Method and apparatus for transmitting and receiving signals and communication system

Abstract

Embodiments of the present invention provide a method and apparatus for transmitting and receiving signals and a communication system. The apparatus for setting information is applied to an IAB node, and the apparatus includes a first processing unit, which controls the node to perform the following operations: namely, uplink backhaul mapping information is set in a first distributed unit (IAB-DU) and a second distributed unit (IAB-DU) in the node, respectively, by different donor central units; and the mobile terminal of the node transmits signals based on the uplink backhaul mapping information.

Description

Technical Field

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

Background Art

[0002] IAB (Integrated access and backhaul) realizes the function of wireless relay in the next-generation radio access network (NG-RAN: next generation radio access network). The IAB node supports access and backhaul by New Radio (NR). The network-side termination of the NR backhaul is called an IAB-donor, which represents a network device (e.g., gNB) having a function to support IAB.

[0003] The IAB-node can be connected to one IAB-donor by one-hop or multi-hop. These multi-hop connections form a DAG (Directed Acyclic Graph) 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 referred to as IAB-DU. The IAB-DU is the termination of the radio access (NR access) interface to the terminal device (UE) and the next-hop IAB-node, and is also the termination of the F1 protocol to the gNB-CU (central unit) in the IAB-donor. The IAB-DU can serve ordinary UEs and IAB sub-nodes. The IAB-DU realizes the function of a network-side device, is connected to the downstream child IAB-node, provides NR radio interface access to the UE and the downstream child IAB-node, and establishes an F1 connection with the IAB donor-CU.

[0005] In addition to gNB-DU functionality, the IAB-node also supports some UE functionality, referred to as IAB-MT (Mobile Termination). IAB-MT includes, for example, physical layer, layer 2, RRC, and NAS functionality, connected to the gNB-DU of another IAB-node or IAB-donor, connected to the gNB-CU in the IAB-donor, and connected to the core network. IAB-MT can support, for example, UE physical layer, access stratum (AS), radio resource control (RRC) layer, and non-access stratum (NAS) layer functionality, and can connect to the IAB parent node.

[0006] The IAB-donor is the network-side termination node, providing network access to the IAB-MT or UE via backhaul or access links. The IAB-donor is further divided into an IAB-donor-CU (central unit) and an IAB-donor-DU. The IAB-DU and IAB-donor-CU are connected by an F1 interface. In a standalone network scenario, the gNB and IAB-donor-CU are connected by an Xn interface.

[0007] To support multi-hop routing of data packets, the IAB has introduced the Backhaul Adaptation Protocol (BAP) sublayer. The BAP sublayer sits above the Radio Link Control (RLC) sublayer and below the IP layer, supporting functions such as data packet destination node and path selection, data packet routing and forwarding, bearer mapping, flow control feedback, and backhaul link failure notification.

[0008] Figure 1 shows the relationship between IAB parent and child nodes. As shown in Figure 1, in the IAB parent and child node relationship structure 10, IAB-node 100 includes IAB-MT function unit 101 and IAB-DU function unit 102. Adjacent nodes on the interface of IAB-DU function unit 102 are called child nodes, and communication can be performed between child nodes 201, 202, 203, IAB-DU function unit 102, and child nodes 201, 202, 203 via a wireless interface (Uu), as shown in Figure 1. Adjacent nodes on the interface of IAB-MT function unit 101 are called parent nodes, and communication can be performed between parent nodes 301, 302, IAB-MT function unit 101, and parent nodes 301, 302 via a wireless interface (Uu), as shown in Figure 1.

[0009] As shown in Figure 1, the direction from IAB-node 100 to child nodes 201, 202, and 203 is referred to as the downstream direction, and the direction from IAB-node 100 to parent nodes 301 and 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.

[0010] The above-mentioned introduction of background art is intended to clearly and completely explain the proposed technical aspects of the present invention and to facilitate understanding by those skilled in the art. These technical aspects, as described in the background art of the present invention, should not be construed as being well-known to those skilled in the art. [Overview of the project] [Problems that the invention aims to solve]

[0011] In a multi-hop scenario, to enable data packet forwarding, the IAB node must determine the target node to which the data packet will arrive, then, based on the routing table, determine that it will reach the next hop node corresponding to the target node, and then transmit the packet. The donor-CU uses F1AP (F1 application protocol) signaling to configure the mapping for the IAB node from each F1-U Tunnel on the uplink from the IAB node, non-UE associated F1AP messages, UE-associated F1AP messages, and non-F1 traffic to BAP routing indicators (IDs, identifiers).

[0012] Based on routing indicator mapping information, the IAB node determines the BAP routing indicators corresponding to different types of uplink IP packets from the IAB node, and encapsulates a BAP subheader containing the BAP routing indicator information for these uplink IP packets. The Donor-CU uses F1AP signaling to configure mappings for the donor-DU from different types of downlink data packets to BAP routing indicators. Based on routing indicator mapping information, the Donor-DU determines the BAP routing indicators corresponding to received downlink IP packets, and encapsulates a BAP subheader containing the BAP routing indicator information for these downlink IP packets.

[0013] The BAP routing identifier includes the destination BAP address and the path identity between the IAB node and the donor-DU. The BAP address is also referred to as DESTINATION in the BAP header. Each IAB node and donor-DU is assigned one BAP address.

[0014] During IAB node integration, the RRC can configure one default BH (backhaul) RLC channel and one default BAP routing indicator for non-F1-U traffic. These settings can be updated in topology adaptation scenarios.

[0015] Upstream, the IAB-donor-CU configures mapping relationships for the IAB node between upstream F1 and non-F1 traffic from the IAB node and the appropriate BAP routing ID, the BAP address of the next hop, and the BH RLC channel. Specific mapping relationships may be configured for each F1-U GTP-U tunnel, non-UE related F1AP messages, UE related F1AP messages, and non-F1 traffic.

[0016] An IAB node may have redundant pathways to different IAB-donor-CUs. For an IAB node working in Stand Alone (SA) mode, NR-DC (NR-NR Dual Connectivity) allows the IAB-MT and two parent nodes to have backhaul links simultaneously, thus achieving backhaul route redundancy. The two parent nodes can be connected to different IAB-donor-CUs, which can control the establishment and release of redundant routes through these two parent nodes. The gNB-DU function of the parent node and the corresponding IAB-donor-CU both serve as the master node (MN) and / or secondary node (SN) of the IAB-MT. The NR-DC framework, for example, the MCG (master cell group) / SCG (secondary cell group) process, is used to configure dual radio connectivity from the IAB node to the parent node.

[0017] An IAB-MT can migrate under a parent node under a different IAB-donor-CU. In such cases, the juxtaposed IAB-DU and the descendant node's IAB-DU maintain F1 connectivity with the original IAB-donor-CU. This type of migration is called an inter-donor partial migration. The IAB node to which this IAB-MT is migrated to the new IAB-donor-CU is the boundary IAB node. After the inter-donor partial migration, F1 traffic from the IAB-DU and descendant nodes is routed through the BAP layer of the IAB topology to which the IAB-MT was migrated. SA mode can support inter-donor partial migrations.

[0018] When an IAB node in SA mode declares an RLF for a backhaul link, it can perform RLF recovery on parent nodes under a different IAB-donor-CU. Similar to partial migration between donors, juxtaposed IAB-DUs and descendant node IAB-DUs can maintain an F1 connection with the original IAB-donor-CU.

[0019] Figure 2 illustrates a partial migration scenario. IAB node 3 is called a boundary IAB node. A boundary IAB node is one in which one of its RRC and F1 interfaces is terminated by a different IAB-donor-CU. Boundary IAB nodes are suitable for partial migration, inter-donor topology redundancy, and inter-donor RLF (radio link failure) recovery. For example, in Figure 2, node 3's DU is terminated by CU1 and its MT has an RRC connection to CU2, thus satisfying the definition of a boundary IAB node. A descendant IAB node is a node that accesses the network via a boundary IAB node, and each node is independently connected to its parent node (single connection), such as IAB node 4. An F1-terminating node refers to a donor-CU that terminates the F1 interface of boundary IAB nodes and descendant nodes, for example, donor-CU1 (in Figure 2, the F1 interfaces of IAB-DU3 and IAB-DU4 are terminated by donor-CU1). A non-F1-terminating node refers to a CU with donor functionality that does not terminate the F1 interface of boundary IAB nodes and descendant nodes, for example, donor-CU2. Since non-F1-terminating nodes have RRC connections with IAB-MTs, non-F1-terminating nodes are also referred to as donor nodes of IAB-MTs, and non-F1-terminating donor CUs can also be referred to as donor CUs of IAB-MTs.

[0020] In Figure 2, IAB-MT3 changes from a single connection to its parent node IAB node 1 to a single connection to its parent node IAB node 2. IAB-DU3 and its child node IAB node 4 still have an F1 connection to donor-CU1, but the path this F1 connection takes passes through IAB node 2 and finally reaches CU1. In a partial transition scenario like the one shown in Figure 2, the boundary node is the transition node. The partial transition scenario is also suitable for partial RLF recovery.

[0021] Mobile IABs (mIABs), or mobile relays, face one challenge in terms of mobility over a relatively wide area: the IAB donor (i.e., the F1 terminal donor) needs to change during the process of moving, meaning the IAB-DU F1 interface needs to migrate, a process known as IAB-DU migration. The PDCP and Radio Resource Control (RRC) connections of the terminal equipment (e.g., user equipment) served by the mobile IAB may both be affected.

[0022] The inventors of this invention have discovered the following: In the case of an IAB-DU migration scenario, in order to perform the switching of the serving terminal equipment, a mobile IAB node must simultaneously support two logical mobile IAB-DUs, and these two DUs have F1AP association relationships with the source CU and target CU, respectively. However, the prior art does not define how an IAB node can support two or more DUs.

[0023] Embodiments of the present invention provide a method and apparatus for transmitting and receiving signals and a communication system, wherein the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in an IAB node are each configured with uplink backhaul mapping information by different donor central units, thereby enabling the IAB node to support two or more distributed units (DUs). [Means for solving the problem]

[0024] According to one aspect of an embodiment of the present invention, a signal transmitting and receiving device is provided, which is applied to an IAB node, the device including a first processing unit, the first processing unit controlling the node to cause the node to perform the following operations, namely, Uplink backhaul mapping information is set in the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) of the node, respectively, by different donor central units; and The mobile terminal of the node transmits a signal based on the uplink backhaul mapping information.

[0025] According to another aspect of the embodiments of the present invention, a signal transceiver is provided and applied to an IAB node. The device includes a second processing unit, and the second processing unit controls the node to cause the node to perform the following operations, that is, The mobile terminal (MT) in the node uses a common default BAP setting for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, or uses respective default BAP settings respectively; and The mobile terminal MT in the node transmits a signal based on the default BAP setting.

[0026] According to another aspect of the embodiments of the present invention, a signal transceiver is provided and applied to an IAB node. The device includes a third processing unit, and the third processing unit controls the node to cause the node to perform the following operations, that is, For the data reaching in the downstream direction of the node, the node determines to transmit the downstream data to the first distributed unit (IAB-DU) or the second distributed unit (IAB-DU) of the node based on the IP address.

[0027] According to another aspect of the embodiments of the present invention, a signal transceiver is provided and applied to an IAB node. The device includes a fourth processing unit, and the fourth processing unit controls the node to cause the node to perform the following operations, Before performing DU migration, the node performs a dual active protocol stack (DAPS) setting for the terminal device it serves.

Advantages of the Invention

[0028] The advantageous effect of the embodiments of the present invention is at least the following, namely, that an IAB node can be made to support two or more DUs.

[0029] Specific embodiments of the present invention will be disclosed in detail by referring to the following description and drawings, and will show embodiments in which the principles of the present invention can be adopted. However, the embodiments of the present invention are not limited to these in scope. Embodiments of the present invention may include various changes, modifications and substitutions as long as they are within the scope of the attached claims.

[0030] Furthermore, features described and / or shown in one embodiment may be used in the same or similar manner in one or more other embodiments, combined with or substituting features in other embodiments.

[0031] When used herein, terms such as “contains / have” 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 explanation of the drawing]

[0032] Elements and features described in one drawing or one embodiment of the present invention can be combined with elements and features shown in one or more other drawings or embodiments. Furthermore, similar reference numerals in the drawings are used to indicate corresponding parts in several drawings and to indicate corresponding parts used in multiple embodiments. [Figure 1] This diagram shows the relationship between IAB parent and child nodes. [Figure 2] This is a diagram illustrating a partial transition scenario. [Figure 3] This is an illustrative diagram showing how an IAB node can use multiple IAB-DUs during the DU migration process. [Figure 4] This figure shows the method for transmitting and receiving signals in the first embodiment. [Figure 5] This diagram shows the method for transmitting and receiving signals in the second embodiment. [Figure 6] This is a diagram showing the DU transition. [Figure 7] This diagram shows the method for transmitting and receiving signals in the third embodiment. [Figure 8] This diagram shows the process during UE switching. [Figure 9] This figure shows the method for transmitting and receiving signals in the embodiment described in the fourth side. [Figure 10] This figure shows a signal transmitting and receiving device in the fifth embodiment. [Figure 11] This figure shows a signal transmitting and receiving device in the sixth embodiment. [Figure 12] This is a diagram showing the signal transmission and reception device in the seventh side embodiment. [Figure 13] This figure shows the signal transmitting and receiving device in the eighth side embodiment. [Figure 14] This figure shows the configuration of an electronic device in an embodiment of the present invention. [Modes for carrying out the invention]

[0033] The aforementioned and other features of the present invention will become clear by referring to the attached drawings and the following description. While the specification and drawings disclose specific embodiments of the present invention, these represent only a limited number of embodiments in which the principles of the present invention can be employed. It should be understood that the present invention is not limited to the described embodiments, but rather includes all modifications, variations, and substitutions within the scope of the attached claims.

[0034] In embodiments of the present invention, the terms "communication network" or "wireless communication network" may refer to a network conforming to any communication standard such as NR (New Radio), LTE (Long Term Evolution), LTE-A (LTE-Advanced), WCDMA (Wideband Code Division Multiple Access), HSPA (High-Speed ​​Packet Access), etc.

[0035] Furthermore, communication between devices in a communication system may be carried out according to any stage of communication protocol, and may include, but is not limited to, the following communication protocols: namely, 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G, New Radio (NR), and / or other conventional or future-developed communication protocols.

[0036] In embodiments of the present invention, the term "network device" refers, for example, to a device in a communication system that connects terminal devices to a communication network and provides services to said terminal devices. Network devices may include, but are not limited to, the following: "nodes" and / or "donors" in the IAB architecture, base stations (BS), access points (AP), transmission and reception points (TRP), broadcast transmitters, mobile management entities (MME), network gateways, servers, radio network controllers (RNC), base station controllers (BSC), etc.

[0037] Among these, base stations may include, but are not limited to, Node B (NodeB or NB), Evolutionary Node B (eNodeB or eNB), 5G base stations (gNB), and may also include RRH (Remote Radio Head), RRU (Remote Radio Unit), relay, or low-power nodes (e.g., femto, pico). Furthermore, the term “base station” may include some or all of these functions, and each base station can provide communication coverage to a specific geographical area. For example, a 5G base station gNB may include one gNB CU and one or more gNB DUs, where the CU / DU is a logical node of the gNB having some of the functions of the gNB. The term “cell” may refer to a base station and / or the area it covers, depending on the context in which the term is used.

[0038] In embodiments of the present invention, the terms "User Equipment" (UE) or "Terminal Equipment" (TE) refer to devices that access a communication network via network equipment and receive services from the network. User equipment may be fixed or mobile, and may also be referred to as a mobile station (MS), terminal, subscriber station (SS), access terminal (AT), or station. For example, it may be terminal equipment served by an IAB node or IAB donor under an IAB architecture.

[0039] User devices may include, but are not limited to, the following: cellular phones, PDAs (Personal Digital Assistants), wireless modems, wireless communication devices, mobile devices, machine-type communication devices, laptop computers, cordless phones, smartphones, smartwatches, digital cameras, etc.

[0040] Furthermore, in scenarios such as IoT (Internet of Things), user devices may also be monitoring or measuring devices or equipment, and may include, but are not limited to, the following: machine-type communication (MTC) terminals, in-vehicle communication terminals, D2D (device-to-device) terminals, M2M (machine-to-machine) terminals, etc.

[0041] Furthermore, the terms “network side” or “network device side” refer to the network side, which may be a base station and may include one or more network devices as described above. The terms “user side” or “terminal side” or “terminal device side” refer to the user or terminal side, which may be a UE and may include one or more terminal devices as described above.

[0042] In each embodiment of the present invention, the upper-layer signaling may be, for example, a radio resource control (RRC) signaling, referred to as an RRC message, and including, for example, a Master Information Block (MIB), system information, a dedicated RRC message, or referred to as an RRC IE (RRC information element). The upper-layer signaling may further be, for example, an F1-C signaling, also known as the F1AP protocol. However, the present invention is not limited thereto.

[0043] In this invention, each embodiment is described using a multi-hop IAB network deployment scenario as an example, in which multiple terminal devices (e.g., UEs) are connected to an IAB-donor by multi-hop IAB nodes and finally access a network, which is, for example, a 5G network.

[0044] The IAB node to which terminal devices (e.g., user devices) are connected is movable.

[0045] Each embodiment of the present invention is also applicable to other mobile nodes, such as relays. Each embodiment of the present invention will be explained using an IAB as an example.

[0046] In a DU migration scenario, the moving IAB node must simultaneously support two logical moving IAB-DUs in order to perform the switching of the serving UE, and these two DUs have F1AP association relationships with the source CU and target CU, respectively.

[0047] Terminal devices (e.g., UEs) connected to a mobile IAB node are switched from a cell of a logical mobile IAB-DU (i.e., a source logical mobile IAB-DU) that has an F1AP association relationship with a source CU to a logical mobile IAB-DU (i.e., a target logical mobile IAB-DU) that has an F1AP association relationship with a target CU.

[0048] During the DU transition process, the UE treats the cells of the two logical DUs as different physical cells (for example, if the cells use similar carriers, they use different PCIs), and these two logical DU cells use separate physical resources (i.e., different carriers in the conventional Layer 1, or, if they use the same carriers, orthogonal time and frequency resources).

[0049] Figure 3 shows an example of an IAB node using multiple IAB-DUs during the DU migration process. IAB node 3 includes two DU units, a first IAB-DU and a second IAB-DU. The first IAB-DU in Figure 3 makes an F1 connection for IAB-DU3a and the source IAB-donor-CU (donor-CU1), and may also be called the source IAB-DU, or it may be a normal IAB-DU that does not undergo DU migration. The second IAB-DU in Figure 3 makes an F1 connection for IAB-DU3b and the target IAB-donor-CU (donor-CU2), and may also be called the target IAB-DU. These two IAB-DUs may be logical IAB-DUs or virtual IAB-DUs; that is, from the perspective of the UE, they are no different from normal IAB-DUs or gNB-DUs, have the functionality of normal DUs, and are simply integrated within the IAB, with the integration method being determined by the implementation (realization). Furthermore, these two IAB-DUs can also use the conventional IAB-DU implementation methods; in other words, they are physically two IAB-DUs.

[0050] Each embodiment of the present invention will be described based on the above-described scenario. However, the embodiments of the present invention are not limited to the above-described scenario.

[0051] <Example of the first side view> Currently, the uplink BH mapping information for the BAP layer is configured by the F1AP, meaning that the IAB-donor-CU configures the IAB-DU via F1AP signaling (F1-C, F1 control plane). These configurations are stored as corresponding configuration variables in the BAP layer, including, for example, the Uplink Traffic to Routing ID Mapping Configuration and the Uplink Traffic to BH RLC Channel Mapping Configuration, and are used to select the BAP routing ID and BH RLC channel for data when an IAB node needs to receive data from a higher layer and transmit it upstream.

[0052] To support a single node containing multiple IAB-DUs, different F1-Cs must each configure the aforementioned uplink BH mapping information for their respective IAB-DUs. In this way, uplink traffic from different IAB-DUs can be mapped to different BAP routing IDs and / or BH RLC channels, thus enabling separation of source F1 and target F1 paths.

[0053] An embodiment of the first aspect of the present invention provides a method for transmitting and receiving signals, the method of transmitting and receiving signals applied to an IAB node, for example, IAB node 3 shown in Figure 3 (for example, IAB node 3 has IAB-MT3, IAB-DU3a and IAB-DU3b), which will be referred to as the IAB node or the node in the following description.

[0054] In the embodiment of the first aspect, the first distribution unit (e.g., IAB-DU3a in Figure 3) is controlled by the first donor central unit (e.g., Donor-CU1 in Figure 3), and the second distribution unit (e.g., IAB-DU3b in Figure 3) is controlled by the second donor central unit (e.g., Donor-CU2 in Figure 3).

[0055] Of these, the first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration does not occur, or the sole F1 terminal donor central unit of the node, or the source donor central unit in the distributed unit migration process, and the second donor central unit is the target donor central unit of the node in the distributed unit migration process.

[0056] Figure 4 shows a method for transmitting and receiving signals in an embodiment of the first side. As shown in Figure 4, the method includes the following, namely, 401: Uplink backhaul mapping information is set in the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node by different donor central units; and 402: The mobile terminal (MT) of the IAB node transmits a signal based on the uplink backhaul mapping information.

[0057] In operation 401 of the present invention, uplink backhaul mapping information is set for the DU. In operation 402, the MT transmits an uplink signal based on the set uplink backhaul mapping information, and the method by which the MT transmits the uplink signal can be found in related technologies.

[0058] In the present invention, operation 401 can be achieved by either method 1 or method 2 below.

[0059] (Method 1) A second backhaul adaptive protocol entity (BAP entity) distinct from the first backhaul adaptive protocol entity (BAP entity) is established at the node, and this second BAP entity may be a newly added BAP entity at that node. Of these, the first BAP entity maintains the variables set by the first donor central unit (donor-CU) in the node's BAP layer, and the second BAP entity maintains the variables set by the second donor central unit (donor-CU) in the node's BAP layer.

[0060] The first donor-CU is, for example, Donor-CU 1 in Figure 3, and is also called the source donor-CU. The second donor-CU is, for example, Donor-CU 2 in Figure 3, and is also called the target donor-CU.

[0061] In at least one embodiment of Method 1, a conventional MT BAP entity (i.e., the first BAP entity) stores or uses the mapping settings from uplink traffic to routing indicators and from uplink traffic to BH RLC channels, which were set by the first donor-CU associated with F1 (e.g., the source donor-CU). The second BAP entity stores or uses the mapping settings from uplink traffic to routing indicators and from uplink traffic to BH RLC channels, which were set by the second donor-CU associated with F1 (e.g., the target donor-CU).

[0062] In the BAP layer data transmission process, for upstream data transmission, the IAB-MT selects the corresponding first or second BAP entity based on the IAB-DU to which the traffic belongs. Subsequently, each IAB-MT entity performs its own operations and does not affect the others. The IAB-DU to which the traffic belongs can be determined by which IAB-DU the Backhaul Adaptive Protocol Service Data Unit (BAP SDU) received from the upper layer originates, or by the donor-CU corresponding to the target IP address of the BAP SDU received from the upper layer.

[0063] The establishment of the second BAP entity may be performed simultaneously with the establishment of the first BAP entity. In this way, for mobile IAB nodes, the efficiency of the migration can be improved by preparing for the migration in advance. Alternatively, the establishment of the second BAP entity may be performed after the IAB node receives notification of the DU migration. The method for establishing the second BAP entity may be configured on the network side, for example, by RRC signaling.

[0064] In at least some embodiments of Method 1, new configuration information (e.g., the new configuration information is second configuration information) may be added to the RRC layer, and the second configuration information is used to configure the second BAP entity of the IAB node. Alternatively, a new instruction may be added to the first BAP configuration (bap-Config) IE in the RRC reconfiguration message, indicating that the bap-Config configuration information pertains to the second BAP entity. Alternatively, a new IE, i.e., second BAP configuration information, may be added to the RRC reconfiguration message, for example, referred to as bap-Config2 IE, and used to configure the second BAP entity of the IAB node. The second BAP configuration information may include one or more configuration pieces relating to the second IAB-DU, and these configuration pieces may include at least one of the following, for example, the BAP address, the uplink default BAP routing indicator, and the uplink default backhaul radio link control (BH RLC) channel.

[0065] Furthermore, in at least some embodiments of Method 1, if the IAB node's IAB-MT has received a first BAP setting included in the RRC message and the setting is set to a first value (for example, setup), and the IAB node has not established a BAP entity, the IAB node establishes BAP entities for the IAB-MT and IAB-DU respectively. For example, the IAB node establishes a first BAP entity for the IAB-MT and a DU BAP entity for the IAB-DU, and the first BAP entity and the DU BAP entity may be established together.

[0066] The method for establishing a second BAP entity will be described using, as an example, the establishment of a second BAP entity by adding second BAP configuration information in at least some embodiments of Method 1.

[0067] At the RRC layer of the node, the following operation occurs: when the IAB-MT receives the second BAP configuration information included in the RRC reset message, and the second BAP configuration information is set to the first value (for example, the first value is setup) and the second BAP entity has not been established, the BAP layer is instructed to establish the second BAP entity corresponding to the second BAP configuration information on the MT side for the second IAB-DU.

[0068] In the BAP layer of the node, the following operation takes place: after receiving instructions from the upper layer regarding the establishment of a second BAP entity, the MT side establishes the second BAP entity for the second IAB-DU.

[0069] After both the IAB-DU migration and the switching of all terminal devices (e.g., user equipment UEs) served by the IAB-DU are complete, all terminal devices (e.g., user equipment UEs) will then access the second IAB-DU (e.g., IAB-DU3b in Figure 3). By changing the original second IAB-DU to the first IAB-DU and the original first IAB-DU to the second IAB-DU, preparations can be made for the next DU migration during the IAB node migration process. That is, the original second IAB-DU has become the source IAB-DU, and the original first IAB-DU has become the target IAB-DU. Alternatively, the original first IAB-DU (i.e., the current second IAB-DU formed after the conversion) may be released.

[0070] The release method includes the following: the IAB node voluntarily performs a release; or the RRC layer may request a release for the current second IAB-DU, i.e., the network side notifies the IAB-MT to perform a release for the current second IAB-DU via RRC signaling.

[0071] For example, the process by which the RRC layer requests a release for the current second IAB-DU may be as follows: when the IAB-MT receives a second BAP setting included in the RRC message and the second BAP setting is set to a second value (for example, release), it may instruct the BAP layer to release the second BAP entity, and the BAP layer releases the second BAP entity after receiving instructions from the upper layer regarding the release of the second BAP entity.

[0072] In at least some embodiments of Method 1, Method 1 can be implemented by enhancing the actions taken when an IAB node receives an RRCReconfiguration message containing a first BAP configuration and / or a second BAP configuration.

[0073] For example, the following table (Table 1) is one example of enhancing the BAP configuration process in TS38.331.

[0074] [Table 1] (Method 2) In Method 2, the same BAP entity is still used on the MT side of the IAB node. Each IAB node stores the F1AP BAP settings for the first IAB-DU and the F1AP BAP settings for the second IAB-DU, of which the BAP settings include, namely, mapping settings from uplink traffic to routing indicators and / or mapping settings from uplink traffic to BH RLC channels. These uplink backhaul settings are used on the MT side.

[0075] In at least some embodiments of Method 2, the BAP layer may add variables for the second IAB-DU, and the BAP layer may maintain these variables for the second IAB-DU. These variables may include, for example, a mapping configuration from the second uplink traffic to a routing marker (e.g., referred to as Uplink Traffic to Routing ID Mapping Configuration 2) and / or a mapping configuration from the second uplink traffic to a BH RLC channel (e.g., referred to as Uplink Traffic to BH RLC Channel Mapping Configuration 2).

[0076] Of these, the mapping configuration from the second uplink traffic to the routing indicator includes at least one traffic type specifier and at least one BAP routing indicator. The mapping configuration from the second uplink traffic to the BH RLC channel includes at least one traffic type specifier, at least one exit link indicator and at least one exit BH RLC channel indicator.

[0077] In the IAB node, the BAP entity maps backhaul adaptive protocol service data units (BAP SDUs) received from the upper layer that need to be transmitted upstream to BAP addresses and BAP path identifiers based on the following configuration variables: This is the Uplink Traffic to Routing ID Mapping Configuration, which is obtained from F1AP signaling to the IAB node, and this F1AP signaling does not include signaling to the second IAB-DU; and This is a mapping configuration from the second uplink traffic to routing IDs (e.g., Uplink Traffic to Routing ID Mapping Configuration 2), which is obtained from F1AP signaling to the second IAB-DU.

[0078] Data transmitted upstream may originate from different logical IAB-DUs. For example, when all UEs have not yet switched over, some terminal devices (e.g., UEs) may still be in the first IAB-DU, while others have switched to the second IAB-DU. In this case, the upstream data needs to select the routing indicator for the CU configuration to which the UE belongs by selecting different mapping settings for the corresponding IAB-DU.

[0079] In an IAB node, the BAP entity may perform the following operations on BAP SDUs received from the upper layer that need to be transmitted upstream: For BAP SDUs encapsulating F1-U data packets, if the BAP SDU originates from a second IAB-DU, the corresponding entry is selected from the mapping settings from the second uplink traffic to routing indicators based on the traffic type designator corresponding to the destination IP address and tunnel endpoint identifier (TEID).

[0080] The following table (Table 2) shows one example of enhancing BAP routing indicator selection for TS38.340 IAB nodes in Method 2.

[0081] [Table 2] The above describes the selection process for BAP routing IDs in Method 2, but the process for uplink BH RLC channel mapping is similar.

[0082] In the IAB node, for BAP SDUs received from the upper layer that need to be transmitted upstream, the BAP entity maps them to the exit BH RLC channel marker based on the following configuration variables, i.e., This is the Uplink Traffic to BH RLC Channel Mapping Configuration, which is obtained from F1AP signaling to the IAB node, and this F1AP signaling does not include signaling to the second IAB-DU; and This is a mapping configuration from the second uplink traffic to the BH RLC channel indicator (for example, referred to as Uplink Traffic to BH RLC Channel Mapping Configuration 2), which is obtained from F1AP signaling to the second IAB-DU.

[0083] In an IAB node, after an exit link has been selected for a BAP SDU received from a higher layer that needs to be transmitted upstream, the BAP entity may perform the following operations: For a BAP SDU encapsulating an F1-U data packet, if the BAP SDU originates from a second IAB-DU, the system selects the corresponding entry from the mapping configuration from the second uplink traffic to routing indicators, based on the traffic type designator corresponding to the destination IP address and TEID, and the link indicator corresponding to the selected exit link. If a corresponding entry exists, the system selects the exit BH RLC channel corresponding to the exit BH RLC channel indicator in that entry. If no corresponding entry is found (does not exist), the system selects any exit BH RLC channel on the exit link.

[0084] The embodiment of the first aspect can solve problems such as the BAP configuration of multiple logical IAB-DUs of an IAB node in the case of DU migration, thereby supporting the long-distance movement of IAB nodes and improving the performance of the IAB node in serving users (e.g., users in cars or trains).

[0085] <Example of the second aspect> The IAB-MT may be configured by RRC with a first default BAP configuration. These configurations include the first default uplink BAP routing identifier (defaultUL-BAP-RoutingID) and the first default uplink BH RLC channel (defaultUL-BH-RLC-Channel). These default BAP configurations are used for uplink non-F1-U data packets until the F1AP configures or reconfigures the mapping configuration from the first uplink traffic to the routing identifier and the mapping configuration from the first uplink traffic to the BH RLC channel identifier.

[0086] When an IAB node establishes a second IAB-DU, it is necessary to clarify whether to use a single common default BAP setting for non-F1-U.

[0087] To solve the above-mentioned problems, a second aspect of the present invention provides a method for transmitting and receiving signals, which is applied to an IAB node, for example, IAB node 3 shown in Figure 3 (for example, IAB node 3 has IAB-MT3, IAB-DU3a and IAB-DU3b), which will be referred to as the IAB node or the node in the following description.

[0088] In the second aspect of the embodiment, the first distribution unit (e.g., IAB-DU3a in Figure 3) is controlled by the first donor central unit (e.g., Donor-CU1 in Figure 3), and the second distribution unit (e.g., IAB-DU3b in Figure 3) is controlled by the second donor central unit (e.g., Donor-CU2 in Figure 3).

[0089] Of these, the first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration does not occur, or the source donor central unit during the distributed unit migration process, and the second donor central unit is the target donor central unit of the node during the distributed unit migration process.

[0090] Figure 5 shows a method for transmitting and receiving signals in an embodiment of the second aspect. As shown in Figure 5, the method includes the following, namely, 501: A mobile terminal (MT) in the node uses a common default BAP setting for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, or uses their respective default BAP settings; and 502: The mobile terminal MT at the node transmits a signal based on the default BAP setting.

[0091] Method 1 of Operation 501 uses a common default BAP setting for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) on the node.

[0092] In at least some embodiments of Method 1, the IAB node may perform the following operations on the BAP SDU received from the upper layer that needs to be transmitted upstream: namely, If, after the RRC has set the first default uplink BAP routing sign, the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the routing sign for the IAB-DU from the BAP SDU, then for non-F1-U data packets, the RRC selects the BAP address and BAP path sign configured in the first default uplink BAP routing sign.

[0093] In at least some embodiments of Method 1, the IAB node may, after an exit link is selected, perform the following operations on a BAP SDU received from a higher layer that needs to be transmitted upstream: If, after the RRC has set the first default uplink BH RLC channel identifier, the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the BH RLC channel for IAB-DUs from the BAP SDU, then for non-F1-U data packets, the F1AP selects the exit BH RLC channel corresponding to the first default uplink BH RLC channel identifier.

[0094] Method 2 of Operation 501 uses the default BAP settings for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, respectively. For example, non-F1-U data corresponding to the first IAB-DU uses the first default BAP setting, a second default BAP setting is defined for the second IAB-DU, and non-F1-U data corresponding to the second IAB-DU uses the second default BAP setting.

[0095] Figure 6 shows a DU transition. In the scenario shown in Figure 6, the target path used by the second IAB-DU (i.e., IAB-DU3b) to reach the second donor-CU (i.e., Donor-CU2) passes through Donor-DU12, and the source path from the first IAB-DU (i.e., IAB-DU3a) to the first donor-CU (i.e., Donor-CU1) passes through Donor-DU11, which is different from Donor-DU11. Because the BAP destination (i.e., donor-DU) has changed, the BAP routing indicators for the target path and source path are also different.

[0096] In the scenario shown in Figure 6, the second default BAP setting and the first default BAP setting are different. Therefore, uplink non-F1-U traffic corresponding to the two IAB-DUs (e.g., IAB-DU3a and IAB-DU3b) can use different default paths.

[0097] In at least some embodiments of Method 2, the second BAP default setting may be added to the RRC message, which may include a second default uplink BAP routing indicator and a second default uplink BH RLC channel.

[0098] For example, two fields may be added to the bap-Config IE in an RRC reconfiguration message (e.g., RRCReconfiguration), for example, called defaultUL-BAP-RoutingID2 and defaultUL-BH-RLC-Channel2. Alternatively, one instruction may be added to the bap-Config IE indicating that its default setting should be used for non-F1-U (e.g., F1-C) traffic corresponding to the first or second IAB-DU. Furthermore, a new IE may be added to the RRCReconfiguration message, for example, called bap-Config2, which contains the second BAP default setting.

[0099] In at least some embodiments of Method 2, the IAB node may perform the following operations on the BAP SDU received from the upper layer that needs to be transmitted upstream: namely, If the traffic relates to the second IAB-DU, and the second default uplink BAP routing sign is configured, and the F1AP has not configured or reconfigured the mapping from uplink traffic to routing sign for the second IAB-DU since the last configuration or reconfiguration by the RRC, then select the BAP address and BAP path sign configured in the second default uplink BAP routing sign for non-F1-U data packets.

[0100] In at least some embodiments of Method 2, after an exit link has been selected, the IAB node may perform the following operations on BAP SDUs received from the upper layer that need to be transmitted upstream: If the traffic relates to the second IAB-DU, and a second default uplink BH RLC channel is configured, and the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the BH RLC channel for the second IAB-DU after the second default uplink BH RLC channel has been configured by the RRC, then the F1AP selects the exit BH RLC channel corresponding to the second default uplink BH RLC channel indicator for non-F1-U data packets.

[0101] <Example of the third side> When two or more IAB-DUs are established at an IAB node, the problem to be solved regarding the processing of data arriving downstream from that IAB node is to determine which IAB-DU should receive the data and which DU should receive it to send it to the terminal equipment (e.g., user equipment UE) it serves.

[0102] To solve the above-mentioned problems, a third aspect of the present invention provides a method for transmitting and receiving signals, which is applied to an IAB node, for example, IAB node 3 shown in Figure 3 (for example, IAB node 3 has IAB-MT3, IAB-DU3a and IAB-DU3b), which will be referred to as the IAB node or the node in the following description.

[0103] In the third embodiment, the first distribution unit (e.g., IAB-DU3a in Figure 3) is controlled by the first donor central unit (e.g., Donor-CU1 in Figure 3), and the second distribution unit (e.g., IAB-DU3b in Figure 3) is controlled by the second donor central unit (e.g., Donor-CU2 in Figure 3).

[0104] Of these, the first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration does not occur, or the source donor central unit during the distributed unit migration process, and the second donor central unit is the target donor central unit of the node during the distributed unit migration process.

[0105] Figure 7 shows a method for transmitting and receiving signals in an embodiment of the third side. As shown in Figure 7, the method includes the following, namely, 701: With respect to data arriving downstream of the node, the node determines, based on its IP address, that it will transmit the downstream data to the node's first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

[0106] In operation 701, the IP address may be either the target IP address or the source IP address.

[0107] In method 1 of operation 701, the node determines, based on the target IP address, that the downstream data will be transmitted to the node's first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

[0108] In at least some embodiments of Method 1, a different IP address may be assigned to the second IAB-DU than that of the first IAB-DU. For example, when an IAB node requests an IP address from the donor-CU via RRC, it may include the purpose of use of the IP address, or it may define a new purpose, for example, called "Used by the second IAB-DU". In this way, the donor-CU can understand that the requested IP address is for use by the second IAB-DU. When the donor-CU assigns an IP address to the IAB node via an RRC message, it may include the purpose of use (iab-IP-Usage) corresponding to the IP address. When the RRC message received by the IAB node contains the assigned IP address (for example, in iab-IP-AddressToAddModList IE) and the corresponding purpose indicates "Used by the second IAB-DU", the IAB node stores the IP address as the IP address of the second IAB-DU, or replaces the existing IP address of the second IAB-DU (if configured) with the IP address.

[0109] In at least some embodiments of Method 1, when a BAP data PDU (protocol data unit) is received from a lower layer, the receiving unit of the BAP entity may perform the following operations, namely: If the destination field of the BAP data PDU matches the BAP address set by the IAB-donor providing this entry BH RLC channel, the BAP header of the BAP data PDU is removed and the BAP SDU is passed to the upper layer. If the IAB node contains two DUs, the upper layer determines to which DU to transmit the BAP SDU based on the target IP address of the BAP SDU. That is, if the target IP address belongs to the first IAB-DU, the BAP SDU is transmitted to the first IAB-DU, and if the target IP address belongs to the second IAB-DU, the BAP SDU is transmitted to the second IAB-DU.

[0110] In method 2 of operation 701, the node determines, based on the source IP address, that the downstream data will be transmitted to the node's first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

[0111] The source IP address of the F1 data is the IP address of the donor-CU. Since the two IAB-DUs terminate at different donor-CUs, the source IP address allows us to determine which DU the downlink data is destined for.

[0112] In at least some embodiments of Method 2, when a BAP data PDU (protocol data unit) is received from a lower layer, the receiving unit of the BAP entity may perform the following operations, namely: If the destination field of the BAP data PDU matches the BAP address set by the IAB-donor providing this entry BH RLC channel, the BAP header of the BAP data PDU is removed and the BAP SDU is passed to the upper layer. If the IAB node contains two DUs, the upper layer determines to which DU to transmit the BAP SDU based on the source IP address of the BAP SDU. That is, if the source IP address belongs to the first donor-CU, the BAP SDU is transmitted to the first IAB-DU, and if the source IP address belongs to the second donor-CU, the BAP SDU is transmitted to the second IAB-DU.

[0113] <Example of the fourth side view> The DU migration process is relatively long because it requires the migration of all F1-related, F1-U tunnel, and all UE context information. Transmission may be interrupted when a mobile IAB node connects to a donor node via multi-hop. Figure 8 shows the situation during UE switching. As shown in Figure 8, after the UE is switched to donor-CU2, some downlink data reaches the IAB node from the source path, and this downlink data is called on-the-fly data. When the IAB node receives this downlink data, the UE switching is complete, so this data cannot be accurately transmitted to the UE. Thus, the loss of data packets during the switching process can cause transmission interruptions.

[0114] To solve the above-mentioned problems, a fourth embodiment of the present invention provides a method for transmitting and receiving signals, which is applied to an IAB node, for example, IAB node 3 shown in Figure 3 (for example, IAB node 3 has IAB-MT3, IAB-DU3a and IAB-DU3b), which will be referred to as the IAB node or the node in the following description.

[0115] In the fourth embodiment, the first distribution unit (e.g., IAB-DU3a in Figure 3) is controlled by the first donor central unit (e.g., Donor-CU1 in Figure 3), and the second distribution unit (e.g., IAB-DU3b in Figure 3) is controlled by the second donor central unit (e.g., Donor-CU2 in Figure 3).

[0116] Of these, the first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration does not occur, or the source donor central unit during the distributed unit migration process, and the second donor central unit is the target donor central unit of the node during the distributed unit migration process.

[0117] Figure 9 shows a method for transmitting and receiving signals in an embodiment of the fourth side view. As shown in Figure 9, the method includes the following, namely, 901: Before performing the DU migration, configure the wireless bearer dual-active protocol stack for the terminal devices served by the node.

[0118] In at least some embodiments of operation 901, all radio bearers of terminal equipment (e.g., user equipment UE) served by the node can be configured as dual active protocol stack (DAPS) bearers. This allows the terminal equipment (e.g., user equipment UE) to receive downlink data transmitted by two donor-CUs (e.g., first donor-CU and second donor-CU) by simultaneously connecting to two IAB-DUs (e.g., first IAB-DU and second IAB-DU) via the DAPS bearers. In this way, transmission interruptions during the switching process can be effectively reduced.

[0119] In at least some embodiments, the node configures the wireless bearer as a dual-active protocol stack bearer via RRC configuration. That is, the network side configures the node's wireless bearer as a dual-active protocol stack bearer via RRC signaling.

[0120] <Example of the fifth side> A fifth embodiment of the present invention provides a signal transmitting and receiving device, which corresponds to the signal transmitting and receiving method described in the first embodiment. The device is applied to an IAB node.

[0121] Figure 10 shows a signal transmitting and receiving device in the fifth side embodiment. As shown in Figure 10, the signal transmitting and receiving device 1000 includes a first processing unit 1001, which controls the node to cause the node to perform the following operations, namely, Uplink backhaul mapping information is set in the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) of the node, respectively, by different donor central units; and The mobile terminal of the node transmits a signal based on the uplink backhaul mapping information.

[0122] In at least one embodiment, the first processing unit controls the node to perform the following operations, namely, A second BAP entity, distinct from the first backhaul adaptive protocol entity (BAP Entity), is established at the node. Of these, the first BAP entity maintains the variables set by the first donor central unit (donor-CU) in the node's BAP layer, and the second BAP entity maintains the variables set by the second donor central unit in the node's BAP layer.

[0123] In at least one embodiment, the second BAP entity stores or uses mapping settings from uplink traffic to routing indicators and mapping settings from uplink traffic to BH RLC channels, which are set by the second donor central unit associated with F1.

[0124] In at least one embodiment, the first processing unit controls the node to perform the following operations, namely, For upstream data transmission, the node is instructed to select the corresponding first BAP entity or second BAP entity based on the DU to which the data transmission traffic belongs.

[0125] In at least one embodiment, the DU to which the traffic belongs is determined by which DU the backhaul adaptive protocol service data unit (BAP SDU) received from the upper layer originates; or The DU to which the traffic belongs is determined by the donor central unit (donor-CU) corresponding to the target IP address of the BAP SDU received from the upper layer.

[0126] In at least one embodiment, the first processing unit controls the node to perform the following operations, namely, The Radio Resource Control (RRC) layer of the node receives the second configuration information, and this second configuration information is used to configure the second BAP entity.

[0127] In at least one embodiment, the second configuration information is a new information element (IE) newly added to the RRC reconfiguration message.

[0128] The second configuration information includes at least one of the following pieces of information for the DU corresponding to the second BAP entity: namely, the BAP address, the uplink default BAP routing indicator, and the uplink default backhaul radio link control (BH RLC) channel.

[0129] In at least one embodiment, if the RRC message received by the node includes the second BAP configuration information, and the second BAP entity of the node has not been established when the second BAP configuration information is set to a first value, the node establishes the second BAP entity corresponding to the second BAP configuration information on the mobile terminal (IAB-MT) side.

[0130] In at least one embodiment, the BAP layer of the node establishes the second BAP entity after receiving instructions from a higher layer regarding the establishment of the second BAP entity.

[0131] In at least one embodiment, when all terminal devices under the node are switched to access via the second IAB-DU, the second IAB-DU is changed to the first IAB-DU, and the original first IAB-DU is changed to the second IAB-DU.

[0132] In at least one embodiment, the first processing unit controls the node to perform the following operation, namely, to release the second BAP entity.

[0133] In at least one embodiment, the node releases the second BAP entity when the RRC message received by the node includes the second BAP configuration information and the second BAP configuration information is set to the second value.

[0134] In at least one embodiment, the BAP layer releases the second BAP entity after the node receives instructions from a higher layer regarding the release of the second BAP entity.

[0135] In at least one embodiment, if a BAP entity for the node has not been established when an RRC message received by the node includes a first BAP setting and the setting is set to a first value, the node establishes BAP entities for its mobile terminal (IAB-MT) and first distribution unit (IAB-DU), respectively.

[0136] In at least one embodiment, the first processing unit controls the node to perform the following operations, namely, Each of the aforementioned nodes saves the F1AP BAP settings for the first IAB-DU and the F1AP BAP settings for the second IAB-DU.

[0137] In at least one embodiment, the BAP configuration includes a mapping configuration from uplink traffic to routing indicators and / or a mapping configuration from uplink traffic to BH RLC channels.

[0138] In at least one embodiment, the BAP layer maintains the variables for the second IAB-DU.

[0139] In at least one embodiment, the variable includes a mapping setting from second uplink traffic to routing indicators and / or a mapping setting from second uplink traffic to BH RLC channels.

[0140] In at least one embodiment, the mapping configuration from the second uplink traffic to the routing indicator includes one traffic type specifier and one BAP routing indicator; or the mapping configuration from the second uplink traffic to the BH RLC channel includes one traffic type specifier, one exit link indicator and one exit BH RLC channel indicator.

[0141] In at least one embodiment, the node maps backhaul adaptive protocol service data units (BAP SDUs) received from the upper layer that need to be transmitted upstream to BAP addresses and BAP path identifiers based on the following configuration variables: The first uplink traffic to routing ID mapping configuration is obtained from F1AP signaling to the node, and the F1AP signaling does not include signaling to the second IAB-DU; and This is a mapping setting from the second uplink traffic to the routing indicator, and this setting is obtained from the F1AP signaling to the second IAB-DU.

[0142] In at least one embodiment, the node performs the following operations on the BAP SDU received from the upper layer that needs to be transmitted upstream: For a BAP SDU encapsulating an F1-U data packet, if the BAP SDU originates from the second IAB-DU, the corresponding entry is selected from the mapping settings from the second uplink traffic to routing indicators based on the traffic type designator corresponding to the destination IP address and tunnel endpoint identifier (TEID).

[0143] In at least one embodiment, the node maps BAP SDUs received from the upper layer that need to be transmitted upstream to the exit BH RLC channel marker based on the following configuration variables: This is the Uplink Traffic to BH RLC Channel Mapping Configuration, which is obtained from F1AP signaling to the node, and the F1AP signaling does not include signaling to the second IAB-DU; and This is a mapping setting from the second uplink traffic to the BH RLC channel indicator, which is obtained from the F1AP signaling to the second IAB-DU.

[0144] In at least one embodiment, after an exit link is selected for a BAP SDU received from a higher layer that needs to be transmitted upstream, the BAP entity further performs the following operations: For a BAP SDU encapsulating an F1-U data packet, if the BAP SDU originates from a second IAB-DU, the system selects the corresponding entry from the mapping configuration from the second uplink traffic to routing indicators, based on the traffic type designator corresponding to the destination IP address and TEID, and the link indicator corresponding to the selected exit link. If an entry exists, the system selects the exit BH RLC channel corresponding to the exit BH RLC channel indicator in that entry; if no corresponding entry exists, the system selects any exit BH RLC channel on the exit link.

[0145] In at least one embodiment, the first distribution unit is controlled by a first donor central unit, and the second distribution unit is controlled by a second donor central unit.

[0146] In at least one embodiment, the first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration is not performed, or is the source donor central unit in the distributed unit migration process, and the second donor central unit is the target donor central unit of the node in the distributed unit migration process.

[0147] <Example of the sixth side view> A sixth embodiment of the present invention provides a signal transmitting and receiving device. This device is applied to an IAB node and corresponds to the signal transmitting and receiving method in the second embodiment.

[0148] Figure 11 shows a signal transmitting and receiving device in the sixth side embodiment. As shown in Figure 11, the device 1100 includes a second processing unit 1101.

[0149] The second processing unit 1101 controls the node to perform the following operations, namely, The mobile terminal (MT) in the node uses a common default BAP setting for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, or uses their respective default BAP settings; and The mobile terminal MT at the node transmits a signal based on the default BAP settings.

[0150] In at least one embodiment, when using a common default BAP setting for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, In the aforementioned node, the BAP entity performs the following operation on the BAP SDU received from the upper layer that needs to be transmitted upstream: If the RRC layer has set the first default uplink BAP routing marker, and the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the routing marker for the IAB-DU from the BAP SDU, then for non-F1-U data packets, the F1AP selects the BAP address and BAP path marker configured in the first default uplink BAP routing marker.

[0151] In at least one embodiment, when using a common default BAP setting for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, At the aforementioned node, after an exit link is selected for the BAP SDU received from the upper layer that needs to be transmitted upstream, the BAP entity further performs the following operations, namely: If the RRC layer has set up the first default uplink BH RLC channel marker, and the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the BH RLC channel marker for the IAB-DU from the BAP SDU, then for non-F1-U data packets, the F1AP selects the exit BH RLC channel corresponding to the first default uplink BH RLC channel marker.

[0152] In at least one embodiment, when using the respective default BAP settings for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, A second default BAP setting is defined for the aforementioned second IAB-DU, The non-F1-U data corresponding to the first IAB-DU uses the first default BAP setting. Non-F1-U data corresponding to the second IAB-DU uses the second default BAP setting.

[0153] In at least one embodiment, the second BAP default setting is set in the RRC message.

[0154] The aforementioned second BAP default setting includes a second default uplink BAP routing indicator and a second default uplink BH RLC channel.

[0155] In at least one embodiment, the node performs the following operation on the BAP SDU received from the upper layer that needs to be transmitted upstream: If the traffic relates to a second IAB-DU, a second default uplink BAP routing sign is configured, and the F1AP has not configured or reconfigured the mapping from uplink traffic to routing sign for the second IAB-DU since the last configuration or reconfiguration by the RRC, then for non-F1-U data packets, the BAP address and BAP path sign configured in the second default uplink BAP routing sign are selected.

[0156] In at least one embodiment, the node, after an exit link has been selected for a BAP SDU received from a higher layer that needs to be transmitted upstream, performs the following operations: If the traffic relates to a second IAB-DU, a second default uplink BH RLC channel is configured, and the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the BH RLC channel for the second IAB-DU after the second default uplink BH RLC channel has been configured by the RRC, then for non-F1-U data packets, the F1AP selects the exit BH RLC channel corresponding to the second default uplink BH RLC channel indicator.

[0157] In at least one embodiment, the first distribution unit is controlled by a first donor central unit, and the second distribution unit is controlled by a second donor central unit.

[0158] In at least one embodiment, the first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration is not taking place, or is the source donor central unit during the distributed unit migration process, and the second donor central unit is the target donor central unit of the node during the distributed unit migration process.

[0159] <Example of the seventh side view> In the seventh embodiment, a signal transmitting and receiving device is provided, which is applied to an IAB node and corresponds to the signal transmitting and receiving method in the third embodiment.

[0160] Figure 12 shows a signal transmitting and receiving device in the seventh side embodiment. As shown in Figure 12, the device 1200 includes a third processing unit 1201, which controls the node to perform the following operations, namely, With respect to data arriving downstream of the node, the node determines, based on its IP address, that it will transmit the downstream data to the node's first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

[0161] In at least one embodiment, the node determines, based on the target IP address, that the downstream data will be transmitted to the node's first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

[0162] In at least one embodiment, the third processing unit controls the node to perform the following operations, namely, When the node requests an IP address from the donor central unit (donor-CU) via RRC, the purpose of use of the IP address is included, and the purpose of use is used to indicate that the IP address should be used by the second distributed unit (IAB-DU).

[0163] In at least one embodiment, if the RRC message received by the node includes an assigned IP address and indicates that the corresponding purpose of use is to be used by the second distributed unit (IAB-DU), the node stores the IP address as the IP address of the second IAB-DU.

[0164] In at least one embodiment, when a BAP data protocol data unit (PDU) is received from a lower layer, the receiving unit of the BAP entity performs the following operations, namely: If the destination field of the BAP data PDU matches a BAP address set by the IAB-donor providing the ingress BH RLC channel, remove the BAP header from the BAP data PDU and pass the BAP SDU to the upper layer; and The upper layer decides to transmit the BAP SDU to the first distributed unit (IAB-DU) or the second distributed unit (IAB-DU) based on the target IP address of the BAP SDU.

[0165] In at least one embodiment, the node determines, based on the source IP address, that the downstream data is to be transmitted to the node's first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

[0166] In at least one embodiment, when a BAP data PDU (protocol data unit) is received from a lower layer, the receiving unit of the BAP entity performs the following operations, namely: If the destination field of the BAP data PDU matches a BAP address set by the IAB-donor providing the ingress BH RLC channel, remove the BAP header from the BAP data PDU and pass the BAP SDU to the upper layer; and The upper layer decides to transmit the BAP SDU to the first distributed unit (IAB-DU) or the second distributed unit (IAB-DU) based on the source IP address of the BAP SDU.

[0167] In at least one embodiment, the first distribution unit is controlled by a first donor central unit, and the second distribution unit is controlled by a second donor central unit.

[0168] In at least one embodiment, the first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration is not performed, or is the source donor central unit in the distributed unit migration process, and the second donor central unit is the target donor central unit of the node in the distributed unit migration process.

[0169] <Example of the eighth side view> In the eighth embodiment, a signal transmitting and receiving device is provided, which is applied to an IAB node and corresponds to the signal transmitting and receiving method in the fourth embodiment.

[0170] Figure 13 shows a signal transmitting and receiving device in the eighth side embodiment. As shown in Figure 13, the device 1300 includes a fourth processing unit 1301, which controls the node to perform the following operations, namely, Before performing the DU migration, the node configures the wireless bearer's dual active protocol stack (DAPS) for the terminal devices it serves.

[0171] Among these, the wireless bearers of all terminal devices served by the aforementioned node are configured as DAPS bearers.

[0172] <Example of the ninth side view> Embodiments of the present invention further provide a communication system which may include an IAB node and a donor central unit CU. At least one of the MT of the IAB node, the DU of the IAB node, and the CU may have the electronic equipment configuration shown in Figure 14.

[0173] Figure 14 shows the configuration of an electronic device in an embodiment of the present invention. As shown in Figure 14, the terminal device 1400 may include a processor 1410 (for example, a central processor CPU) and a memory unit 1420, the memory unit 1420 being connected to the processor 1410. The memory unit 1420 can store various types of data, and can also store a program 1430 for information processing, and can execute the program 1430 under the control of the processor 1410.

[0174] For example, the processor 1410 may execute a program to control the electronic device so that it implements the methods described in the first to fourth embodiments.

[0175] Furthermore, as shown in Figure 14, the electronic device 1400 may also include a transceiver 1440, an antenna 1450, and the functions of the aforementioned components are the same as in the prior art, and a detailed explanation is omitted here. Note that the electronic device 1400 does not need to include all the components shown in Figure 14. Also, the electronic device 1400 may include components not shown in Figure 14, for which prior art can be referenced.

[0176] In embodiments of the present invention, a computer program is further provided, in which, when the program is executed on an IAB node, the program causes the IAB node to perform the method described in the embodiments of the first to fourth aspects.

[0177] In embodiments of the present invention, a storage medium storing a computer program is provided, wherein the computer program causes a terminal device to execute the methods described in the embodiments of the first to fourth aspects.

[0178] Furthermore, the above-described apparatus and method may be implemented by software or hardware, or by a combination of hardware and software. The present invention further relates to a computer-readable program as described below, that is, the program, when executed by a logic component, causes the logic component to implement the above-described apparatus or component, or to the logic component to implement each of the above-described method or step. The logic component may be, for example, an FPGA (Field Programmable Gate Array), a microprocessor, or a processor used in a computer. The present invention further relates to a storage medium storing the above-described program, for example, a hard disk, a magnetic disk, an optical hard disk, a DVD, a flash memory, etc.

[0179] Furthermore, one or more combinations of the functional blocks shown in the drawings and / or one or more combinations of functional blocks may be implemented as a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), 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 shown in the drawings and / or one or more combinations of functional blocks may further be configured as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors connected to a DSP by communication or any other combination of any other configuration.

[0180] Although preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and any modifications to the present invention that do not deviate from the spirit of the invention fall within the technical scope of the present invention.

[0181] Furthermore, the following additional information is disclosed regarding the above-mentioned embodiments.

[0182] <Method relating to the first embodiment> (Note 1) A method for transmitting and receiving signals, which is applied to an IAB node, and the method is Uplink backhaul mapping information is set in the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) of the node, respectively, by different donor central units; and The mobile terminal of the node transmits a signal based on the uplink backhaul mapping information.

[0183] (Note 2) The method described in Appendix 1, wherein the method further includes: This includes establishing a second BAP entity at the node that is different from the first backhaul adaptive protocol entity (BAP Entity), The first BAP entity maintains the variables set by the first donor central unit (donor-CU) in the BAP layer of the node, The aforementioned second BAP entity maintains the variables set by the second donor central unit in the BAP layer of the node.

[0184] (Note 3) The method described in Appendix 2, The aforementioned second BAP entity stores or uses mapping settings from uplink traffic to routing indicators and mapping settings from uplink traffic to BH RLC channels, which are configured by the second donor central unit associated with F1.

[0185] (Note 4) The method described in Appendix 2, wherein the method further includes: With respect to upstream data transmission, the node selects a corresponding first BAP entity or a second BAP entity based on the DU to which the data transmission traffic belongs.

[0186] (Note 5) The method described in Appendix 4, The DU to which the traffic belongs is determined by determining which DU the Backhaul Adaptive Protocol Service Data Unit (BAP SDU) received from the upper layer originates; or The DU to which the traffic belongs is determined by the donor central unit (donor-CU) corresponding to the target IP address of the BAP SDU received from the upper layer.

[0187] (Note 6) The method described in Appendix 2, wherein the method is The Radio Resource Control (RRC) layer of the node receives second configuration information, The aforementioned second configuration information is used to configure the aforementioned second BAP entity.

[0188] (Note 7) The method described in Appendix 6, The aforementioned second configuration information is a new information element (IE) that is newly added in the RRC reset message. The second configuration information includes at least one of the following pieces of information for the DU corresponding to the second BAP entity: namely, the BAP address, the uplink default BAP routing indicator, and the uplink default backhaul radio link control (BH RLC) channel.

[0189] (Note 8) The method described in Appendix 6, The RRC message received by the node includes the second BAP configuration information, and when the second BAP configuration information is set to the first value, if the node's second BAP entity has not been established, the node establishes the second BAP entity corresponding to the second BAP configuration information on the mobile terminal (IAB-MT) side.

[0190] (Note 9) The method described in Appendix 8, The BAP layer of the node establishes the second BAP entity after receiving instructions from the upper layer regarding the establishment of the second BAP entity.

[0191] (Note 10) The method described in Appendix 2, When all terminal devices under the node are switched to access via the second IAB-DU, the second IAB-DU is changed to the first IAB-DU, and the original first IAB-DU is changed to the second IAB-DU.

[0192] (Note 11) The method described in Appendix 10, wherein the method further includes: This includes releasing the aforementioned second BAP entity.

[0193] (Note 12) The method described in Appendix 11, The RRC message received by the node includes the second BAP configuration information, and when the second BAP configuration information is set to the second value, the node releases the second BAP entity.

[0194] (Note 12a) The method described in Appendix 11, After the node receives instructions from the upper layer regarding the release of the second BAP entity, the BAP layer releases the second BAP entity.

[0195] (Note 13) The method described in Appendix 2, The RRC message received by the node includes a first BAP setting, and when this setting is set to a first value, if the node's BAP entity has not been established, the node establishes BAP entities for its mobile terminal (IAB-MT) and first distribution unit (IAB-DU), respectively.

[0196] (Note 14) The method described in Appendix 1, Each of the aforementioned nodes stores the BAP settings for the first IAB-DU and the BAP settings for the second IAB-DU of F1AP.

[0197] (Note 15) The method described in Appendix 14, The BAP configuration includes mapping settings from uplink traffic to routing indicators and / or mapping settings from uplink traffic to BH RLC channels.

[0198] (Note 16) The method described in Appendix 14, The BAP layer maintains the variables for the second IAB-DU.

[0199] (Note 17) The method described in Appendix 16, The aforementioned variables include mapping settings from the second uplink traffic to routing indicators and / or mapping settings from the second uplink traffic to the BH RLC channel.

[0200] (Note 18) The method described in Appendix 17, The aforementioned mapping configuration from the second uplink traffic to the routing indicator includes one traffic type specifier and one BAP routing indicator; or The mapping configuration from the second uplink traffic to the BH RLC channel includes one traffic type designator, one exit link indicator, and one exit BH RLC channel indicator.

[0201] (Note 19) The method described in Appendix 14, In the aforementioned node, the BAP entity maps the backhaul adaptive protocol service data units (BAP SDUs) received from the upper layer that need to be transmitted upstream to the BAP address and BAP path indicator based on the following configuration variables, i.e., The first uplink traffic to routing ID mapping configuration is obtained from F1AP signaling to the node, and the F1AP signaling does not include signaling to the second IAB-DU; and This is a mapping setting from the second uplink traffic to the routing marker, which is obtained from the F1AP signaling to the second IAB-DU.

[0202] (Note 20) The method described in Appendix 19, In the aforementioned node, the BAP entity performs the following operations on the BAP SDU received from the upper layer that needs to be transmitted upstream: For a BAP SDU encapsulating an F1-U data packet, if the BAP SDU originates from the second IAB-DU, the corresponding entry is selected from the mapping settings from the second uplink traffic to routing indicators based on the traffic type designator corresponding to the destination IP address and tunnel endpoint identifier (TEID).

[0203] (Note 21) The method described in Appendix 14, In the aforementioned node, the BAP entity maps the BAP SDU received from the upper layer that needs to be transmitted upstream to the exit BH RLC channel marker based on the following configuration variables, i.e., This is the Uplink Traffic to BH RLC Channel Mapping Configuration, which is obtained from F1AP signaling to the node, and the F1AP signaling does not include signaling to the second IAB-DU; and This is a mapping setting from the second uplink traffic to the BH RLC channel indicator, which is obtained from the F1AP signaling to the second IAB-DU.

[0204] (Note 22) The method described in Appendix 21, In the aforementioned node, after an exit link is selected for the BAP SDU received from the upper layer that needs to be transmitted upstream, the BAP entity performs the following operations, namely: For a BAP SDU encapsulating an F1-U data packet, if the BAP SDU originates from a second IAB-DU, select the corresponding entry from the mapping configuration from the second uplink traffic to routing indicators, based on the traffic type designator corresponding to the destination IP address and TEID, and the link indicator corresponding to the selected exit link. If an entry exists, select the exit BH RLC channel corresponding to the exit BH RLC channel label in that entry. If no corresponding entry exists, it selects any exit BH RLC channel on the exit link.

[0205] (Note 23) The method described in Appendix 1, The aforementioned first distributed unit is controlled by the first donor central unit, The aforementioned second distributed unit is controlled by the second donor central unit.

[0206] (Note 24) The method described in Appendix 23, The first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration does not occur, or the source donor central unit during the distributed unit migration process. The aforementioned second donor central unit is the target donor central unit of the node in the distributed unit transition process.

[0207] <Method relating to the second aspect of the embodiment> (Note 1) A method for transmitting and receiving signals, which is applied to an IAB node, and the method is The mobile terminal (MT) in the node uses a common default BAP setting for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, or uses their respective default BAP settings; and This includes the mobile terminal MT at the node transmitting a signal based on the default BAP settings.

[0208] (Note 2) The method described in Appendix 1, When setting a common default BAP configuration for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the aforementioned node, In the aforementioned node, the BAP entity performs the following operation on the BAP SDU received from the upper layer that needs to be transmitted upstream: If the RRC layer has set the first default uplink BAP routing indicator, and the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the routing indicator for the IAB-DU from the BAP SDU, then the F1AP will select the BAP address and BAP path indicator set in the first default uplink BAP routing indicator for non-F1-U data packets.

[0209] (Note 3) The method described in Appendix 1, When using a common default BAP setting for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the aforementioned node, At the aforementioned node, after an exit link is selected for the BAP SDU received from the layer that needs to be transmitted upstream, the BAP entity performs the following operations, namely: After the RRC layer has set up the first default uplink BH RLC channel marker, if the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the BH RLC channel marker for the IAB-DU from the BAP SDU, it will select the exit BH RLC channel corresponding to the first default uplink BH RLC channel marker for non-F1-U data packets.

[0210] (Note 4) The method described in Appendix 1, When using the respective default BAP settings for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, A second default BAP setting is defined for the aforementioned second IAB-DU, The non-F1-U data corresponding to the first IAB-DU uses the first default BAP setting. The non-F1-U data corresponding to the second IAB-DU uses the second default BAP setting.

[0211] (Note 5) The method described in Appendix 4, The aforementioned second BAP default setting is set in the RRC message, The aforementioned second BAP default configuration includes a second default uplink BAP routing indicator and a second default uplink BH RLC channel.

[0212] (Note 6) The method described in Appendix 4, In the aforementioned node, the BAP entity performs the following operation on the BAP SDU received from the upper layer that needs to be transmitted upstream: If the traffic relates to a second IAB-DU, a second default uplink BAP routing sign is set, and the F1AP has not performed any mapping from uplink traffic to routing sign for the second IAB-DU since the last time the second default uplink BAP routing sign was set or reset by the RRC, then select the BAP address and BAP path sign set in the second default uplink BAP routing sign for non-F1-U data packets.

[0213] (Note 7) The method described in Appendix 4, In the aforementioned node, after an exit link is selected for the BAP SDU received from the upper layer that needs to be transmitted upstream, the BAP entity performs the following operations, namely: If the traffic relates to a second IAB-DU, a second default uplink BH RLC channel is configured, and the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the BH RLC channel for the second IAB-DU after the second default uplink BH RLC channel has been configured by the RRC, then the system selects the exit BH RLC channel corresponding to the second default uplink BH RLC channel indicator for non-F1-U data packets.

[0214] (Note 8) The method described in Appendix 1, The aforementioned first distributed unit is controlled by the first donor central unit, The aforementioned second distributed unit is controlled by the second donor central unit.

[0215] (Note 9) The method described in Appendix 8, The first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration does not occur, or the source donor central unit during the distributed unit migration process. The aforementioned second donor central unit is the target donor central unit of the node in the distributed unit transition process.

[0216] <Method relating to the third aspect of the embodiment> (Note 1) A method for transmitting and receiving signals, which is applied to an IAB node, and the method is This includes determining, based on the IP address, that the node will transmit data arriving downstream of the node to its first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

[0217] (Note 2) The method described in Appendix 1, The node determines, based on the target IP address, that the downstream data will be transmitted to the node's first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

[0218] (Note 3) The method described in Appendix 2, wherein the method further includes: When the node requests an IP address from the donor central unit (donor-CU) via RRC, the purpose of use of the IP address is included, and the purpose of use is used to indicate that the IP address will be used by the second distributed unit (IAB-DU).

[0219] (Note 4) The method described in Appendix 3, If the RRC message received by the node includes an assigned IP address and the corresponding purpose of use indicates that it will be used by the second distributed unit (IAB-DU), the node stores the IP address as the IP address of the second IAB-DU.

[0220] (Note 5) The method described in Appendix 2, When receiving one BAP data protocol data unit (PDU) from the lower layer, the receiving part of the BAP entity performs the following operations, that is, When the destination field of the BAP data PDU matches the BAP address set by the IAB-donor that provides the ingress BH RLC channel, remove the BAP header of the BAP data PDU and pass the BAP SDU to the upper layer; and The upper layer determines to transmit the BAP SDU to the first distributed unit (IAB-DU) or the second distributed unit (IAB-DU) based on the target IP address of the BAP SDU.

[0221] (Appendix 6) The method described in Appendix 1, The node determines that the data in the downstream direction is transmitted to the first distributed unit (IAB-DU) or the second distributed unit (IAB-DU) of the node based on the source IP address.

[0222] (Appendix 7) The method described in Appendix 6, When receiving one BAP data PDU (protocol data unit) from the lower layer, the receiving part of the BAP entity performs the following operations, that is, When the destination field of the BAP data PDU matches the BAP address set by the IAB-donor that provides the ingress BH RLC channel, remove the BAP header of the BAP data PDU and pass the BAP SDU to the upper layer; and The upper layer determines to transmit the BAP SDU to the first distributed unit (IAB-DU) or the second distributed unit (IAB-DU) based on the source IP address of the BAP SDU.

[0223] (Appendix 8) The method described in Appendix 1, The first distributed unit is controlled by the first donor central unit, The aforementioned second distributed unit is controlled by the second donor central unit.

[0224] (Note 9) The method described in Appendix 8, The first donor central unit is the F1 terminal donor central unit of the node when distributed unit migration does not occur, or the source donor central unit during the distributed unit migration process. The aforementioned second donor central unit is the target donor central unit of the node in the distributed unit transition process.

[0225] <Method relating to the fourth aspect embodiment> (Note 1) A method for transmitting and receiving signals, which is applied to an IAB node, and the method is This includes configuring the wireless bearer's dual active protocol stack (DAPS) for the terminal equipment served by the node before performing the DU migration.

[0226] (Note 2) The method described in Appendix 1, The aforementioned node configures the wireless bearers of all terminal devices it serves as DAPS bearers.

Claims

1. A signal transmission and reception device, Applied to an IAB node, the apparatus includes a first processing unit, the first processing unit controls the node to cause the node to perform the following operations, namely, Uplink backhaul mapping information is set in the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, respectively, by different donor central units; and A device in which the mobile terminal of the node transmits a signal based on the uplink backhaul mapping information.

2. The apparatus according to claim 1, The first processing unit controls the node to perform the following operations, namely, A second BAP entity, distinct from the first backhaul adaptive protocol entity (BAP Entity), is established at the aforementioned node. The first BAP entity maintains the variables set by the first donor central unit (donor-CU) in the BAP layer of the node, The aforementioned second BAP entity is a device that maintains the variables set by the second donor central unit in the BAP layer of the node.

3. The apparatus according to claim 2, The first processing unit controls the node to perform the following operations, namely, A device that, for upstream data transmission, causes the node to select a corresponding first BAP entity or a second BAP entity based on the DU to which the data transmission traffic belongs.

4. The apparatus according to claim 2, The first processing unit controls the node to perform the following operations, namely, A device that causes the Radio Resource Control (RRC) layer of the node to receive second configuration information, and uses the second configuration information to configure the second BAP entity.

5. The apparatus according to claim 4, The aforementioned second configuration information is a new information element (IE) that is newly added to the RRC reset message. The device wherein the second configuration information includes at least one of the following pieces of information for the DU corresponding to the second BAP entity: namely, the BAP address, the uplink default BAP routing indicator, and the uplink default backhaul radio link control (BH RLC) channel.

6. The apparatus according to claim 5, A device wherein the RRC message received by the node includes the second BAP configuration information, and when the second BAP configuration information is set to a first value, if the node's second BAP entity has not been established, the node establishes the second BAP entity corresponding to the second BAP configuration information on the mobile terminal (IAB-MT) side.

7. The apparatus according to claim 1, The first processing unit controls the node to perform the following operations, namely, A device in which the node stores the BAP settings for the first IAB-DU and the BAP settings for the second IAB-DU of F1AP.

8. The apparatus according to claim 7, The BAP layer maintains the variables for the second IAB-DU, The aforementioned variables include a device that includes mapping settings from second uplink traffic to routing indicators and / or mapping settings from second uplink traffic to BH RLC channels.

9. The apparatus according to claim 7, At the aforementioned node, the BAP entity maps the backhaul adaptive protocol service data unit (BAP SDU) received from the upper layer, which needs to be transmitted upstream, to the BAP address and BAP path indicator based on the following configuration variables, i.e., The configuration is an Uplink Traffic to Routing ID Mapping Configuration, which is obtained from F1AP signaling to the node, and the F1AP signaling does not include signaling to the second IAB-DU; and This is a mapping configuration from the second uplink traffic to a routing indicator, which is obtained from F1AP signaling to the second IAB-DU.

10. The apparatus according to claim 9, At the aforementioned node, with respect to the BAP SDU received from the upper layer that needs to be transmitted upstream, the BAP entity further performs the following operations, namely: A device that, with respect to a BAP SDU encapsulating an F1-U data packet, selects a corresponding entry from the mapping configuration from the second uplink traffic to routing identifiers based on a traffic type specifier corresponding to the destination IP address and tunnel endpoint identifier (TEID), provided that the BAP SDU originates from the second IAB-DU.

11. A signal transmission and reception device, Applied to an IAB node, the apparatus includes a second processing unit, which controls the node to perform the following operations, namely, The mobile terminal (MT) in the node uses a common default BAP setting for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, or uses the respective default BAP settings; and A device in which a mobile terminal MT at the node transmits a signal based on the default BAP setting.

12. The apparatus according to claim 11, When using the respective default BAP settings for the first distributed unit (IAB-DU) and the second distributed unit (IAB-DU) in the node, A second default BAP setting is defined for the second IAB-DU, The non-F1-U data corresponding to the first IAB-DU uses the first default BAP setting. The device uses the second default BAP setting for non-F1-U data corresponding to the second IAB-DU.

13. The apparatus according to claim 12, At the aforementioned node, the BAP entity performs the following operation on the BAP SDU received from the upper layer that needs to be transmitted upstream: A device that selects the BAP address and BAP path sign set in the second default uplink BAP routing sign for non-F1-U data packets, provided that the traffic relates to the second IAB-DU, the second default uplink BAP routing sign is set, and the F1AP has not performed any mapping from uplink traffic to routing sign for the second IAB-DU since the last time the second default uplink BAP routing sign was set or reset by the RRC.

14. The apparatus according to claim 12, At the aforementioned node, after an exit link is selected for the BAP SDU received from the upper layer that needs to be transmitted upstream, the BAP entity performs the following operations, namely: A device that selects an exit BH RLC channel corresponding to the second default uplink BH RLC channel indicator for non-F1-U data packets, when the traffic relates to a second IAB-DU, a second default uplink BH RLC channel is configured, and after the RRC has configured the second default uplink BH RLC channel, the F1AP has not configured or reconfigured the mapping from the first uplink traffic to the BH RLC channel for the second IAB-DU.

15. A signal transmission and reception device, Applied to an IAB node, the apparatus includes a third processing unit, which controls the node to perform the following operations, namely, A device that determines, based on the IP address, that data arriving downstream of the node will be transmitted to the node's first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

16. The apparatus according to claim 15, The node is a device that determines, based on the target IP address, that the downstream data is transmitted to the node's first distributed unit (IAB-DU) or second distributed unit (IAB-DU).

17. The apparatus according to claim 16, The third processing unit controls the node to perform the following operations, namely, A device that, when the node requests an IP address from the donor central unit (donor-CU) via RRC, includes the purpose of use of the IP address, said purpose of use is used to indicate that the IP address should be used by the second distributed unit (IAB-DU).

18. The apparatus according to claim 17, A device in which, if an RRC message received by the node includes an assigned IP address and indicates that the corresponding purpose of use is to be used by the second distributed unit (IAB-DU), the node stores the IP address as the IP address of the second IAB-DU.

19. The apparatus according to claim 16, When receiving a BAP data protocol data unit (PDU) from a lower layer, the receiving unit of the BAP entity performs the following operations, namely: If the destination field of the BAP data PDU matches the BAP address set by the IAB-donor providing the ingress BH RLC channel, remove the BAP header from the BAP data PDU and pass the BAP SDU to the upper layer; and A device in which the upper layer determines, based on the target IP address of the BAP SDU, to transmit the BAP SDU to the first distributed unit (IAB-DU) or the second distributed unit (IAB-DU).

20. The apparatus according to claim 15, The node is a device that determines, based on the source IP address, that the downstream data is transmitted to the first distributed unit (IAB-DU) or second distributed unit (IAB-DU) of the node.

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