presence of a feature, element, step, or assembly, but do not exclude the presence or addition of one or more other features, elements, steps, or assemblies. [Brief description of the drawings]

[0023] Elements and features described in one drawing or one embodiment of the invention may be combined with elements and features shown in one or more other drawings or embodiments, and in the drawings, like reference numerals are used to indicate corresponding parts in the several drawings and to indicate corresponding parts used in several embodiments. [Figure 1] FIG. 1 illustrates an IAB topology structure. [Diagram 2] A diagram showing discarding uplink data. [Diagram 3] FIG. 1 is a diagram showing changes in network topology due to the movement of an IAB-node. [Figure 4] FIG. 2 is a diagram illustrating a method for transmitting and receiving signals in an embodiment of the first aspect of the present invention. [Diagram 5] FIG. 1 illustrates how an IAB-node and its child nodes make routing changes. [Figure 6] A diagram showing a downstream child node of an IAB-node sending a termination instruction. [Figure 7] FIG. 1 illustrates how an IAB-node and its child nodes make routing changes when the IAB-node has dual connections. [Figure 8] FIG. 4 is a diagram showing a method of transmitting and receiving signals in an embodiment of the second aspect of the present invention. [Figure 9] FIG. 11 is a diagram showing a method of transmitting and receiving signals in an embodiment of the third aspect of the present invention. [Figure 10] FIG. 13 illustrates an apparatus for transmitting and receiving signals in an embodiment of the fourth aspect of the present invention. [Figure 11] FIG. 13 illustrates an apparatus for transmitting and receiving signals in an embodiment of the fifth aspect of the present invention. [Figure 12] FIG. 13 illustrates an apparatus for transmitting and receiving signals in an embodiment of the sixth aspect of the present invention. [Figure 13] FIG. 2 is a configuration diagram of a network device according to an embodiment of the present invention. [Figure 14] FIG. 2 is a diagram illustrating a terminal device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The above and other features of the present invention will become apparent from the following detailed description and accompanying drawings, in which: Although the specification and drawings disclose specific embodiments of the present invention, they represent only some of the embodiments that may employ the principles of the present invention, and it should be understood that the present invention is not limited to the described embodiments, and that the present invention also includes all modifications, variations, and alternatives within the scope of the appended claims.

[0025] In an embodiment of the present invention, the term "communication network" or "wireless communication network" may refer to a network conforming to any communication standard, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), etc.

[0026] Additionally, communications between devices in the communications system may be performed according to any stage of communications protocol, including, but not limited to, the following communications protocols: 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G, New Radio (NR), and / or other conventional or future developed communications protocols.

[0027] In the embodiment of the present invention, the term "network device" refers to a device that connects a terminal device to a communication network and provides services to the terminal device in a communication system, for example, the network device may include, but is not limited to, a base station (BS), an access point (AP), a transmission reception point (TRP), a broadcast transmitter, a mobile management entity (MME), a network gateway, a server, a radio network controller (RNC), a base station controller (BSC), etc.

[0028] Among them, the base station may include, but is not limited to, the following: Node B (NodeB or NB), evolved Node B (eNodeB or eNB), 5G base station (gNB), etc., and may further include RRH (Remote Radio Head), RRU (Remote Radio Unit), relay, or low power node (e.g., femto, pico, etc.). In addition, the term "base station" may include some or all of the functions thereof, and each base station can provide communication coverage for a specific geographical area. The term "cell" may refer to a base station and / or the area it covers, depending on the context of the term.

[0029] In the embodiments of the present invention, the term "User Equipment" (UE) or "Terminal Equipment" (TE) refers to a device that accesses a communication network and receives services from the network, for example, via a network device. A User Equipment may be fixed or mobile, and may also be called a Mobile Station (MS), a terminal, a Subscriber Station (SS), an Access Terminal (AT), a station, etc.

[0030] Among these, user devices may include, but are not limited to, the following: cellular phones, personal digital assistants (PDAs), wireless modems, wireless communication devices, handheld devices, machine type communication devices, laptop computers, cordless telephones, smartphones, smart watches, digital cameras, etc.

[0031] Furthermore, in scenarios such as the Internet of Things (IoT), the user equipment may also be a monitoring or measuring device or equipment, including, but not limited to, a Machine Type Communication (MTC) terminal, an in-vehicle communication terminal, a Device to Device (D2D) terminal, a Machine to Machine (M2M) terminal, etc.

[0032] In addition, the term "network side" or "network device side" refers to the network side, which may be a base station or a core network device, and may include one or more network devices as described above. The term "user side" or "terminal side" or "terminal device side" refers to the user or terminal side, which may be a UE, and may include one or more terminal devices as described above. In this specification, unless otherwise specified, "device" may refer to a network device or a terminal device.

[0033] In the embodiment of the present invention, the higher layer signaling may be, for example, Radio Resource Control (RRC) signaling, for example, referred to as RRC message, including, for example, MIB, system information, dedicated RRC message; or referred to as RRC information element (RRC IE). The higher layer signaling may be, for example, F1-C signaling, or referred to as F1AP protocol, but the present invention is not limited thereto.

[0034] When an IAB-node disconnects from its original parent IAB-node and connects to a new parent IAB-node during the process of migration, this may result in a change in the routing from the IAB-node and the IAB-node's child nodes to the Donor-CU, i.e., a change in the network topology.

[0035] Figure 3 shows the change in network topology due to the movement of IAB-node. As shown in Figure 3, after IAB-node5 switches from the cell under IAB-node3 to the cell under IAB-node4, the routing from IAB-node5 and its downstream child node IAB-node6 to Donor-CU all change.

[0036] Regarding the network topology update process when the IAB-node moves in the DU under the same donor-CU, when the IAB-node switches, the Donor-CU sets the default backhaul RLC channel and default BAP routing ID of the target path for uplink F1-C and non-F1 data for the IAB-node through the RRC reconfiguration message, and when the Donor-DU changes after switching, the Donor-CU may set the IP address for the IAB-node that can be routed to the target Donor-DU, among which the default routing ID includes the BAP address and route ID of the target Donor-DU. After the IAB-node switches to a new parent node, the IAB-node starts to apply the above-mentioned configuration, i.e., transfers the transmission path to the target side.

[0037] Various embodiments of the present invention will now be described with reference to the accompanying drawings, in which: It should be noted that these embodiments are merely illustrative and are not intended to limit the present invention.

[0038] <Example of the first aspect> In an embodiment of a first aspect of the present invention, there is provided a method for transmitting and receiving a signal, the method being applied to an IAB-node.

[0039] 4 is a diagram illustrating a method for transmitting and receiving signals in an embodiment of the first aspect. As shown in FIG. 4, the method includes the following steps (operations).

[0040] Operation 401: When the destination BAP address of the first route of the IAB-node is unreachable (when the destination BAP address of the first route of the IAB-node cannot be reached), perform a routing change on the unsuccessfully transmitted data of the first route or the received data of the first route; and Operation 402: Transmit unsuccessfully transmitted first-path data or received first-path data based on the changed routing.

[0041] According to the present invention, a routing change is made to the data on the first path, and the data can be sent based on the changed routing, thereby preventing data loss.

[0042] In the operation 401 of the present invention, performing a routing change on the data of the first route includes the following: changing the destination BAP address of the data of the first route to the destination BAP address of the second route; or changing the destination BAP address of the data of the first route to the destination BAP address of the second route, and changing the route indicator of the data of the first route to the route indicator of the second route. The data of the first route that has not been successfully sent is data of the first route that has already been generated or already received, and has not been sent in the buffer, or has already been sent but has not received an accurate response from the RLC layer. When the destination BAP address of the routing of the first route cannot be reached, the IAB-node can change the routing of the data of the first route, so that the data can be sent according to the routing of the second route after the change, and can reach Donor-CU.

[0043] In the present invention, the first route may be the uplink data transmission route before the IAB-node moves, and the route formed after the routing change is the second route.

[0044] In operation 402 of the present invention, transmitting data of the first path may include transmitting the data of the first path on a backhaul RLC channel between the IAB-node and a next hop node of the second path.

[0045] When the IAB-node changes the routing of the data of the first route, it transmits the data of the first route to the next hop node of the second route. If the Donor-CU has already set up a mapping relationship for the IAB-node from the backhaul RLC channel or the access RLC channel between the IAB-node and the previous hop node to the backhaul RLC channel between the IAB-node and the next hop node of the second route, i.e., if an appropriate next hop RLC channel already exists, the IAB-node can select a backhaul RLC channel to transmit the data of the first route based on this mapping relationship. For example, if the IAB-node already maintains a connection with the next hop node of the second route, and if the above mapping relationship does not exist, the IAB-node can select any one backhaul RLC channel to the next hop node of the second route to transmit the data of the first route, and if the IAB-node does not have a connection with the next hop node of the second route, the IAB-node can transmit the data of the first route after establishing a connection with it.

[0046] FIG. 5 is a diagram showing how the IAB-node and its child nodes make routing changes.

[0047] As shown in Figure 5, for example, when IAB-node3 leaves parent node IAB-node1 and is connected to IAB-node2, Donor-DU of IAB-node1 has changed, so IAB-node3, 4, and 5 reroute the uplink data of the original path that has not reached IAB-node1 (the destination BAP address in the BAP packet header is 1 and the path indicator is 1), i.e., change the destination BAP address in the BAP packet header to the address of the new Donor-DU (BAP address is 2), and transmit it to the backhaul RLC channel between IAB-node2. In this way, when IAB-node3 transmits the uplink data of the original path (i.e., the first path) along the target path (i.e., the second path), this data is not discarded by the target Donor-DU (BAP address is 2).

[0048] In at least one embodiment, as shown in FIG. 4, the method may further include the following steps (operations):

[0049] Operation 403: Stop changing the routing for the data of the first route.

[0050] When the IAB-node considers that the transmission of the data of the first route has been completed, it stops the routing change for the data of the first route. In operation 403, the IAB-node may stop the routing change for the data of the first route under any one of the following conditions:

[0051] Condition 1: After the IAB-node triggers a routing change to the data of the first route, a timer is started, and after the timer expires, the routing change to the data of the first route is stopped, and when the timer expires, it is considered that the data of the first route does not exist in the IAB-node and child nodes, and the routing change can be stopped.

[0052] Condition 2: When the IAB-node completes transmission of the IAB-node's unsuccessfully transmitted data for the first route, it stops the routing change for the data for the first route, and if the IAB-node and child node perform routing changes simultaneously, when the IAB-node and child node complete transmission of their own buffered unsuccessfully transmitted data for the first route, they can determine that the data for the first route does not exist and stop the routing change.

[0053] Condition 3: When the IAB-node has completed transmission of unsuccessfully transmitted data on the first route and has determined that the downstream child node has completed transmission of unsuccessfully transmitted data on the first route, the routing change for the data on the first route is stopped. This condition is applicable when the IAB-node and the child node do not perform routing changes at the same time, or when the child node does not perform routing changes. When the IAB-node has completed transmission of its own buffered data on the first route and has determined that the downstream child node has completed transmission of unsuccessfully transmitted data on the first route, the data on the first route is considered to be non-existent.

[0054] In condition 3, when the IAB-node receives a termination instruction sent by the downstream child node of the IAB-node, the IAB-node determines that the downstream child node has completed the transmission of unsuccessfully transmitted data on the first path. The termination instruction may be placed (included) in the packet header of the data PDU of the BAP, or may be placed in the control PDU of the BAP.

[0055] Fig. 6 is a diagram showing a downstream child node of an IAB-node sending a termination instruction. As shown in Fig. 6, after each downstream child node of an IAB-node completes the transmission of its own buffered data of the first path that has not been successfully transmitted, it transmits a termination instruction to the parent node of the downstream child node. Note that when a child node receives a termination instruction from a downstream child node, it does not directly forward the data, but transmits its own termination instruction to the parent node when it completes the transmission of its own buffered data of the first path, or transmits a termination instruction to the parent node after stopping the routing change for the data of the first path.

[0056] In at least one embodiment, when the destination BAP address of the first route of the IAB-node cannot be reached, the following cases include case 1 or case 2.

[0057] Case 1: After IAB-node switches to a new parent node ( (caused by IAB-node switching to a new parent node) The destination BAP address of the first route becomes unreachable; and Case 2: After a radio link failure occurs on the link between the IAB-node and the first parent node (Due to a radio link failure on the link between the IAB-node and the first parent node) , the destination BAP address of the first route becomes unreachable.

[0058] In at least one embodiment, as shown in FIG. 4, the method further includes the steps (operations) of:

[0059] Operation 404: The IAB-node receives the rerouting parameters sent by the donor central unit (Donor-CU).

[0060] When an IAB-node leaves its original parent node, it is often the case that parameters related to routing changes are not set, e.g., routing for a second path is not established, or even a connection with the next hop node of the second path is not established. In this case, by obtaining the relevant settings in operation 40, the IAB-node can make a routing change in operation 401.

[0061] In the implementation manner 1 of operation 404, the route reconfiguration parameters may include the destination BAP address and route indicator of the first route. In this way, when some original route data does not require routing change, or the IAB-node does not know which original route needs routing change, the Donor-CU can configure the route that the IAB-node needs to make a routing change.

[0062] In implementation mode 2 of operation 404, the route reconfiguration parameters may include a mapping between a destination BAP address of the first route and a destination BAP address of the second route, or may include a mapping between a destination BAP address and a route indicator of the first route and a destination BAP address and a route indicator of the second route, so that different first routes can be routed to different Donor-DUs using different second route routing, thereby meeting different QoS requirements of uplink data.

[0063] In the implementation manner 3 of operation 404, the route reconfiguration parameters may include a destination BAP address of the second route, a route indicator of the second route, and a backhaul RLC channel indicator from the IAB-node to the next hop node of the second route, where the destination BAP address of the second route and the route indicator of the second route are used to replace the destination BAP address and the route indicator in the BAP packet header of the data of the first route, and the backhaul RLC channel from the IAB-node to the next hop node of the second route is an uplink backhaul RLC channel for transmitting the data of the first route to the next hop node of the second route.

[0064] In the implementation manner 3 of the operation 404, the destination BAP address of the second path is the destination BAP address for uplink F1-C and non-F1 data, and the path indicator of the second path is the path indicator for uplink F1-C and non-F1 data; or the destination BAP address of the second path is the destination BAP address for uplink F1-U data, and the path indicator of the second path is the path indicator for uplink F1-U data. In this way, when the second path routing for uplink F1-C and non-F1 data has already been set in the IAB-node, the IAB-node can use the second path routing for the F1-C and non-F1 data as the routing for the data of the first path; and when the second path routing for uplink F1-U data is further set in the IAB-node, the IAB-node can use the second path routing for the F1-U data as the routing for the data of the first path.

[0065] In the implementation manner 3 of the operation 404, the backhaul RLC channel indicator from the IAB-node to the next hop node of the second path is a backhaul RLC channel indicator for uplink F1-C and non-F1 data, or a backhaul RLC channel indicator for uplink F1-U data. In this way, when the IAB-node is configured with a backhaul RLC channel for uplink F1-C and non-F1 data, the IAB-node can use the backhaul RLC channel for the F1-C and non-F1 data as a channel for transmitting data of the first path; and when the IAB-node is further configured with a backhaul RLC channel for uplink F1-U data, the IAB-node can use the channel for the F1-U data as a channel for transmitting data of the first path.

[0066] In the first example of implementation methods 1 to 3 of operation 404, when the destination BAP address of the first route of the IAB-node is unreachable as in the above-mentioned case 1, that is, when the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, the route reconfiguration parameters can be sent by the RRC reconfiguration message for switching sent by the Donor-CU, and the IAB-node triggers a routing change for the data of the first route when it completes random access to the new parent node.

[0067] In the second example of the implementation manners 1 to 3 of the operation 404, when the destination BAP address of the first route of the IAB-node is unreachable in the above-mentioned case 1, the route reconfiguration parameters can be sent by the F1AP message received from the Donor-CU after the IAB-node completes switching to the new parent node, and the IAB-node stops sending data of the first route when switching to the new parent node, for example, the IAB-node can stop sending a scheduling request (SR, Schedule Request) or a buffer size request (BSR, Buffer Size Request) to the parent node, or stop scheduling uplink resource grants for the child node. The IAB-node can trigger a routing change for the data of the first route when it receives the F1AP message. Because the data of the first route cannot reach the destination Donor-DU after the IAB-node switches, data loss can be avoided by stopping the sending of data of the first route immediately after switching.

[0068] In the third example of the implementation manners 1 to 3 of the operation 404, when the destination BAP address of the first path of the IAB-node is unreachable in the above-mentioned case 2, that is, when the destination BAP address of the first path becomes unreachable after the link between the IAB-node and the first parent node experiences a radio link failure, the path reconfiguration parameter can be sent by the RRC reconfiguration message or F1AP message received from the Donor-CU after the IAB-node completes re-establishment to the new parent node, and when the link between the IAB-node and the first parent node experiences a radio link failure, the IAB-node can stop sending data of the first path, for example, the IAB-node can stop sending SR and BSR to the parent node, or stop scheduling uplink resource grants for the child node. The IAB-node triggers a routing change for the data of the first path after receiving the path reconfiguration parameter. Since the data of the first path cannot reach the destination Donor-DU after the link between the IAB-node and the parent node fails, the data transmission of the first path can be immediately stopped to avoid data loss.

[0069] In the fourth example of the implementation manners 1 to 3 of the operation 404, when the destination BAP address of the first route of the IAB-node is unreachable as in the above-mentioned case 2, the route reconfiguration parameters can be sent by the F1AP message received from the Donor-CU after the IAB-node reports the radio link failure information to the Donor-CU, and the IAB-node stops sending data of the first route when a radio link failure occurs on the link between the IAB-node and the first parent node, for example, the IAB-node can stop sending SR and BSR to the parent node, or stop scheduling the uplink resource grant for the child node. The IAB-node triggers a routing change for the data of the first route when it receives the F1AP message.

[0070] In the present invention, when the routing of the second path already exists in the IAB-node, the data of the first path can be changed in routing without performing operation 404. For example, the IAB-node forms a dual connection with the first parent node and the second parent node, in which a wireless link failure occurs on the link between the IAB-node and the first parent node, and a wireless link failure does not occur on the link between the IAB-node and the second parent node. In this case, immediately after the RLF occurs on the link between the IAB-node and the first parent node, a routing change is triggered for the data of the first path, and the destination BAP address in the BAP data packet header of the path passing through (via) the first parent node is replaced with the destination BAP address of the path passing through the link between the IAB-node and the second parent node, or the destination BAP address and the path indicator are respectively replaced with the destination BAP address and the path indicator of the path passing through the link between the IAB-node and the second parent node. Then, the first path is a path that passes through the link between the IAB-node and the first parent node, and the second path is a path that passes through the link between the IAB-node and the second parent node.

[0071] Figure 7 is a diagram showing how IAB-node and its child nodes change routing when IAB-node has dual connectivity. As shown in Figure 7, IAB-node1 and IAB-node2 are the first and second parent nodes of IAB-node 3, respectively. RLF occurs on the link between IAB-node 3 and the first parent node IAB-node1, and RLF does not occur on the link between IAB-node 3 and the second parent node IAB-node2. In this case, IAB-node3 and its child nodes route data of the first path to the second path, and the second path passes through the link where RLF does not occur.

[0072] The method of transmitting and receiving signals in FIG. 4 will be described below in conjunction with a specific embodiment.

[0073] [Example 1] In the first embodiment, the case where the destination BAP address of the first route of the IAB-node is unreachable is the above-mentioned case 1 (i.e., the case where the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node).

[0074] In this embodiment, after the IAB-node switches, the original Donor-DU and the target Donor-DU are different. The IAB-node or its child node performs routing change on the uplink F1 data of the original path (i.e., the first path) that is buffered and received from the downstream node, and replaces the BAP address of the original Donor-DU in the BAP packet header with the BAP address of the target Donor-DU (i.e., the destination BAP address of the second path), or replaces the BAP address of the original Donor-DU and the original path indicator with the target Donor-DU address and the target path (i.e., the second path) indicator, respectively. Then, the IAB-node can transmit the data of the first path according to the changed routing by transmitting the uplink F1 data of the original path to the backhaul RLC channel between the IAB-node and the next hop node of the target path.

[0075] The process by which the IAB-node makes a routing change to the uplink F1 data of the original route that has been buffered and received from the downstream node is as follows.

[0076] When the IAB-node switches to a new parent node, the target transmission path parameters for uplink F1-C and non-F1 data are set by the RRC message sent by the donor-CU via the original path, which includes the target Donor-DU address, path indicator and uplink UL BH RLC channel. The donor-CU can set the target side routing for uplink F1-U data by the same RRC message, which includes the target Donor-DU address and path indicator and UL BH RLC channel.

[0077] The IAB-node can transmit the buffered original path uplink F1-U data using the destination Donor-DU address, the target side path indicator, and the uplink UL BH RLC channel of the uplink F1-C and non-F1 data, or can transmit the original path uplink data with the destination path parameters for the uplink F1-U data. Alternatively, the Donor-CU may set parameters exclusively for the routing change of the original path uplink data. To identify the original path uplink data, the IAB-node can reserve the original destination address and path indicator for a certain period after switching, or the Donor-CU can set the routing indicator (original Donor-DU address and original path indicator) of the uplink data that needs to be rerouted in the IAB-node.

[0078] To meet different QoS requirements of uplink data, uplink data of different original Donor-DUs or original routes may need to be routed to different target Donor-DUs or transmitted using different target routes. Donor-CU can set up a mapping between the original Donor-DU address and the target Donor-DU address, or set up a mapping between the BAP address and original route indicator of the original Donor-DU and the target Donor-DU address and the target route indicator.

[0079] The relevant configuration of the data routing change of the original route can be sent to the IAB-node by an RRC reconfiguration message at the time of switching or an F1AP message after the switching is completed.

[0080] In this embodiment, the manner in which the IAB-node activates the routing change of the data of the original route (i.e., the manner in which the routing change in operation 401 is triggered) includes: the IAB-node completing random access to the target cell when the route update setting has already been stored in the IAB-node; or receiving a setting regarding the routing change of the data of the original route sent by an F1AP message after the IAB-node completes the switch.

[0081] In this embodiment, the method of inactivating the rerouting of data of the original route (ie, performing operation 403) includes the following.

[0082] After activating the routing change of the data of the original route, start a timer, and deactivate the routing change of the data of the original route after the timer expires; or, when the IAB-node completes the transmission of currently buffered data of the original route that has not been successfully transmitted, deactivate the routing change of the data of the original route; or, when the IAB-node determines that it has already completed the transmission of all data of the original route in downstream nodes and has completed the transmission of currently unsuccessfully transmitted data of the original route, deactivate the routing change of the data of the original route, for example, when a child node inactivates the routing change, it sends an end instruction to a parent node, and when the IAB-node receives this end instruction, it means that all downstream child nodes have completed the transmission of data of the original route and completed the routing change.

[0083] Furthermore, in this embodiment, since the uplink data generated after switching is generated according to the target side route, there is no need to update the routing of the uplink data generated after switching.

[0084] In addition, in Example 1, the method of a child node activating a routing change of data of the original route includes activating a routing change of data of the original route when a switching success indication message sent by the IAB-node after completing random access to the target cell is received if a route update setting has already been stored in the child node; or activating a routing change of data of the original route when the IAB-node receives a setting regarding a routing change of data of the original route sent by the Donor-CU using an F1AP message after completing the switching.

[0085] In embodiment 1, the method for deactivating a routing change of data of an original path of a child node includes: starting a timer after the child node activates the routing change, and deactivating the routing change of data of the original path after the timer expires; or deactivating when the child node completes sending currently buffered data of the original path that has not been successfully sent; or deactivating when the child node determines that it has already completed sending all data of the original path at downstream nodes and completed sending data of the original path that has not been successfully sent.

[0086] [Example 2] In Example 2, the case where the destination BAP address of the first route of the IAB-node is unreachable is the above-mentioned case 2 (i.e., the destination BAP address of the first route becomes unreachable after a wireless link failure occurs in the link between the IAB-node and the first parent node).

[0087] In this embodiment 2, after the IAB-node completes the re-establishment, the original Donor-DU and the new Donor-DU become different.

[0088] After the IAB re-establishes a connection to the new cell, some uplink data of the original route may not have been transmitted to the original parent node, and this data may be discarded by the new Donor-DU if it is transmitted directly via the new route.

[0089] The IAB-node or its child node performs routing changes on the buffered and uplink F1 data of the original route received from the downstream node, and replaces the BAP address of the original Donor-DU in the BAP packet header with the BAP address of the new Donor-DU, or replaces the BAP address of the original Donor-DU and the original route indicator with the new Donor-DU address and new route indicator, respectively.

[0090] When the IAB-node has completed the re-establishment to the new cell, it makes routing changes to the uplink F1 data of the original route that has been buffered and received from downstream nodes.

[0091] During re-establishment, new transmission path parameters (including destination Donor-DU address, target path indicator, and uplink UL BH RLC channel) for uplink F1-C and non-F1 data are configured by the donor-CU. The donor-CU can configure new transmission path parameters for uplink F1-U data by the same RRC message. The IAB-node can transmit the buffered uplink F1-U data of the original path using the transmission path parameters (including Donor-DU address, path indicator, and uplink UL BH RLC channel) for uplink F1-C and non-F1 data, or can transmit the uplink data of the original path using the transmission path parameters for F1-U. Alternatively, the Donor-CU may configure parameters exclusively for the routing change of uplink data of the original path. In order to identify the uplink data of the original route, after successful re-establishment, the IAB-node can reserve the original destination address and route indicator for a certain period of time, or the Donor-CU can set the original Donor-DU address and original route indicator that need to be rerouted to the IAB-node.

[0092] To meet different QoS requirements of uplink data, different uplink data may need to be rerouted to different target Donor-DUs or transmitted using different target routes. Donor-CU can set up a mapping between the original Donor-DU BAP address and the target Donor-DU BAP address, or can set up a mapping between the original Donor-DU BAP address and the original route indicator and the target Donor-DU address and the target route indicator.

[0093] The relevant configuration of the uplink data routing change of the original path may be sent to the IAB-node by a post-reestablishment RRC reconfiguration message or a post-reestablishment F1AP message.

[0094] After completing access to the new cell, the IAB-node can prevent the uplink data from being discarded by the new Donor-DU by stopping transmission of the uplink data on the original transmission path.

[0095] In this embodiment, the method by which the IAB-node activates a data routing change (i.e., the method of the routing change in trigger operation 401) may include receiving a configuration regarding the data routing change of the original route sent by an RRC message or an F1AP message after the IAB-node completes the re-establishment.

[0096] In this embodiment, the method of inactivating the routing change of the data of the original route (ie, performing operation 403) can be referred to in the first embodiment, and the detailed description thereof will be omitted here.

[0097] In addition, in Example 2, in the process of a child node making a routing change to uplink data of the original route, a method for activating a routing change of data of the original route includes, when a route update setting is stored in the child node, for example, when the IAB-node re-establishes a connection to a target cell during IAB-node switching, activating the routing change when the child node receives a re-establishment success indication message sent by the IAB-node after completing random access to the new cell; or activating the routing change when the child node receives a setting regarding a routing change of data of the original route sent by the Donor-CU.

[0098] In the second embodiment, the method of inactivating the routing change of the data of the original route of the child node can be seen from the first embodiment, and a detailed description thereof will be omitted here.

[0099] [Example 3] In the third embodiment, when a dual connection is established for the IAB-node, an F1 transmission path is transferred from one cell group (CG) to another CG, and, for example, an RLF occurs in a BH link between the IAB-node and a parent node of one CG. After an RLF occurs in one path of the IAB-node, some uplink data transmitted by this RLF path may not reach the parent node, and if these data are directly transmitted via another path where RLF has not occurred, they may be discarded by the Donor-DU of the other path.

[0100] The IAB-node performs routing changes on the buffered and received uplink F1 data of the route via the RLF link from the downstream node, and replaces the BAP address of the Donor-DU corresponding to the route via the RLF link in the BAP packet header with the BAP address of the Donor-DU corresponding to the route not via the RLF occurring link, or further replaces the indicator of the route via the RLF occurring link with the indicator of the route not via the RLF occurring link.

[0101] When RLF occurs in one connection, the IAB-node can send an RLF report to the Donor-CU via an RRC message. For example, when RLF occurs in a master cell group (MCG), it sends master cell group failure information (MCGfailureInformation), and when RLF occurs in a secondary cell group (SCG), it sends secondary cell group failure information (SCGFailureInformation).

[0102] After the Donor-CU receives the RLF report, the Donor-CU can set parameters for uplink data, i.e., destination Donor-DU address, route indicator, and UL BH RLC channel, and the IAB-node can reroute the uplink data of the route via the RLF-occurring link according to the routing change parameters set by the Donor-CU. The Donor-CU can further set a routing indicator of the uplink data that needs to be rerouted in the IAB-node.

[0103] To satisfy different QoS requirements of uplink data, different uplink data may need to be rerouted to different target Donor-DUs or transmitted using different target routes. The Donor-CU can configure different routings to be used by different routes via the RLF-generating link.

[0104] In this embodiment, the manner in which the IAB-node activates a data routing change (i.e., the manner in which the routing change in operation 401 is triggered) includes: the IAB-node detecting that an RLF has occurred on one link; or the IAB-node receiving a configuration regarding a routing change of uplink data sent by the Donor-CU.

[0105] In this embodiment, the method of inactivating the routing change of the data of the original route (ie, performing operation 403) can be referred to in the first embodiment, and the detailed description thereof will be omitted here.

[0106] Also, the uplink data generated after the F1 transmission path transfers from one CG to another CG does not need to have its routing updated because it is generated according to the new path.

[0107] In addition, in the third embodiment, when the IAB-node detects an RLF, it transmits an RLF indication to the child node, and the RLF indication includes a routing indicator (including a route indicator and a destination BAP address) of a route via the RLF-occurring link. The child node performs a routing change for the uplink F1 data of the route via the RLF link that has not been successfully transmitted and that has been received from the downstream node.

[0108] The Donor-CU can set relevant parameters for rerouting the RLF path, i.e., destination BAP address, path indicator, and UL BH RLC channel, and the child node reroutes the uplink data of the RLF-generated path according to the parameters. The Donor-CU can further set the routing indicator (including destination BAP address and path indicator) of the uplink F1 data that needs to be rerouted to the child node.

[0109] In addition, in the third embodiment, the method of the child node activating a data routing change includes: activating a data routing change of a path when the child node receives an RLF indication transmitted by an IAB-node; or activating a data routing change when the child node receives a configuration related to rerouting uplink data transmitted by a Donor-CU.

[0110] In the third embodiment, the method of making a child node inactive can be seen in the first embodiment, and a detailed description thereof will be omitted here.

[0111] According to the embodiment of the first aspect of the present invention, a routing change is made to data on the first path, and thus data can be sent based on the changed routing, thereby preventing data loss.

[0112] <Example of the second aspect> In view of at least the same problem as in the embodiment of the first aspect, a method for transmitting and receiving signals in an embodiment of the second aspect of the present invention is provided, which corresponds to the method in the embodiment of the first aspect. The method for transmitting and receiving signals in the embodiment of the second aspect of the present invention is applied to a child node of an IAB-node.

[0113] 8 is a diagram illustrating a method for transmitting and receiving signals in an embodiment of the second aspect. As shown in FIG. 8, the method includes the following steps (operations):

[0114] Operation 801: When the destination BAP address of the first route of the IAB-node is unreachable, perform a routing change on the data of the first route that has not been successfully transmitted or the data of the first route that has been received; and Operation 802: Transmit unsuccessfully transmitted first-path data or received first-path data based on the changed routing.

[0115] According to the embodiment of the first aspect of the present invention, a routing change is made to data on the first path, and thus data can be sent based on the changed routing, thereby preventing data loss.

[0116] In operation 801, making a routing change to the data of the first path includes changing a destination BAP address of the data of the first path to a destination BAP address of the second path; or changing a destination BAP address of the data of the first path to a destination BAP address of the second path, and changing a route indicator of the data of the first path to a route indicator of the second path.

[0117] In operation 802, transmitting data of the first path includes transmitting the data of the first path on a backhaul RLC channel between the child node and a next hop node of the second path.

[0118] When the child node changes the routing of the data of the first route, the child node transmits the data of the first route to the next hop node under the second route. If the Donor-CU has already set up a mapping relationship for the child node from the backhaul RLC channel or the access RLC channel between the child node and the previous hop node to the backhaul RLC channel between the child node and the next hop node of the second route, i.e., if a suitable next hop RLC channel already exists, the child node can select a backhaul RLC channel to transmit the data of the first route based on this mapping relationship. For example, if the child node maintains a connection with the next hop node of the second route, and if the above mapping relationship does not exist, the child node can select any one backhaul RLC channel to the next hop node of the second route to transmit the data of the first route, and if the child node does not have a connection with the next hop node of the second route, the IAB-node can transmit the data of the first route after establishing a connection with it.

[0119] In this embodiment, the case where the destination BAP address of the first route of the IAB-node is unreachable includes the following case 1 or case 2, namely: Case 1: The destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node; and Case 2: The destination BAP address of the first route becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node.

[0120] As shown in FIG. 8, the method further includes the following steps (operations):

[0121] Operation 803: Stop changing the routing for the data of the first path.

[0122] The child node stops rerouting the data of the first path when it considers the data of the first path to be complete. In at least one embodiment, operation 803 is performed if any one of the following conditions is met:

[0123] Condition 1: After a child node triggers a routing change to the data of the first route, a timer is started, and after the timer expires, the routing change to the data of the first route is stopped, and when the timer expires, it is assumed that the data of the first route no longer exists in the child node and its downstream child node, and the routing change can be stopped.

[0124] Condition 2: After a child node completes transmission of unsuccessfully transmitted data on the first route, it stops the routing change for the data on the first route, and when the child node and its downstream child node simultaneously perform routing changes, when the child node and its downstream child node complete transmission of their own buffered data on the first route that was not successfully transmitted, they can determine that the data on the first route is no longer present in the child node and its downstream child node, and stop the routing change.

[0125] Condition 3: When a child node completes the transmission of data on the first path that has not been successfully transmitted, and when it is determined that a downstream child node has completed the transmission of data on the first path that has not been successfully transmitted, stop changing the routing for data on the first path, this condition can be applied when a child node and its downstream child node do not simultaneously perform a routing change, or when its downstream child node does not perform a routing change, when a child node completes the transmission of its buffered data on the first path, and can determine that its downstream child node has already completed the transmission of data on the first path that has not been successfully transmitted, it considers that there is no need to reroute data on the first path. For example, when a child node receives a termination instruction sent by its downstream child node, it can determine that the downstream child node has completed the transmission of data on the first path that has not been successfully transmitted.

[0126] As shown in FIG. 8, the method further includes the following steps (operations):

[0127] Operation 804: The child node receives the rerouting parameters sent by the Donor-CU.

[0128] When the IAB-node leaves the original parent node, the child node often does not have parameters related to the routing change set, for example, the child node does not have a second route routing established. In this case, the relevant settings can be obtained by operation 804. In the implementation manner 1 of operation 804, the route reconfiguration parameters include the destination BAP address and route indicator of the first route. In this way, when some original route data does not require a routing change, or the child node does not know which original route needs a routing change, the Donor-CU can configure the route that the child node needs to make a routing change.

[0129] In the implementation manner 2 of operation 804, the route reconfiguration parameters include a mapping between a destination BAP address of a first route and a destination BAP address of a second route, or a mapping between a destination BAP address and a route indicator of a first route and a destination BAP address and a route indicator of a second route, so that different first routes can be routed to different Donor-DUs using different routing of the second route, thereby meeting different QoS requirements of uplink data.

[0130] In the implementation manner 3 of operation 804, the path reconfiguration parameters include a destination BAP address of the second path, a path indicator of the second path, and a backhaul RLC channel indicator from the child node to the next hop node of the second path, where the destination BAP address of the second path and the path indicator of the second path are for replacing the destination BAP address and the path indicator in the data BAP packet header of the first path, and the backhaul RLC channel from the child node to the next hop node of the second path is an uplink backhaul RLC channel for transmitting data of the first path to the next hop node of the second path.

[0131] In the implementation manner 3 of the operation 804, the destination BAP address of the second path is the destination BAP address for uplink F1-C and non-F1 data, and the path indicator of the second path is the path indicator for uplink F1-C and non-F1 data; or the destination BAP address of the second path is the destination BAP address for uplink F1-U data, and the path indicator of the second path is the path indicator for uplink F1-U data. In this way, when the second path routing for uplink F1-C and non-F1 data has already been set in the child node, the second path routing for the F1-C and non-F1 data can be used as the routing for data of the first path; and when the second path routing for uplink F1-U data is further set in the child node, the second path routing for the F1-U data can be used as the routing for data of the first path.

[0132] In the implementation manner 3 of the operation 804, the backhaul RLC channel indicator to the next hop node of the second path is a backhaul RLC channel indicator for uplink F1-C and non-F1 data, or a backhaul RLC channel indicator for uplink F1-U data. In this way, when a backhaul RLC channel for uplink F1-C and non-F1 data is configured in the child node, the backhaul RLC channel for the F1-C and non-F1 data can be used as a channel for transmitting data of the first path; and when a backhaul RLC channel for uplink F1-U data is further configured in the child node, the channel for the F1-U data can be used as a channel for transmitting data of the first path.

[0133] In the first example of implementation methods 1 to 3 of operation 804, when the destination BAP address of the first route of the IAB-node is unreachable as in the above-mentioned case 1, that is, when the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, the route reconfiguration parameters are sent by the RRC reconfiguration message before the IAB-node switches, and the child node triggers a routing change for the data of the first route when it receives a switching success indication sent by the IAB-node after completing random access to the new parent node.

[0134] In the second example of the implementation manners 1 to 3 of the operation 804, when the destination BAP address of the first path of the IAB-node is unreachable as in the above-mentioned case 1, the path reconfiguration parameters are sent by the F1AP message received from the Donor-CU after the IAB-node completes the switching, and the child node stops the data of the first path when it receives the switching success indication sent by the IAB-node after completing the random access to the new parent node, for example, the child node may stop sending SR and BSR, or stop scheduling the uplink resource grant of the downstream node. The child node triggers a routing change for the data of the first path when it receives the F1AP message. Because the data of the first path cannot reach the destination Donor-DU after the IAB-node switches, data loss can be avoided by stopping the sending of the data of the first path immediately after the IAB-node switches.

[0135] In the third example of the implementation manners 1 to 3 of the operation 804, when the destination BAP address of the first route of the IAB-node is unreachable in the above-mentioned case 2, that is, when the destination BAP address of the first route becomes unreachable after the radio link failure occurs on the link between the IAB-node and the first parent node, the route reconfiguration parameters are sent by the RRC reconfiguration message sent by the Donor-CU before the radio link failure occurs on the IAB-node, and the child node triggers a routing change for the data of the first route when it receives the re-establishment success indication sent by the IAB-node after completing random access to the new parent node. Because the parameters related to the routing change are already stored in the child node when the IAB-node completes random access, the child node can immediately trigger a routing change for the data of the first route.

[0136] In the fourth example of the implementation manners 1 to 3 of the operation 804, when the destination BAP address of the first route of the IAB-node is unreachable in the above-mentioned case 2, the route reconfiguration parameters are sent by the RRC reconfiguration message or F1AP message received from the Donor-CU after the IAB-node completes the re-establishment to the new parent node, and the child node stops sending data of the first route when it receives the re-establishment success indication sent by the IAB-node after completing the random access to the new parent node, for example, the child node may stop sending SR and BSR to the parent node or stop scheduling the uplink resource grant of the downstream node. The child node triggers a routing change for the data of the first route after receiving the route reconfiguration parameters. After the IAB-node re-establishes the connection to the new parent node, the data of the first route cannot reach the destination Donor-DU, so that the child node immediately stops sending data of the first route after the IAB-node performs the re-establishment, thereby avoiding data loss.

[0137] In the fifth example of the implementation methods 1 to 3 of operation 804, when the destination BAP address of the first route of the IAB-node is unreachable as in the above-mentioned case 2, the route reconfiguration parameters are sent by the F1AP message received from the Donor-CU after the IAB-node reports radio link failure information to the Donor-CU, and the child node stops sending data of the first route when it receives the RLF indication sent by the IAB-node when a radio link failure occurs in the link between the IAB-node and the first parent node, and the child node triggers a routing change for the data of the first route when it receives the F1AP message.

[0138] Also, in at least one embodiment, when the child node already has a second route routing, when performing operation 804, a routing change can be made to the data of the first route. For example, the IAB-node forms a dual connection with a first parent node and a second parent node, in which a radio link failure occurs on the link between the IAB-node and the first parent node, and a radio link failure does not occur on the link between the IAB-node and the second parent node. In this case, when the child node receives an RLF indication sent by the IAB-node when a radio link failure (RLF) occurs on the link between the IAB-node and the first parent node, the child node triggers a routing change to the data of the first route, thereby replacing the destination BAP address in the BAP data packet header of the route via the link between the IAB-node and the first parent node with the destination BAP address corresponding to the route passing through the link between the IAB-node and the second parent node, or replacing the destination BAP address and the route indicator with the destination BAP address and the route indicator of the route passing through the link between the IAB-node and the second parent node, respectively. Then, the first path is a path that passes through the link between the IAB-node and the first parent node, and the second path is a path that passes through the link between the IAB-node and the second parent node. The RLF indication may also include a destination BAP address and a path indicator of the first path, so that when an RLF occurs in the IAB-node, the child node can know which path is affected by the RLF and needs to make a routing change.

[0139] In the embodiment of the second aspect, reference can be made to the explanations of the first to third embodiments of the first aspect for examples of behavior of child nodes.

[0140] According to the embodiment of the second aspect of the present invention, a routing change is made to the data of the first path, and thus the data can be sent based on the routing after the child node change, thereby preventing data loss.

[0141] <Example of the third aspect> In view of at least the same problem as the embodiment of the first aspect, a method for transmitting and receiving signals in an embodiment of a third aspect of the present invention is provided, which corresponds to the method in the embodiment of the first aspect. The method for transmitting and receiving signals in the embodiment of the third aspect of the present invention is applied to a Donor Central Unit (Donor-CU) of an IAB node (IAB-node).

[0142] 9 is a diagram illustrating a method for transmitting and receiving signals in an embodiment of the third aspect. As shown in FIG. 9, the method includes the following steps (operations):

[0143] Operation 901: When the destination BAP address of the first route of the IAB-node is unreachable, a route reconfiguration parameter is sent to the IAB-node or a child node of the IAB-node.

[0144] In operation 901, the route reconfiguration parameters are used by the IAB-node or a child node of the IAB-node to make a routing change to the first route data that has not been successfully transmitted or has been received.

[0145] According to an embodiment of the third aspect of the present invention, the IAB-node or its child node can use the route reconfiguration parameters to make routing changes to data on the first route, thereby enabling the IAB-node or the child node to send data based on the changed routing, thereby avoiding data loss.

[0146] In at least one embodiment, the cases where the destination BAP address of the first route of the IAB-node is unreachable include the following cases: Case 1: The destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node; or Case 2: The destination BAP address of the first route becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node.

[0147] In implementation manner 1 of operation 901, the route reconfiguration parameters may include a destination BAP address and a route indicator of the first route.

[0148] In implementation mode 2 of operation 901, the route reconfiguration parameters may include a mapping between a destination BAP address of the first route and a destination BAP address of the second route, or may include a mapping between a destination BAP address and a route indicator of the first route and a destination BAP address and a route indicator of the second route.

[0149] In the implementation manner 3 of operation 901, the path reconfiguration parameters include the destination BAP address of the second path, the path indicator of the second path, and the backhaul RLC channel indicator from IAB-node to the next hop node of the second path, where the destination BAP address of the second path is the destination BAP address for uplink F1-C and non-F1 data, and the path indicator of the second path is the path indicator for uplink F1-C and non-F1 data; or the destination BAP address of the second path is the destination BAP address for uplink F1-U data, and the path indicator of the second path is the path indicator for uplink F1-U data.

[0150] In implementation manner 3 of operation 901, the backhaul RLC channel indicator to the next hop node of the second path is a backhaul RLC channel indicator for uplink F1-C and non-F1 data; or a backhaul RLC channel indicator for uplink F1-U data.

[0151] In the first example of implementation methods 1 to 3 of operation 901, when the destination BAP address of the first route of the IAB-node is unreachable as in the above-mentioned case 1 (i.e., when the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node), the Donor-CU sends an RRC reconfiguration message including route reconfiguration parameters to the IAB-node or to a child node before the IAB-node switches; or, the Donor-CU sends an F1AP message including route reconfiguration parameters to the IAB-node or to a child node after the IAB-node completes switching to a new parent node.

[0152] In the second example of implementation methods 1 to 3 of operation 901, when the destination BAP address of the first route of the IAB-node is unreachable as in the above-mentioned case 1, the Donor-CU sends an RRC reconfiguration message or an F1AP message including route reconfiguration parameters to the IAB-node or to a child node after the IAB-node reports radio link failure information to the Donor-CU.

[0153] In the third example of implementation methods 1 to 3 of operation 901, when the destination BAP address of the first route of the IAB-node is unreachable as in the above-mentioned case 2 (i.e., when the destination BAP address of the first route becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node), the Donor-CU sends an RRC reconfiguration message or an F1AP message including route reconfiguration parameters to the IAB-node or to the child node after the IAB-node completes re-establishment to the new parent node.

[0154] In the fourth example of implementation methods 1 to 3 of operation 901, when the destination BAP address of the first route of the IAB-node is unreachable as in the above-mentioned case 2, the Donor-CU sends an RRC reconfiguration message including route reconfiguration parameters to the child node before a radio link failure occurs in the IAB-node.

[0155] In the embodiment of the third aspect, the explanation of the first to third embodiments in the embodiment of the first aspect can be referred to for examples related to actions of child nodes.

[0156] According to an embodiment of the third aspect of the present invention, the IAB-node or its child node can use the route reconfiguration parameters to make routing changes to data on the first route, thereby allowing the IAB-node or child node to send data based on the changed routing, thereby avoiding data loss.

[0157] <Example of the fourth aspect> In an embodiment of the present invention, there is provided an apparatus for transmitting and receiving signals. The apparatus may be, for example, an IAB node, or one or more components or assemblies arranged in an IAB node, for example, IAB-node 3 shown in Fig. 5. The apparatus corresponds to a method in an embodiment of the first aspect.

[0158] 10 is a diagram showing a device for transmitting and receiving signals in an embodiment of the fourth aspect of the present invention. As shown in FIG. 10, the device 1000 for transmitting and receiving signals includes:

[0159] A first processing unit 1001: used to change the routing of data of the first route that has not been successfully sent or data of the first route that has been received when the destination BAP address of the first route of the IAB-node is unreachable; and A first transceiver unit 1002 is used for transmitting the unsuccessfully transmitted data of the first path or the received data of the first path according to the changed routing.

[0160] In at least one embodiment, making a routing change to the data of the first path includes changing a destination BAP address of the data of the first path to a destination BAP address of a second path; or changing a destination BAP address of the data of the first path to a destination BAP address of the second path and changing a path indicator of the data of the first path to a path indicator of the second path.

[0161] Transmitting the data of the first path includes transmitting the data of the first path on a backhaul RLC channel between the IAB-node and a next hop node of the second path.

[0162] In at least one embodiment, the case where the destination BAP address of the first path of an IAB-node is unreachable includes the case where the destination BAP address of the first path becomes unreachable after the IAB-node switches to a new parent node; or the case where the destination BAP address of the first path becomes unreachable after a wireless link failure occurs on the link between the IAB-node and the first parent node.

[0163] In at least one embodiment, the first processing unit 1001 further performs the following operations (steps): starting a timer after triggering the routing change to be made to the data of the first path, and stopping the routing change to the data of the first path after the timer expires; When the transmission of the unsuccessfully transmitted data of the first path is completed, stopping the routing change for the data of the first path; or When the transmission of the data on the first path that has not been successfully transmitted is completed and it is determined that the downstream child node has completed the transmission of the data on the first path that has not been successfully transmitted, the routing change for the data on the first path is stopped.

[0164] In at least one embodiment, when the IAB-node receives an end indication sent by the downstream child node, the first processing unit 1001 determines that the downstream child node has completed transmitting the unsuccessfully transmitted data on the first path.

[0165] In at least one embodiment, when the destination BAP address of the first path becomes unreachable after a wireless link failure occurs on the link between the IAB-node and the first parent node, the second path is a path that passes through a link between the IAB-node and the second parent node, in which no wireless link failure occurs on the link between the IAB-node and the second parent node.

[0166] In at least one embodiment, after a radio link failure (RLF) occurs on the link between the IAB-node and a first parent node, the first processing unit 1001 triggers the IAB-node to make a routing change to the data of the first path.

[0167] In at least one embodiment, the first transceiver unit 1002 further receives route reconfiguration parameters sent by the Donor-CU, where the route reconfiguration parameters include a destination BAP address and a route indicator of the first route.

[0168] In at least one embodiment, the first transceiver unit 1002 further receives route reconfiguration parameters sent by the Donor-CU, the route reconfiguration parameters including a mapping between a destination BAP address of the first route and a destination BAP address of the second route, or a mapping between a destination BAP address and a route indicator of the first route and a destination BAP address and a route indicator of the second route.

[0169] In at least one embodiment, the first transceiver unit 1002 further receives route reconfiguration parameters sent by Donor-CU, the route reconfiguration parameters including a destination BAP address of the second route, a route indicator of the second route, and a backhaul RLC channel indicator from the IAB-node to the next hop node of the second route.

[0170] In at least one embodiment, the destination BAP address of the second path is a destination BAP address for uplink F1-C and non-F1 data, and the path indicator of the second path is a path indicator for uplink F1-C and non-F1 data; or, the destination BAP address of the second path is a destination BAP address for uplink F1-U data, and the path indicator of the second path is a path indicator for uplink F1-U data.

[0171] In at least one embodiment, the backhaul RLC channel indication to the next hop node of the second path is a backhaul RLC channel indication for uplink F1-C and non-F1 data; or a backhaul RLC channel indication for uplink F1-U data.

[0172] In at least one embodiment, when the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, the route reconfiguration parameters are sent in an RRC reconfiguration message for switching sent by the Donor-CU, during which, when the IAB-node completes random access to the new parent node, the first processing unit 1001 triggers a routing change for the data of the first route.

[0173] In at least one embodiment, when the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, the route reconfiguration parameters are sent in an F1AP message received from Donor-CU after the IAB-node completes switching to a new parent node, wherein, when the IAB-node switches to a new parent node, the first transceiver unit 1002 stops sending data of the first route, and when the IAB-node receives the F1AP message, the first processing unit 1001 triggers a routing change for the data of the first route.

[0174] In at least one embodiment, when the destination BAP address of the first route becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node, the route reconfiguration parameters are sent by an RRC reconfiguration message or an F1AP message received from a Donor-CU after the IAB-node completes re-establishment to a new parent node, wherein, when a radio link failure occurs on the link between the IAB-node and the first parent node, the first transceiver unit 1002 stops sending data of the first route, and after the first transceiver unit 1002 receives the route reconfiguration parameters, the first processing unit 1001 triggers a routing change for the data of the first route.

[0175] In at least one embodiment, when the destination BAP address of the first route becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node, the route reconfiguration parameters are sent by an F1AP message received from the Donor-CU after the IAB-node reports radio link failure information to the Donor-CU, wherein, when a radio link failure occurs on the link between the IAB-node and the first parent node, the first transceiver unit 1002 stops sending data of the first route, and when the first transceiver unit 1002 receives the F1AP message, the first processing unit 1001 triggers a routing change for the data of the first route.

[0176] According to an embodiment of the fourth aspect of the present invention, a routing change is made to data on the first path, and data can be sent based on the changed routing, thereby preventing data loss.

[0177] <Example of the fifth aspect> An embodiment of the present invention provides an apparatus for transmitting and receiving signals, which may be, for example, a child node of an IAB node, or one or more components or assemblies disposed in the child node, for example, an IAB node such as IAB-node 3 shown in Fig. 5. The apparatus corresponds to a method in an embodiment of the second aspect.

[0178] 11 is a diagram showing a device for transmitting and receiving signals in an embodiment of the fifth aspect of the present invention. As shown in FIG. 11, the device for transmitting and receiving signals 1100 includes:

[0179] A second processing unit 1101 is used to change the routing of data of the first route that has not been successfully sent or data of the first route that has been received when the destination BAP address of the first route of the IAB-node is unreachable; and A second transceiver unit 1102 is used for transmitting the unsuccessfully transmitted data of the first path or the received data of the first path according to the changed routing.

[0180] In at least one embodiment, making a routing change to the data of the first path includes changing a destination BAP address of the data of the first path to a destination BAP address of a second path; or changing a BAP address of the data of the first path to a BAP address of the second path and changing a path indicator of the data of the first path to a path indicator of the second path.

[0181] In at least one embodiment, transmitting the data of the first path includes transmitting the data of the first path on a backhaul RLC channel between the child node and a next hop node of the second path.

[0182] In at least one embodiment, the case where the destination BAP address of the first path of an IAB-node is unreachable includes the case where the destination BAP address of the first path becomes unreachable after the IAB-node switches to a new parent node; or the case where the destination BAP address of the first path becomes unreachable after a wireless link failure occurs on the link between the IAB-node and the first parent node.

[0183] In at least one embodiment, the second processing unit 1101 further performs the following operations (steps): starting a timer after triggering the routing change to be made to the data of the first path, and stopping the routing change to the data of the first path after the timer expires; After completing the unsuccessfully transmitted data transmission of the first path, stopping the routing change for the data of the first path; or When the transmission of the data on the first path that has not been successfully transmitted is completed, and when it is determined that the downstream child node has completed the transmission of the data on the first path that has not been successfully transmitted, the routing change for the data on the first path is stopped.

[0184] In at least one embodiment, the second processing unit 1101 determines that the downstream child node of the child node has completed transmitting the unsuccessfully transmitted data on the first path when it receives a termination indication transmitted by the downstream child node of the child node.

[0185] In at least one embodiment, when the destination BAP address of the first path becomes unreachable after a wireless link failure occurs on the link between the IAB-node and the first parent node, the second path is a path that passes through a link between the IAB-node and the second parent node, in which no wireless link failure occurs on the link between the IAB-node and the second parent node.

[0186] In at least one embodiment, when the second transceiver unit 1102 receives a radio link failure (RLF) indication sent by the IAB-node when a RLF occurs on the link between the IAB-node and a first parent node, the second processing unit 1101 triggers the child node to make a routing change to the data of the first path.

[0187] In at least one embodiment, the RLF indication includes a destination BAP address and a route indicator for the first route.

[0188] In at least one embodiment, the second transceiver unit 1102 further receives a route reconfiguration parameter sent by the Donor-CU, where the route reconfiguration parameter includes a destination BAP address and a route indicator of the first route.

[0189] In at least one embodiment, the second transceiver unit 1102 further receives route reconfiguration parameters sent by the Donor-CU, the route reconfiguration parameters including a mapping between a destination BAP address of the first route and a destination BAP address of the second route, or a mapping between a destination BAP address and a route indicator of the first route and a destination BAP address and a route indicator of the second route.

[0190] In at least one embodiment, the second transceiver unit 1102 further receives route reconfiguration parameters sent by the Donor-CU, the route reconfiguration parameters including a destination BAP address of the second route, a route indicator of the second route, and a backhaul RLC channel indicator from the child node to the next hop node of the second route.

[0191] In at least one embodiment, the destination BAP address of the second path is a destination BAP address for uplink F1-C and non-F1 data, and the path indicator of the second path is a path indicator for uplink F1-C and non-F1 data; or, the destination BAP address of the second path is a destination BAP address for uplink F1-U data, and the path indicator of the second path is a path indicator for uplink F1-U data.

[0192] In at least one embodiment, the backhaul RLC channel indication to the next hop node of the second path is a backhaul RLC channel indication for uplink F1-C and non-F1 data; or a backhaul RLC channel indication for uplink F1-U data.

[0193] In at least one embodiment, when the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, the route reconfiguration parameters are sent in an RRC reconfiguration message before the IAB-node switches, wherein, when the second transceiver unit 1102 receives a switching success indication sent by the IAB-node after completing random access to the new parent node, the second processing unit 1101 triggers a routing change for the data of the first route.

[0194] In at least one embodiment, when the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, the route reconfiguration parameters are sent in an F1AP message received from Donor-CU after the IAB-node completes the switching, wherein, when the second transceiver unit 1102 receives a switching success indication sent by the IAB-node after completing random access to the new parent node, it stops sending data of the first route; and, when the second transceiver unit 1102 receives the F1AP message, the second processing unit 1101 triggers a routing change for the data of the first route.

[0195] In at least one embodiment, when the destination BAP address of the first path becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node, the path reconfiguration parameters are sent in an RRC reconfiguration message sent by the Donor-CU before a radio link failure occurs to the IAB-node, wherein, when the second transceiver unit 1102 receives a re-establishment success indication sent by the IAB-node after completing random access to a new parent node, the second processing unit 1101 triggers a routing change for the data of the first path.

[0196] In at least one embodiment, when the destination BAP address of the first route becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node, the route reconfiguration parameters are sent in an RRC reconfiguration message or an F1AP message received from the Donor-CU after the IAB-node completes re-establishment to a new parent node, wherein, when the second transceiver unit 1102 receives a re-establishment success indication sent by the IAB-node after completing random access to a new parent node, it stops sending data of the first route; and, after the second transceiver unit 1102 receives the route reconfiguration parameters, the second processing unit 1101 triggers a routing change for the data of the first route.

[0197] In at least one embodiment, when the destination BAP address of the first route becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node, the route reconfiguration parameters are sent by an F1AP message received from the Donor-CU after the IAB-node reports radio link failure information to the Donor-CU, wherein, when the second transceiver unit 1102 receives an RLF indication sent by the IAB-node when a radio link failure occurs on the link between the IAB-node and the first parent node, it stops sending data of the first route; and, when the second transceiver unit 1102 receives the F1AP message, the second processing unit 1101 triggers a routing change for the data of the first route.

[0198] According to an embodiment of the fifth aspect of the present invention, a routing change is made to data on the first path, and thus data can be sent based on the changed routing, thereby preventing data loss.

[0199] <Example of the sixth aspect> In an embodiment of the present invention, there is provided an apparatus for transmitting and receiving signals, which may be, for example, a donor central unit (IAB-donor CU) or one or more components or assemblies arranged in the donor central unit (IAB-donor CU), for example, the Donor CU shown in Fig. 5. The apparatus for transmitting and receiving corresponds to the method for transmitting and receiving signals as described in the embodiment of the third aspect.

[0200] 12 is a diagram showing an apparatus for transmitting and receiving signals in an embodiment of the sixth aspect. As shown in FIG. 12, the apparatus 1200 includes:

[0201] Third transceiver unit 1201: Used for sending route reconfiguration parameters to an IAB-node or a child node of the IAB-node when the destination BAP address of the first route of the IAB-node is unreachable, in which the route reconfiguration parameters are used by the IAB-node or the child node to make routing changes to the data of the first route that has not been successfully sent or the data of the first route that has been received.

[0202] In at least one embodiment, the rerouting parameters include a destination BAP address and a route indicator of the first route.

[0203] In at least one embodiment, the route reconfiguration parameters include a mapping between a destination BAP address of the first route and a destination BAP address of the second route, or a mapping between a destination BAP address and a route indicator of the first route and a destination BAP address and a route indicator of the second route.

[0204] In at least one embodiment, the case where the destination BAP address of the first path of an IAB-node is unreachable includes the case where the destination BAP address of the first path becomes unreachable after the IAB-node switches to a new parent node; or the case where the destination BAP address of the first path becomes unreachable after a wireless link failure occurs on the link between the IAB-node and the first parent node.

[0205] In at least one embodiment, the route reconfiguration parameters include a destination BAP address of the second route, a route indicator of the second route, and a backhaul RLC channel indicator from the IAB-node to a next hop node of the second route.

[0206] In at least one embodiment, the destination BAP address of the second path is a destination BAP address for uplink F1-C and non-F1 data, and the path indicator of the second path is a path indicator for uplink F1-C and non-F1 data; or, the destination BAP address of the second path is a destination BAP address for uplink F1-U data, and the path indicator of the second path is a path indicator for uplink F1-U data.

[0207] In at least one embodiment, the backhaul RLC channel indication to the next hop node of the second path is a backhaul RLC channel indication for uplink F1-C and non-F1 data; or a backhaul RLC channel indication for uplink F1-U data.

[0208] In at least one embodiment, when the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, the third transceiver unit 1201 sends an RRC reconfiguration message including the route reconfiguration parameters to the IAB-node or the child node before the IAB-node switches; or, the third transceiver unit 1201 sends an F1AP message including the route reconfiguration parameters to the IAB-node or the child node after the IAB-node completes switching to a new parent node.

[0209] In at least one embodiment, when the destination BAP address of the first path becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node, the third transceiver unit 1201 sends an RRC reconfiguration message or an F1AP message including the path reconfiguration parameters to the IAB-node or the child node after the IAB-node completes re-establishment to a new parent node.

[0210] In at least one embodiment, when the destination BAP address of the first path becomes unreachable after a radio link failure occurs on the link between the IAB-node and the first parent node, the third transceiver unit 1201 sends an RRC reconfiguration message or an F1AP message including the path reconfiguration parameters to the IAB-node or the child node after the IAB-node reports radio link failure information to the Donor-CU.

[0211] In at least one embodiment, when the destination BAP address of the first path becomes unreachable after a radio link failure occurs on the link between the IAB-node and a first parent node, the third transceiver unit 1201 sends an RRC reconfiguration message including the path reconfiguration parameters to the child node before a radio link failure occurs to the IAB-node.

[0212] According to an embodiment of the third aspect of the present invention, the IAB-node or its child node can use the route reconfiguration parameters to make routing changes to data on the first route, thereby allowing the IAB-node or child node to send data based on the changed routing, thereby avoiding data loss.

[0213] The above-mentioned embodiments are provided to exemplify the embodiments of the present invention, but the present invention is not limited thereto, and appropriate modifications may be made based on the above-mentioned embodiments. For example, each of the above-mentioned embodiments may be used alone, or a combination of two or more of the above-mentioned embodiments may be used.

[0214] <Example of the seventh aspect> An embodiment of the present invention further provides a communication system, which can be seen from FIG. 1, in which the same contents as those of the embodiments of the first to sixth aspects will not be described again.

[0215] In some embodiments, a communication system may include:

[0216] A donor central unit (IAB-donor CU) including a device 1200 for transmitting and receiving signals as described in the embodiment of the fourth aspect; IAB node: including the device 1000 for transmitting and receiving signals according to the embodiment of the fourth aspect; and Child node: includes the device 1100 for transmitting and receiving signals as described in the embodiment of the fifth aspect.

[0217] Wherein, the IAB node (IAB) may include an IAB-MT functional unit and an IAB-DU functional unit, wherein the IAB-MT functional unit may have the same structure as a terminal device, and the IAB-DU functional unit and the donor central unit (IAB-donor CU) may be units having the same structure as a network device.

[0218] Fig. 13 is a block diagram of a network device in an embodiment of the present invention. As shown in Fig. 13, the network device 1300 includes a processor 1310 (e.g., a central processing unit CPU) and a memory 1320, and the memory 1220 is connected to the processor 1310. The memory 1320 can store various data, and can also store a program 1330 for information processing, and can execute the program 1330 under the control of the processor 1310.

[0219] For example, the processor 1310 may be configured to execute a program to implement a method performed by the IAB-DU in the embodiment of the first aspect or the IAB-donor CU in the embodiment of the second aspect.

[0220] In addition, as shown in Fig. 13, the network device 1300 may further include a transceiver 1340, an antenna 1350, etc., among which, the functions of these components are similar to those of the prior art, so detailed description thereof will be omitted here. It is not necessary for the network device 1300 to include all the components shown in Fig. 13. In addition, the network device 1300 may further include components not shown in Fig. 13, and the prior art can be referred to for this.

[0221] FIG. 14 is a diagram illustrating a terminal device according to an embodiment of the present invention. As shown in FIG. 14, the terminal device 1400 includes a processor 1410 and a memory 1420, where the memory 1420 stores data and programs and is connected to the processor 1410. It should be noted that the diagram is merely an example, and other types of structures may be used to supplement or replace the structures to achieve the telecommunication function or other functions. For example, the processor 1410 may be configured to execute a program to achieve the method performed by the IAB-MT described in the embodiment of the first aspect.

[0222] As shown in Fig. 14, the terminal device 1400 may further include a communication module 1430, an input unit 1440, a display 1450, a power supply 1460, etc. Among them, the functions of these components are similar to those of the prior art, so detailed descriptions thereof will be omitted here. It is not necessary for the terminal device 1400 to include all the components shown in Fig. 14. In addition, the terminal device 1400 may further include components not shown in Fig. 14, but the prior art can be referred to for this.

[0223] An embodiment of the present invention further provides a computer program, which, when executed by an IAB, causes the IAB to perform the method for transmitting and receiving signals according to an embodiment of the first aspect.

[0224] An embodiment of the present invention further provides a storage medium having a computer program stored thereon, wherein the computer program causes an IAB to perform the method for transmitting and receiving signals according to an embodiment of the first aspect.

[0225] An embodiment of the present invention further provides a computer program, wherein, when the program is executed in a child node of an IAB-node, the program causes the child node to perform a method according to an embodiment of the second aspect.

[0226] An embodiment of the present invention further provides a storage medium storing a computer program, wherein the computer program causes a child node of an IAB-node to perform the method described in the embodiment of the second aspect.

[0227] An embodiment of the present invention further provides a computer program, which, when executed by a Donor-CU, causes the Donor-CU to perform the method described in the embodiment of the third aspect.

[0228] In a further embodiment of the present invention, a storage medium storing a computer program is provided, wherein the computer program causes a Donor-CU to perform the method according to the embodiment of the third aspect.

[0229] The above-mentioned devices and methods may be realized by software or hardware, or may be realized by a combination of hardware and software. The present invention further relates to a computer readable program, which, when executed by a logic component, causes the logic component to realize the above-mentioned devices or components, or causes the logic component to realize the various methods or steps described above. The logic component may be, for example, a Field Programmable Gate Array (FPGA), a microprocessor, a processor for use in a computer, etc. The present invention further relates to a storage medium, such as a hard disk, a magnetic disk, an optical hard disk, a DVD, a flash memory, etc., storing the above-mentioned program.

[0230] Furthermore, one or more combinations of the functional blocks described in the drawings and / or one or more combinations of the functional blocks may be implemented as a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic component, discrete gate or transistor logic component, discrete hardware assembly, or any other suitable combination for performing the functions described herein. Also, one or more combinations of the functional blocks described in the drawings and / or one or more combinations of the functional blocks may further be configured as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors connected in communication with the DSP, or any other configuration combination.

[0231] As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to such embodiments, and any changes to the present invention belong to the technical scope of the present invention as long as they do not depart from the spirit of the present invention.

[0232] Also, regarding the above-described embodiments and the like, the following additional remarks are disclosed.

[0233] (Additional Remark) <IAB-node Side Method> (Additional Remark 1) A method for transmitting and receiving signals, which is applicable to an IAB node (IAB-node), the method comprising: When the destination BAP address of the first path of the IAB-node is unreachable, performing a routing change on the data of the first path that has not been successfully transmitted or the data of the first path that has been received; and Transmitting the data of the first path that has not been successfully transmitted or the data of the first path that has been received based on the changed routing.

[0234] (Additional Remark 2) The method according to Additional Remark 1, wherein Making a routing change to the data of the first path includes: Changing the destination BAP address of the data of the first path to a destination BAP address of the second path; or changing a destination BAP address of the data of the first path to a destination BAP address of the second path, and changing a path indicator of the data of the first path to a path indicator of the second path.

[0235] (Appendix 3) 3. The method according to claim 2, comprising: Transmitting the first path data includes: transmitting data of the first path through a backhaul RLC channel between the IAB-node and a next hop node of the second path.

[0236] (Appendix 4) 4. The method according to claim 3, comprising: If the destination BAP address of the first route of the IAB-node is unreachable, The destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node; or The method includes a case where a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node.

[0237] (Appendix 5) The method according to claim 4, further comprising: starting a timer after the IAB-node triggers a routing change to the data of the first route, and stopping the routing change to the data of the first route after the timer expires; When the IAB-node completes transmission of the unsuccessfully transmitted data of the first path, stopping the routing change for the data of the first path; or and stopping routing changes to data on the first path when the IAB-node has completed transmission of unsuccessfully transmitted data on the first path and when it is determined that a downstream child node has completed transmission of unsuccessfully transmitted data on the first path.

[0238] (Appendix 6) 6. The method according to claim 5, The method of the present invention further comprises determining, when the IAB-node receives an end instruction sent by the downstream child node, that the downstream child node has completed sending the unsuccessfully sent data on the first path.

[0239] (Appendix 7) 5. The method according to claim 4, When a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node, The second path is a path passing through a link between the IAB-node and a second parent node, in which no wireless link failure occurs on the link between the IAB-node and the second parent node.

[0240] (Appendix 8) 8. The method according to claim 7, The method includes triggering the IAB-node to make a routing change to the data of the first path after a radio link failure (RLF) occurs on a link between the IAB-node and a first parent node.

[0241] (Appendix 9) The method according to claim 4, further comprising: The IAB-node receives a route reconfiguration parameter transmitted by the Donor-CU; The rerouting parameters include a destination BAP address and a route indicator of the first route.

[0242] (Appendix 10) The method according to claim 4, further comprising: The IAB-node receives a route reconfiguration parameter transmitted by the Donor-CU; The method, wherein the route reconfiguration parameters include a mapping between a destination BAP address of the first route and a destination BAP address of the second route, or a mapping between a destination BAP address and a route indicator of the first route and a destination BAP address and a route indicator of the second route.

[0243] (Appendix 11) The method according to claim 4, further comprising: The IAB-node receives a route reconfiguration parameter transmitted by a Donor-CU; The method, wherein the route reconfiguration parameters include a destination BAP address of the second route, a route indicator of the second route, and a backhaul RLC channel indicator from the IAB-node to a next hop node of the second route.

[0244] (Appendix 12) 12. The method according to claim 11, The destination BAP address of the second path is a destination BAP address for uplink F1-C and non-F1 data, and the path indicator of the second path is a path indicator for uplink F1-C and non-F1 data; or The destination BAP address of the second path is a destination BAP address for uplink F1-U data, and the path marker of the second path is a path marker for uplink F1-U data.

[0245] (Appendix 13) 12. The method according to claim 11, a backhaul RLC channel indicator to a next hop node of the second path; a backhaul RLC channel indication for uplink F1-C and non-F1 data; or a backhaul RLC channel indication for uplink F1-U data.

[0246] (Appendix 14) The method according to any one of claims 9-11, comprising: If the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, The route reconfiguration parameters are transmitted by an RRC reconfiguration message for switching transmitted by a Donor-CU; The method further comprises: triggering a routing change to data on the first path when the IAB-node completes a random access to a new parent node.

[0247] (Appendix 15) The method according to any one of claims 9-11, comprising: If the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, The rerouting parameters are sent in an F1AP message received from a Donor-CU after the IAB-node has completed switching to a new parent node; The method further comprises: Stopping the transmission of data on the first path when the IAB-node switches to a new parent node; and triggering a routing change to the data of the first path when the IAB-node receives the F1AP message.

[0248] (Appendix 16) The method according to any one of claims 9-11, comprising: When a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node, The route reconfiguration parameters are sent in an RRC reconfiguration message or an F1AP message received from a Donor-CU after the IAB-node has completed reestablishment to a new parent node; The method further comprises: When a radio link failure occurs in the link between the IAB-node and the first parent node, stop transmitting the data of the first path; and A method, including triggering a routing change for the data of the first path after the IAB-node receives the path reconfiguration parameter.

[0249] (Appendix 17) The method according to any one of Appendices 9-11, When the destination BAP address of the first path becomes unreachable after a radio link failure occurs in the link between the IAB-node and the first parent node, The path reconfiguration parameter is transmitted by an F1AP message received from the Donor-CU after the IAB-node reports radio link failure information to the Donor-CU, The method further includes, When a radio link failure occurs in the link between the IAB-node and the first parent node, stop transmitting the data of the first path; and A method, including triggering a routing change for the data of the first path when the IAB-node receives the F1AP message.

[0250] <Method on the IAB-node child node side> (Appendix 1) A method for transmitting and receiving signals, which is applied to a child node of an IAB node (IAB-node), and the method includes, When the destination BAP address of the first path of the IAB-node is unreachable, perform a routing change on the data of the first path that has not been successfully transmitted or the data of the first path received; and A method, including transmitting the data of the first path that has not been successfully transmitted or the data of the first path received based on the changed routing.

[0251] (Appendix 2) The method according to Appendix 1, Making a routing change to the data of the first path includes: Changing the destination BAP address of the data of the first path to a destination BAP address of the second path; or changing a BAP address of the data of the first path to a BAP address of a second path, and changing a path indicator of the data of the first path to a path indicator of the second path.

[0252] (Appendix 3) 3. The method according to claim 2, comprising: Transmitting the first path data includes: transmitting data of the first path on a backhaul RLC channel between the child node and a next hop node of the second path.

[0253] (Appendix 4) 4. The method according to claim 3, comprising: If the destination BAP address of the first route of the IAB-node is unreachable, The destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node; or The method includes a case where a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node.

[0254] (Appendix 5) The method according to claim 4, further comprising: starting a timer after the child node triggers a routing change to the data of the first path, and stopping the routing change to the data of the first path after the timer expires; After the child node completes transmission of the unsuccessfully transmitted data of the first path, stopping the routing change for the data of the first path; or and stopping routing changes to data on the first path when it is determined that the child node has completed transmission of unsuccessfully transmitted data on the first path and that a downstream child node has completed transmission of unsuccessfully transmitted data on the first path.

[0255] (Appendix 6) 6. The method according to claim 5, determining that the downstream child node has completed transmitting the unsuccessfully transmitted data of the first path when the child node receives a completion indication transmitted by the downstream child node of the child node.

[0256] (Appendix 7) 5. The method according to claim 4, When a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node, The second path is a path that passes through a link between the IAB-node and a second parent node, and no wireless link failure occurs on the link between the IAB-node and the second parent node.

[0257] (Appendix 8) 8. The method according to claim 7, The method includes triggering the child node to make a routing change to the data of the first path when the child node receives a radio link failure (RLF) indication transmitted when an RLF occurs on a link between the IAB-node and a first parent node.

[0258] (Appendix 9) 9. The method according to claim 8, comprising: The RLF indication includes a destination BAP address and a route indicator of the previous first route.

[0259] (Appendix 10) The method according to claim 4, further comprising: The child node receives a route reconfiguration parameter transmitted by the Donor-CU; The rerouting parameters include a destination BAP address and a route indicator of the first route.

[0260] (Appendix 11) The method according to claim 4, further comprising: The child node receives a route reconfiguration parameter transmitted by the Donor-CU; The method, wherein the route reconfiguration parameters include a mapping between a destination BAP address of the first route and a destination BAP address of the second route, or a mapping between a destination BAP address and a route indicator of the first route and a destination BAP address and a route indicator of the second route.

[0261] (Appendix 12) The method according to claim 4, further comprising: The child node receives a route reconfiguration parameter transmitted by the Donor-CU; The method, wherein the route reconfiguration parameters include a destination BAP address of the second route, a route indicator of the second route, and a backhaul RLC channel indicator from the child node to a next hop node of the second route.

[0262] (Appendix 13) 13. The method of claim 12, The destination BAP address of the second path is a destination BAP address for uplink F1-C and non-F1 data, and the path indicator of the second path is a path indicator for uplink F1-C and non-F1 data; or The destination BAP address of the second path is a destination BAP address for uplink F1-U data, and the path marker of the second path is a path marker for uplink F1-U data.

[0263] (Appendix 14) 13. The method of claim 12, a backhaul RLC channel indicator to a next hop node of the second path; a backhaul RLC channel indication for uplink F1-C and non-F1 data; or a backhaul RLC channel indication for uplink F1-U data.

[0264] (Appendix 15) 13. The method according to any one of claims 10-12, comprising: If the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, The route reconfiguration parameters are transmitted by an RRC reconfiguration message before the IAB-node is switched; The method further comprises: triggering a routing change to data on the first path when the child node receives a switching success indication sent by the IAB-node after completing random access to a new parent node.

[0265] (Appendix 16) 13. The method according to any one of claims 10-12, comprising: If the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, The rerouting parameters are sent in an F1AP message received from the Donor-CU after the IAB-node completes the switchover; The method further comprises: When the child node receives a switching success indication sent by the IAB-node after completing random access to a new parent node, the child node stops sending data of the first path; and triggering a routing change to the first path data when the child node receives the F1AP message.

[0266] (Appendix 17) 13. The method according to any one of claims 10-12, comprising: When a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node, The route reconfiguration parameters are transmitted by an RRC reconfiguration message transmitted by a Donor-CU before a radio link failure occurs at the IAB-node; The method further comprises: triggering a routing change to data on the first path when the child node receives a re-establishment success indication sent by the IAB-node after completing random access to a new parent node.

[0267] (Appendix 18) 13. The method according to any one of claims 10-12, comprising: When a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node, The route reconfiguration parameters are sent in an RRC reconfiguration message or an F1AP message received from a Donor-CU after the IAB-node has completed reestablishment to a new parent node; The method further comprises: When the child node receives a re-establishment success indication sent by the IAB-node after completing random access to a new parent node, the child node stops sending data on the first path; and triggering a routing change to the first route data after the child node receives the route reconfiguration parameters.

[0268] (Appendix 19) 13. The method according to any one of claims 10-12, comprising: When a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node, The path reconfiguration parameter is transmitted by an F1AP message received from the Donor-CU after the IAB-node reports radio link failure information to the Donor-CU. The method further includes when the child node receives an RLF indication transmitted when a radio link failure occurs in the link between the IAB-node and the first parent node, stopping the transmission of data on the first path; and when the child node receives the F1AP message, triggering a routing change for the data on the first path.

[0269] <Method on the Donor-CU side> (Appendix 1) A method for transmitting and receiving signals, which is applied to a donor central unit (Donor-CU), the method includes when the destination BAP address of the first path of the IAB-node is unreachable, transmitting path reconfiguration parameters to the IAB-node or a child node of the IAB-node, wherein the path reconfiguration parameter is used to perform a routing change on the data of the first path that has not been successfully transmitted or the received data of the first path.

[0270] (Appendix 2) The method according to Appendix 1, wherein the path reconfiguration parameter includes the destination BAP address and path identifier of the first path.

[0271] (Appendix 3) The method according to Appendix 1, wherein the path reconfiguration parameter includes a mapping between the destination BAP address of the first path and the destination BAP address of the second path, or includes a mapping between the destination BAP address and path identifier of the first path and the destination BAP address and path identifier of the second path.

[0272] (Appendix 4) 2. The method according to claim 1, comprising: If the destination BAP address of the first route of the IAB-node is unreachable, The destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node; or The method includes a case where a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node.

[0273] (Appendix 5) 5. The method according to claim 4, The method, wherein the route reconfiguration parameters include a destination BAP address of the second route, a route indicator of the second route, and a backhaul RLC channel indicator from the IAB-node to a next hop node of the second route.

[0274] (Appendix 6) 6. The method according to claim 5, The destination BAP address of the second path is a destination BAP address for uplink F1-C and non-F1 data, and the path indicator of the second path is a path indicator for uplink F1-C and non-F1 data; or The destination BAP address of the second path is a destination BAP address for uplink F1-U data, and the path marker of the second path is a path marker for uplink F1-U data.

[0275] (Appendix 7) 6. The method according to claim 5, a backhaul RLC channel indicator to a next hop node of the second path; a backhaul RLC channel indication for uplink F1-C and non-F1 data; or a backhaul RLC channel indication for uplink F1-U data.

[0276] (Appendix 8) 6. The method according to claim 5, If the destination BAP address of the first route becomes unreachable after the IAB-node switches to a new parent node, The Donor-CU sends an RRC reconfiguration message including the path reconfiguration parameters to the IAB-node or the child node before switching the IAB-node; or The method includes the Donor-CU sending an F1AP message including the route reconfiguration parameters to the IAB-node or the child node after the IAB-node completes switching to a new parent node.

[0277] (Appendix 9) 6. The method according to claim 5, When a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node, The method includes the Donor-CU sending an RRC reconfiguration message or an F1AP message including the path reconfiguration parameters to the IAB-node or the child node after the IAB-node completes reestablishment to a new parent node.

[0278] (Appendix 10) 6. The method according to claim 5, When a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node, The method includes the Donor-CU sending an RRC reconfiguration message or an F1AP message including the path reconfiguration parameters to the IAB-node or the child node after the IAB-node reports radio link failure information to the Donor-CU.

[0279] (Appendix 11) 6. The method according to claim 5, When a destination BAP address of the first path becomes unreachable after a wireless link failure occurs on a link between the IAB-node and a first parent node, The method includes the Donor-CU sending an RRC reconfiguration message including the path reconfiguration parameters to the child node before a radio link failure occurs to the IAB-node.

Claims

1. A device for transmitting and receiving signals, which is applied to an IAB node, a processor for rerouting first path data when a destination BAP address of the first path of the IAB-node is unreachable; and a transmitter for transmitting the first route data based on the changed route; The transmitter further transmits the first path data to a backhaul RLC channel between the IAB-node and a next hop node of a second path.

2. 2. The apparatus of claim 1, Changing the route of the first route data Changing the destination BAP address of the first route data to a destination BAP address of a second route; or changing a destination BAP address of the first route data to a destination BAP address of a second route, and changing a route identifier (ID) of the first route data to a route identifier of the second route.

3. 2. The apparatus of claim 1, If the destination BAP address of the first route of the IAB-node is unreachable, The destination BAP address of the first path becomes unreachable because the IAB-node has switched to a new parent node; or The apparatus further includes a case where a destination BAP address of the first path becomes unreachable due to a radio link failure occurring on a link between the IAB-node and a first parent node.

4. 4. The apparatus of claim 3, The processor further comprises: triggering the initiation of a timer after modifying the route of the first route data, and stopping the modification of the route of the first route data after the timer expires; Stopping the rerouting of the first route data after completing the transmission of the unsuccessfully transmitted first route data; or The device stops changing the route of the first route data when it completes transmission of the unsuccessfully transmitted first route data and determines that a downstream child node has completed transmission of the unsuccessfully transmitted first route data.

5. 3. The apparatus of claim 2, Further comprising a receiver; The receiver receives a route reconfiguration parameter transmitted by a Donor-CU; The route reconfiguration parameters include a mapping between a destination BAP address of the first route and a destination BAP address of the second route, or a mapping between a destination BAP address and a route indicator of the first route and a destination BAP address and a route indicator of the second route.

6. 3. The apparatus of claim 2, Further comprising a receiver; The receiver receives a route reconfiguration parameter transmitted by a Donor-CU; The route reconfiguration parameters include a destination BAP address of the second route, a route indicator of the second route, and a backhaul RLC channel indicator from the IAB-node to a next hop node of the second route.

7. A device for transmitting and receiving signals, which is applied to a child node of an IAB node, a processor for rerouting first path data when a destination BAP address of the first path of the IAB-node is unreachable; and a transmitter for transmitting the first route data based on the changed route; The transmitter further transmits the first path data on a backhaul RLC channel between the child node and a next hop node of a second path.

8. 8. The apparatus of claim 7, Changing the route of the first route data Changing the destination BAP address of the first route data to a destination BAP address of a second route; or changing a destination BAP address of the first route data to a destination BAP address of a second route, and changing a route identifier (ID) of the first route data to a route identifier of the second route.

9. 8. The apparatus of claim 7, If the destination BAP address of the first route of the IAB-node is unreachable, The destination BAP address of the first path becomes unreachable because the IAB-node has switched to a new parent node; or The apparatus further includes a case where a destination BAP address of the first path becomes unreachable due to a radio link failure occurring on a link between the IAB-node and a first parent node.

10. 10. The apparatus of claim 9, The processor further comprises: triggering the initiation of a timer after modifying the route of the first route data, and stopping the modification of the route of the first route data after the timer expires; Stopping the rerouting of the first route data after completing the transmission of the unsuccessfully transmitted first route data; or An apparatus for stopping rerouting of the first route data when it is determined that transmission of the unsuccessfully transmitted first route data is completed and a downstream child node has completed transmission of the unsuccessfully transmitted first route data.

11. 10. The apparatus of claim 9, When a destination BAP address of the first path becomes unreachable due to a radio link failure occurring on a link between the IAB-node and a first parent node, The second path is a path passing through a link between the IAB-node and a second parent node, and the link between the IAB-node and the second parent node is free of radio link failures.

12. 10. The apparatus of claim 9, Further comprising a receiver; An apparatus for receiving route reconfiguration parameters sent by a Donor-CU, the route reconfiguration parameters including a destination BAP address and a route indicator of the first route.

13. 13. The apparatus of claim 12, When the destination BAP address of the first route becomes unreachable due to the IAB-node switching to a new parent node, The route reconfiguration parameters are transmitted by an RRC reconfiguration message before the IAB-node switches, and when the receiver receives a switching success indication transmitted by the IAB-node after completing random access to a new parent node, the processor triggers a change in the route of the first route data.

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