Distributed unit migration method, control device and communication system

Abstract

Embodiments of the present invention provide a method for distributed unit migration, a control device, and a communication system. The device is applied to an IAB node and includes a first processing unit, the first processing unit controls the node such that the node's F1 termination donor migrates from a first donor aggregation unit (donor-CU) to a third donor-CU, the first donor-CU being different from the third donor-CU, the node's radio resource control (RRC) termination donor being a second donor-CU, the second donor-CU being identical to the first donor-CU, or identical to the third donor-CU, or different from both the first and third donor-CUs.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of communication technologies.

Background Art

[0002] Integrated access and backhaul (IAB) realizes the function of wireless relay in the next generation radio access network (NG-RAN). An integrated access and backhaul node (IAB-node) supports access and backhaul via new radio (NR). The network-side end point of the NR backhaul is called an IAB-donor, which represents a network device (e.g., gNB) that supports the IAB function.

[0003] An IAB-node can be connected to one IAB-donor via single-hop or multi-hop. These multi-hop connections form a topological structure of a directed acyclic graph (DAG) with the IAB-donor as the root node. The IAB-donor performs unified resource management, topology management, and routing management of the IAB network topology.

[0004] The IAB-node supports the functionality of the gNB-DU (distributed unit). The IAB-node DU, also known as the IAB-DU, is the endpoint for the radio access (NR access) interface between the terminal device (UE) and the next-hop IAB-node, and the endpoint for the F1 protocol to the gNB-CU (IAB-node: aggregate unit) at the IAB-donor. The IAB-DU can provide services to normal UEs and IAB child nodes. The IAB-DU implements the functionality of the network-side device, connects to downstream child IAB-nodes, provides NR air interfaces to UEs and downstream child IAB-nodes, and establishes F1 connectivity with the IAB donor-CU.

[0005] In addition to gNB-DU functionality, an IAB-node supports some UE functionality known as IAB-MT (mobile termination). IAB-MT includes physical layer, Layer 2, RRC, and NAS functions for connecting to gNB-DUs of other IAB-nodes or IAB-donors, continuing to gNB-CUs on IAB-donors, and continuing to the core network. IAB-MT can support functions such as the UE physical layer, access stratum (AS), radio resource control (RRC) layer, and non-access stratum (NAS) layer, and can connect to an IAB parent node.

[0006] An IAB-donor is the network-side termination node, providing network access for the IAB-MT or UE via a backhaul or access link. An 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 via an F1 interface. In scenarios where the network is deployed independently, the gNB and IAB-donor-CU are connected via an Xn interface.

[0007] To support multi-hop routing and forwarding of 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 packet destination node and route selection, packet routing and forwarding, bearer mapping, flow control feedback, and backhaul link failure notification.

[0008] Figure 1 is a schematic diagram of an example of 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 an IAB-MT function unit 101 and an IAB-DU function unit 102. The adjacent nodes on the interface of the IAB-DU function unit 102 are called child nodes, and include, for example, child nodes 201, 202, and 203 shown in Figure 1. Communication can be made between the IAB-DU function unit 102 and child nodes 201, 202, and 203 via an air interface (Uu). The adjacent nodes on the interface of the IAB-MT function unit 101 are called parent nodes, and include, for example, parent nodes 301 and 302 shown in Figure 1. Communication can be made between the IAB-MT function unit 101 and parent nodes 301 and 302 via an air interface (Uu).

[0009] As shown in Figure 1, the direction from IAB-node 100 to child nodes 201, 202, and 203 is called the downstream direction, and the direction from IAB-node 100 to parent nodes 301 and 302 is called the upstream direction. An IAB-donor (not shown) performs centralized resource, topology, and routing management for the IAB topology structure 10.

[0010] Furthermore, the above explanation of the background art is merely intended to provide a clearer and more complete explanation of the present invention and to facilitate understanding for those skilled in the art. These elements, as described in the background art section 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 the forwarding of data packets, the IAB node must determine the destination node to which the data packet will arrive, then, based on the routing table, determine the next-hop node corresponding to the destination node and transmit the packet. The donor-CU configures the mapping from each uplink F1-U Tunnel initiated from the IAB node, non-UE associated F1AP messages, UE-associated F1AP messages, and non-F1 traffic to BAP routing identifiers for the IAB node via F1AP (F1 application protocol) signaling.

[0012] The IAB node determines the BAP routing identifiers corresponding to different types of uplink IP packets originating from the IAB node based on routing identifier mapping information, and encapsulates a BAP subheader containing the BAP routing identifier information for these uplink IP packets. The Donor-CU configures the mapping from different types of downlink data packets to BAP routing identifiers for the donor-DU via F1AP signaling. The Donor-DU determines the BAP routing identifiers corresponding to received downlink IP packets based on routing identifier mapping information, and encapsulates a BAP subheader containing the BAP routing identifiers for these downlink IP packets.

[0013] The BAP routing identifier includes the destination BAP address and the path identifier (path identity) from the IAB node to the donor-DU. The BAP address is also referred to as DESTINATION in the BAP header. One BAP address is configured for each IAB node and donor-DU.

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

[0015] In the upstream direction, the IAB-donor-CU configures the mapping relationships for the IAB node, including upstream F1 and non-F1 traffic from the IAB node, the appropriate BAP routing ID, the next-hop BAP address, and the BH RLC channel. Specific mapping relationships are 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 can have redundant paths to different IAB-donor-CUs. When an IAB node operates in Stand Alone (SA) mode, it may allow the IAB-MT and two parent nodes to have backhaul links simultaneously via NR-DC (NR-NR Dual Connectivity) to achieve redundancy in the backhaul path. The two parent nodes can be connected to different IAB-donor-CUs, and these IAB-donor-CUs can control the establishment and release of redundant paths through the two parent nodes. The gNB-DU function of a parent node, together with its corresponding IAB-donor-CU, acts as the master node (MN) and / or secondary node (SN) of the IAB-MT. The NR-DC framework, for example, the procedures related to MCG (master cell group) / SCG (secondary cell group) are used to configure dual radio connectivity from the IAB node to the parent node.

[0017] An IAB-MT can migrate to a parent node under another IAB-donor-CU. In this case, the colocated IAB-DU and the IAB-DU of the descendant node maintain an F1 connection to the original IAB-donor-CU. This migration is called an inter-donor partial migration. The IAB node to which this IAB-MT migrates to the new IAB-donor-CU is the boundary IAB node. After the inter-donor partial migration, the F1 traffic of the IAB-DU and descendant node is routed through the BAP layer of the IAB topology to which the IAB-MT migrated. SA mode can support inter-donor partial migrations.

[0018] When an IAB node in SA mode declares a backhaul link RLF, RLF recovery can be performed on the parent node under a different IAB-donor-CU. Similar to inter-donor partial migrations, collocated IAB-DUs and the IAB-DUs of descendant nodes can maintain an F1 connection with the original IAB-donor-CU.

[0019] Figure 2 is a schematic diagram of an example of a partial migration scenario. IAB node 3 is called a boundary IAB node. A boundary IAB node means that its RRC interface and F1 interface terminate at different IAB-donor-CUs. Boundary IAB nodes are applied to partial migration, redundancy of donor topologies, and donor-to-donor RLF (radio link failure) recovery. For example, in Figure 2, node 3's DU terminates at CU1 and its MT has an RRC connection to CU2, thus meeting the definition of a boundary IAB node. A descendant IAB node means a node connected to the network via a boundary IAB node, and each node is single-connected to its parent node, for example, IAB node 4. An F1-terminating node means a donor-CU that terminates the F1 interface of the boundary IAB node and the descendant node, for example, donor-CU1 (the F1 interfaces of IAB-DU3 and IAB-DU4 in Figure 2 terminate at donor-CU1). A non-F1-terminating node refers to a CU (Control Unit) that has donor functionality but does not terminate the F1 interface of the boundary IAB node and its descendant nodes, such as donor-CU2. Because non-F1-terminating nodes have RRC connections with IAB-MTs, they are also called IAB-MT donor nodes, and non-F1-terminating donor CUs are also called IAB-MT donor CUs.

[0020] In Figure 2, IAB-MT3's connection has been changed 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 taken by this F1 connection goes through IAB node 2 and finally reaches CU1. In a partial migration scenario like the one in Figure 2, the boundary node is the migration node. The partial migration scenario can similarly be applied to partial RLF recovery.

[0021] The mobility of mobile IABs (mIABs) or mobile relays over large areas presents the challenge of needing to change the IAB donor (i.e., the F1 termination donor) during transit, i.e., migrating the IAB-DU F1 interface. This migration procedure is called IAB-DU migration. Packet Data Aggregation Protocol (PDCP) and Radio Resource Control (RRC) connectivity of terminal equipment (e.g., user equipment UEs) served by mobile IABs is also affected.

[0022] In a DU migration scenario, to perform the handover of the served UE, the mobile IAB node must simultaneously support two logical mobile IAB-DUs, and these two DUs, the source CU and the target CU, each have an F1AP association.

[0023] A UE connected to a mobile IAB node hands over from a cell in a logical movement IAB-DU that has a source CU and F1AP association (i.e., the source logical movement IAB-DU) to a logical movement IAB-DU that has a target CU and F1AP association (i.e., the target logical movement IAB-DU).

[0024] In the DU migration process, the UE regards the cells of two logical DUs as different physical cells (for example, when the cells use the same carrier, the cells use different PCIs), and these two logical DU cells use separate physical resources (that is, different carriers in the conventional layer 1, or orthogonal time and frequency resources of the same carrier).

[0025] According to the discovery of the inventors of the present invention, in the prior art, the methods and procedures for IAB nodes to achieve DU migration are not defined.

[0026] An embodiment of the present invention provides a method, a control device, and a communication system for distributed unit migration, in which the F1 termination donor of an IAB node migrates from a first donor aggregation unit (donor-CU) to a third donor-CU different from the first donor-CU, so that the DU of the IAB node can migrate.

Means for Solving the Problem

[0027] In one aspect of an embodiment of the present invention, there is provided a control device for distributed unit migration applied to an access backhaul integrated node (IAB-node), including a first processing unit, and the first processing unit controls the node so that the F1 termination donor of the node migrates from a first donor aggregation unit (donor-CU) to a third donor-CU, the first donor-CU is different from the third donor-CU, the radio resource control (RRC) termination donor of the node is a second donor-CU, the second donor-CU is the same as the first donor-CU, or the second donor-CU is the same as the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU.

[0028] In another aspect of an embodiment of the present invention, there is provided a control device for distributed unit migration, which is applied to a first donor aggregation unit (donor-CU), and includes a second processing unit. The second processing unit controls the first donor-CU such that the F1 termination donor of an access backhaul integrated node (IAB-node) migrates from the first donor-CU to a third donor-CU. The first donor-CU is different from the third donor-CU, and the radio resource control (RRC) termination donor of the node is a second donor-CU, where the second donor-CU is the same as the first donor-CU, or the second donor-CU is the same as the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU.

[0029] In another aspect of an embodiment of the present invention, there is provided a control device for distributed unit migration, which is applied to a third donor aggregation unit (donor-CU), and includes a third processing unit. The third processing unit controls the third donor-CU such that the F1 termination donor of an access backhaul integrated node (IAB-node) migrates from a first donor-CU to the third donor-CU. The first donor-CU is different from the third donor-CU, and the radio resource control (RRC) termination donor of the node is a second donor-CU, where the second donor-CU is the same as the first donor-CU, or the second donor-CU is the same as the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU.

[0030] In another embodiment of the present invention, a distributed unit migration control device is provided that is applied to a second donor aggregation unit (donor-CU), comprising a fourth processing unit, the fourth processing unit controlling the fourth donor-CU such that the F1 termination donor of an access backhaul integration node (IAB-node) migrates from the first donor aggregation unit (donor-CU) to the third donor-CU, wherein the first donor-CU is different from the third donor-CU, the radio resource control (RRC) termination donor of the node is the second donor-CU, the second donor-CU is identical to the first donor-CU, or the second donor-CU is identical to the third donor-CU, or the second donor-CU is different from both the first and third donor-CUs.

[0031] The advantageous effects of the embodiments of the present invention are as follows: It is possible to achieve DU migration of IAB nodes.

[0032] As shown in the following description and drawings, specific embodiments of the present invention are disclosed in detail, illustrating methods in which the principles of the present invention can be employed. However, the scope of embodiments of the present invention is not limited to these. Embodiments of the present invention include modified, altered, and equivalent forms within the scope of the gist and items of the appended claims.

[0033] Features described and / or shown in one embodiment may be used in the same or similar manner in one or more other embodiments, may be combined with features in other embodiments, or may be replaced by features in other embodiments.

[0034] In this text, the terms "includes / have" mean the presence of a feature, component, step, or constituent element, and do not exclude the presence or addition of one or more other features, components, steps, or constituent elements. [Brief explanation of the drawing]

[0035] Elements and features described in one drawing and one embodiment of the embodiments of the present invention may be combined with elements and features shown in one or more drawings or embodiments. In addition, similar reference numerals in the drawings may indicate corresponding elements in multiple drawings, and may indicate corresponding elements used in one or more embodiments. [Figure 1] This is a schematic diagram illustrating an example of the relationship between IAB parent and child nodes. [Figure 2] This is a schematic diagram illustrating an example of a partial transition scenario. [Figure 3] This is a schematic diagram illustrating an example scenario in which an IAB node uses multiple IAB-DUs in the DU migration procedure. [Figure 4] This is a schematic diagram of another example scenario in which an IAB node uses multi-IAB-DU in the DU migration procedure. [Figure 5] This is a schematic diagram of another example scenario in which an IAB node uses multi-IAB-DU in the DU migration procedure. [Figure 6] This is a schematic diagram of an example of a distributed unit migration method according to Example 1. [Figure 7] This is a schematic diagram of an example of IAB-DU transition. [Figure 8] This is a schematic diagram of an example of the new F1AP procedure. [Figure 9] This is a schematic diagram of an example of a control device for distributed unit migration according to Example 2. [Figure 10] This is a schematic diagram of an example of a control device for distributed unit migration according to Example 3. [Figure 11] This is a schematic diagram of an example of a control device for distributed unit migration according to Embodiment 4. [Figure 12] This is a schematic diagram of an example of a control device for distributed unit migration according to Example 5. [Figure 13] This is a schematic diagram of an example of the configuration of an electronic device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0036] The above and other features of the present invention will become apparent from the following description. Specific embodiments of the present invention are disclosed in detail in the specification and drawings, and some embodiments in which the principles of the present invention can be employed are shown. However, the present invention is not limited to the embodiments described. The present invention includes all modified, altered and equivalent versions of the appended claims.

[0037] In embodiments of the present invention, terms such as "first," "second," etc., are used in titles to distinguish different elements, but do not represent a spatial arrangement or temporal order of these elements, and these elements are not limited to these terms. The term "and / or" includes any one or more of the terms listed in the relevant list and all combinations thereof. The terms "include," "comprehensible," "have," etc., mean the presence of the listed features, elements, components, or components, but do not exclude the presence or addition of one or more other features, elements, components, or components.

[0038] In the embodiments of the present invention, singular nouns such as "one" and "the" should be understood broadly as "one type" or "one category," including plural forms, and not limited to "one." Furthermore, the term "the foregoing" should be understood to include both singular and plural forms unless the context explicitly indicates otherwise. Also, unless the context explicitly indicates otherwise, the term "as described" should be understood as "at least partially described," and the term "based on" should be understood as "based on at least partially."

[0039] In embodiments of the present invention, the terms "communication network" or "wireless communication network" may mean a network conforming to any communication standard, such as new radio (NR), Long Term Evolution (LTE), Advanced Long Term Evolution (LTE-A, LTE-Advanced), Wideband Code Division Multiple Access (WCDMA®), or High-Speed ​​Packet Access (HSPA).

[0040] Furthermore, communication between devices in a communication system may be carried out according to a communication protocol of any stage, and such communication protocol may include, but is not limited to, 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G, and new radio (NR), and / or other currently known communication protocols or other communication protocols to be developed in the future.

[0041] In embodiments of the present invention, the term "network device" means, for example, a device within a communication system that allows a terminal device to access the communication system and provides services to said terminal device. A network device may include, but is not limited to, an access backhaul integration node (IAB-node), relay device (relay), base station (BS), access point (AP), transmission reception point (TRP), broadcast transmitter, mobile management entity (MME), gateway, server, radio network controller (RNC), base station controller (BSC), and the like.

[0042] Here, base stations may include, but are not limited to, node B (NodeB or NB), evolutionary node B (eNodeB or eNB), and 5G base stations (gNB), as well as remote radio heads (RRH), remote radio units (RRU), relays, or low-power nodes (e.g., femto, pico). The term “base station” may also include some or all of their functions, and each base station may provide communication coverage to a specific geographic area. The term “cell” may mean a base station and / or its coverage area, depending on the context in which the term is used.

[0043] In embodiments of the present invention, the terms "User Equipment" (UE) or "Terminal Equipment" (TE) refer to a device that accesses a communication network and receives network services, for example, via a network device. The terminal equipment may be fixed or mobile, and may be referred to as a mobile station (MS), terminal, subscriber station (SS), access terminal (AT), mobile termination (MT), station, etc.

[0044] Here, terminal devices may include, but are not limited to, mobile phones (cellular phones), personal digital assistants (PDAs), radio modulators / demodulators, wireless communication devices, handheld devices, machine-type communication devices, laptop computers, cordless phones, smartphones, smartwatches, digital cameras, and the like.

[0045] Furthermore, in scenarios such as the Internet of Things (IoT), the terminal device may be a monitoring or measurement device or apparatus, and may include, but is not limited to, machine-type communication (MTC) terminals, in-vehicle communication terminals, device-to-device (D2D) terminals, and machine-to-machine (M2M) terminals.

[0046] Furthermore, the terms "network side" or "network device side" mean the network side, which may be a base station or include one or more network devices as described above. The terms "user side" or "terminal side" or "user terminal side" mean the user or terminal side, which may be a UE or include one or more terminal devices as described above.

[0047] In embodiments 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 MIB, system information, a dedicated RRC message, or referred to as an RRC IE (RRC information element). The upper layer signaling may also be, for example, an F1-C signaling, or referred to as an F1AP protocol. However, the present invention is not limited to these.

[0048] In this invention, each embodiment will be described using a multi-hop IAB network deployment scenario as an example. Here, multiple terminal devices (e.g., UEs) are connected to an IAB-donor via multi-hop IAB nodes and finally access the network. This network is, for example, a 5G network.

[0049] The IAB node connected to the terminal device (e.g., the user device) is movable.

[0050] Each embodiment of the present invention may also be applied to other mobile nodes, such as relay devices. Each embodiment of the present invention will be described using an IAB as an example.

[0051] <Example 1> Figure 3 is a schematic diagram of one example scenario in which an IAB node uses multi-IAB-DU in the DU migration procedure. Figure 4 is a schematic diagram of another example scenario in which an IAB node uses multi-IAB-DU in the DU migration procedure. Figure 5 is a schematic diagram of yet another example scenario in which an IAB node uses multi-IAB-DU in the DU migration procedure.

[0052] As shown in Figure 3, IAB node 3 includes two DU parts, namely a first IAB-DU and a second IAB-DU. The first IAB-DU is IAB-DU3a in Figure 3 and is connected via F1 to the source IAB-donor-CU (donor-CU1). The first IAB-DU may also be called the source IAB-DU and may be a normal IAB-DU that does not normally undergo DU migration. The second IAB-DU is IAB-DU3b in Figure 3 and is connected via F1 to the target IAB-donor-CU (IAB-DU). The second IAB-DU may also be called the target IAB-donor-CU. These two IAB-DUs may be logical IAB-DUs or virtual IAB-DUs; that is, from the perspective of a terminal device (e.g., a user device UE), they are no different from normal IAB-DUs or gNB-DUs, possessing the functions of a normal DU and being integrated within the IAB node, with the integration method determined by the implementation. The first and second IAB-DUs can also be implemented using the conventional IAB-DU implementation method, i.e., by using two physical IAB-DUs.

[0053] Considering the DU migration independently, that is, assuming that the MT does not migrate simultaneously during the DU migration, there are mainly three scenarios depending on the initial migration state of the IAB node and the selection status of the target IAB-donor-CU, which are shown in Figures 3 to 5.

[0054] Scenario 1: Corresponds to Figure 3. Before the DU migration, the IAB node is already in a partially migrated state (MT and DU are controlled by separate donor-CUs). The IAB-DU migrates the F1 terminating node to the IAB-MT's donor-CU. After the DU migration, the IAB node's MT and DU (and the UEs served by the migrating IAB node) terminate to the same donor-CU. This process may also be referred to as a full migration.

[0055] Scenario 2: Corresponds to Figure 4. Before the DU transition, the MT and DU of the IAB node (and the UE served by the moving IAB node) terminate to the same donor-CU. The IAB-DU switches the F1 termination node to a different donor node. After the DU transition, the IAB node is in a partial transition state (MT and DU are controlled by separate donor-CUs).

[0056] Scenario 3: Corresponds to Figure 5. Before the DU transition, the IAB node is in a partial transition state. The IAB-DU switches the F1 termination node to a different donor-CU than the IAB-MT's donor-CU. After the DU transition, the IAB node's MT and DU are still in a partial transition state (but the DU's donor-CU has been changed).

[0057] In these three scenarios and in each embodiment of the present invention, the source F1-terminating donor-CU of the IAB node (abbreviated as source donor-CU) may also be called the first donor-CU, i.e., the donor-CU of the first IAB-DU, for example, in Figures 3 and 5, the first donor-CU is Donor-CU1. In Figure 4, the first donor-CU is Donor-CU2.

[0058] In these three scenarios and in each embodiment of the present invention, the IAB node's target F1-terminating donor-CU (abbreviated as target donor-CU) is referred to as the third donor-CU, i.e., the donor-CU of the second IAB-DU. For example, in Figures 4 and 5, the third donor-CU is Donor-CU3. In Figure 3, the third donor-CU is Donor-CU2.

[0059] In these three scenarios and in each embodiment of the present invention, the IAB-MT donor-CU, i.e., the IAB-MT RRC connection donor-CU, is referred to as the second donor-CU, and is Donor-CU2 in Figures 3 to 5. When the IAB-MT donor-CU is not the same as the F1-terminating node, it is also referred to as a non-F1-terminating donor-CU.

[0060] Scenario 3 may be considered a more general scenario and includes a first donor-CU, a second donor-CU, and a third donor-CU. Scenarios 1 and 2 are special cases of Scenario 3, namely, in Scenario 1, Donor-CU2 is both the second donor-CU and the third donor-CU. In Scenario 2, Donor-CU2 is both the first donor-CU and the second donor-CU.

[0061] Each embodiment of the present invention will be described based on the above scenario. However, each embodiment of the present invention is not limited to the above scenario.

[0062] Example 1 provides a method for migrating distributed units. The method for migrating distributed units is as follows: This applies to a communication system including an IAB node (for example, IAB node 3 shown in Figure 5), a first donor-CU (for example, donor-CU1 shown in Figure 5), a second donor-CU (for example, donor-CU2 shown in Figure 5), and a third donor-CU (for example, donor-CU3 shown in Figure 5).

[0063] Figure 6 is a schematic diagram of an example of a distributed unit migration method according to Example 1. As shown in Figure 6, the method includes the following steps.

[0064] Step 601: The F1 terminal donor of the access backhaul integration node (IAB-node) migrates from the first donor aggregation unit (donor-CU) to the third donor-CU. Here, the first donor-CU is different from the third donor-CU.

[0065] In Example 1, the Radio Resource Control (RRC) termination donor of the node is a second donor-CU. The second donor-CU is identical to the first donor-CU, or identical to the third donor-CU, or different from both the first and third donor-CUs.

[0066] The following explanation is as follows:

[0067] An IAB node is, for example, IAB node 3 shown in Figure 5, and IAB node 3 can be referred to as this IAB node or this node.

[0068] The first donor-CU is, for example, donor-CU1 shown in Figure 5, and the first donor-CU can also be called the donor-CU of the IAB node's source F1-terminating donor-CU (abbreviated as source donor-CU), i.e., the first IAB-DU (for example, IAB-DU3a in Figure 5).

[0069] The second donor-CU is, for example, donor-CU2 shown in Figure 5, and the second donor-CU can also be called the IAB-MT donor-CU, that is, the IAB-MT RRC connection donor-CU. Here, if the IAB-MT donor-CU is not the same as the F1-terminating node, it is also called a non-F1-terminating donor-CU.

[0070] The third donor-CU is, for example, donor-CU3 shown in Figure 5, and the third donor-CU can also be called the target F1-terminating donor-CU of the IAB node (abbreviated as target donor-CU), that is, the donor-CU of the second IAB-DU (for example, IAB-DU3b in Figure 5).

[0071] Here, the second IAB-DU (i.e., the target IAB-DU) is also referred to as the collocated IAB-DU of the first IAB-DU (i.e., the source IAB-DU).

[0072] Figure 7 is a schematic diagram of an example of the IAB-DU migration, showing the implementation of step 601.

[0073] As shown in Figure 7, the steps in the IAB-DU transition are as follows:

[0074] Step 0: Step F1-terminating donor-CU (i.e., the first donor-CU) selects a target F1-terminating donor-CU (i.e., the third donor-CU). The specific selection method may be determined by the implementation of the first donor-CU, or by pre-configuration, operational management and maintenance (OAM) configuration, etc.

[0075] Step 1: The source F1-terminating donor-CU notifies the source IAB-DU (i.e., the first IAB-DU) of information about the target F1-terminating donor-CU via F1AP signaling. This prompts the target IAB-DU (the second IAB-DU) to request the establishment of F1 from the target donor-CU. Information about the target F1-terminating donor-CU is provided. This includes the TNL address (transport network layer address, i.e., IP address) and / or base station identifier (e.g., global base station identifier, Global gNB ID), etc.

[0076] Step 2: The target IAB-DU sends an F1 SETUP REQUEST message to the target F1-terminating donor-CU. The message includes the BAP address of the IAB node, one or more cell identifiers of the target IAB-DU, and the base station identifier and / or TNL address of the IAB-MT's donor-CU (second donor-CU).

[0077] Step 3: Target F1-terminating donor-CU sends an F1 setup response message back to target IAB-DU.

[0078] Step 4: The source IAB-DU notifies the source F1-terminating donor-CU via F1AP signaling of a message indicating the successful establishment of the F1 interface with the target donor-CU. This message may include one or more cell identifiers activated by the target donor-CU. The one or more cell identifiers activated by the target donor-CU may be obtained in Step 3.

[0079] Step 5: The source F1-terminating donor-CU sends a HANDOVER REQUEST message to the target F1-terminating donor-CU. This message includes user equipment context (UE context) information and is used to request the handover preparation of the terminal equipment (e.g., user equipment UE) served by the IAB node.

[0080] Step 6: If the base station identifier of the second donor-CU received in Step 2 is not the base station identifier of the receiving side (e.g., the target donor-CU), the target donor-CU sends an IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message to the IAB-MT's donor-CU (the donor-CU corresponding to the base station identifier received in Step 2) for F1 transmission migration. This IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message includes IAB node identification information, which includes, for example, the non-F1-terminating node UE XnAP ID and / or the IAB node's BAP address.

[0081] In step 6, if the IAB node's identification information includes a non-F1-terminating node UE XnAP ID, the source F1-terminating donor-CU must pre-send a UE Xn message to the target F1-terminating donor-CU to inform it of the UE XnAP ID of the IAB node's non-F1-terminating donor-CU. This Xn message may also include information such as the IAB node's BAP address and the IAB-DU's F1 transition request, so that the target donor-CU can prepare resource allocation. This exchange of Xn messages may occur in a previous step, for example, step 0. The UE XnAP ID of the IAB node's non-F1-terminating donor-CU may also be included in the handover request message in step 5, i.e., a new IE indicating the UE XnAP ID at the target base station of the IAB node providing services to the UE may be added to the Xn handover request message (Note: Here, UE means IAB-MT). The traffic profile, quality of service (QoS) parameters, and other information included in the IAB transmission transition management request message are obtained from the UE context information in step 5. If the base station identifier of the second donor-CU received in step 2 is the base station identifier of the receiving side (e.g., the target donor-CU), steps 6 and 7 are skipped.

[0082] Step 7: The IAB-MT donor-CU sends an IAB Transport Migration Management Response message to the target donor-CU. This message includes a Differentiated Services Code Point (DSCP) and flow label mapping configuration for downstream traffic, and UL Non-F1 Terminating BH Info to configure the uplink backhaul mapping configuration for the IAB node. The uplink backhaul mapping configuration means a mapping configuration from uplink traffic to BAP routing identifiers and a mapping configuration from uplink traffic to BH RLC channels.

[0083] Step 8: The target donor-CU establishes a UE context in the target IAB-DU using the F1AP UE Context Setup process and performs the uplink backhaul mapping configuration for the IAB node. Here, the UE context information is obtained in Step 5, and the information required for the uplink backhaul mapping configuration is obtained in Step 7.

[0084] Step 9: The target donor-CU sends a HANDOVER REQUEST ACKNOWLEDGE message back to the source donor-CU.

[0085] Step 10: Perform the UE handover procedure. This UE handover procedure includes the terminal device (e.g., user device UE) accessing a designated cell in the second IAB-DU based on the received RRC Reconfiguration message, SN STATUS TRANSFER, path switch procedure, and UE context release procedure. The target donor-CU generates the IP header of the downlink data based on the DSCP and flow label information received in Step 7.

[0086] Step 11: If the IAB-MT's donor-CU is not the source F1-terminating donor CU, the IAB-MT's donor-CU (i.e., the second donor-CU) sends an IAB TRANSPORT MIGRATION MODIFICATION REQUEST message to the source F1-terminating donor-CU. The message includes the IAB node's identification information and requests the release of offloaded traffic (e.g., all of it), i.e., requests that all traffic fall back to the source donor-CU. The IAB-MT's donor-CU can trigger the IAB TRANSPORT MIGRATION MODIFICATION REQUEST procedure to the source donor-CU by determining whether the migration for the IAB node's F1 transmission is complete through the traffic offloading procedures in Steps 6 and 7. If the IAB-MT's donor-CU is the source F1-terminating donor CU, Steps 11 and 12 are skipped.

[0087] Step 12: The source donor-CU sends an IAB Transport Migration Modification Response message back to the IAB-MT's donor-CU.

[0088] Step 13: Remove the F1 connection from source IAB-DU to source donor-CU. The F1 removal procedure may be initiated by source IAB-DU or by source donor-CU.

[0089] In at least one embodiment of the present invention, steps 11 and 12 can be replaced by an IAB Transport Migration Management procedure in which the source donor-CU initiates a rollback or release of traffic offload. For example, the source donor-CU may send an IAB Transport Migration Management Request message to the IAB-MT's donor-CU, which may include an instruction to release traffic (e.g., release all traffic). The IAB-MT's donor-CU replies with an IAB Transport Migration Management Response message. The source donor-CU triggers the IAB Transport Migration Management procedure upon completion of the UE handover.

[0090] In at least one embodiment of the present invention, step 5 may be performed concurrently with the execution of the preceding step, for example, after step 0.

[0091] In at least one embodiment of the present invention, steps 11 and 12 may be performed before step 13, or steps 11 and 12 may be performed simultaneously with step 13, or steps 11 and 12 may be performed after step 13.

[0092] In at least one embodiment of the present invention, for Scenario 1, steps 6 and 7 are not performed because the target donor-CU and the IAB-MT donor-CU are the same node. In this case, all the information obtained in step 7 is generated internally by the target donor-CU itself.

[0093] In at least one embodiment of the present invention, for scenario 2, steps 11 and 12 are not performed because the source donor-CU and the IAB-MT donor-CU are the same node.

[0094] In at least one embodiment of the present invention, steps 1 and 4 may be carried out as follows.

[0095] The first donor-CU (gNB-CU) sends the first information to the first IAB-DU (gNB-DU), and the second IAB-DU, which is the collocated IAB-DU of the first IAB-DU (meaning an IAB-DU on the same IAB node), requests the establishment of an F1 relationship with the third donor-CU. The first information includes information about the third donor-CU, including its TNL address and / or base station identifier. After the F1 establishment between the second IAB-DU and the third donor-CU (gNB-CU) is successfully completed, i.e., after the second IAB-DU receives the F1 SETUP RESPONSE message from the third donor-CU, the first IAB-DU sends the second information to the first donor-CU to confirm that the F1 establishment between the collocated IAB-DU (i.e., the second IAB-DU) and the third donor-CU is complete. The second piece of information may include one or more activated cell identifiers obtained from the F1 SETUP RESPONSE sent by the third donor-CU. If the F1 establishment between the second IAB-DU and the third donor-CU fails, i.e., if the second IAB-DU receives an F1 SETUP FAILURE message from the third donor-CU, the first IAB-DU sends the third piece of information to the first donor-CU indicating that the F1 establishment failed.

[0096] The first, second, and third pieces of information can utilize F1AP signaling.

[0097] In at least some embodiments, existing F1AP procedures may be extended, for example, the gNB-CU Configuration Update procedure may be extended. That is, a new information element (IE) may be added to the CONFIGURATION UPDATE message to indicate a first piece of information. A CONFIGURATION UPDATE ACKNOWLEDGE message may be used, or a new IE may be added to the message, to indicate a second piece of information. A CONFIGURATION UPDATE FAILURE message may be used, or a new IE may be added to the message, to indicate a third piece of information. Similarly, an extended gNB-DU Resource Configuration procedure may be added. The first, second, and third pieces of information may be included in the GNB-DU Resource Configuration message, the GNB-DU Resource Configuration ACKNOWLEDGE message, and the GNB-DU Resource Configuration FAILURE message, respectively.

[0098] In at least some other embodiments, a new F1AP procedure may be added, which uses a non-UE-related IAB procedure and includes a first, second, and third piece of information. For example, the first, second, and third pieces of information may be included in the TARGET F1 SETUP message, the TARGET F1 SETUP ACKNOWLEDGE message, and the TARGET F1 SETUP FAILURE message, respectively.

[0099] For example, Figure 8 is a schematic diagram of an example of a new F1AP procedure. As shown in Figure 8, the new F1AP procedure may include the following steps.

[0100] Step 801: The first donor-CU (gNB-CU) sends a TARGET F1 SETUP message to the first IAB-DU (gNB-DU).

[0101] Step 802: If the F1AP procedure is successful, the first IAB-DU (gNB-DU) sends a TARGET F1 SETUP ACKNOWLEDGE message to the first donor-CU (gNB-CU).

[0102] Furthermore, if the F1AP procedure fails, the first IAB-DU (gNB-DU) sends a TARGET F1 SETUP FAILURE message to the first donor-CU (gNB-CU).

[0103] When an IAB node performs migrations for both MT and DU, the donor-CU of the MT changes midway through the procedure, and the donor-CU of the DU also changes. Such a migration procedure can lead to confusion in the communication between multiple donor-CUs, potentially sending information to the wrong donor-CU and causing the migration to fail.

[0104] To solve these problems, in at least some embodiments of the present invention, simultaneous transitions of MT and DU may be avoided by the following method.

[0105] In step 6 of Figure 7, the IAB-MT donor-CU receives an IAB transmission transition management request from the target donor-CU to request traffic offload, which includes the IAB node's identification information. The IAB-MT donor-CU determines that the IAB node is performing a DU transition by associating the IAB node's identification information with the traffic offload already present in the target donor-CU. At this point, the IAB-MT donor-CU avoids the IAB-MT handoff (MT transition). Alternatively, the target donor-CU sends an Xn message to the IAB-MT donor-CU, which includes an IAB node identification message indicating that it will not perform the IAB-MT handoff procedure. Alternatively, the IAB node sends a notification message to the IAB-MT donor-CU via RRC signaling indicating that it is performing a DU transition. In Scenario 1, the IAB-MT donor-CU is the target donor-CU, so in Step 2, the IAB-MT donor-CU will know that the IAB is performing a DU transition, and from this point onward, the IAB-MT handoff can be avoided.

[0106] After step 10 in Figure 7 (i.e., when all UE handovers are complete), the target donor-CU notifies the IAB-MT donor-CU of the completion of the DU transition via an Xn message, or the IAB node notifies the IAB-MT donor-CU of the completion of the DU transition via an RRC message. In this case, the IAB-MT donor-CU may perform the IAB-MT handoff if necessary. In Scenario 1, the IAB-MT donor-CU may determine whether or not it is possible to perform the IAB-MT handoff.

[0107] Furthermore, in Figure 7, NGC represents the next-generation core network, such as the 5G core network.

[0108] Embodiment 1 of the present invention can support the long-distance movement of IAB nodes and improve the performance of IAB node service users (e.g., users in cars or trains) by solving the problems of the DU migration process of IAB nodes.

[0109] <Example 2> Embodiment 2 of the present invention provides a control device for distributed unit migration, corresponding to the IAB node method in the distributed unit migration method described in Embodiment 1. The device is applied to an IAB node.

[0110] Figure 9 is a schematic diagram of an example of a control device for distributed unit migration according to Embodiment 2. As shown in Figure 9, the control device 900 for distributed unit migration includes a first processing unit 901.

[0111] The first processing unit 901 controls the node so that the node's F1 termination donor transitions from the first donor aggregation unit (donor-CU) to the third donor-CU. Unlike the third donor-CU, the first donor-CU has a second donor-CU as its radio resource control (RRC) termination donor, and the second donor-CU is either identical to the first donor-CU, or identical to the third donor-CU, or different from both the first and third donor-CUs.

[0112] In at least one embodiment, the first processing unit controls the node so that the node's first distributed unit (IAB-DU) receives information about a third donor-CU transmitted by the first donor-CU via F1AP signaling.

[0113] In at least one embodiment, a first donor-DU receives first information transmitted by the first IAB-DU, such that a second IAB-DU requests the establishment of an F1 association to a third donor-CU, the first information includes information of the third donor-CU, and the second IAB-DU is a collocated IAB-DU of the first IAB-DU.

[0114] In at least one embodiment, the first information is transmitted using F1AP signaling, and the first information is a new information element (IE) in the F1AP signaling, or a new F1AP procedure is added and transmitted.

[0115] In at least one embodiment, information relating to a third donor-CU includes a transport network layer address (TNL) and / or a base station identifier.

[0116] In at least one embodiment, the first processing unit controls the node so that its second distributed unit (IAB-DU) sends an F1 setup request message to a third donor-CU. The second IAB-DU is a collocated IAB-DU of the first IAB-DU.

[0117] In at least one embodiment, the F1 establishment request message includes the node's backhaul adaptation protocol (BAP) address, one or more cell identifiers of a second distributed unit (IAB-DU), and the TNL address of a second donor-CU, and / or a base station identifier.

[0118] In at least one embodiment, the first processing unit controls the node such that the second IAB-DU receives an F1 setup response message returned by the third donor-CU.

[0119] In at least one embodiment, the first processing unit controls the node such that the first distributed unit (IAB-DU) notifies the first donor-CU via F1AP signaling of a message regarding the successful establishment of an F1 interface with the third donor-CU.

[0120] In at least one embodiment, after the F1 establishment between the second IAB-DU and the third donor-CU is complete, the first IAB-DU sends second information to the first donor-CU to confirm the completion of the F1 establishment between the second IAB-DU and the third donor-CU.

[0121] In at least one embodiment, if the F1 establishment between the second IAB-DU and the third donor-CU fails, the first IAB-DU sends third information to the first donor-CU to indicate that the F1 establishment failed.

[0122] In at least one embodiment, the second or third information is transmitted using F1AP signaling, and the second or third information is a new information element (IE) in the F1AP signaling, or a new F1AP procedure is added and transmitted.

[0123] In at least one embodiment, the message indicating the successful establishment of the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU.

[0124] In at least one embodiment, the node receives an uplink backhaul mapping configuration performed by a third donor-CU.

[0125] In at least one embodiment, the first processing unit controls the node so that, after the transition is complete, the node removes the F1 connection from the first IAB-DU to the first donor-CU.

[0126] In at least one embodiment, the removal procedure is initiated by a first IAB-DU or by a first donor-CU.

[0127] In at least one embodiment, the first processing unit controls the node to send information about the initiation of a DU transition to the second donor-CU.

[0128] In at least one embodiment, the first processing unit controls the node so that, after the transition is complete, the node sends information regarding the completion of the DU transition to the second donor-CU.

[0129] <Example 3> Embodiment 3 of the present invention provides a control device for distributed unit migration, corresponding to the method of the first donor-CU in the distributed unit migration method described in Embodiment 1. The device is applied to the first donor-CU.

[0130] Figure 10 is a schematic diagram of an example of a control device for distributed unit migration according to Embodiment 3. As shown in Figure 10, the control device 1000 for distributed unit migration includes a second processing unit 1001.

[0131] The second processing unit 1001 controls the first donor-CU so that the F1 termination donor of the access backhaul integration node (IAB-node) transitions from the first donor aggregation unit (donor-CU) to the third donor-CU. Unlike the third donor-CU, the first donor-CU is the second donor-CU, and the second donor-CU is either identical to the first donor-CU, or identical to the third donor-CU, or different from both the first and third donor-CUs.

[0132] In at least one embodiment, the second processing unit controls the first donor-CU so that the first donor-CU notifies the node's first distributed unit (IAB-DU) of information about the third donor-CU via F1AP signaling.

[0133] In at least one embodiment, the first donor-CU transmits first information to the first IAB-DU such that the second IAB-DU requests the establishment of an F1 association to the third donor-CU. The first information includes information of the third donor-CU, and the second IAB-DU is a collocated IAB-DU of the first IAB-DU.

[0134] In at least one embodiment, the first information is transmitted using F1AP signaling, and the first information is a new information element (IE) in the F1AP signaling, or a new F1AP procedure is added and transmitted.

[0135] In at least one embodiment, information relating to a third donor-CU includes a transport network layer address (TNL) and / or a base station identifier.

[0136] In at least one embodiment, the second processing unit controls the first donor-CU so that the first donor-CU receives a message regarding the successful establishment of an F1 interface with a third donor-CU, which has been notified by the first distributed unit (IAB-DU) via F1AP signaling.

[0137] In at least one embodiment, after the F1 establishment between the second IAB-DU and the third donor-CU is complete, the first IAB-DU sends second information to the first donor-CU to confirm the completion of the F1 establishment between the second IAB-DU and the third donor-CU.

[0138] In at least one embodiment, if the F1 establishment between the second IAB-DU and the third donor-CU fails, the first IAB-DU sends third information to the first donor-CU to indicate that the F1 establishment failed.

[0139] In at least one embodiment, the second or third information is transmitted using F1AP signaling, and the second or third information is a new information element (IE) in the F1AP signaling, or a new F1AP procedure is added and transmitted.

[0140] In at least one embodiment, the message indicating the successful establishment of the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU.

[0141] In at least one embodiment, the second processing unit controls the first donor-CU to send a HANDOVER REQUEST message to the third donor-CU.

[0142] In at least one embodiment, the first donor-CU sends an Xn message to the third donor-CU to notify the node's second donor-CU of the user device Xn interface identifier (UE XnAP ID).

[0143] In at least one embodiment, a HANDOVER REQUEST message includes user device context (UE context) information and is used to request the handover preparation of electronic equipment served by a node.

[0144] In at least one embodiment, the HANDOVER REQUEST message includes a non-F1-terminating donor-CU UE XnAP ID in the node's second donor-CU.

[0145] In at least one embodiment, the second processing unit controls the first donor-CU to receive an IAB Transport Migration Modification Request message sent by the second donor-CU, if the second donor-CU is different from the first donor-CU.

[0146] In at least one embodiment, the IAB transmission transition change request message includes node identification information, and the IAB transmission transition change request message requests the release of offloaded traffic.

[0147] In at least one embodiment, the first donor-CU sends an IAB Transport Migration Modification Response message back to the second donor-CU.

[0148] In at least one embodiment, if the second donor-CU is different from the first donor-CU, the first donor-CU sends an IAB Transport Migration Management Request message to the second donor-CU.

[0149] In at least one embodiment, the IAB Transport Migration Management Request message includes node identification information and / or traffic release instruction information.

[0150] In at least one embodiment, the first donor-CU receives an IAB Transport Migration Management Response message returned by the second donor-CU.

[0151] In at least one embodiment, the first donor-CU receives a HANDOVER REQUEST ACKNOWLEDGE message sent by the third donor-CU, and the first donor-CU hands over the terminal device served by the node to the third donor-CU.

[0152] In at least one embodiment, the second processing unit controls the first donor-CU to remove the F1 connection from the first IAB-DU to the first donor-CU.

[0153] In at least one embodiment, the removal procedure is initiated by a first IAB-DU or by a first donor-CU.

[0154] <Example 4> Embodiment 4 of the present invention provides a control device for distributed unit migration, corresponding to the method of a third donor-CU in the distributed unit migration method described in Embodiment 1. The device is applied to the third donor-CU.

[0155] Figure 11 is a schematic diagram of an example of a distributed unit migration control device according to Embodiment 4. As shown in Figure 11, the distributed unit migration control device 1100 includes a third processing unit 1101. The third processing unit 1101 controls the third donor-CU so that the F1 termination donor of the access backhaul integration node (IAB-node) migrates from the first donor aggregation unit (donor-CU) to the third donor-CU. Unlike the third donor-CU, the first donor-CU has a second donor-CU as its radio resource control (RRC) termination donor. The second donor-CU is either identical to the first donor-CU, or identical to the third donor-CU, or different from both the first and third donor-CUs.

[0156] In at least one embodiment, the third processing unit controls the third donor-CU to receive an F1 setup request message sent by the node's second distributed unit (IAB-DU).

[0157] In at least one embodiment, the F1 establishment request message includes the node's backhaul adaptation protocol (BAP) address, one or more cell identifiers of a second distributed unit (IAB-DU), and the TNL address of a second donor-CU, and / or a base station identifier.

[0158] In at least one embodiment, a third processing unit controls a third donor-CU to send an F1 setup response message to a second IAB-DU, the second IAB-DU being a collocated IAB-DU of the first IAB-DU.

[0159] In at least one embodiment, the third processing unit controls the third donor-CU to receive a handover request message sent by the first donor-CU.

[0160] In at least one embodiment, a HANDOVER REQUEST message includes user device context (UE context) information and is used to request the handover preparation of electronic equipment served by a node.

[0161] In at least one embodiment, the third processing unit controls the third donor-CU to send an IAB Transport Migration Management Request message to the second donor-CU if the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU.

[0162] In at least one embodiment, the third processing unit controls the third donor-CU to send an instruction message to the second donor-CU indicating that the second donor-CU will not perform the migration procedure for the node's mobile terminal (IAB-MT).

[0163] In at least one embodiment, the third processing unit controls the third donor-CU so that the third donor-CU transmits information to the second donor-CU regarding the completion of the DU transition.

[0164] In at least one embodiment, the IAB transmission transition management request message includes node identification information.

[0165] In at least one embodiment, the node identification information includes a non-F1-terminating node UE XnAP ID and / or the node's BAP address.

[0166] In at least one embodiment, a third donor-CU receives an Xn message sent by the first donor-CU, and the Xn message notifies the node's user device Xn interface identifier (UE XnAP ID) in the second donor-CU.

[0167] In at least one embodiment, the IAB transmission transition management request message includes a traffic profile, which is obtained from the handover request message.

[0168] In at least one embodiment, the third processing unit controls the third donor-CU to receive an IAB Transport Migration Management Response message sent by the second donor-CU.

[0169] In at least one embodiment, the IAB transmission transition management response message is: Differentiated Services Code Points (DSCPs) and flow labels for downstream traffic, and / or Includes uplink non-F1 termination backhaul information (UL Non-F1 Terminating BH Info) for configuring the node's uplink backhaul mapping configuration.

[0170] In at least one embodiment, the third processing unit controls the third donor-CU to establish a user device context in the second IAB-DU via the F1AP user device context setup procedure and to perform an uplink backhaul mapping configuration for the node.

[0171] In at least one embodiment, the third processing unit controls the third donor-CU so that the third donor-CU generates an IP header for downlink data based on differentiated service code point and flow label information.

[0172] In at least one embodiment, the third donor-CU sends a HANDOVER REQUEST ACKNOWLEDGE message to the first donor-CU.

[0173] <Example 5> Embodiment 5 of the present invention provides a control device for distributed unit migration, corresponding to the second donor-CU method in the distributed unit migration method described in Embodiment 1. The device is applied to the second donor-CU.

[0174] Figure 12 is a schematic diagram of an example of a distributed unit migration control device according to Embodiment 5. As shown in Figure 12, the distributed unit migration control device 1200 includes a fourth processing unit 1201. The fourth processing unit 1201 controls the second donor-CU so that the F1 termination donor of the access backhaul integration node (IAB-node) migrates from the first donor aggregation unit (donor-CU) to the third donor-CU. Unlike the third donor-CU, the first donor-CU is the second donor-CU, and the second donor-CU is identical to the first donor-CU, or identical to the third donor-CU, or different from both the first and third donor-CUs.

[0175] In at least one embodiment, the fourth processing unit controls the second donor-CU to receive an IAB Transport Migration Management Request message transmitted by the third donor-CU if the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU.

[0176] In at least one embodiment, the IAB transmission transition management request message includes node identification information.

[0177] In at least one embodiment, the node identification information includes a non-F1-terminating node UE XnAP ID and / or the node's BAP address.

[0178] In at least one embodiment, the fourth processing unit controls the second donor-CU to send an IAB Transport Migration Management Response message to the third donor-CU.

[0179] In at least one embodiment, the IAB transmission transition management response message is: Differentiated Services Code Points (DSCPs) and flow labels for downstream traffic, and / or Includes uplink non-F1 termination backhaul information (UL Non-F1 Terminating BH Info) for configuring the node's uplink backhaul mapping configuration.

[0180] In at least one embodiment, the fourth processing unit controls the second donor-CU so that the second donor-CU avoids the migration of the node's mobile terminal (IAB-MT).

[0181] In at least one embodiment, the fourth processing unit controls the second donor-CU to receive an instruction message sent by the third donor-CU indicating that the second donor-CU will not perform the migration procedure for the node's mobile terminal (IAB-MT), or a notification message sent by the node indicating that the node is performing a DU migration.

[0182] In at least one embodiment, the fourth processing unit receives information regarding the completion of the DU migration transmitted by the third donor-CU or the node and controls the second donor-CU to perform the migration procedure for the node's mobile terminal (IAB-MT).

[0183] In at least one embodiment, the fourth processing unit controls the second donor-CU to send an IAB TRANSPORT MIGRATION MODIFICATION REQUEST message to the first donor-CU if the second donor-CU is different from the first donor-CU.

[0184] In at least one embodiment, the IAB transmission transition change request message includes node identification information, and the IAB transmission transition change request message requests the release of offloaded traffic.

[0185] In at least one embodiment, a second donor-CU receives an IAB Transport Migration Modification Response message returned by the first donor-CU.

[0186] In at least one embodiment, if the second donor-CU is different from the first donor-CU, the second donor-CU receives an IAB Transport Migration Management Request message sent by the first donor-CU.

[0187] In at least one embodiment, the IAB Transport Migration Management Request message includes node identification information and / or traffic release instruction information.

[0188] In at least one embodiment, the second donor-CU sends an IAB Transport Migration Management Response message back to the first donor-CU.

[0189] <Example 6> Embodiment 6 of the present invention further provides a communication system. The communication system may include an IAB node, a first donor aggregation unit CU, a second donor aggregation unit CU, and a third donor aggregation unit CU. The MT of the IAB node, the DU of the IAB node, and at least one of the first donor aggregation unit CU, the second donor aggregation unit CU, and the third donor aggregation unit CU may have the electronic equipment configuration shown in Figure 12.

[0190] Figure 13 is a schematic diagram of an example of the configuration of an electronic device according to an embodiment of the present invention. As shown in Figure 13, the electronic device 1300 may include a processor 1310 (for example, a CPU of a central processing unit) and a memory 1320. The memory 1320 is connected to the processor 1310. The memory 1320 may store various types of data, and may also store an information processing program 1330, and execute the program 1330 under the control of the processor 1310.

[0191] For example, the processor 1310 may be configured to control the electronic device in order to execute a program to implement the methods of Examples 1 to 4.

[0192] Furthermore, as shown in Figure 13, the electronic equipment 1300 may further include a transceiver 1340 and an antenna 1350, etc. The functions of the above units are the same as in the prior art, and their explanation is omitted here. Note that the electronic equipment 1300 does not need to include all the units shown in Figure 13. Also, the electronic equipment 1300 may further include units not shown in Figure 13, and prior art may be referenced.

[0193] In embodiments of the present invention, the present invention further provides a computer program that, when the program is executed on at least one of the IAB node, the first donor aggregation unit CU, the second donor aggregation unit CU, and the third donor aggregation unit CU, causes at least one of the IAB node, the first donor aggregation unit CU, the second donor aggregation unit CU, and the third donor aggregation unit CU to perform the corresponding steps in the method described in Embodiment 1.

[0194] Embodiments of the present invention further provide a storage medium in which a computer program is stored, wherein when the computer program is executed, at least one of the IAB node, the first donor aggregation unit CU, the second donor aggregation unit CU, and the third donor aggregation unit CU is instructed to perform the corresponding steps in the method described in Embodiment 1.

[0195] The above-described apparatus and method of the present invention may be implemented by hardware, or by combining hardware and software. The present invention relates to a computer-readable program, and when the program is executed by a logic unit, the logic unit may implement the above-described apparatus or configuration requirements, or the logic unit may implement the above-described methods or steps. The present invention relates to a storage medium for storing the above-described program, such as a hard disk, magnetic disk, optical disk, DVD, flash memory, etc.

[0196] Each processing method in each apparatus described with reference to embodiments of the present invention may be implemented using hardware, software modules executed by a processor, or a combination of both. For example, one or more functional block diagrams shown in the drawings, or one or more combinations of functional block diagrams, may correspond to each software module of a computer program process, or to each hardware module. These software modules may correspond to each step shown in the drawings. These hardware modules may be implemented by hardwareizing these software modules, for example, using a field-programmable gate array (FPGA).

[0197] The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, mobile hard disk, CD-ROM, or any other form of storage medium known to those skilled in the art. The storage medium may be connected to the processor so that the processor reads information from and / or writes information to the storage medium, or the storage medium may be a component of the processor. The processor and the storage medium may reside in an ASIC. The software module may be stored in the memory of the mobile terminal or on a memory card inserted into the mobile terminal. For example, if the device (e.g., a mobile terminal) uses a relatively large capacity MEGA-SIM card or a high-capacity flash memory device, the software module may be stored on the MEGA-SIM card or high-capacity flash memory device.

[0198] One or more functional blocks and / or one or more combinations of functional blocks in the functional block diagrams shown in the drawings may be implemented by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic unit, a discrete hardware component, or any suitable combination thereof for performing the functions described herein. One or more functional blocks and / or one or more combinations of functional blocks in the functional block diagrams shown in the drawings may be implemented, for example, by a combination of computing equipment, such as a combination of a DSP and a microprocessor, a combination of multiple microprocessors, one or more microprocessors combined with DSP communication, or any other configuration.

[0199] Although the present invention has been described above with reference to specific embodiments, the above description is merely illustrative and does not limit the scope of protection of the present invention. Various modifications and changes can be made to the present invention as long as they do not deviate from the spirit and principles of the present invention, and these modifications and changes are also within the scope of the present invention.

[0200] The following further notes are disclosed regarding embodiments including the above-described examples.

[0201] System-wide approach: (Note 1) A method for migrating distributed units, This includes the step of the F1 terminal donor of the access backhaul integration node (IAB-node) migrating from the first donor aggregation unit (donor-CU) to the third donor-CU, Unlike the third donor-CU, the first donor-CU is The Radio Resource Control (RRC) termination donor of the node is a second donor-CU, The method wherein the second donor-CU is identical to the first donor-CU, or the second donor-CU is identical to the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU. (Note 2) The method according to Appendix 1, further comprising the step of the first donor-CU notifying the first distributed unit (IAB-DU) of the node of information regarding the third donor-CU via F1AP signaling. (Note 3) The first donor-CU transmits first information to the first IAB-DU so that the second IAB-DU requests the establishment of an F1-related connection to the third donor-CU, and the first information includes information from the third donor-CU. The method described in Appendix 2, wherein the second IAB-DU is a collocated IAB-DU of the first IAB-DU. (Note 4) The above first information uses F1AP signaling, The first information described above is a new information element (IE) in F1AP signaling, or is transmitted by adding a new F1AP procedure, as described in Appendix 2. (Note 5) The information regarding the third donor-CU is as follows: The method described in Appendix 2, including the transport network layer address (TNL) and / or base station identifier. (Note 6) The method according to Appendix 2, further comprising the step of the second distributed unit (IAB-DU) of the node sending an F1 setup request message to the third donor-CU. (Note 7) The method according to Appendix 6, wherein the F1 establishment request message includes the backhaul adaptation protocol (BAP) address of the node, one or more cell identifiers of the second distributed unit (IAB-DU), and the TNL address of the second donor-CU, and / or the base station identifier. (Note 8) The method according to Appendix 6, further comprising the step of the second IAB-DU receiving an F1 Establishment Response message returned by the third donor-CU. (Note 9) The method according to Appendix 2, further comprising the step of the first distributed unit (IAB-DU) notifying the first donor-CU via F1AP signaling of a message relating to the successful establishment of an F1 interface with the third donor-CU. (Note 10) The method according to Appendix 9, wherein, after the establishment of F1 between the second IAB-DU and the third donor-CU is completed, the first IAB-DU transmits second information to the first donor-CU to confirm the completion of the establishment of F1 between the second IAB-DU and the third donor-CU. (Note 11) The method according to Appendix 9, wherein if the F1 establishment between the second IAB-DU and the third donor-CU fails, the first IAB-DU transmits third information to the first donor-CU to indicate that the F1 establishment failed. (Note 12) The second or third information described above is obtained using F1AP signaling. The second or third piece of information is a new information element (IE) in F1AP signaling, or is transmitted by adding a new F1AP procedure, as described in Appendix 10 or 11. (Note 13) The method according to Appendix 9, wherein the message indicating the successful establishment of the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU. (Note 14) The method according to Appendix 8, further comprising the step of the first donor-CU sending a HANDOVER REQUEST message to the third donor-CU. (Note 15) The aforementioned handover request (HANDOVER REQUEST) message includes user device context (UE context) information, The method described in Appendix 14, wherein the handover request message is used to request the preparation of a handover of electronic equipment served by the node. (Note 16) The method according to Appendix 14, further comprising the step of the third donor-CU sending an IAB Transport Migration Management Request message to the second donor-CU if the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU. (Note 16a) The method according to Appendix 16, further comprising the step of the second donor-CU avoiding the migration of the node's mobile terminal (IAB-MT). (Note 16b) The method according to Appendix 16, wherein the second donor-CU receives an instruction message transmitted by the third donor-CU indicating that the second donor-CU will not perform the migration procedure for the node's mobile terminal (IAB-MT), or receives a notification message transmitted by the node indicating that the node is performing a DU migration. (Note 16c) The second donor-CU receives information regarding the completion of the DU transition transmitted by the third donor-CU or the node, The method according to Appendix 16a or 16b, further comprising the step of the second donor-CU performing a migration procedure for the mobile terminal (IAB-MT) of the node. (Note 17) The IAB transmission transition management request message is the method described in Appendix 16, which includes the identification information of the node. (Note 18) The identification information of the node is as described in Appendix 17, including the non-F1-terminating node UE XnAP ID and / or the BAP address of the node. (Note 19) The method according to Appendix 18, wherein the first donor-CU pre-sends an Xn message to the third donor-CU to notify it of the user device Xn interface identifier (UE XnAP ID) in the second donor-CU of the node. (Note 19a) The method described in Appendix 19, wherein the Xn message is the handover request message. (Note 20) The IAB transmission transition management request message includes a traffic profile, the traffic profile is obtained from the handover request message, as described in Appendix 16. (Note 21) The method as described in Appendix 16, further comprising the step of the second donor-CU sending an IAB Transport Migration Management Response message to the third donor-CU. (Note 22) The aforementioned IAB transmission transition management response message is: Differentiated Services Code Points (DSCPs) and flow labels for downstream traffic, and / or The method according to Appendix 21, including uplink non-F1 termination backhaul information (UL Non-F1 Terminating BH Info) for configuring the uplink backhaul mapping configuration of the node. (Note 23) The method according to Appendix 21, further comprising the step of the third donor-CU establishing a user device context in the second IAB-DU via the F1AP user device context setup procedure and performing an uplink backhaul mapping configuration for the node. (Note 24) The method according to Appendix 23, further comprising the step of the third donor-CU generating an IP header for downlink data based on the differentiated service code point and the flow label information. (Note 25) If the second donor-CU is different from the first donor-CU, The method according to Appendix 21, further comprising the step of the second donor-CU sending an IAB Transport Migration Modification Request message to the first donor-CU. (Note 26) The aforementioned IAB transmission transition change request message includes node identification information, The IAB transmission transition change request message requests the release of offloaded traffic, as described in Appendix 25. (Note 27) The method according to Appendix 25, further comprising the step of the first donor-CU sending an IAB Transport Migration Modification Response message back to the second donor-CU. (Note 28) If the second donor-CU is different from the first donor-CU, The method according to Appendix 21, further comprising the step of the first donor-CU sending an IAB Transport Migration Management Request message to the second donor-CU. (Note 29) The IAB Transport Migration Management Request message includes node identification information and / or traffic release instruction information, as described in Appendix 28. (Note 30) The method as described in Appendix 29, further comprising the step of the second donor-CU sending an IAB Transport Migration Management Response message back to the first donor-CU. (Note 31) The third donor-CU sends a HANDOVER REQUEST ACKNOWLEDGE message to the first donor-CU, The method according to Appendix 23, further comprising the step of the first donor-CU handing over a terminal device served by the node to the third donor-CU. (Note 32) The method according to Appendix 31, further comprising the step of removing the F1 connection from the first IAB-DU to the first donor-CU. (Note 33) The removal procedure described above is initiated by the first IAB-DU or the first donor-CU, as described in Appendix 32.

[0202] IAB-node method: (Note 1) A method for migrating distributed units, applicable to an access backhaul integration node (IAB-node), The step includes the transition of the F1 terminal donor of the node from a first donor aggregation unit (donor-CU) to a third donor-CU, Unlike the third donor-CU, the first donor-CU is The Radio Resource Control (RRC) termination donor of the node is a second donor-CU, The method wherein the second donor-CU is identical to the first donor-CU, or the second donor-CU is identical to the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU. (Note 2) The method according to Appendix 1, further comprising the step of a first distributed unit (IAB-DU) of the node receiving information about the third donor-CU transmitted by the first donor-CU via F1AP signaling. (Note 3) The first donor-DU receives first information transmitted by the first IAB-DU so that the second IAB-DU requests the establishment of an F1 association with the third donor-CU, and the first information includes information of the third donor-CU. The method described in Appendix 2, wherein the second IAB-DU is a collocated IAB-DU of the first IAB-DU. (Note 4) The above first information uses F1AP signaling, The first information described above is a new information element (IE) in F1AP signaling, or is transmitted by adding a new F1AP procedure, as described in Appendix 2. (Note 5) The information regarding the third donor-CU is as follows: The method described in Appendix 2, including the transport network layer address (TNL) and / or base station identifier. (Note 6) The method according to Appendix 2, further comprising the step of a second distributed unit (IAB-DU) of the node sending an F1 setup request message to the third donor-CU, wherein the second IAB-DU is a collocated IAB-DU of the first IAB-DU. (Note 7) The method according to Appendix 6, wherein the F1 establishment request message includes the backhaul adaptation protocol (BAP) address of the node, one or more cell identifiers of the second distributed unit (IAB-DU), and the TNL address of the second donor-CU, and / or the base station identifier. (Note 8) The method according to Appendix 6, further comprising the step of the second IAB-DU receiving an F1 Establishment Response message returned by the third donor-CU. (Note 9) The method according to Appendix 2, further comprising the step of the first distributed unit (IAB-DU) notifying the first donor-CU via F1AP signaling of a message relating to the successful establishment of an F1 interface with the third donor-CU. (Note 10) The method according to Appendix 9, wherein, after the establishment of F1 between the second IAB-DU and the third donor-CU is completed, the first IAB-DU transmits second information to the first donor-CU to confirm the completion of the establishment of F1 between the second IAB-DU and the third donor-CU. (Note 11) The method according to Appendix 9, wherein if the F1 establishment between the second IAB-DU and the third donor-CU fails, the first IAB-DU transmits third information to the first donor-CU to indicate that the F1 establishment failed. (Note 12) The second or third information described above is obtained using F1AP signaling. The second or third piece of information is a new information element (IE) in F1AP signaling, or is transmitted by adding a new F1AP procedure, as described in Appendix 10 or 11. (Note 13) The method according to Appendix 9, wherein the message indicating the successful establishment of the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU. (Note 14) The method according to Appendix 2, wherein the node receives the uplink backhaul mapping configuration performed by the third donor-CU. (Note 15) The method according to Appendix 2, further comprising the step of the node removing the F1 connection from the first IAB-DU to the first donor-CU after the transition is completed. (Note 16) The removal procedure described above is initiated by the first IAB-DU or the first donor-CU, as described in Appendix 15. (Note 17) The method according to Appendix 2, further comprising the step of the node transmitting information regarding the commencement of a DU transition to the second donor-CU. (Note 18) The method according to Appendix 17, further comprising the step of the node transmitting information regarding the completion of the DU migration to the second donor-CU after the migration is completed.

[0203] The first donor-CU method: (Note 1) A method for transferring distributed units, applicable to a first donor aggregation unit (donor-CU), The step includes the migration of an F1 terminal donor of an access backhaul integration node (IAB-node) from the first donor aggregation unit (donor-CU) to a third donor-CU, Unlike the third donor-CU, the first donor-CU is The Radio Resource Control (RRC) termination donor of the node is a second donor-CU, The method wherein the second donor-CU is identical to the first donor-CU, or the second donor-CU is identical to the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU. (Note 2) The method according to Appendix 1, further comprising the step of the first donor-CU notifying the first distributed unit (IAB-DU) of the node of information regarding the third donor-CU via F1AP signaling. (Note 3) A step in which the first donor-CU transmits first information to the first IAB-DU such that the second IAB-DU requests the establishment of an F1 relationship with the third donor-CU, the first information comprising information of the third donor-CU, The method described in Appendix 2, wherein the second IAB-DU is a collocated IAB-DU of the first IAB-DU. (Note 4) The above first information uses F1AP signaling, The first information described above is a new information element (IE) in F1AP signaling, or is transmitted by adding a new F1AP procedure, as described in Appendix 2. (Note 5) The information regarding the third donor-CU is as follows: The method described in Appendix 2, including the transport network layer address (TNL) and / or base station identifier. (Note 6) The method according to Appendix 2, further comprising the step of the first donor-CU receiving a message relating to the success of establishing an F1 interface with the third donor-CU, which has been notified by the first distributed unit (IAB-DU) via F1AP signaling. (Note 7) The method according to Appendix 6, wherein, after the establishment of F1 between the second IAB-DU and the third donor-CU is completed, the first IAB-DU transmits second information to the first donor-CU to confirm the completion of the establishment of F1 between the second IAB-DU and the third donor-CU. (Note 8) The method according to Appendix 6, wherein if the F1 establishment between the second IAB-DU and the third donor-CU fails, the first IAB-DU transmits third information to the first donor-CU to indicate that the F1 establishment failed. (Note 9) The second or third information described above is obtained using F1AP signaling. The second or third piece of information is a new information element (IE) in F1AP signaling, or is transmitted by adding a new F1AP procedure, as described in Appendix 7 or 8. (Note 10) The method according to Appendix 6, wherein the message indicating the successful establishment of the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU. (Note 11) The method according to Appendix 6, further comprising the step of the first donor-CU sending a HANDOVER REQUEST message to the third donor-CU. (Note 11a) The method according to Appendix 1, wherein the first donor-CU sends an Xn message to the third donor-CU to notify the user device Xn interface identifier (UE XnAP ID) in the second donor-CU of the node. (Note 12) The aforementioned handover request (HANDOVER REQUEST) message includes user device context (UE context) information, The method described in Appendix 11, wherein the handover request message is used to request the preparation of a handover of electronic equipment served by the node. (Note 13) If the second donor-CU is different from the first donor-CU, The method according to Appendix 11, further comprising the step of the first donor-CU receiving an IAB Transport Migration Modification Request message transmitted by the second donor-CU. (Note 14) The aforementioned IAB transmission transition change request message includes node identification information, The IAB transmission transition change request message requests the release of offloaded traffic, as described in Appendix 13. (Note 15) The method described in Appendix 13, wherein the first donor-CU replies with an IAB Transport Migration Modification Response message to the second donor-CU. (Note 16) If the second donor-CU is different from the first donor-CU, The method according to Appendix 11, wherein the first donor-CU transmits an IAB Transport Migration Management Request message to the second donor-CU. (Note 17) The IAB Transport Migration Management Request message, as described in Appendix 16, includes node identification information and / or traffic release instruction information. (Note 18) The method described in Appendix 17, wherein the first donor-CU receives an IAB Transport Migration Management Response message returned by the second donor-CU. (Note 19) The first donor-CU receives a HANDOVER REQUEST ACKNOWLEDGE message sent by the third donor-CU, The method according to Appendix 11, wherein the first donor-CU hands over the terminal device served by the node to the third donor-CU. (Note 20) The method described in Appendix 19, which removes the F1 connection from the first IAB-DU to the first donor-CU. (Note 21) The removal procedure is as described in Appendix 20, initiated by the first IAB-DU or the first donor-CU.

[0204] The third donor-CU method: (Note 1) A method for transferring distributed units, applicable to a third donor aggregation unit (donor-CU), The process further includes the step of the F1 terminal donor of the access backhaul integration node (IAB-node) migrating from the first donor aggregation unit (donor-CU) to the third donor-CU, Unlike the third donor-CU, the first donor-CU is The Radio Resource Control (RRC) termination donor of the node is a second donor-CU, The method wherein the second donor-CU is identical to the first donor-CU, or the second donor-CU is identical to the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU. (Note 2) The method according to Appendix 1, further comprising the step of the third donor-CU receiving an F1 setup request message sent by the second distributed unit (IAB-DU) of the node. (Note 3) The method according to Appendix 2, wherein the F1 establishment request message includes the backhaul adaptation protocol (BAP) address of the node, one or more cell identifiers of the second distributed unit (IAB-DU), and the TNL address of the second donor-CU, and / or the base station identifier. (Note 4) The process further includes the step of the third donor-CU sending an F1 setup response message to the second IAB-DU, The method described in Appendix 2, wherein the second IAB-DU is a collocated IAB-DU of the first IAB-DU. (Note 4a) The method according to Appendix 1, further comprising the step of the third donor-CU receiving a handover request message sent by the first donor-CU. (Note 4b) The aforementioned handover request (HANDOVER REQUEST) message includes user device context (UE context) information, The handover request message is used to request the handover preparation of electronic equipment served by the node, as described in Appendix 4a. (Note 5) The method as described in Appendix 2, further comprising the step of the third donor-CU sending an IAB Transport Migration Management Request message to the second donor-CU if the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU. (Note 5a) The method according to Appendix 5, further comprising the step of the third donor-CU sending an instruction message to the second donor-CU indicating that the second donor-CU will not perform the migration procedure for the node's mobile terminal (IAB-MT). (Note 5b) The method according to Appendix 5a, further comprising the step of the third donor-CU transmitting information to the second donor-CU regarding the completion of the DU transition. (Note 6) The IAB transmission transition management request message includes the node identification information as described in Appendix 5. (Note 7) The identification information of the node is as described in Appendix 6, including the non-F1-terminating node UE XnAP ID and / or the BAP address of the node. (Note 8) The method according to Appendix 7, wherein the third donor-CU receives an Xn message transmitted by the first donor-CU, and the Xn message notifies the user device Xn interface identifier (UE XnAP ID) in the second donor-CU of the node. (Note 9) The IAB transmission transition management request message includes a traffic profile, the traffic profile is obtained from the handover request message, as described in Appendix 5. (Note 10) The method according to Appendix 5, further comprising the step of: the third donor-CU receiving an IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE message transmitted by the second donor-CU. (Appendix 11) The IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE message includes a Differentiated Services Code Point (DSCP) and a flow label for downstream traffic, and / or The method according to Appendix 10, further comprising UL Non-F1 Terminating BH Info for configuring the uplink backhaul mapping configuration of the node. (Appendix 12) The method according to Appendix 10, further comprising the step of: the third donor-CU establishing a user equipment context in the second IAB-DU via an F1AP UE Context Setup procedure and performing an uplink backhaul mapping configuration for the node. (Appendix 13) The method according to Appendix 12, further comprising the step of: the third donor-CU generating an IP header for downlink data based on the differentiated services code point and the flow label information. (Appendix 14) The method according to Appendix 12, wherein the third donor-CU transmits a HANDOVER REQUEST ACKNOWLEDGE message to the first donor-CU.

[0205] Method of the second donor-CU: (Appendix 1) A method for distributed unit migration applied to a second donor central unit (donor-CU), comprising: The method further includes the step of a F1 terminating donor of an access backhaul integrated node (IAB-node) migrating from a first donor aggregation unit (donor-CU) to a third donor-CU, where the first donor-CU is different from the third donor-CU, the radio resource control (RRC) terminating donor of the node is the second donor-CU, where the second donor-CU is the same as the first donor-CU, or the second donor-CU is the same as the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU. (Appendix 2) The method according to Appendix 1, further includes the step of the second donor-CU receiving an IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message transmitted by the third donor-CU when the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU. (Appendix 3) The method according to Appendix 2, wherein the IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message includes identification information of the node. (Appendix 4) The method according to Appendix 3, wherein the identification information of the node includes a non-F1-terminating node UE XnAP ID and / or the BAP address of the node. (Appendix 5) The method according to Appendix 2, further includes the step of the second donor-CU transmitting an IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE message to the third donor-CU. (Appendix 6) The IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE message Differentiated Services Code Points (DSCPs) and flow labels for downstream traffic, and / or The method according to Appendix 5, including uplink non-F1 termination backhaul information (UL Non-F1 Terminating BH Info) for configuring the uplink backhaul mapping configuration of the node. (Note 7) The method according to Appendix 2, further comprising the step of the second donor-CU avoiding the migration of the node's mobile terminal (IAB-MT). (Note 8) The method according to Appendix 2, further comprising the step of the second donor-CU receiving an instruction message transmitted by the third donor-CU indicating that the second donor-CU will not perform the migration procedure for the node's mobile terminal (IAB-MT), or receiving a notification message transmitted by the node indicating that the node is performing a DU migration. (Note 8a) The second donor-CU receives information regarding the completion of the DU transition transmitted by the third donor-CU or the node, The method according to Appendix 7 or 8, further comprising the step of the second donor-CU performing a migration procedure for the node's mobile terminal (IAB-MT). (Note 9) If the second donor-CU is different from the first donor-CU, The method according to Appendix 2, further comprising the step of the second donor-CU sending an IAB Transport Migration Modification Request message to the first donor-CU. (Note 10) The aforementioned IAB transmission transition change request message includes node identification information, The IAB transmission transition change request message requests the release of offloaded traffic, as described in Appendix 9. (Note 11) The method described in Appendix 9, wherein the second donor-CU receives an IAB Transport Migration Modification Response message returned by the first donor-CU. (Note 12) If the second donor-CU is different from the first donor-CU, The method described in Appendix 2, wherein the second donor-CU receives an IAB Transport Migration Management Request message transmitted by the first donor-CU. (Note 13) The IAB Transport Migration Management Request message, as described in Appendix 12, includes node identification information and / or traffic release instruction information. (Note 14) The method described in Appendix 12, wherein the second donor-CU replies an IAB Transport Migration Management Response message to the first donor-CU.

Claims

1. A control device for distributed unit migration applied to an access backhaul integration node (IAB-node), comprising a first processing unit, the first processing unit being: The node is controlled so that the F1 terminal donor of the node transitions from the first donor aggregation unit (donor-CU) to the third donor-CU. Unlike the third donor-CU, the first donor-CU is The Radio Resource Control (RRC) termination donor of the node is a second donor-CU, An apparatus wherein the second donor-CU is identical to the first donor-CU, or the second donor-CU is identical to the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU.

2. The first processing unit is, Control the node such that the first distributed unit (IAB-DU) of the node receives information about the third donor-CU transmitted by the first donor-CU via F1AP signaling. The first IAB-DU receives first information transmitted by the first donor-CU so that the second IAB-DU requests the establishment of an F1 association with the third donor-CU, and the first information includes information from the third donor-CU. The apparatus according to claim 1, wherein the second IAB-DU is a collocated IAB-DU of the first IAB-DU.

3. The first processing unit is, The node is further controlled so that the second distributed unit (IAB-DU) of the node sends an F1 Establish Request (F1 SETUP REQUEST) message to the third donor-CU. The apparatus according to claim 2, wherein the F1 establishment request message includes the backhaul adaptation protocol (BAP) address of the node, one or more cell identifiers of the second distributed unit (IAB-DU), and the TNL address of the second donor-CU, and / or a base station identifier.

4. The first processing unit is, The apparatus according to claim 2, wherein the node is controlled such that the first distributed unit (IAB-DU) notifies the first donor-CU via F1AP signaling of a message relating to the successful establishment of an F1 interface with the third donor-CU.

5. The first processing unit is, The apparatus according to claim 1, wherein, after the transition is completed, the node is controlled to remove the F1 connection from the first IAB-DU to the first donor-CU.

6. A distributed unit migration control device applied to a first donor aggregation unit (donor-CU), comprising a second processing unit, the second processing unit controlling the first donor-CU so that the F1 terminal donors of the access backhaul integration node (IAB-node) migrate from the first donor aggregation unit (donor-CU) to a third donor-CU. Unlike the third donor-CU, the first donor-CU is The Radio Resource Control (RRC) termination donor of the node is a second donor-CU, An apparatus wherein the second donor-CU is identical to the first donor-CU, or the second donor-CU is identical to the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU.

7. The second processing unit is, The apparatus according to claim 6, wherein the first donor-CU is controlled to notify the first distributed unit (IAB-DU) of the node of information regarding the third donor-CU via F1AP signaling.

8. The first donor-CU transmits first information to the first IAB-DU so that the second IAB-DU requests the establishment of an F1 association with the third donor-CU, the first information includes information of the third donor-CU, The apparatus according to claim 7, wherein the second IAB-DU is a collocated IAB-DU of the first IAB-DU.

9. The information regarding the third donor-CU is as follows: The apparatus according to claim 7, comprising a transmission network layer address (TNL) and / or a base station identifier.

10. The second processing unit is, The first donor-CU is further controlled to send a HANDOVER REQUEST message to the third donor-CU. The aforementioned handover request message includes user device context information. The apparatus according to claim 6, wherein the handover request message is used to request the handover preparation of electronic equipment served by the node.

11. The apparatus according to claim 6, wherein the first donor-CU transmits an Xn message to the third donor-CU to notify the user device Xn interface identifier (UE XnAP ID) in the second donor-CU of the node.

12. The second processing unit is, The apparatus according to claim 6, wherein the first donor-CU is further controlled to receive an IAB Transport Migration Modification Request message transmitted by the second donor-CU, the IAB Transport Migration Modification Request message requests the release of offloaded traffic.

13. The second processing unit is, The apparatus according to claim 6, wherein the first donor-CU is further controlled to transmit an IAB Transmission Migration Management Request message to the second donor-CU, the IAB Transmission Migration Management Request message requests the release of offloaded traffic.

14. A distributed unit migration control device applied to a third donor aggregation unit (donor-CU), comprising a third processing unit, the third processing unit controlling the third donor-CU so that the F1 terminal donors of the access backhaul integration node (IAB-node) migrate from the first donor aggregation unit (donor-CU) to the third donor-CU. Unlike the third donor-CU, the first donor-CU is The Radio Resource Control (RRC) termination donor of the node is a second donor-CU, An apparatus wherein the second donor-CU is identical to the first donor-CU, or the second donor-CU is identical to the third donor-CU, or the second donor-CU is different from the first donor-CU and the third donor-CU.

15. The third processing unit is, The third donor-CU is controlled to receive a handover request message transmitted by the first donor-CU. The aforementioned handover request message includes user device context information. The apparatus according to claim 14, wherein the handover request message is used to request the handover preparation of electronic equipment served by the node.

16. The third processing unit is, The apparatus according to claim 15, further controlling the third donor-CU to transmit an IAB Transmission Migration Management Request message to the second donor-CU.

17. The IAB transmission transition management request message includes the identification information of the node, The apparatus according to claim 16, wherein the identification information of the node includes a non-F1-terminating node user equipment Xn interface identifier (non-F1-terminating node UE XnAP ID) and / or the BAP address of the node.

18. The apparatus according to claim 16, wherein the IAB transmission transition management request message includes a traffic profile, the traffic profile is obtained from the handover request message.

19. The third processing unit is, The third donor-CU is further controlled to receive the IAB Transmission Migration Management Response message transmitted by the second donor-CU, The IAB transmission transition management response message is: Differentiated Services Code Points (DSCPs) and flow labels for downstream traffic, and / or The apparatus according to claim 16, comprising uplink non-F1 termination backhaul information (UL Non-F1 Terminating BH Info) for configuring the uplink backhaul mapping configuration of the node.

20. The third processing unit is, The apparatus according to claim 19, wherein the third donor-CU further controls the third donor-CU to establish a user device context in the second IAB-DU via the F1AP user device context establishment (UE Context Setup) procedure and to perform an uplink backhaul mapping configuration for the node.

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