Distributed unit migration method, control device and communication system

Abstract

The embodiment of the invention provides a distributed unit migration method, a management device and a communication system, the device is applied to an IAB node, the device comprises a first processing unit, and the first processing unit controls the node to execute the following operation: an F1 termination host of the node migrates from a first donor-CU to a third donor-CU, the first donor-CU is different from the third donor-CU, a radio resource control (PRC) termination host of the node is a second donor-CU, and 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 both the first donor-CU and the third donor-CU.

Description

Distributed unit migration method, control device and communication system Technical Field

[0001] The embodiments of the present application relate to the field of communication technologies. Background Art

[0002] Integrated access and backhaul (IAB) implements wireless relay functionality in the next-generation radio access network (NG-RAN). An IAB-node supports access and backhaul over New Radio (NR). The network-side termination point for NR backhaul is called an IAB-donor, which represents a network device (e.g., a gNB) that supports IAB functionality.

[0003] An IAB node can connect to an IAB host (IAB donor) via one or more hops. These multi-hop connections form a directed acyclic graph (DAG) topology with the IAB host as the root node. The IAB host is responsible for centralized resource management, topology management, and routing management within the IAB network topology.

[0004] The IAB-node supports the gNB-distributed unit (gNB-DU) functionality. The IAB-node DU, also known as the IAB-DU, terminates the radio access (NR) interface to the user equipment (UE) and the next-hop IAB-node. It also terminates the F1 protocol to the gNB-central unit (CU) on the IAB-donor. The IAB-DU can serve both standard UEs and IAB child nodes. Implementing network-side device functionality, the IAB-DU connects to downstream child IAB-nodes, provides NR air interface access to the UE and downstream child IAB-nodes, and establishes an F1 connection with the IAB donor-CU.

[0005] In addition to gNB-DU functionality, the IAB-node also supports a subset of UE functionality, known as IAB-MT (Mobile Termination). The IAB-MT includes physical layer, layer 2, RRC, and NAS functionality for connecting to a gNB-DU on another IAB-node or IAB-donor, connecting to a gNB-CU on an IAB-donor, and connecting to the core network. The IAB-MT supports UE physical layer, access stratum (AS), radio resource control (RRC), and non-access stratum (NAS) layer functionality and can connect to an IAB parent node.

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

[0007] To support multi-hop routing of data packets, IAB introduces the Backhaul Adaptation Protocol (BAP) sublayer. Located above the radio link control (RLC) sublayer and below the IP layer, the BAP sublayer supports packet destination and path selection, packet routing, bearer mapping, flow control feedback, and backhaul link failure notification.

[0008] Figure 1 is a schematic diagram of the IAB parent-child node relationship. As shown in Figure 1, in the IAB parent-child node relationship structure 10, IAB-node 100 includes an IAB-MT functional unit 101 and an IAB-DU functional unit 102. The neighboring nodes on the interface of IAB-DU functional unit 102 are called child nodes, such as child nodes 201, 202, and 203 shown in Figure 1. The IAB-DU functional unit 102 and child nodes 201, 202, and 203 can communicate over the air interface (Uu). The neighboring nodes on the interface of IAB-MT functional unit 101 are called parent nodes, such as parent nodes 301 and 302 shown in Figure 1. The IAB-MT functional unit 101 and parent nodes 301 and 302 can communicate over the 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 10.

[0010] It should be noted that the above introduction to the technical background is merely intended to provide a clear and complete description of the technical solutions of this application and facilitate understanding by those skilled in the art. Simply because these solutions are described in the background technology section of this application, it should not be assumed that the above technical solutions are well known to those skilled in the art.

[0011] Summary of the Invention

[0012] In multi-hop scenarios, to relay data packets, the IAB node needs to determine the destination node for the packet, then determine the next hop corresponding to the destination node based on the routing table and send the packet. The donor-CU configures the IAB node through F1AP (F1 application protocol) signaling, mapping 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.

[0013] The IAB node determines the BAP routing identifiers corresponding to different types of uplink IP packets initiated from the IAB node based on the routing identifier mapping information, and encapsulates the BAP subheader containing the BAP routing identifier information for these uplink IP packets. The Donor-CU configures the mapping of different types of downlink data packets to BAP routing identifiers for the donor-DU through F1AP signaling. The Donor-DU determines the BAP routing identifiers corresponding to the received downlink IP packets based on the routing identifier mapping information, and encapsulates the BAP subheader containing the BAP routing identifier downlink for these downlink IP packets.

[0014] The BAP routing identifier includes the destination BAP address and the path identity from the IAB node to the donor-DU. The BAP address is also called the destination in the BAP header. Each IAB node and donor-DU is configured with a BAP address.

[0015] During IAB node integration, RRC can configure a default BH (backhaul) RLC channel and a default BAP routing identifier for non-F1-U traffic. These configurations can be updated during topology adaptation.

[0016] In the upstream direction, the IAB-donor-CU configures the IAB node with a mapping between upstream F1 and non-F1 traffic originating from the IAB node and the appropriate BAP routing ID, next-hop BAP address, and BH RLC channel. Specific mappings are configured for each F1-U GTP-U tunnel, non-UE-associated F1AP message, UE-associated F1AP message, and non-F1 traffic.

[0017] An IAB node can have redundant paths to different IAB-donor-CUs. For IAB nodes operating in Stand Alone (SA) mode, NR-NR Dual Connectivity (NR-DC) allows the IAB-MT and two parent nodes to have simultaneous backhaul links, thereby achieving backhaul route redundancy. Two parent nodes can be connected to different IAB-donor-CUs, which can control the establishment and release of redundant routes passing through the two parent nodes. The gNB-DU function of the parent node and the corresponding IAB-donor-CU together assume the role of master node (MN) and / or secondary node (SN) of the IAB-MT. The NR-DC framework—such as the MCG (master cell group) / SCG (secondary cell group) related procedures—is used to configure the dual radio connection between the IAB node and the parent node.

[0018] An IAB-MT can migrate to a parent node under a different IAB-donor-CU. In this case, the collocated IAB-DU and the IAB-DU of the descendant node maintain the F1 connection with the original IAB-donor-CU. This migration is called inter-donor partial migration. The IAB node to which the IAB-MT migrates to the new IAB-donor-CU is the border IAB node. After the inter-donor partial migration, the F1 traffic of the IAB-DU and the descendant node is routed via the BAP layer of the IAB topology to which the IAB-MT migrates. SA mode can support inter-donor partial migration.

[0019] When an SA-mode IAB node declares a backhaul link RLF, it can perform RLF recovery on the parent node under a different IAB-donor-CU. Similar to inter-host partial migration, the collocated IAB-DU and the IAB-DU of the descendant node can maintain the F1 connection with the original IAB-donor-CU.

[0020] Figure 2 shows a partial migration scenario. IAB node 3 is called a boundary IAB node. A boundary IAB node refers to a node whose RRC interface and F1 interface terminate at different IAB-donor-CUs. Boundary IAB nodes are suitable for partial migration, inter-host topology redundancy, and inter-host RLF (radio link failure) recovery. For example, in Figure 2, the DU of node 3 terminates at CU1, and the MT has an RRC connection to CU2, so it meets the definition of a boundary IAB node. Descendant IAB nodes refer to nodes that access the network through a boundary IAB node, and each node is single-connected to its parent node, such as IAB node 4. An F1-terminating node refers to a donor-CU that terminates the F1 interface of a boundary IAB node and a descendant node, such as donor-CU1 (the F1 of IAB-DU3 and IAB-DU4 in Figure 2 terminates at donor-CU1). A non-F1-terminating node is a CU with host functionality that does not terminate the F1 interface of a boundary IAB node or descendant node, such as donor-CU2. Because non-F1-terminating nodes have an RRC connection with the IAB-MT, they can also be called IAB-MT host nodes, and non-F1-terminating host CUs can also be called IAB-MT host CUs.

[0021] In Figure 2, IAB-MT3 changes from a single connection to its parent node, IAB Node 1, to a single connection to its parent node, IAB Node 2. Both IAB-DU3 and its child node, IAB Node 4, maintain an F1 connection to donor-CU1, but this F1 connection passes through IAB Node 2 and ultimately reaches CU1. In the partial migration scenario shown in Figure 2, the edge node is the migration node. Partial migration scenarios are also applicable to partial RLF recovery.

[0022] A mobile IAB (mIAB) or mobile relay faces a mobility challenge within a large area: when it moves, it needs to change the IAB host (i.e., the F1 termination host). This means that the F1 interface of the IAB-DU needs to be migrated. This migration process is called IAB-DU migration. This affects the Packet Data Convergence Protocol (PDCP) and Radio Resource Control (RRC) connections of the terminal devices (e.g., user equipment (UE)) served by the mobile IAB.

[0023] In the DU migration scenario, in order to perform the handover of the served UE, the mobile IAB node needs to support two logical mobile IAB-DUs at the same time. These two DUs have F1AP associations with the source CU and the target CU respectively.

[0024] A UE connected to a mobile IAB node is handed over from a cell having a logical mobile IAB-DU associated with an F1AP and a source CU (ie, a source logical mobile IAB-DU) to a cell having a logical mobile IAB-DU associated with an F1AP and a target CU (ie, a target logical mobile IAB-DU).

[0025] During DU migration, the UE regards the cells of the two logical DUs as different physical cells (for example, if the cells use the same carrier, then the cells use different PCIs), and the cells of the two logical DUs use separate physical resources (that is, different carriers in traditional layer 1, or orthogonal time and frequency resources in the case of the same carrier).

[0026] The inventors of the present application have discovered that in the prior art, there is no definition of a method and process for an IAB node to implement DU migration.

[0027] Embodiments of the present application provide a method, apparatus, and communication system for distributed unit migration, wherein the F1 termination host of an IAB node migrates from a first host central unit (donor-CU) to a third donor-CU different from the first donor-CU, thereby enabling the DU of the IAB node to be migrated.

[0028] According to one aspect of an embodiment of the present application, a control device for distributed unit migration is provided, which is applied to an integrated access backhaul node (IAB-node). The device includes a first processing unit, which controls the node to perform the following operations:

[0029] The F1 termination host of the node is migrated from the first donor-CU to the third donor-CU.

[0030] The first donor-CU is different from the third donor-CU.

[0031] The radio resource control (RRC) termination host of the node is the second donor-CU,

[0032] 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 both the first donor-CU and the third donor-CU.

[0033] According to another aspect of an embodiment of the present application, a distributed unit migration control device is provided, which is applied to a first host central unit (donor-CU). The device includes a second processing unit, which controls the first donor-CU so that the F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first host central unit (donor-CU) to a third donor-CU.

[0034] The first donor-CU is different from the third donor-CU.

[0035] The radio resource control (RRC) termination host of the node is the second donor-CU,

[0036] 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 both the first donor-CU and the third donor-CU.

[0037] According to another aspect of an embodiment of the present application, a distributed unit migration control device is provided, which is applied to a third host central unit (donor-CU). The device includes a third processing unit, which controls the third donor-CU so that the F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first host central unit (donor-CU) to the third donor-CU.

[0038] The first donor-CU is different from the third donor-CU.

[0039] The radio resource control (RRC) termination host of the node is the second donor-CU,

[0040] 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 both the first donor-CU and the third donor-CU.

[0041] According to another aspect of an embodiment of the present application, a distributed unit migration control device is provided, which is applied to a second host central unit (donor-CU). The device includes a fourth processing unit, which controls the fourth donor-CU to cause the F1 termination host of the access backhaul integrated node (IAB-node) to migrate from the first host central unit (donor-CU) to the third donor-CU.

[0042] The first donor-CU is different from the third donor-CU.

[0043] The radio resource control (RRC) termination host of the node is the second donor-CU,

[0044] 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 both the first donor-CU and the third donor-CU.

[0045] The beneficial effect of the embodiment of the present application is that DU migration of the IAB node can be achieved.

[0046] With reference to the following description and accompanying drawings, specific embodiments of the present application are disclosed in detail, indicating the manner in which the principles of the present application can be employed. It should be understood that the embodiments of the present application are not limited in scope. Within the spirit and scope of the appended claims, the embodiments of the present application include many variations, modifications and equivalents.

[0047] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0048] It should be emphasized that the term "include / comprising" when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The elements and features described in one figure or one embodiment of the present application can be combined with the elements and features shown in one or more other figures or embodiments. In addition, in the accompanying drawings, similar reference numerals represent corresponding parts in several figures and can be used to indicate corresponding parts used in more than one embodiment.

[0050] Figure 1 is a schematic diagram of the IAB parent-child node relationship;

[0051] Figure 2 shows a partial migration scenario;

[0052] FIG3 is a schematic diagram of a scenario in which an IAB node uses multiple IAB-DUs during DU migration;

[0053] FIG4 is a schematic diagram of another scenario in which an IAB node uses multiple IAB-DUs during DU migration;

[0054] FIG5 is a schematic diagram of another scenario in which an IAB node uses multiple IAB-DUs during DU migration;

[0055] FIG6 is a schematic diagram of a method for migrating a distributed unit according to an embodiment of the first aspect;

[0056] Figure 7 is a schematic diagram of IAB-DU migration;

[0057] Figure 8 is a schematic diagram of the new F1AP process;

[0058] FIG9 is a schematic diagram of a control device for distributed unit migration according to an embodiment of the second aspect;

[0059] FIG10 is a schematic diagram of a control device for distributed unit migration according to an embodiment of the third aspect;

[0060] FIG11 is a schematic diagram of a control device for distributed unit migration according to an embodiment of the fourth aspect;

[0061] FIG12 is a schematic diagram of a control device for distributed unit migration according to an embodiment of the fifth aspect;

[0062] FIG13 is a schematic diagram of the composition of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0063] The above and other features of the present application will become apparent through the following description with reference to the accompanying drawings. In the description and the accompanying drawings, specific embodiments of the present application are disclosed in detail, which illustrate some embodiments in which the principles of the present application can be adopted. It should be understood that the present application is not limited to the described embodiments. On the contrary, the present application includes all modifications, variations and equivalents that fall within the scope of the appended claims.

[0064] In the embodiments of the present application, the terms "first", "second", etc. are used to distinguish different elements from the name, but do not indicate the spatial arrangement or temporal order of these elements, and these elements should not be limited by these terms. The term "and / or" includes any one and all combinations of one or more of the associated listed terms. The terms "comprising", "including", "having", etc. refer to the presence of the stated features, elements, components or components, but do not exclude the presence or addition of one or more other features, elements, components or components.

[0065] In the embodiments of this application, the singular forms "a," "the," etc. include plural forms and should be broadly understood to mean "a" or "a type" rather than being limited to "one." Furthermore, the term "said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise. Furthermore, the term "according to" should be understood to mean "at least in part based on...", and the term "based on" should be understood to mean "at least in part based on...", unless the context clearly indicates otherwise.

[0066] In the embodiments of the present application, the term "communication network" or "wireless communication network" may refer to a network that complies with any of the following communication standards, such as New Radio (NR), Long Term Evolution (LTE), Enhanced Long Term Evolution (LTE-A, LTE-Advanced), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), etc.

[0067] Furthermore, communication between devices in the communication system may be carried out according to communication protocols of any stage, for example, including but not limited to the following communication protocols: 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G and 5G, New Radio (NR), etc., and / or other communication protocols currently known or to be developed in the future.

[0068] In the embodiments of the present application, the term "network device" refers to, for example, a device in a communication system that connects a terminal device to a communication network and provides services for the terminal device. Network devices may include, but are not limited to, the following devices: an integrated access and backhaul node (IAB-node), a relay, a base station (BS), an access point (AP), a transmission reception point (TRP), a broadcast transmitter, a mobile management entity (MME), a gateway, a server, a radio network controller (RNC), a base station controller (BSC), and the like.

[0069] Base stations may include, but are not limited to, NodeB (NB), evolved NodeB (eNodeB or eNB), and 5G base stations (gNB), among others. They may also include remote radio heads (RRHs), remote radio units (RRUs), relays, or low-power nodes (e.g., femeto, pico, etc.). The term "base station" may include some or all of their functions, and each base station may provide communication coverage for a specific geographic area. The term "cell" may refer to a base station and / or its coverage area, depending on the context in which the term is used.

[0070] In the embodiments of the present application, the term "user equipment" (UE) or "terminal equipment" (TE) refers to, for example, a device that accesses a communication network through a network device and receives network services. A terminal device can be fixed or mobile and may also be referred to as a mobile station (MS), a terminal, a subscriber station (SS), an access terminal (AT), a mobile termination (MT), a station, etc.

[0071] Among them, terminal devices may include but are not limited to the following devices: cellular phones, personal digital assistants (PDAs), wireless modems, wireless communication devices, handheld devices, machine-type communication devices, laptop computers, cordless phones, smart phones, smart watches, digital cameras, etc.

[0072] For another example, in scenarios such as the Internet of Things (IoT), the terminal device can also be a machine or device for monitoring or measurement, including but not limited to: machine type communication (MTC) terminal, vehicle-mounted communication terminal, device-to-device (D2D) terminal, machine-to-machine (M2M) terminal, and so on.

[0073] In addition, the term "network side" or "network device side" refers to one side of the network, which can be a base station or one or more network devices as mentioned above. The term "user side" or "terminal side" or "terminal device side" refers to the user or terminal side, which can be a UE or one or more terminal devices as mentioned above.

[0074] In various embodiments of the present application, high-layer signaling may be, for example, radio resource control (RRC) signaling; for example, an RRC message, including, for example, an MIB, system information, or a dedicated RRC message; or an RRC information element (RRC IE). High-layer signaling may also be, for example, F1-C signaling, or F1AP protocol. However, the present application is not limited thereto.

[0075] In this application, various embodiments are described using a multi-hop IAB network deployment scenario as an example, wherein multiple terminal devices (e.g., UEs) are connected to an IAB-donor through multi-hop IAB nodes and finally access a network, such as a 5G network.

[0076] The IAB node to which a terminal device (eg, user equipment) is connected may be mobile.

[0077] The various embodiments of the present application can be applied to other mobile nodes, such as relays, etc. The various embodiments of the present application are described using IAB as an example.

[0078] Embodiments of the first aspect

[0079] Figure 3 is a schematic diagram of a scenario in which an IAB node uses multiple IAB-DUs during DU migration; Figure 4 is a schematic diagram of another scenario in which an IAB node uses multiple IAB-DUs during DU migration; and Figure 5 is a schematic diagram of yet another scenario in which an IAB node uses multiple IAB-DUs during DU migration.

[0080] As shown in Figure 3, IAB node 3 contains two DU components: a first IAB-DU and a second IAB-DU. The first IAB-DU, IAB-DU3a in Figure 3, establishes an F1 connection with the source IAB-donor-CU (donor-CU1). This first IAB-DU can also be referred to as the source IAB-DU or a normal IAB-DU that has not undergone DU migration. The second IAB-DU, IAB-DU3b in Figure 3, establishes an F1 connection with the target IAB-donor-CU (donor-CU2). This second IAB-DU can also be referred to as the target IAB-DU. These two IAB-DUs can be logical IAB-DUs or virtual IAB-DUs. From the perspective of a terminal device (e.g., a user equipment (UE),) these two IAB-DUs are indistinguishable from normal IAB-DUs or gNB-DUs and have the functionality of normal DUs, but are integrated within the IAB node. The integration method is implementation-dependent. The first IAB-DU and the second IAB-DU may also use a traditional IAB-DU implementation method, that is, physically speaking, they are two IAB-DUs.

[0081] If DU migration is considered independently, that is, MT cannot migrate simultaneously during DU migration, then based on the initial migration state of the IAB node and the selection of the target IAB-donor-CU, it can be mainly divided into three scenarios, which are illustrated in Figures 3 to 5 respectively.

[0082] Scenario 1: Corresponding to Figure 3. Before DU migration, the IAB node is already in a partially migrated state (the mobile operator and DU are controlled by different donor-CUs). The IAB-DU migrates the F1 termination point to the donor-CU of the IAB-MT. After DU migration, the IAB node's mobile operator and DU (as well as the UE served by the mobile IAB node) terminate on the same donor-CU. This process is also called a full migration.

[0083] Scenario 2: Corresponds to Figure 4. Before DU migration, the IAB node's mobile operator (MT) and DU (and the UE served by the mobile IAB node) terminate on the same donor-CU. The IAB-DU switches the F1 termination node to a different donor node. After DU migration, the IAB node is in a partially migrated state (MT and DU are controlled by different donor-CUs).

[0084] Scenario 3: Corresponding to Figure 5. Before DU migration, the IAB node is in the partially migrated state. The IAB-DU switches the F1 termination node to a different donor-CU than the IAB-MT's donor-CU. After DU migration, the IAB node's MT and DU remain in the partially migrated state (but with the DU's donor-CU switched).

[0085] In these three scenarios and the embodiments of the present application, the source F1-terminating donor-CU of the IAB node (referred to as the source donor-CU) can be called the first donor-CU, that is, 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.

[0086] In these three scenarios and the embodiments of the present application, the target F1-terminating donor-CU of the IAB node (referred to as the target donor-CU) is called the third donor-CU, that is, 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.

[0087] In these three scenarios and the embodiments of this application, the IAB-MT donor-CU, or the donor-CU to which the IAB-MT's RRC connection is connected, is referred to as the second donor-CU, and is referred to as Donor-CU2 in Figures 3-5 . If 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.

[0088] Scenario 3 can be considered a more general scenario, which includes the first, second, and third donor-CUs. Scenario 1 and Scenario 2 are special cases of Scenario 3. In Scenario 1, Donor-CU2 is both the second and third donor-CUs; in Scenario 2, Donor-CU2 is both the first and second donor-CUs.

[0089] The embodiments of the present application are described based on the above-mentioned scenarios. It should be noted that the embodiments of the present application are not limited to the above-mentioned scenarios.

[0090] An embodiment of the first aspect of the present application provides a method for distributed unit migration, which is applied to a communication system including an IAB node (for example, the 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).

[0091] FIG6 is a schematic diagram of a method for migrating a distributed unit according to an embodiment of the first aspect. As shown in FIG6 , the method includes:

[0092] 601. The F1 termination host of the integrated access backhaul node (IAB-node) migrates from a first donor central unit (donor-CU) to a third donor-CU, wherein the first donor-CU is different from the third donor-CU.

[0093] In an embodiment of the first aspect, a radio resource control (RRC) termination host of the IAB 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 both the first donor-CU and the third donor-CU.

[0094] In the instructions below:

[0095] The IAB node is, for example, the IAB node 3 shown in FIG5 , and the IAB node 3 may be referred to as the IAB node or the node;

[0096] The first donor-CU is, for example, donor-CU1 shown in FIG5 . The first donor-CU may also be referred to as the source F1-terminating donor-CU of the IAB node (referred to as the source donor-CU), that is, the donor-CU of the first IAB-DU (for example, IAB-DU3a in FIG5 );

[0097] The second donor-CU is, for example, donor-CU2 shown in FIG5 . The second donor-CU may also be referred to as an IAB-MT donor-CU, that is, an IAB-MT RRC-connected donor-CU. 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.

[0098] The third donor-CU is, for example, donor-CU3 shown in Figure 5. The third donor-CU can also be called the target F1-terminating donor-CU of the IAB node (referred to as target donor-CU), that is, the donor-CU of the second IAB-DU (for example, IAB-DU3b in Figure 5).

[0099] The second IAB-DU (ie, target IAB-DU) is also referred to as a concatenated IAB-DU of the first IAB-DU (ie, source IAB-DU).

[0100] FIG. 7 is a schematic diagram of IAB-DU migration, which is used to implement operation 601 .

[0101] As shown in Figure 7, the steps of IAB-DU migration are as follows:

[0102] Step 0. The source 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 can be based on the implementation decision of the first donor-CU, or based on pre-configuration, Operations, Administration, and Maintenance (OAM) configuration, etc.

[0103] 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 through F1AP signaling. As a result, the target IAB-DU (i.e., the second IAB-DU) requests F1 establishment from the target donor-CU. The information about the target F1-terminating donor-CU includes: TNL address (transport network layer address, i.e., IP address) and / or base station identifier (such as global base station identifier, Global gNB ID), etc.

[0104] Step 2. The target IAB-DU sends an F1 setup request (F1SETUPREQUEST) message to the target F1-terminating donor-CU. The message contains 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 donor-CU (second donor-CU) of the IAB-MT.

[0105] Step 3. The target F1-terminating donor-CU responds with an F1 SETUP RESPONSE message to the target IAB-DU.

[0106] Step 4. The source IAB-DU notifies the source F1-terminating donor-CU via F1AP signaling of the successful establishment of the F1 interface with the target donor-CU. The message may include one or more cell identifiers activated by the target donor-CU, which may be obtained in step 3.

[0107] Step 5. The source F1-terminating donor-CU sends a handover request (HANDOVER REQUEST) message to the target F1-terminating donor-CU. The message includes user equipment context (UE context) information. The message is used to request handover preparation for the terminal device (e.g., user equipment UE) served by the IAB node.

[0108] Step 6. If the base station identifier of the second donor-CU received in step 2 is not the base station identifier of the recipient (e.g., the target donor-CU), the target donor-CU sends an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message to the donor-CU of the IAB-MT (the donor-CU corresponding to the base station identifier received in step 2) for F1 transport migration. The IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message includes IAB node identification information, such as a non-F1-terminating node UE Xn interface identifier (non-F1-terminating node UE XnAP ID) and / or the BAP address of the IAB node.

[0109] In step 6, if the IAB node's identification information includes the non-F1-terminating node UE XnAP ID, the source F1-terminating donor-CU must first send an Xn message to inform the target F1-terminating donor-CU of the IAB node's UE XnAP ID at the non-F1-terminating donor-CU. This Xn message may also include the IAB node's BAP address, the IAB-DU's F1 migration request, and other information to help the target donor-CU prepare for resource allocation. This Xn message exchange can occur in a previous step, such as step 0. The IAB node's UE XnAP ID at the non-F1-terminating donor-CU can also be included in the handover request message in step 5. This involves adding a new IE to the Xn handover request message to indicate the UE XnAP ID of the IAB node serving the UE at the target base station (Note: the UE here refers to the IAB-MT). The traffic profile and quality of service (QoS) parameters included in the IAB transport migration management request message are derived 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 recipient (eg, the target donor-CU), steps 6 and 7 are skipped.

[0110] Step 7. The IAB-MT's donor-CU sends an IAB Transport Migration Management Response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message to the target donor-CU. This message contains the mapping configuration of the Differentiated Services Code Point (DSCP) and flow label for downlink traffic, and the UL Non-F1 Terminating BH Info (UL Non-F1 Terminating BH Info) used to configure the uplink backhaul mapping configuration of the IAB node. The uplink backhaul mapping configuration refers to the mapping configuration of uplink traffic to the BAP routing identifier and the mapping configuration of uplink traffic to the BH RLC channel.

[0111] Step 8. The target donor-CU establishes a UE context on the target IAB-DU through the UE Context Setup process of the F1AP and configures the uplink backhaul mapping for the IAB node. The UE context information is obtained in step 5, and the information required for the uplink backhaul mapping configuration is obtained in step 7.

[0112] Step 9. The target donor-CU replies with a HANDOVER REQUEST ACKNOWLEDGE message to the source donor-CU.

[0113] Step 10. Perform a UE handover process, which includes: the terminal device (e.g., user equipment UE) accessing the designated cell of the second IAB-DU according to the received RRC reconfiguration message, a sequence number status transfer (SN STATUS TRANSFER), a path switch process, and a UE context release process. The target donor-CU generates an IP header for the downlink data based on the DSCP and flow label information received in step 7.

[0114] 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 (IAB TRANSPORT MIGRATION MODIFICATION REQUEST) message to the source F1-terminating donor-CU. This message contains the IAB node's identification information and requests the release (e.g., full release) of the offloaded traffic, meaning that all traffic is returned to the source donor-CU. The IAB-MT's donor-CU knows whether the IAB node's F1 transport migration is complete through the traffic offloading process performed in steps 6 and 7, thereby triggering the IAB transport migration modification process to the source donor-CU. If the IAB-MT's donor-CU is the source F1-terminating donor CU, steps 11 and 12 are skipped.

[0115] Step 12. The source donor-CU replies with an IAB TRANSPORT MIGRATION MODIFICATION RESPONSE message to the donor-CU of the IAB-MT.

[0116] Step 13. Clear the F1 connection from the source IAB-DU to the source donor-CU. The F1 removal process can be initiated by the source IAB-DU or the source donor-CU.

[0117] In at least one embodiment of the present application, steps 11 and 12 may be replaced with an IAB Transport Migration Management process, in which the source donor-CU initiates the fallback or release of traffic offloading. For example, the source donor-CU sends an IAB Transport Migration Management Request message to the donor-CU of the IAB-MT, which may include an indication of traffic release (e.g., releasing all traffic). The donor-CU of the IAB-MT replies with an IAB Transport Migration Management Response message. The source donor-CU triggers the IAB Transport Migration Management process by completing the UE handover.

[0118] In at least one embodiment of the present application, step 5 may be performed simultaneously with the previous steps, for example, after step 0.

[0119] In at least one embodiment of the present application, step 11 and step 12 may be performed before step 13, or, step 11 and step 12 may be performed simultaneously with step 13, or, step 11 and step 12 may be performed after step 13.

[0120] In at least one embodiment of the present application, for scenario 1, because the target donor-CU and the IAB-MT donor-CU are the same node, steps 6 and 7 are not performed. In this case, all the information obtained in step 7 is generated internally by the target donor-CU itself.

[0121] In at least one embodiment of the present application, for scenario 2, since the source donor-CU and the donor-CU of the IAB-MT are the same node, step 11 and step 12 do not need to be performed.

[0122] In at least one embodiment of the present application, steps 1 and 4 may be implemented as follows:

[0123] The first donor-CU (gNB-CU) sends a first message to the first IAB-DU (gNB-DU), requesting that the collocated IAB-DU (i.e., the IAB-DU on the same IAB node) of the first IAB-DU establish an F1 association with the third donor-CU. The first message 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, that is, after the second IAB-DU receives the F1 SETUP RESPONSE message from the third donor-CU, the first IAB-DU sends a second message to the first donor-CU, confirming the completion of the F1 establishment between the collocated IAB-DU (i.e., the second IAB-DU) and the third donor-CU. The second message may include one or more activated cell identifiers, which are obtained from the F1 SETUP RESPONSE message sent by the third donor-CU. If the F1 setup between the second IAB-DU and the third donor-CU fails, that is, the second IAB-DU receives an F1 SETUP FAILURE message from the third donor-CU, the first IAB-DU sends a third message to the first donor-CU, indicating that the F1 setup failed.

[0124] The first, second and third information may use F1AP signaling.

[0125] In at least some embodiments, the existing F1AP procedure may be enhanced, such as the gNB-CU Configuration Update procedure. Specifically, a new information element (IE) may be added to the GNB-CU Configuration Update message to represent the first information; a GNB-CU Configuration Update Acknowledgement message may be used or a new IE may be added to the message to represent the second information; and a GNB-CU Configuration Update Failure message may be used or a new IE may be added to the message to represent the third information. Similarly, the gNB-DU Resource Configuration procedure may be enhanced to include the first, second, and third information in the GNB-DU Resource Configuration message, the GNB-DU Resource Configuration Acknowledgement message, and the GNB-DU Resource Configuration Failure message, respectively.

[0126] In at least some other embodiments, a new F1AP process may be added, which uses a non-UE-associated IAB process. The process includes a first message, a second message, and a third message, for example, respectively called a target F1 setup (TARGET F1 SETUP) message, a target F1 setup confirmation (TARGET F1 SETUP ACKNOWLEDGE) message, and a target F1 setup failure (TARGET F1 SETUP FAILURE) message, which respectively include the first information, the second information, and the third information.

[0127] For example, Figure 8 is a schematic diagram of a new F1AP process. As shown in Figure 8, the new F1AP process may include the following steps:

[0128] 801. The first donor-CU (gNB-CU) sends a TARGET F1 SETUP message to the first IAB-DU (gNB-DU).

[0129] 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).

[0130] In addition, 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).

[0131] If an IAB node performs migration of both the mobile and DU nodes simultaneously, the MT's donor-CU and the DU's donor-CU will change during the migration process. This can cause confusion in the information exchange between multiple donor-CUs, potentially sending information to the wrong donor-CU, leading to migration failure.

[0132] In order to solve the above problem, in at least some embodiments of the present application, the following method can be used to avoid simultaneous migration of the MT and the DU.

[0133] In step 6 of Figure 7 , the IAB-MT's donor-CU receives an IAB transport migration management request from the target donor-CU, requesting traffic offload. The request includes the IAB node's identification information. The IAB-MT's donor-CU uses the IAB node's identification information and the existing traffic offload association with the source donor-CU to determine that the IAB node is performing a DU migration. The IAB-MT's donor-CU avoids performing an IAB-MT handover (MT migration) at this point. Alternatively, the target donor-CU sends an Xn message to the IAB-MT's donor-CU, which includes the IAB node's identification information, indicating that the IAB-MT handover process should not proceed. Alternatively, the IAB node sends a notification message to the IAB-MT's donor-CU via RRC signaling, indicating that the IAB node is performing a DU migration. In scenario 1, the IAB-MT's donor-CU is the target donor-CU. Therefore, in step 2, the IAB-MT's donor-CU is aware that the IAB is performing a DU migration and can avoid an IAB-MT handover from this point on.

[0134] After step 10 in Figure 7 (i.e., all UE handovers are complete), the target donor-CU notifies the IAB-MT's donor-CU of the DU migration completion via an Xn message, or the IAB node via an RRC message. In this case, the IAB-MT's donor-CU can perform the IAB-MT handover if necessary. In scenario 1, the IAB-MT's donor-CU can independently determine whether the IAB-MT handover is possible.

[0135] In addition, in Figure 7, NGC represents a next-generation core network, for example, a 5G core network.

[0136] The embodiments of the first aspect of the present application solve the process problem of IAB node DU migration, thereby supporting long-distance movement of IAB nodes and improving the performance of IAB nodes in serving users (such as users in cars and trains).

[0137] Embodiments of the second aspect

[0138] The second embodiment of the present application provides a control device for distributed unit migration, which corresponds to the method for the IAB node in the distributed unit migration method described in the first embodiment. The device is applied to the IAB node.

[0139] FIG9 is a schematic diagram of a control device for distributed unit migration according to an embodiment of the second aspect. As shown in FIG9 , the control device 900 for distributed unit migration includes a first processing unit 901. The first processing unit 901 controls the node so that the node performs the following operations:

[0140] The F1 termination host of the node migrates from the first host central 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 host of the node is the 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 both the first donor-CU and the third donor-CU.

[0141] In at least one embodiment, the first processing unit controls the node to perform the following operations:

[0142] The first distributed unit (IAB-DU) of the node receives information about the third donor-CU sent by the first donor-CU through F1AP signaling.

[0143] In at least one embodiment, the first IAB-DU receives first information sent by the first donor-CU to request the second IAB-DU to establish an F1 association with the third donor-CU, where 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.

[0144] In at least one embodiment, the first information uses F1AP signaling, wherein the first information is a new information element (IE) in the F1AP signaling, or the first information is sent using a new F1AP procedure.

[0145] In at least one embodiment, the information about the third donor-CU includes:

[0146] Transport network layer address (TNL) address, and / or base station identifier.

[0147] In at least one embodiment, the first processing unit controls the node to further perform the following operations:

[0148] A second distributed unit (IAB-DU) of the node sends an F1 SETUP REQUEST message to the third donor-CU, where the second IAB-DU is a concatenated IAB-DU of the first IAB-DU.

[0149] In at least one embodiment, 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 and / or base station identifier of the second donor-CU.

[0150] In at least one embodiment, the first processing unit controls the node to perform the following operations:

[0151] The second IAB-DU receives an F1 SETUP RESPONSE message replied by the third donor-CU.

[0152] In at least one embodiment, the first processing unit controls the node to perform the following operations:

[0153] The first distributed unit (IAB-DU) notifies the first donor-CU of the successful establishment of the F1 interface with the third donor-CU through F1AP signaling.

[0154] In at least one embodiment, after the F1 establishment between the second IAB-DU and the third donor-CU is completed, 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.

[0155] 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 the F1 establishment failure.

[0156] In at least one embodiment, the second information or the third information uses F1AP signaling.

[0157] The second information or the third information is a new information element (IE) in the F1AP signaling, or the second information or the third information is sent using a new F1AP process.

[0158] In at least one embodiment, the message of successfully establishing the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU.

[0159] In at least one embodiment, the node receives the uplink backhaul mapping configuration performed by the third donor-CU.

[0160] In at least one embodiment, the first processing unit controls the node to perform the following operations:

[0161] After the migration is completed, the node clears the F1 connection from the first IAB-DU to the first donor-CU.

[0162] In at least one embodiment, the clearing process is initiated by the first IAB-DU or the first donor-CU.

[0163] In at least one embodiment, the first processing unit controls the node to perform the following operations:

[0164] The node sends information about the start of DU migration to the second donor-CU.

[0165] In at least one embodiment, the first processing unit controls the node to perform the following operations:

[0166] After the migration is completed, the node sends information about the completion of DU migration to the second donor-CU.

[0167] Embodiments of the third aspect

[0168] The third aspect of the present application provides a control device for distributed unit migration, which corresponds to the method of the first donor-CU in the distributed unit migration method described in the first aspect. The device is applied to the first donor-CU.

[0169] Figure 10 is a schematic diagram of a control device for distributed unit migration of an embodiment of the third aspect. As shown in Figure 10, the control device 1000 for distributed unit migration includes a second processing unit 1001, which controls the first donor-CU so that the F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first host central 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 host of the node is the 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 both the first donor-CU and the third donor-CU.

[0170] In at least one embodiment, the second processing unit controls the first donor-CU to perform the following operations:

[0171] The first donor-CU notifies the first distributed unit (IAB-DU) of the node of information about the third donor-CU through F1AP signaling.

[0172] In at least one embodiment, the first donor-CU sends first information to the first IAB-DU to request the second IAB-DU to establish an F1 association with the third donor-CU, where the first information includes information about the third donor-CU, and the second IAB-DU is a collocated IAB-DU of the first IAB-DU.

[0173] In at least one embodiment, the first information uses F1AP signaling, wherein the first information is a new information element (IE) in the F1AP signaling, or the first information is sent using a new F1AP procedure.

[0174] In at least one embodiment, the information about the third donor-CU includes:

[0175] Transport network layer address (TNL) address, and / or base station identifier.

[0176] In at least one embodiment, the second processing unit controls the first donor-CU to further perform the following operations:

[0177] The first donor-CU receives a message notified by the first distributed unit (IAB-DU) through F1AP signaling regarding the successful establishment of the F1 interface with the third donor-CU.

[0178] In at least one embodiment, after the F1 establishment between the second IAB-DU and the third donor-CU is completed, 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.

[0179] 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 the F1 establishment failure.

[0180] In at least one embodiment, the second information or the third information uses F1AP signaling.

[0181] The second information or the third information is a new information element (IE) in the F1AP signaling, or the second information or the third information is sent using a new F1AP process.

[0182] In at least one embodiment, the message of successfully establishing the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU.

[0183] In at least one embodiment, the second processing unit controls the first donor-CU to further perform the following operations:

[0184] The first donor-CU sends a handover request (HANDOVER REQUEST) message to the third donor-CU.

[0185] In at least one embodiment, the first donor-CU sends an Xn message to the third donor-CU to inform the node of the user equipment Xn interface identifier (UE XnAP ID) of the second donor-CU.

[0186] In at least one embodiment, the handover request (HANDOVER REQUEST) message includes user equipment context (UE context) information, and the handover request message is used to apply for handover preparation for the electronic device served by the node.

[0187] In at least one embodiment, the handover request (HANDOVER REQUEST) message includes the user equipment Xn interface identifier (non-F1-terminating donor-CU UE XnAP ID) of the node in the second donor-CU.

[0188] In at least one embodiment, the second processing unit controls the first donor-CU to further perform the following operations:

[0189] In the case where the second donor-CU is different from the first donor-CU,

[0190] The first donor-CU receives an IAB transport migration modification request (IAB TRANSPORT MIGRATION MODIFICATION REQUEST) message sent by the second donor-CU.

[0191] In at least one embodiment, the IAB transport migration modification request message includes identification information of the node, and the IAB transport migration modification request message requests to release the offloaded traffic.

[0192] In at least one embodiment, the first donor-CU replies to the second donor-CU with an IAB TRANSPORT MIGRATION MODIFICATION RESPONSE message.

[0193] In at least one embodiment, when the second donor-CU is different from the first donor-CU,

[0194] The first donor-CU sends an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message to the second donor-CU.

[0195] In at least one embodiment, the IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message includes identification information of the node and / or traffic release indication information.

[0196] In at least one embodiment, the first donor-CU receives an IAB transport migration management response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message replied by the second donor-CU.

[0197] In at least one embodiment, the first donor-CU receives a HANDOVER REQUEST ACKNOWLEDGE message sent by the third donor-CU;

[0198] The first donor-CU switches the terminal device served by the node to the third donor-CU.

[0199] In at least one embodiment, the second processing unit controls the first donor-CU to further perform the following operations: clearing the F1 connection from the first IAB-DU to the first donor-CU.

[0200] In at least one embodiment, the clearing process is initiated by the first IAB-DU or the first donor-CU.

[0201] Embodiments of the fourth aspect

[0202] The fourth aspect of the present application provides a control device for distributed unit migration, which corresponds to the method of the third donor-CU in the distributed unit migration method described in the first aspect. The device is applied to the third donor-CU.

[0203] Figure 11 is a schematic diagram of a control device for distributed unit migration of an embodiment of the fourth aspect. As shown in Figure 11, the control device 1100 for distributed unit migration includes a third processing unit 1101, which controls the third donor-CU so that the F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first host central 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 host of the node is the 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 both the first donor-CU and the third donor-CU.

[0204] In at least one embodiment, the third processing unit controls the third donor-CU to perform the following operations:

[0205] The third donor-CU receives an F1 SETUP REQUEST message sent by the second distributed unit (IAB-DU) of the node.

[0206] In at least one embodiment, 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 and / or base station identifier of the second donor-CU.

[0207] In at least one embodiment, the third processing unit controls the third donor-CU to further perform the following operations:

[0208] The third donor-CU replies with an F1 SETUP RESPONSE message to the second IAB-DU.

[0209] The first IAB-DU is a concatenated IAB-DU of the second IAB-DU.

[0210] In at least one embodiment, the third processing unit controls the third donor-CU to perform the following operations:

[0211] The third donor-CU receives a handover request (HANDOVER REQUEST) message sent by the first donor-CU.

[0212] In at least one embodiment, the handover request (HANDOVER REQUEST) message includes user equipment context (UE context) information,

[0213] The handover request message is used to apply for handover preparation for the electronic device served by the node.

[0214] In at least one embodiment, the third processing unit controls the third donor-CU to further perform the following operations:

[0215] If the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU, the third donor-CU sends an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message to the second donor-CU.

[0216] In at least one embodiment, the third processing unit controls the third donor-CU to further perform the following operations:

[0217] The third donor-CU sends an indication message to the second donor-CU, instructing the second donor-CU not to perform the migration process of the mobile terminal (IAB-MT) of the node.

[0218] In at least one embodiment, the third processing unit controls the third donor-CU to further perform the following operations:

[0219] The third donor-CU sends information about DU migration completion to the second donor-CU.

[0220] In at least one embodiment, the IAB transmission migration management request message includes identification information of the node.

[0221] In at least one embodiment,

[0222] The identification information of the node includes a non-F1-terminating node UE Xn interface identifier (non-F1-terminating node UE XnAP ID) and / or a BAP address of the node.

[0223] In at least one embodiment, the third donor-CU receives an Xn message sent by the first donor-CU, where the Xn message informs the node of a user equipment Xn interface identifier (UE XnAP ID) of the second donor-CU.

[0224] In at least one embodiment, the IAB transport migration management request message includes a traffic profile, and the traffic profile is obtained from the handover request message.

[0225] In at least one embodiment, the third processing unit controls the third donor-CU to further perform the following operations:

[0226] The third donor-CU receives the IAB transport migration management response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message sent by the second donor-CU.

[0227] In at least one embodiment, the IAB transmission migration management response message includes:

[0228] Differentiated Services Code Point (DSCP) and flow label for downstream traffic; and / or

[0229] Uplink non-F1 terminating backhaul information (UL Non-F1Terminating BH Info) used to configure the uplink backhaul mapping configuration of the node.

[0230] In at least one embodiment, the third processing unit controls the third donor-CU to further perform the following operations:

[0231] The third donor-CU establishes a user equipment context on the second IAB-DU through a user equipment context setup (UE Context Setup) process of F1AP, and performs uplink backhaul mapping configuration for the node.

[0232] In at least one embodiment, the third processing unit controls the third donor-CU to further perform the following operations:

[0233] The third donor-CU generates an IP header for the downlink data based on the differentiated services code point and the flow label information.

[0234] In at least one embodiment, the third donor-CU sends a HANDOVER REQUEST ACKNOWLEDGE message to the first donor-CU.

[0235] Embodiments of the fifth aspect

[0236] The fifth aspect of the present application provides a control device for distributed unit migration, which corresponds to the method for the second donor-CU in the distributed unit migration method described in the first aspect. The device is applied to the second donor-CU.

[0237] Figure 12 is a schematic diagram of a control device for distributed unit migration of an embodiment of the fifth aspect. As shown in Figure 12, the control device 1200 for distributed unit migration includes a fourth processing unit 1201, which controls the second donor-CU so that the F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first host central 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 host of the node is the 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 both the first donor-CU and the third donor-CU.

[0238] In at least one embodiment, the fourth processing unit controls the second donor-CU to perform the following operations: if the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU, then the second donor-CU receives the IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message sent by the third donor-CU.

[0239] In at least one embodiment, the IAB transmission migration management request message includes identification information of the node.

[0240] In at least one embodiment, the identification information of the node includes a non-F1-terminating node UE Xn interface identifier (non-F1-terminating node UE XnAP ID) and / or a BAP address of the node.

[0241] In at least one embodiment, the fourth processing unit controls the second donor-CU to perform the following operations:

[0242] The second donor-CU sends an IAB transport migration management response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message to the third donor-CU.

[0243] In at least one embodiment, the IAB transmission migration management response message includes:

[0244] The third donor-CU is used to set a Differentiated Services Code Point (DSCP) and a flow label for downlink traffic; and / or

[0245] Uplink non-F1 terminating backhaul information (UL Non-F1 Terminating BH Info) configured for the third donor-CU to configure the uplink backhaul mapping configuration of the node.

[0246] In at least one embodiment, the fourth processing unit controls the second donor-CU to further perform the following operations:

[0247] The second donor-CU avoids migration of the mobile terminal (IAB-MT) of the node.

[0248] In at least one embodiment, the fourth processing unit controls the second donor-CU to further perform the following operations:

[0249] The second donor-CU receives an indication message sent by the third donor-CU, instructing the second donor-CU not to perform the migration process of the mobile terminal (IAB-MT) of the node; or receives a notification message sent by the node, indicating that the node is performing DU migration.

[0250] In at least one embodiment, the fourth processing unit controls the second donor-CU to further perform the following operations:

[0251] The second donor-CU receives information about DU migration completion sent by the third donor-CU or the node; and

[0252] The second donor-CU performs a migration process of the mobile terminal (IAB-MT) of the node.

[0253] In at least one embodiment, the fourth processing unit controls the second donor-CU to further perform the following operations:

[0254] In the case where the second donor-CU is different from the first donor-CU,

[0255] The second donor-CU sends an IAB transport migration modification request (IAB TRANSPORT MIGRATION MODIFICATION REQUEST) message to the first donor-CU.

[0256] In at least one embodiment, the IAB transmission migration modification request message includes identification information of the node.

[0257] The IAB transmits a migration modification request message to request the release of the offloaded traffic.

[0258] In at least one embodiment, the second donor-CU receives an IAB transport migration modification response (IAB TRANSPORT MIGRATION MODIFICATION RESPONSE) message replied by the first donor-CU.

[0259] In at least one embodiment, when the second donor-CU is different from the first donor-CU,

[0260] The second donor-CU receives an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message sent by the first donor-CU.

[0261] In at least one embodiment, the IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message includes identification information of the node and / or traffic release indication information.

[0262] In at least one embodiment, the second donor-CU replies to the first donor-CU with an IAB transport migration management response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message.

[0263] Embodiments of the sixth aspect

[0264] Embodiments of the present application also provide a communication system, which may include an IAB node, a first host central unit (CU), a second host central unit (CU), and a third host central unit (CU). The MT of the IAB node, the DU of the IAB node, and at least one of the first, second, and third host central units (CU) may comprise the electronic device shown in FIG12 .

[0265] Figure 13 is a schematic diagram of the components of an electronic device according to an embodiment of the present application. As shown in Figure 13 , terminal device 1300 may include a processor 1310 (e.g., a central processing unit (CPU)) and a memory 1320; memory 1320 is coupled to processor 1310. Memory 1320 can store various data and also stores an information processing program 1330, which is executed under the control of processor 1310.

[0266] For example, the processor 1310 may be configured to execute a program, thereby controlling the electronic device to implement the methods in the embodiments of the first aspect to the fourth aspect.

[0267] In addition, as shown in FIG13 , electronic device 1300 may further include: a transceiver 1340 and an antenna 1350; wherein, the functions of the above components are similar to those in the prior art and are not further described here. It is worth noting that electronic device 1300 does not necessarily include all the components shown in FIG13 ; in addition, electronic device 1300 may also include components not shown in FIG13 , and reference may be made to the prior art for details.

[0268] An embodiment of the present application also provides a computer program, wherein when the program is executed in at least one of the IAB node, the first host center unit CU, the second host center unit CU and the third host center unit CU, the program causes at least one of the IAB node, the first host center unit CU, the second host center unit CU and the third host center unit CU to perform the corresponding steps in the method described in the embodiment of the first aspect.

[0269] An embodiment of the present application also provides a storage medium storing a computer program, wherein the computer program enables at least one of the IAB node, the first host central unit CU, the second host central unit CU, and the third host central unit CU to perform the corresponding steps in the method described in the embodiment of the first aspect.

[0270] The above devices and methods of the present application can be implemented by hardware or by a combination of hardware and software. The present application relates to such a computer-readable program that, when executed by a logic component, enables the logic component to implement the devices or components described above, or enables the logic component to implement the various methods or steps described above. The present application also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, etc.

[0271] The method / device described in conjunction with the embodiments of the present application can be directly embodied as hardware, a software module executed by a processor, or a combination of the two. For example, one or more of the functional block diagrams shown in the figure and / or one or more combinations of functional block diagrams can correspond to various software modules of the computer program flow or to various hardware modules. These software modules can respectively correspond to the various steps shown in the figure. These hardware modules can be implemented by solidifying these software modules, for example, using a field programmable gate array (FPGA).

[0272] The software module may be located in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. A storage medium may be coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium; or the storage medium may be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The software module may be stored in the memory of the mobile terminal or in a memory card that can be inserted into the mobile terminal. For example, if the device (such as a mobile terminal) uses a large-capacity MEGA-SIM card or a large-capacity flash memory device, the software module may be stored in the MEGA-SIM card or the large-capacity flash memory device.

[0273] One or more of the functional blocks and / or one or more combinations of functional blocks described in the accompanying drawings may be implemented as a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or any appropriate combination thereof for performing the functions described in this application. One or more of the functional blocks and / or one or more combinations of functional blocks described in the accompanying drawings may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in communication with a DSP, or any other such configuration.

[0274] The present application has been described above in conjunction with specific embodiments. However, those skilled in the art should understand that these descriptions are merely illustrative and are not intended to limit the scope of protection of the present application. Those skilled in the art may make various modifications and variations to the present application based on the spirit and principles of the present application, and such modifications and variations are also within the scope of the present application.

[0275] Regarding the implementation methods including the above embodiments, the following additional notes are also disclosed:

[0276] A whole system approach:

[0277] 1. A method for migrating a distributed unit, the method comprising:

[0278] The F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first donor central unit (donor-CU) to the third donor-CU.

[0279] The first donor-CU is different from the third donor-CU.

[0280] The radio resource control (RRC) termination host of the node is the second donor-CU,

[0281] 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 both the first donor-CU and the third donor-CU.

[0282] 2. The method as described in Note 1, wherein the method comprises:

[0283] The first donor-CU notifies the first distributed unit (IAB-DU) of the node of information about the third donor-CU through F1AP signaling.

[0284] 3. The method as described in Note 2, wherein:

[0285] The first donor-CU sends first information to the first IAB-DU to request the second IAB-DU to establish an F1 association with the third donor-CU, where the first information includes information about the third donor-CU.

[0286] The second IAB-DU is a concatenated IAB-DU of the first IAB-DU.

[0287] 4. The method as described in Note 2, wherein:

[0288] The first information uses F1AP signaling,

[0289] The first information is a new information element (IE) in the F1AP signaling, or the first information is sent using a new F1AP process.

[0290] 5. The method as described in Note 2, wherein:

[0291] Information about the third donor-CU includes:

[0292] Transport network layer (TNL) address, and / or base station identifier.

[0293] 6. The method as described in Note 2, wherein the method further comprises:

[0294] The second distributed unit (IAB-DU) of the node sends an F1 SETUP REQUEST message to the third donor-CU.

[0295] 7. The method as described in Supplementary Note 6, wherein:

[0296] The F1 setup 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 and / or base station identifier of the second donor-CU.

[0297] 8. The method as described in Supplementary Note 6, wherein the method further comprises:

[0298] The second IAB-DU receives an F1 SETUP RESPONSE message replied by the third donor-CU.

[0299] 9. The method as described in Supplementary Note 2, wherein the method further comprises:

[0300] The first distributed unit (IAB-DU) notifies the first donor-CU of the successful establishment of the F1 interface with the third donor-CU through F1AP signaling.

[0301] 10. The method as described in Supplementary Note 9, wherein:

[0302] After the F1 establishment between the second IAB-DU and the third donor-CU is completed, 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.

[0303] 11. The method as described in Supplementary Note 9, wherein:

[0304] If 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 fails.

[0305] 12. The method according to Note 10 or 11, wherein:

[0306] The second information or the third information uses F1AP signaling,

[0307] The second information or the third information is a new information element (IE) in the F1AP signaling, or the second information or the third information is sent using a new F1AP process.

[0308] 13. The method as described in Supplementary Note 9, wherein:

[0309] The message of successfully establishing the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU.

[0310] 14. The method according to Supplementary Note 8, wherein the method further comprises:

[0311] The first donor-CU sends a handover request (HANDOVER REQUEST) message to the third donor-CU.

[0312] 15. The method as described in Note 14, wherein:

[0313] The handover request (HANDOVER REQUEST) message includes user equipment context (UE context) information,

[0314] The handover request message is used to apply for handover preparation for the electronic device served by the node.

[0315] 16. The method according to Note 14, wherein the method further comprises:

[0316] If the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU, the third donor-CU sends an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message to the second donor-CU.

[0317] 16a. The method according to Note 16, further comprising:

[0318] The second donor-CU avoids migration of the mobile terminal (IAB-MT) of the node.

[0319] 16b. The method according to Note 16, further comprising:

[0320] The second donor-CU receives an indication message sent by the third donor-CU, instructing the second donor-CU not to perform the migration process of the mobile terminal (IAB-MT) of the node; or receives a notification message sent by the node, indicating that the node is performing DU migration.

[0321] 16c. The method according to Note 16a or 16b, wherein the method further comprises:

[0322] The second donor-CU receives information about DU migration completion sent by the third donor-CU or the node; and

[0323] The second donor-CU performs a migration process of the mobile terminal (IAB-MT) of the node.

[0324] 17. The method as described in Note 16, wherein:

[0325] The IAB transmission migration management request message includes the identification information of the node.

[0326] 18. The method as described in Note 17, wherein:

[0327] The identification information of the node includes a non-F1-terminating node UE Xn interface identifier (non-F1-terminating node UE XnAP ID) and / or a BAP address of the node.

[0328] 19. The method as described in Note 18, wherein:

[0329] The first donor-CU sends an Xn message in advance to inform the third donor-CU of the user equipment Xn interface identifier (UE XnAP ID) of the node in the second donor-CU.

[0330] 19a. The method as described in Note 19, wherein:

[0331] The Xn message is the handover request message.

[0332] 20. The method as described in Supplement 16, wherein:

[0333] The IAB transmission migration management request message includes a traffic profile, and the traffic profile is obtained from the handover request message.

[0334] 21. The method according to Supplementary Note 16, further comprising:

[0335] The second donor-CU sends an IAB transport migration management response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message to the third donor-CU.

[0336] 22. The method as described in Note 21, wherein:

[0337] The IAB transmission migration management response message includes:

[0338] Differentiated Services Code Point (DSCP) and flow label for downstream traffic; and / or

[0339] Uplink non-F1 terminating backhaul information (UL Non-F1Terminating BH Info) used to configure the uplink backhaul mapping configuration of the node.

[0340] 23. The method according to Note 21, further comprising:

[0341] The third donor-CU establishes a user equipment context on the second IAB-DU through a user equipment context setup (UE Context Setup) process of F1AP, and performs uplink backhaul mapping configuration for the node.

[0342] 24. The method according to Note 23, further comprising:

[0343] The third donor-CU generates an IP header for the downlink data based on the differentiated services code point and the flow label information.

[0344] 25. The method according to Note 21, further comprising:

[0345] In the case where the second donor-CU is different from the first donor-CU,

[0346] The second donor-CU sends an IAB transport migration modification request (IAB TRANSPORT MIGRATION MODIFICATION REQUEST) message to the first donor-CU.

[0347] 26. The method as described in Note 25, wherein:

[0348] The IAB transmission migration modification request message includes the identification information of the node,

[0349] The IAB transmits a migration modification request message to request the release of the offloaded traffic.

[0350] 27. The method according to Note 25, further comprising:

[0351] The first donor-CU replies to the second donor-CU with an IAB transport migration modification response (IAB TRANSPORT MIGRATION MODIFICATION RESPONSE) message.

[0352] 28. The method according to Supplementary Note 21, further comprising:

[0353] In the case where the second donor-CU is different from the first donor-CU,

[0354] The first donor-CU sends an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message to the second donor-CU.

[0355] 29. The method as described in Supplementary Note 28, wherein:

[0356] The IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message includes identification information of the node and / or traffic release indication information.

[0357] 30. The method according to Supplementary Note 29, further comprising:

[0358] The second donor-CU replies to the first donor-CU with an IAB transport migration management response (IAB transport migration management response) message.

[0359] 31. The method according to Supplementary Note 23, further comprising:

[0360] The third donor-CU sends a handover request confirmation (HANDOVER REQUEST ACKNOWLEDGE) message to the first donor-CU;

[0361] The first donor-CU switches the terminal device served by the node to the third donor-CU.

[0362] 32. The method according to Note 31, further comprising:

[0363] The F1 connection between the first IAB-DU and the first donor-CU is cleared.

[0364] 33. The method as described in Note 32, wherein:

[0365] The clearing process is initiated by the first IAB-DU or the first donor-CU.

[0366] Method on the IAB-node side:

[0367] 1. A method for migrating a distributed unit, applied to an integrated access backhaul node (IAB-node), comprising:

[0368] The F1 termination host of the node is migrated from the first donor-CU to the third donor-CU.

[0369] The first donor-CU is different from the third donor-CU.

[0370] The radio resource control (RRC) termination host of the node is the second donor-CU,

[0371] 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 both the first donor-CU and the third donor-CU.

[0372] 2. The method as described in Note 1, wherein the method comprises:

[0373] The first distributed unit (IAB-DU) of the node receives information about the third donor-CU sent by the first donor-CU through F1AP signaling.

[0374] 3. The method as described in Note 2, wherein:

[0375] The first IAB-DU receives first information sent by the first donor-CU to request the second IAB-DU to establish an F1 association with the third donor-CU, where the first information includes information about the third donor-CU.

[0376] The second IAB-DU is a concatenated IAB-DU of the first IAB-DU.

[0377] 4. The method as described in Note 2, wherein:

[0378] The first information uses F1AP signaling,

[0379] The first information is a new information element (IE) in the F1AP signaling, or the first information is sent using a new F1AP process.

[0380] 5. The method as described in Note 2, wherein:

[0381] Information about the third donor-CU includes:

[0382] Transport network layer address (TNL) address, and / or base station identifier.

[0383] 6. The method as described in Note 2, wherein the method further comprises:

[0384] A second distributed unit (IAB-DU) of the node sends an F1 SETUP REQUEST message to the third donor-CU, where the second IAB-DU is a concatenated IAB-DU of the first IAB-DU.

[0385] 7. The method as described in Supplementary Note 6, wherein:

[0386] 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 and / or base station identifier of the second donor-CU.

[0387] 8. The method as described in Supplementary Note 6, wherein the method further comprises:

[0388] The second IAB-DU receives an F1 SETUP RESPONSE message replied by the third donor-CU.

[0389] 9. The method as described in Supplementary Note 2, wherein the method further comprises:

[0390] The first distributed unit (IAB-DU) notifies the first donor-CU of the successful establishment of the F1 interface with the third donor-CU through F1AP signaling.

[0391] 10. The method as described in Supplementary Note 9, wherein:

[0392] After the F1 establishment between the second IAB-DU and the third donor-CU is completed, 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.

[0393] 11. The method as described in Supplementary Note 9, wherein:

[0394] If 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 fails.

[0395] 12. The method according to Note 10 or 11, wherein:

[0396] The second information or the third information uses F1AP signaling,

[0397] The second information or the third information is a new information element (IE) in the F1AP signaling, or the second information or the third information is sent using a new F1AP process.

[0398] 13. The method as described in Supplementary Note 9, wherein:

[0399] The message of successfully establishing the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU.

[0400] 14. The method as described in Note 2, wherein:

[0401] The node receives the uplink backhaul mapping configuration performed by the third donor-CU.

[0402] 15. The method as described in Supplementary Note 2, wherein the method further comprises:

[0403] After the migration is completed, the node clears the F1 connection from the first IAB-DU to the first donor-CU.

[0404] 16. The method as described in Note 15, wherein:

[0405] The clearing process is initiated by the first IAB-DU or the first donor-CU.

[0406] 17. The method as described in Supplementary Note 2, wherein the method further comprises:

[0407] The node sends information about the start of DU migration to the second donor-CU.

[0408] 18. The method according to Note 17, further comprising:

[0409] After the migration is completed, the node sends information about the completion of DU migration to the second donor-CU.

[0410] First donor-CU method:

[0411] 1. A distributed unit migration method, applied to a first donor central unit (donor-CU), comprising:

[0412] The F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first donor central unit (donor-CU) to the third donor-CU.

[0413] The first donor-CU is different from the third donor-CU.

[0414] The radio resource control (RRC) termination host of the node is the second donor-CU,

[0415] 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 both the first donor-CU and the third donor-CU.

[0416] 2. The method as described in Note 1, wherein the method comprises:

[0417] The first donor-CU notifies the first distributed unit (IAB-DU) of the node of information about the third donor-CU through F1AP signaling.

[0418] 3. The method as described in Note 2, wherein:

[0419] The first donor-CU sends first information to the first IAB-DU to request the second IAB-DU to establish an F1 association with the third donor-CU, where the first information includes information about the third donor-CU.

[0420] The second IAB-DU is a concatenated IAB-DU of the first IAB-DU.

[0421] 4. The method as described in Note 2, wherein:

[0422] The first information uses F1AP signaling,

[0423] The first information is a new information element (IE) in the F1AP signaling, or the first information is sent using a new F1AP process.

[0424] 5. The method as described in Note 2, wherein:

[0425] Information about the third donor-CU includes:

[0426] Transport network layer address (TNL) address, and / or base station identifier.

[0427] 6. The method as described in Note 2, wherein the method further comprises:

[0428] The first donor-CU receives a message notified by the first distributed unit (IAB-DU) through F1AP signaling regarding the successful establishment of the F1 interface with the third donor-CU.

[0429] 7. The method as described in Supplementary Note 6, wherein:

[0430] After the F1 establishment between the second IAB-DU and the third donor-CU is completed, 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.

[0431] 8. The method as described in Supplementary Note 6, wherein:

[0432] If 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 fails.

[0433] 9. The method as described in Supplement 7 or 8, wherein:

[0434] The second information or the third information uses F1AP signaling,

[0435] The second information or the third information is a new information element (IE) in the F1AP signaling, or the second information or the third information is sent using a new F1AP process.

[0436] 10. The method as described in Supplementary Note 6, wherein:

[0437] The message of successfully establishing the F1 interface with the third donor-CU includes one or more cell identifiers activated by the third donor-CU.

[0438] 11. The method according to Supplementary Note 6, wherein the method further comprises:

[0439] The first donor-CU sends a handover request (HANDOVER REQUEST) message to the third donor-CU.

[0440] 11a. The method as described in Note 1, wherein:

[0441] The first donor-CU sends an Xn message to the third donor-CU to inform the node of the user equipment Xn interface identifier (UE XnAP ID) of the second donor-CU.

[0442] 12. The method as described in Note 11, wherein:

[0443] The handover request (HANDOVER REQUEST) message includes user equipment context (UE context) information,

[0444] The handover request message is used to apply for handover preparation for the electronic device served by the node.

[0445] 13. The method according to Note 11, further comprising:

[0446] In the case where the second donor-CU is different from the first donor-CU,

[0447] The first donor-CU receives an IAB transport migration modification request (IAB TRANSPORT MIGRATION MODIFICATION REQUEST) message sent by the second donor-CU.

[0448] 14. The method as described in Note 13, wherein:

[0449] The IAB transmission migration modification request message includes the identification information of the node,

[0450] The IAB transmits a migration modification request message to request the release of the offloaded traffic.

[0451] 15. The method as described in Note 13, wherein:

[0452] The first donor-CU replies to the second donor-CU with an IAB transport migration modification response (IAB TRANSPORT MIGRATION MODIFICATION RESPONSE) message.

[0453] 16. The method as described in Note 11, wherein:

[0454] In the case where the second donor-CU is different from the first donor-CU,

[0455] The first donor-CU sends an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message to the second donor-CU.

[0456] 17. The method as described in Note 16, wherein:

[0457] The IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message includes identification information of the node and / or traffic release indication information.

[0458] 18. The method as described in Note 17, wherein:

[0459] The first donor-CU receives an IAB transport migration management response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message replied by the second donor-CU.

[0460] 19. The method as described in Note 11, wherein:

[0461] The first donor-CU receives a HANDOVER REQUEST ACKNOWLEDGE message sent by the third donor-CU;

[0462] The first donor-CU switches the terminal device served by the node to the third donor-CU.

[0463] 20. The method as described in Note 19, wherein:

[0464] The F1 connection between the first IAB-DU and the first donor-CU is cleared.

[0465] 21. The method as described in Note 20, wherein:

[0466] The clearing process is initiated by the first IAB-DU or the first donor-CU.

[0467] Third donor-CU method:

[0468] 1. A distributed unit migration method, applied to a third host central unit (donor-CU), comprising:

[0469] The F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first donor central unit (donor-CU) to the third donor-CU.

[0470] The first donor-CU is different from the third donor-CU.

[0471] The radio resource control (RRC) termination host of the node is the second donor-CU,

[0472] 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 both the first donor-CU and the third donor-CU.

[0473] 2. The method as described in Note 1, wherein the method comprises:

[0474] The third donor-CU receives an F1 SETUP REQUEST message sent by the second distributed unit (IAB-DU) of the node.

[0475] 3. The method as described in Note 2, wherein:

[0476] 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 and / or base station identifier of the second donor-CU.

[0477] 4. The method as described in Note 2, wherein the method further comprises:

[0478] The third donor-CU replies with an F1 SETUP RESPONSE message to the second IAB-DU.

[0479] The first IAB-DU is a concatenated IAB-DU of the second IAB-DU.

[0480] 4a. The method as described in Note 1, wherein the method comprises:

[0481] The third donor-CU receives a handover request (HANDOVER REQUEST) message sent by the first donor-CU.

[0482] 4b. The method as described in Note 4a, wherein

[0483] The handover request (HANDOVER REQUEST) message includes user equipment context (UE context) information,

[0484] The handover request message is used to apply for handover preparation for the electronic device served by the node.

[0485] 5. The method as described in Note 2, wherein the method further comprises:

[0486] If the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU, the third donor-CU sends an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message to the second donor-CU.

[0487] 5a. The method as described in Note 5, wherein the method further comprises:

[0488] The third donor-CU sends an indication message to the second donor-CU, instructing the second donor-CU not to perform the migration process of the mobile terminal (IAB-MT) of the node.

[0489] 5b. The method as described in Note 5a, wherein the method further comprises:

[0490] The third donor-CU sends information about DU migration completion to the second donor-CU.

[0491] 6. The method as described in Note 5, wherein:

[0492] The IAB transmission migration management request message includes the identification information of the node.

[0493] 7. The method as described in Supplementary Note 6, wherein:

[0494] The identification information of the node includes a non-F1-terminating node UE Xn interface identifier (non-F1-terminating node UE XnAP ID) and / or a BAP address of the node.

[0495] 8. The method as described in Supplementary Note 7, wherein:

[0496] The third donor-CU receives the Xn message sent by the first donor-CU, where the Xn message informs the node of the user equipment Xn interface identifier (UE XnAP ID) of the second donor-CU.

[0497] 9. The method as described in Note 5, wherein:

[0498] The IAB transmission migration management request message includes a traffic profile, and the traffic profile is obtained from the handover request message.

[0499] 10. The method according to Note 5, further comprising:

[0500] The third donor-CU receives the IAB transport migration management response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message sent by the second donor-CU.

[0501] 11. The method as described in Note 10, wherein:

[0502] The IAB transmission migration management response message includes:

[0503] Differentiated Services Code Point (DSCP) and flow label for downstream traffic; and / or

[0504] Uplink non-F1 terminating backhaul information (UL Non-F1Terminating BH Info) used to configure the uplink backhaul mapping configuration of the node.

[0505] 12. The method according to Supplementary Note 10, further comprising:

[0506] The third donor-CU establishes a user equipment context on the second IAB-DU through a user equipment context setup (UE Context Setup) process of F1AP, and performs uplink backhaul mapping configuration for the node.

[0507] 13. The method according to Note 12, wherein the method further comprises:

[0508] The third donor-CU generates an IP header for the downlink data based on the differentiated services code point and the flow label information.

[0509] 14. The method as described in Note 12, wherein:

[0510] The third donor-CU sends a handover request confirmation (HANDOVER REQUEST ACKNOWLEDGE) message to the first donor-CU.

[0511] Second donor-CU method:

[0512] 1. A distributed unit migration method, applied to a second donor central unit (donor-CU), comprising:

[0513] The F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first donor central unit (donor-CU) to the third donor-CU.

[0514] The first donor-CU is different from the third donor-CU.

[0515] The radio resource control (RRC) termination host of the node is the second donor-CU,

[0516] 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 both the first donor-CU and the third donor-CU.

[0517] 2. The method as described in Note 1, wherein:

[0518] If the base station identifier of the second donor-CU is not the base station identifier of the third donor-CU, the second donor-CU receives the IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message sent by the third donor-CU.

[0519] 3. The method as described in Note 2, wherein:

[0520] The IAB transmission migration management request message includes the identification information of the node.

[0521] 4. The method as described in Note 3, wherein:

[0522] The identification information of the node includes a non-F1-terminating node UE Xn interface identifier (non-F1-terminating node UE XnAP ID) and / or a BAP address of the node.

[0523] 5. The method as described in Note 2, wherein the method further comprises:

[0524] The second donor-CU sends an IAB transport migration management response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message to the third donor-CU.

[0525] 6. The method as described in Note 5, wherein:

[0526] The IAB transmission migration management response message includes:

[0527] The third donor-CU is used to set a Differentiated Services Code Point (DSCP) and a flow label for downlink traffic; and / or

[0528] Uplink non-F1 terminating backhaul information (UL Non-F1 Terminating BH Info) configured for the third donor-CU to configure the uplink backhaul mapping configuration of the node.

[0529] 7. The method as described in Supplementary Note 2, wherein the method further comprises:

[0530] The second donor-CU avoids migration of the mobile terminal (IAB-MT) of the node.

[0531] 8. The method as described in Supplementary Note 2, wherein the method further comprises:

[0532] The second donor-CU receives an indication message sent by the third donor-CU, instructing the second donor-CU not to perform the migration process of the mobile terminal (IAB-MT) of the node; or receives a notification message sent by the node, indicating that the node is performing DU migration.

[0533] 8a. The method according to Note 7 or 8, wherein the method further comprises:

[0534] The second donor-CU receives information about DU migration completion sent by the third donor-CU or the node; and

[0535] The second donor-CU performs a migration process of the mobile terminal (IAB-MT) of the node.

[0536] 9. The method as described in Supplementary Note 2, wherein the method further comprises:

[0537] In the case where the second donor-CU is different from the first donor-CU,

[0538] The second donor-CU sends an IAB transport migration modification request (IAB TRANSPORT MIGRATION MODIFICATION REQUEST) message to the first donor-CU.

[0539] 10. The method as described in Supplementary Note 9, wherein:

[0540] The IAB transmission migration modification request message includes the identification information of the node,

[0541] The IAB transmits a migration modification request message to request the release of the offloaded traffic.

[0542] 11. The method as described in Supplementary Note 9, wherein:

[0543] The second donor-CU receives an IAB transport migration modification response (IAB TRANSPORT MIGRATION MODIFICATION RESPONSE) message replied by the first donor-CU.

[0544] 12. The method as described in Note 2, wherein:

[0545] In the case where the second donor-CU is different from the first donor-CU,

[0546] The second donor-CU receives an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message sent by the first donor-CU.

[0547] 13. The method as described in Note 12, wherein:

[0548] The IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message includes identification information of the node and / or traffic release indication information.

[0549] 14. The method as described in Note 12, wherein:

[0550] The second donor-CU replies to the first donor-CU with an IAB transport migration management response (IAB transport migration management response) message.

Claims

1. A control device for distributed unit migration, applied to an integrated access backhaul node (IAB-node), the device comprising a first processing unit, the first processing unit controlling the node to perform the following operations: The F1 termination host of the node is migrated from the first host central unit (donor-CU) to the third donor-CU, in, The first donor-CU is different from the third donor-CU, The radio resource control (RRC) termination host of the node is the 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 both the first donor-CU and the third donor-CU.

2. The device according to claim 1, wherein: The first processing unit controls the node to perform the following operations: The first distributed unit (IAB-DU) of the node receives information about the third donor-CU sent by the first donor-CU through F1AP signaling, The first IAB-DU receives first information sent by the first donor-CU to request the second IAB-DU to establish an F1 association with the third donor-CU, wherein the first information includes information of the third donor-CU. The second IAB-DU is a concatenated IAB-DU of the first IAB-DU.

3. The device as claimed in claim 2, wherein: The first processing unit controls the node to further perform the following operations: The second distributed unit (IAB-DU) of the node sends an F1 SETUP REQUEST message to the third donor-CU, 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.

4. The device according to claim 2, wherein: The first processing unit controls the node to perform the following operations: The first distributed unit (IAB-DU) notifies the first donor-CU of the successful establishment of the F1 interface with the third donor-CU through F1AP signaling.

5. The device according to claim 1, wherein: The first processing unit controls the node to perform the following operations: After the migration is completed, the node clears the F1 connection from the first IAB-DU to the first donor-CU.

6. A control device for distributed unit migration, applied to a first host central unit (donor-CU), the device comprising a second processing unit, the second processing unit controlling the first donor-CU so that an F1 termination host of an access backhaul integrated node (IAB-node) migrates from the first host central unit (donor-CU) to a third donor-CU, in, The first donor-CU is different from the third donor-CU, The radio resource control (RRC) termination host of the node is the 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 both the first donor-CU and the third donor-CU.

7. The device according to claim 6, wherein: The second processing unit controls the first donor-CU to perform the following operations: The first donor-CU notifies the first distributed unit (IAB-DU) of the node of information about the third donor-CU through F1AP signaling.

8. The device according to claim 7, wherein: The first donor-CU sends first information to the first IAB-DU to request the second IAB-DU to establish an F1 association with the third donor-CU, wherein the first information includes information of the third donor-CU. The second IAB-DU is a concatenated IAB-DU of the first IAB-DU.

9. The device according to claim 7, wherein: Information about the third donor-CU includes: Transport network layer address (TNL) address, and / or base station identifier.

10. The device of claim 6, wherein: The second processing unit controls the first donor-CU to further perform the following operations: The first donor-CU sends a handover request (HANDOVER REQUEST) message to the third donor-CU, The handover request (HANDOVER REQUEST) message includes user equipment context (UE context) information, The switching request message is used to apply for switching preparation for the electronic device served by the node.

11. The device according to claim 6, wherein: The first donor-CU sends an Xn message to the third donor-CU to inform the node of the user equipment Xn interface identifier (UE XnAP ID) of the second donor-CU.

12. The device of claim 6, wherein: The second processing unit controls the first donor-CU to further perform the following operations: The first donor-CU receives an IAB transport migration modification request (IAB TRANSPORT MIGRATION MODIFICATION REQUEST) message sent by the second donor-CU, where the IAB transport migration modification request message requests to release the offloaded traffic.

13. The device of claim 6, wherein: The second processing unit controls the first donor-CU to further perform the following operations: The first donor-CU sends an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message to the second donor-CU, wherein the IAB transport migration management request message requests the release of the unloaded traffic.

14. A control device for distributed unit migration, applied to a third host central unit (donor-CU), the device comprising a third processing unit, the third processing unit controlling the third donor-CU so that the F1 termination host of the access backhaul integrated node (IAB-node) migrates from the first host central unit (donor-CU) to the third donor-CU, in, The first donor-CU is different from the third donor-CU, The radio resource control (RRC) termination host of the node is the 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 both the first donor-CU and the third donor-CU.

15. The device of claim 14, wherein: The third processing unit controls the third donor-CU to perform the following operations: The third donor-CU receives a handover request (HANDOVER REQUEST) message sent by the first donor-CU, The handover request (HANDOVER REQUEST) message includes user equipment context (UE context) information, The switching request message is used to apply for switching preparation for the electronic device served by the node.

16. The device of claim 15, wherein: The third processing unit controls the third donor-CU to further perform the following operations: The third donor-CU sends an IAB transport migration management request (IAB TRANSPORT MIGRATION MANAGEMENT REQUEST) message to the second donor-CU.

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

18. The device of claim 16, wherein: The IAB transmission migration management request message includes a traffic profile, and the traffic profile is obtained from the switching request message.

19. The device of claim 16, wherein: The third processing unit controls the third donor-CU to further perform the following operations: The third donor-CU receives an IAB transport migration management response (IAB TRANSPORT MIGRATION MANAGEMENT RESPONSE) message sent by the second donor-CU, The IAB transmission migration management response message includes: Differentiated Services Code Point (DSCP) and flow label for downstream traffic; and / or Uplink non-F1 terminating backhaul information (UL Non-F1Terminating BH Info) used to configure the uplink backhaul mapping configuration of the node.

20. The device of claim 19, wherein: The third processing unit controls the third donor-CU to further perform the following operations: The third donor-CU establishes a user equipment context on the second IAB-DU through a user equipment context establishment (UE Context Setup) process of F1AP, and performs uplink backhaul mapping configuration for the node.

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