IAB Donor Device and Transmission Transition Management Method

Abstract

An embodiment of the present invention provides an IAB donor device and a transmission transition management method, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor-CU, and resources for serving traffic of the IAB node in a topology of a second donor-CU have already been established, the method includes: a first donor-CU sending a first transmission transition release request for traffic to a second donor-CU, the first transmission transition release request being used to request to release resources for serving the traffic in the topology of the second donor-CU.

Description

[Technical field]

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

[0002] The deployment of future seamless cellular networks requires highly flexible and ultra-dense new radio (NR) cell deployment, and ultra-dense networks are one of the goals of 5G, so the deployment of NR networks that do not require wired backhaul is very important to realize 5G ultra-dense networks. As 5G mmWave reduces cell coverage, wireless self-backhaul systems require multiple hops to meet the deployment needs. With 5G's high bandwidth, massive multiple-input multiple-output (MIMO) and beam systems, 5G makes it easier to develop wireless self-backhaul systems for ultra-dense NR cells than LTE. To develop such a multi-hop system with wireless self-backhaul, 3GPP has started research and standardization of the Integrated access and backhaul (IAB) project in Rel-16.

[0003] Figure 1 is a diagram showing an IAB system. As shown in Figure 1, in the IAB system, access and backhaul adopt wireless transmission over the NR Uu air interface, a relay node simultaneously supports the functions of access and backhaul, the relay node multiplexes the access link and the backhaul link in the time domain, frequency domain or spatial domain, and the access link and the backhaul link can use the same or different frequency bands.

[0004] In the IAB network architecture, the relay node refers to the IAB-node, which supports access and backhaul functions simultaneously. The last one-hop access node on the network side is called the IAB-donor, which supports gNB function and supports IAB-node access. All UE data can be backhauled to the IAB-donor via the IAB-node by one hop or multiple hops.

[0005] The function of the IAB-node is divided into two parts, one part is the gNB-DU function, called IAB-DU (distributed unit), and the other part is the UE function, called IAB-MT (mobile equipment). The IAB-DU realizes the function of the network side equipment, is connected to the downstream child IAB-node (or abbreviated as child node), provides NR air interface access for the UE and the downstream child IAB-node, and establishes an F1 connection with the IAB donor-CU (donor centralized unit). The IAB-MT realizes a part of the function of the terminal equipment, is connected to the upstream parent IAB-node (or abbreviated as parent node) or IAB donor-DU, and includes the functions of the physical layer, layer 2, RRC (Radio Resource Control), and NAS (Non-Access Stratum), and is indirectly connected to the IAB Donor-CU and the core network (Core Network, CN).

[0006] In the IAB system, an IAB-node can access the network in SA (Standalone) mode or non-SA (EN-DC, E-UTRA-NR Dual Connectivity) mode. Figure 2 shows the IAB architecture in SA mode. Figure 3 shows the IAB architecture in EN-DC mode.

[0007] Figure 4 shows one IAB-node, a parent IAB-node, and a child IAB-node. As shown in Figure 4, the IAB-DU of the IAB node is connected to the IAB-MT of the child node as the network side, and the IAB-MT of the IAB node is connected to the IAB-DU of the parent node as the terminal side.

[0008] Figure 5 shows the F1 user plane (F1-U) protocol stack between the IAB-DU and the IAB donor-CU. Figure 6 shows the F1 control plane (F1-C) protocol stack between the IAB-DU and the IAB donor-CU. As shown in Figures 5 and 6, F1-U and F1-C are established on top of the transport (IP) layer between the IAB-DU and the IAB donor-CU, and two hop wireless backhaul and one hop wired backhaul are shown in Figures 5 and 6.

[0009] In the backhaul link, the transport (IP) layer is carried by the Backhaul Adaptation Protocol (BAP) sublayer, the BAP entity in the IAB-node realizes the routing function of the IAB system, and the IAB donor-CU provides the routing table. The BAP PDU (Protocol Data Unit) is carried on the RLC (Radio Link Control) channel of the backhaul link, and multiple RLC channels of the backhaul link may be configured by the IAB-donor to carry tasks (traffic) with different priorities and QoS (Quality of Service), and the BAP entity maps the BAP PDU to different backhaul RLC channels.

[0010] It should be noted that the introduction of the above background art is intended to clearly and completely explain the technical solutions of the present invention, and to facilitate understanding thereof by those skilled in the art, and these technical solutions are described in the background art of the present invention, and therefore should not be construed as being known to those skilled in the art. Summary of the Invention [Problem to be solved by the invention]

[0011] The inventor has found that after the traffic of a migrating node and its child nodes is migrated from the network topology of a first donor-CU to the network topology of a second donor-CU, for example, when the network load of the second donor-CU is relatively large, it may be necessary to migrate (revoke) the traffic already migrated to the second donor-CU back to the first donor-CU. Therefore, it is necessary to release resources for serving the migration traffic (traffic for migration) in the topology of the second donor-CU, and establish resources for serving the traffic in the topology of the first donor-CU. In addition, it is necessary to release resources for serving the migration traffic in the topology of the second donor-CU when the traffic is terminated. However, there is no corresponding solution so far as to how to release the transmission resources of the traffic.

[0012] To address at least one of the above problems, an embodiment of the present invention provides an IAB donor device and transmission transition management method. [Means for solving the problem]

[0013] According to an aspect of an embodiment of the present invention, a transmission transition management method is provided, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor concentration unit (donor-CU), and resources for serving traffic of the IAB node in a topology of a second donor-CU have been established, the method comprising: the first donor-CU sending a first transmission transition release request for the traffic to the second donor-CU; Wherein, the first transmission transition release request is used to request to release resources for serving the traffic in the topology of the second donor-CU.

[0014] According to another aspect of an embodiment of the present invention, a transmission transition management method is provided, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor concentration unit (donor-CU), and resources for serving traffic of the IAB node in a topology of a second donor-CU have been established, the method comprising: the second donor-CU receiving a first transmission transition release request for the traffic of the first donor-CU; Wherein, the first transmission transition release request is used to request to release resources for serving the traffic in the topology of the second donor-CU.

[0015] According to another aspect of an embodiment of the present invention, a transmission transition management method is provided, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor-CU, and resources for serving traffic of the IAB node in a topology of a second donor-CU have been established, the method comprising: the second donor-CU sends a second transmission transition release request for the traffic to the first donor-CU; and The second donor-CU releases resources for serving the traffic in the second donor-CU's topology.

[0016] According to another aspect of an embodiment of the present invention, a transmission transition management method is provided, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor-CU, and resources for serving traffic of the IAB node in a topology of a second donor-CU have been established, the method comprising: the first donor-CU receiving a second transmission transition release request for the traffic of the second donor-CU; Wherein, the second donor-CU releases resources for serving the traffic in the second donor-CU's topology.

[0017] According to another aspect of an embodiment of the present invention, an IAB donor device is provided, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor concentration unit (donor-CU), and resources for serving traffic of the IAB node in a topology of a second donor-CU have already been established, the device comprising: a transmitter for transmitting a first transmission transition release request for the traffic to the second donor-CU; Wherein, the first transmission transition release request is used to request to release resources for serving the traffic in the topology of the second donor-CU.

[0018] According to another aspect of an embodiment of the present invention, an IAB donor device is provided, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor concentration unit (donor-CU), and resources for serving traffic of the IAB node in a topology of a second donor-CU have already been established, the device comprising: a receiving unit for receiving a first transmission transition release request for the traffic of the first donor-CU transmission; Wherein, the first transmission transition release request is used to request to release resources for serving the traffic in the topology of the second donor-CU.

[0019] According to another aspect of an embodiment of the present invention, an IAB donor device is provided, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor-CU, and resources for serving traffic of the IAB node in a topology of a second donor-CU have already been established, the device comprising: a transmitter for transmitting a second transmission transition release request for the traffic to the first donor-CU; and A processor for releasing resources for serving the traffic in the topology of the second donor-CU.

[0020] According to another aspect of an embodiment of the present invention, an IAB donor device is provided, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor-CU, and resources for serving traffic of the IAB node in a topology of a second donor-CU have already been established, the device comprising: a receiving unit for receiving a second transmission transition release request for the traffic of the second donor-CU transmission; Wherein, the second donor-CU releases resources for serving the traffic in the second donor-CU's topology.

[0021] According to another aspect of an embodiment of the present invention, an IAB system is provided, the IAB system including a first donor concentration unit and a second donor concentration unit, The first donor concentrating unit sends a first transmission transition release request for traffic, in which the first transmission transition release request is used to request to release resources for serving the traffic in the topology of a second donor-CU, and the second donor concentrating unit receives the first transmission transition release request; or The second donor concentration unit sends a second transmission transition release request for the traffic and releases resources for serving the traffic in the topology of the second donor-CU, and the first donor concentration unit receives the second transmission transition release request. Effect of the Invention

[0022] The advantageous effects of the embodiment of the present invention are at least as follows: a first donor-CU sends a first transmission transition release request for traffic to a second donor-CU, where the first transmission transition release request is used to request the second donor-CU to release resources for serving the traffic in the topology of the second donor-CU, so that the second donor-CU can release the transmission resources for serving the traffic, allowing the traffic to be migrated to the topology of the first donor-CU or the traffic transmission to be terminated, thereby improving system efficiency and performance.

[0023] Specific embodiments of the present invention are disclosed in detail below with reference to the following description and drawings, which show how the principles of the present invention may be employed, but are not limited in scope to these embodiments, which may include various changes, modifications, and alternatives within the scope of the appended claims.

[0024] Additionally, features described and / or illustrated in one embodiment may be used in the same or similar manner in one or more other embodiments, may be combined with features in the other embodiments, or may be substituted for features in the other embodiments.

[0025] It should be noted that terms such as "comprise / have" when used in this specification refer to the presence of a feature, element, step, or assembly, but do not exclude the presence or addition of one or more other features, elements, steps, or assemblies. [Brief description of the drawings]

[0026] Elements and features described in one drawing or one embodiment of the invention may be combined with elements and features shown in one or more other drawings or embodiments, and in the drawings, like reference numerals are used to indicate corresponding parts in the several drawings and to indicate corresponding parts used in several embodiments.

[0027] The included drawings are used to provide a further understanding of the embodiments of the present invention, and these drawings constitute a part of this specification, illustrate the embodiments of the present invention, and together with the written description, are used to explain the principles of the present invention. Also, it is obvious that the drawings described below are only for illustrating some embodiments of the present invention, and a person skilled in the art can derive other drawings based on these drawings without creative labor. [Figure 1] FIG. 1 illustrates an IAB system. [Diagram 2] A diagram showing the IAB architecture in SA mode. [Diagram 3] A diagram showing the IAB architecture in EN-DC mode. [Figure 4] FIG. 2 is a diagram showing a parent node (parent IAB-node) and a child node (child IAB-node). [Diagram 5] FIG. 2 illustrates the F1-U protocol stack of the IAB system. [Figure 6] FIG. 2 illustrates the F1-C protocol stack of the IAB system. [Figure 7] FIG. 1 illustrates routing in an IAB system. [Figure 8] FIG. 1 illustrates network topology adaptation. [Figure 9] FIG. 2 is a diagram illustrating an example of a transmission transition in an embodiment of the present invention. [Figure 10] FIG. 2 illustrates a transmission transition management method according to an embodiment of the present invention. [Figure 11] A diagram showing the signaling flow of transmission transition release in an embodiment of the present invention. [Figure 12] FIG. 10 illustrates another transmission transition management method in an embodiment of the present invention. [Figure 13] FIG. 10 illustrates another transmission transition management method in an embodiment of the present invention. [Figure 14] A figure showing another signaling flow of transmission transition release in an embodiment of the present invention. [Figure 15]FIG. 10 illustrates another transmission transition management method in an embodiment of the present invention. [Figure 16] FIG. 1 illustrates an IAB donor device in accordance with an embodiment of the present invention. [Figure 17] FIG. 13 illustrates another IAB donor device in accordance with an embodiment of the present invention. [Figure 18] FIG. 13 illustrates another IAB donor device in accordance with an embodiment of the present invention. [Figure 19] FIG. 13 illustrates another IAB donor device in accordance with an embodiment of the present invention. [Figure 20] FIG. 2 illustrates an IAB device in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The above and other features of the present invention will become apparent from the following detailed description and the accompanying drawings, in which: While the specification and drawings disclose certain embodiments of the present invention, these are illustrative of only some of the embodiments which may employ the principles of the present invention, and it is to be understood that the present invention is not limited to the described embodiments, but rather includes all modifications, variations and alternatives which fall within the scope of the appended claims.

[0029] In an embodiment of the present invention, the term "communication network" or "wireless communication network" may refer to a network conforming to any communication standard, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), etc.

[0030] Additionally, communications between devices in the communications system may be performed according to any stage of communications protocol, including, but not limited to, the following communications protocols: 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G, New Radio (NR), and / or other conventional or future developed communications protocols.

[0031] In the embodiment of the present invention, the term "network equipment" refers to an apparatus that connects a terminal equipment to a communication network and provides services to the terminal equipment, for example, in a communication system. The network equipment may include, but is not limited to, a "node" and / or a "donor" under the IAB architecture, a base station (BS), an access point (AP), a transmission reception point (TRP), a broadcast transmitter, a mobile management entity (MME), a network gateway, a server, a radio network controller (RNC), a base station controller (BSC), etc.

[0032] Among them, the base station may include, but is not limited to, the following: Node B (NodeB or NB), evolved Node B (eNodeB or eNB), 5G base station (gNB), etc., and may further include RRH (Remote Radio Head), RRU (Remote Radio Unit), relay, or low power node (e.g., femto, pico, etc.). The term "base station" may also include some or all of the functions thereof, and each base station can provide communication coverage for a specific geographical area. For example, a 5G base station gNB may include one gNB CU and one or more gNB DUs, in which a CU / DU is a logical node of a gNB having some functions of a gNB. The term "cell" may refer to a base station and / or its coverage area, depending on the context in which the term is used.

[0033] In the embodiment of the present invention, the term "User Equipment" (UE) or "Terminal Equipment" (TE) refers to a device that accesses a communication network and receives services from the network, for example, through a network device. The user equipment may be fixed or mobile, and may also be called a mobile station (MS), a terminal, a subscriber station (SS), an access terminal (AT), a station, etc. For example, a terminal equipment served by an IAB node or an IAB donor under the IAB architecture.

[0034] Among these, user equipment may include, but is not limited to, the following: a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a mobile device, a machine type communication device, a laptop computer, a cordless telephone, a smartphone, a smart watch, a digital camera, etc.

[0035] Furthermore, in a scenario such as the Internet of Things (IoT), the user equipment may also be a monitoring or measuring device or apparatus, including, but not limited to, a Machine Type Communication (MTC) terminal, an in-vehicle communication terminal, a Device to Device (D2D) terminal, a Machine to Machine (M2M) terminal, etc.

[0036] The routing function of the IAB system is realized by the BAP layer, and each IAB-node stores the BH routing configuration and the BH RLC channel mapping configuration. The BAP entity performs routing based on the routing configuration, the RLC channel mapping configuration, and the routing ID in the BAP layer data packet header. The Routing ID includes the destination BAP address and the route ID (ID / identifier).

[0037] The routing configuration includes a mapping relationship between the Routing ID and the next-hop node BAP address. The RLC channel mapping configuration includes a mapping relationship between the prior-hop node BAP address, the ingress link RLC channel ID, the next-hop node BAP address, and the egress link RLC channel ID.

[0038] Figure 7 is a diagram of IAB system routing. As shown in Figure 7, for each data packet, the next hop node BAP address can be found from the routing configuration according to the routing ID in the data packet header. The previous hop node BAP address and the ingress link RLC channel ID are all known. In this way, after the next hop node BAP address is determined, the egress link RLC channel ID can be found according to the previous hop node BAP address + ingress link RLC channel ID + next hop node BAP address through the RLC channel mapping configuration.

[0039] The IAB-donor DU stores the BH routing configuration and the Downlink Traffic to BH RLC Channel Mapping Configuration. The IAB-donor DU performs routing based on the routing configuration, the RLC channel mapping configuration, and the Routing ID in the BAP layer data packet header. The routing configuration includes the mapping relationship between the Routing ID and the next hop node address. The downlink RLC channel mapping configuration includes the mapping relationship between the target IP address, the DSCP (Differentiated Services Code Point), the next hop node address, and the egress link RLC channel ID.

[0040] For each downlink data packet arriving at the IAB-donor DU, the IAB-donor DU can find the next-hop node address from the routing configuration according to the Routing ID in the data packet header. Thus, after determining the next-hop node address, it can find the egress link RLC channel ID from the downlink RLC channel mapping configuration according to the IP address and DSCP of the data packet.

[0041] The access IAB node stores uplink backhaul information (BH information), which includes the routing ID used by the traffic, the uplink backhaul RLC channel ID, and the next-hop node address. The access IAB node sets the routing ID in the BAP layer data packet header of the uplink traffic based on the uplink BH information, and selects the BH RLC channel and the next-hop node for transmitting the uplink traffic.

[0042] The above is an exemplary description of the routing and BH RLC channel mapping of the IAB system, and the network topology update of the IAB system will be further described below. Rel-16 NR has already standardized the topology adaptation process when an IAB-node moves under the same donor-CU.

[0043] Figure 8 illustrates intra-CU topology adaptation. When the IAB-node changes its parent node (from IAB-node 1 to IAB-node 2), the donor-CU configures path transition related configuration for the IAB-node through RRC reconfiguration information, allowing the IAB-node to perform F1 transmission path transition.

[0044] The route transition related configuration includes updating the default backhaul RLC channel for uplink F1-C, F1-U and non-F1 data, updating the default BAP routing ID, and updating the IP address for routing to Donor-DU. When the IAB-node accesses a new parent node, it starts applying the above route transition related configuration, and the child nodes of the IAB-node also perform route transition related configuration in the same manner.

[0045] 3GPP Rel-17 supports network topology update and backhaul (BH) Radio Link Failure (RLF) recovery processes when an IAB-node moves under a different donor-CU, and the IAB-node can switch or re-establish a parent node serving a source donor-CU (which may be called an F1-terminating CU or a first donor-CU) to a parent node serving a target donor-CU (which may be called a non-F1-terminating CU or a second donor-CU), and all of the IAB-node's traffic (and its child nodes' traffic) needs to be migrated to the topology of the non-F1-terminating CU. Rel-17 also supports a topology redundancy process when an IAB-node establishes a dual connection with a non-F1-terminating CU, and the transmission path of some of the IAB-node's traffic can be migrated to the topology of the non-F1-terminating CU.

[0046] After the IAB-node is switched / RLF restored from donor- CU 1 (F1-terminating CU) to donor-CU 2 (non-F1-terminating CU), or after the RRC connection with donor-CU 2 is increased, only the RRC connection of the IAB-MT goes to donor- CU 2, and the F1 interface is still terminated in donor- CU 1, at this time the IAB-node may be referred to as a boundary node. Because the RRC connections of its serving child nodes and UEs still belong to donor- CU 1, and the F1 interfaces of the child nodes are also terminated in donor- CU 1, the child nodes of the boundary node still belong to the topology of donor-CU 1.

[0047] In order for the uplink traffic of the child node to be transmitted in the topology of donor-CU 2, the boundary node needs to replace the routing ID (destination address is the donor-DU BAP address of donor-CU 1) of the uplink traffic belonging to the topology of donor-CU 1 with the routing ID (destination address is the donor-DU BAP address of donor-CU 2) of the uplink traffic belonging to the topology of donor-CU 2. In order for the downlink traffic of the child node to be transmitted in the topology of donor-CU 2, the boundary node needs to replace the routing ID (destination address is the donor DU BAP address of donor-CU 2) of the downlink traffic belonging to the topology of donor-CU 1 with the routing ID (destination address is the donor DU BAP address of donor-CU 1) of the downlink traffic. In addition, the uplink traffic of the boundary node itself needs to be updated to the routing ID belonging to the topology of donor-CU 2.

[0048] 9 is a diagram illustrating transmission transfer in an embodiment of the present invention. As shown in FIG. 9, the IAB-MT of IAB node 3 is transferred from donor-CU 1 to donor-CU 2. When the traffic of the child node is transferred to the topology of donor-CU 2, the network device can set the mapping relationship of the routing ID between the topologies (e.g., BAP Header Rewriting information) to the boundary node.

[0049] When the boundary node forwards uplink data to a parent node in the topology of donor-CU2, it needs to replace the routing ID belonging to donor-CU1 with the routing ID belonging to donor-CU2, and then perform routing selection and BH RLC channel selection based on the replaced routing ID. Therefore, the network device can set, in the boundary node, a routing table belonging to the topology of donor-CU2 (before switching, only the routing table of the topology of donor-CU1 is set in the boundary node) and a BH RLC channel mapping table from the topology of donor-CU1 to the topology of donor-CU2.

[0050] Similarly, when forwarding downlink data, routing and BH RLC channel selection need to be performed based on the replaced routing ID, so the network device can configure a downlink BH RLC channel mapping table from the topology of donor-CU 2 to the topology of donor-CU 1 in the boundary node.

[0051] When traffic of the boundary node is migrated to the topology of donor-CU 2, the network device needs to configure uplink backhaul information belonging to the topology of donor-CU 2 to the boundary node, and the information includes a routing ID, an uplink backhaul RLC channel ID, and a next-hop node address.

[0052] When some or all of the traffic transmission is shifted to the donor-CU 2 topology, the donor-CU 2 topology needs to establish resources to serve the traffic, such as configuring a backhaul BH RLC channel and / or BAP sublayer routing for the traffic on a path in the donor-CU 2 topology.

[0053] Donor-CU 1 sends a transmission transition establishment request to donor-CU 2 to configure a routing table belonging to donor-CU 2's topology and a BH RLC channel mapping table between the topologies of the two donor-CUs in the boundary node, and to establish resources for serving transition traffic in donor-CU 2's topology.

[0054] Donor-CU 1 sends to Donor-CU 2 the following information of the traffic flow to be traversed for each request and the IP address request (including the donor-DU BAP address and the IP address anchored to the donor-DU in Donor-CU 1's topology): - Traffic signs; - Traffic quality of service (QoS) information or traffic type and - In addition, for the traffic flow of the child node, it is necessary to further transmit the routing ID and BH RLC channel in the topology of donor-CU 1 (including the egress routing ID and egress BH RLC channel of the downlink traffic, and the ingress routing ID and ingress BH RLC channel of the uplink traffic).

[0055] Donor-CU 2 sends to Donor-CU 1 the following information (for each traffic flow) and IP address response (including the donor-DU BAP address in Donor-CU 1's topology and the IP address anchored to Donor-DU of Donor-CU 2): - Traffic signs; - a routing ID and a BH RLC channel in the topology of donor-CU 2 of the traffic (including an ingress routing ID and an ingress BH RLC channel of the downlink traffic, or an egress routing ID and an egress BH RLC channel of the uplink traffic); - the BAP address of the previous hop in the topology of donor-CU 2 for downlink traffic; - the BAP address of the next hop in the topology of donor-CU 2 for uplink traffic; - QoS mapping information used by downlink traffic (e.g. DSCP or IPv6 flow label) It is.

[0056] In the embodiment of the present invention, unless otherwise specified, the IAB node device includes a transition node or a child node thereof. In addition, "resources for serving the traffic of the IAB node in the topology of the donor-CU have been established" may be expressed as "the traffic of the IAB node has been transitioned to the topology of the donor-CU", and the present invention is not limited to these expressions. The embodiment of the present invention will be further described below.

[0057] <Example of the first aspect> In an embodiment of the present invention, a transmission transition management method is provided, which is described from a first donor concentration unit (donor-CU), in which an IAB-DU of an IAB node maintains an F1 connection with a first donor concentration unit (donor-CU), and resources for serving the traffic of the IAB node in the topology of a second donor-CU have already been established.

[0058] 10 is a diagram showing a transmission transition management method in an embodiment of the present invention. As shown in FIG. 10, the method includes the following steps:

[0059] 1001: A first donor-CU sends a first transmission transition release request for the traffic to a second donor-CU, in which the first transmission transition release request is used to request to release resources for serving the traffic in the topology of the second donor-CU.

[0060] It should be noted that the above-mentioned FIG. 10 is only for illustrative purposes of the embodiment of the present invention, and the present invention is not limited thereto. For example, the execution order between each operation (step) can be appropriately adjusted, or some operations can be added or removed. Those skilled in the art can make appropriate modifications based on the above-mentioned contents without being limited to the description of the above-mentioned FIG. 10.

[0061] In some embodiments, the IAB-MT of the IAB node maintains an RRC connection with the second donor-CU, e.g., the IAB-MT of the transition node maintains an RRC connection with the second donor-CU, or the IAB-MT of the IAB node maintains an RRC connection with the first donor-CU, e.g., a child node of the transition node maintains an RRC connection with the first donor-CU.

[0062] In some embodiments, the traffic includes one or a combination of the following, including, but not limited to, F1 control plane (F1-C) traffic, F1 user plane (F1-U) traffic, and non-F1 traffic.

[0063] In some embodiments, the first donor-CU sends a first transmission transition release request for the traffic to the second donor-CU when transitioning the traffic from the topology of the second donor-CU to the topology of the first donor-CU or when the traffic terminates.

[0064] In some embodiments, the first donor-CU sends the first transport migration release request through the first transport migration management request information, although the present invention is not limited thereto and the transport migration release request may be carried by other information.

[0065] This allows the first transmission transition release request to release the traffic transmission transition setting and reduce or avoid the problem of data dropping, thereby improving system efficiency and performance.

[0066] The following describes an example of migrating traffic from the topology of the second donor-CU to the topology of the first donor-CU.

[0067] In some embodiments, when the traffic is transitioned from the topology of the second donor-CU to the topology of the first donor-CU, the first donor-CU configures the IAB node to update the uplink BH information of the traffic.

[0068] For example, when the traffic of the transition node is transitioned from the topology of the second donor-CU to the topology of the first donor-CU, the first donor-CU configures the transition node to update the uplink BH information of the traffic.

[0069] In some embodiments, when migrating the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the first donor-CU configures the IAB node to release at least one of the following: BAP header rewrite information between the topology of the first donor-CU and the topology of the second donor-CU, routing information in the topology of the second donor-CU, and BH RLC channel mapping information between the topology of the first donor-CU and the topology of the second donor-CU.

[0070] After the traffic of the child node is migrated to the first donor-CU, the migration node needs to release the configuration information between topologies, so the migration node may be configured to release one or any two or all of the following: release of BAP header rewrite information, release of routing information, and release of RLC channel mapping configuration, and the present invention is not limited thereto.

[0071] For example, when migrating a child node's traffic from the topology of the second donor-CU to the topology of the first donor-CU, the first donor-CU configures the migration node to release at least one of the following: BAP header rewrite information between the topology of the first donor-CU and the topology of the second donor-CU, routing information in the topology of the second donor-CU, and BH RLC channel mapping information between the topology of the first donor-CU and the topology of the second donor-CU.

[0072] In some embodiments, when transitioning the traffic from the second donor-CU's topology to the first donor-CU's topology, the first donor-CU configures the IAB node with an augmentation of routing information in the first donor-CU's topology and / or BH RLC channel mapping information in the first donor-CU's topology.

[0073] For example, for the uplink and / or downlink traffic of the child node migrated to the first donor-CU, configure the migration node with an increase in routing information or BH RLC channel mapping information in the topology of the first donor-CU.

[0074] In some embodiments, the first donor-CU configures an IP address for the IAB node that is anchored to the donor-DU of the first donor-CU.

[0075] For example, the donor-DU of the first donor-CU has a source IP address filtering function, i.e., it can drop uplink data containing IP addresses assigned by other donor-DUs. In this case, when the traffic of the transition node is migrated to the topology of the first donor-CU, the transition node needs to set the IP address carried by the uplink traffic to the IP address assigned by the donor-DU of the first donor-CU. Therefore, the first donor-CU sets the IP address assigned by the donor-DU of the topology of the first donor-CU to the transition node.

[0076] Although the traffic (including uplink and downlink traffic) routing ID of the child node is always the routing ID belonging to the topology of the first donor-CU, when the traffic of the child node is migrated to the topology of the first donor-CU, the IP address anchored to the donor-DU of the second donor-CU needs to be replaced with the IP address anchored to the donor-DU of the first donor-CU. Since the child node selects the IP address to use based on the address of the donor-DU of the first donor-CU, the setting for the IP address of the traffic needs to be made for the BAP address of the donor-DU of the first donor-CU, including replacing the IP address anchored to the donor-DU of the second donor-CU with the IP address anchored to the donor-DU of the first donor-CU.

[0077] In an embodiment of the present invention, an "IP address anchored to IAB donor-DU" may be understood as an "IP address assigned by the donor-DU" or a "Transport Network Layer (TNL) address(es) that is (are) routable via the IAB-donor-DU", and these terms are interchangeable and the present invention is not limited thereto.

[0078] In some embodiments, the first donor-CU configures the BAP sublayer routing and / or backhaul (BH) radio link control (RLC) channels that the traffic uses on paths in the first donor-CU's topology.

[0079] In some embodiments, the first transmission transition release request includes an indication of the traffic that needs to be released.

[0080] The following further exemplarily describes a transmission transition change process initiated by the first donor-CU through signaling interaction.

[0081] 11 is a diagram showing a signaling flow of a transmission transition release in an embodiment of the present invention. For example, when donor-CU 1 needs to migrate (return) traffic whose transmission path has already been migrated to donor-CU 2's topology back to donor-CU 1's topology, or when the traffic is terminated, - donor-CU 1 sends a first transport migration management release request to donor-CU 2 via a TRANSPORT MIGRATION MANAGEMENT REQUEST message or a TRANSPORT MIGRATION RELEASE message, which may include an indication of the traffic that needs to be released.

[0082] When migrating traffic that has already been migrated to donor-CU 2's topology to donor-CU 1's topology, the transition node redirects the traffic to donor-CU 2's topology (path 1 in FIG. 11).

[0083] Donor-CU 1 needs to establish resources that traffic uses in donor-CU1's topology. For example, donor-CU 1 configures uplink BH information (including routing ID, BH RLC channel ID, and next-hop node address belonging to the first donor-CU's topology) for the transition node's traffic (including user plane and non-user plane traffic) in the transition node through F1AP information. Also, for example, donor-CU 1 can configure BAP header rewrite information between topologies for child node's traffic, routing information belonging to donor-CU 2's topology, and release of BH RLC channel mapping information between the two topologies for the transition node.

[0084] In addition, donor-CU1 can configure IP addresses anchored to donor-DU of donor-CU1 for the transition node and child node through the RRC reconfiguration information (because traffic transitioned to donor-CU1 needs to use donor-DU of donor-CU1).

[0085] Optionally, donor-CU 1 can further configure BH RLC channels and routing of traffic on paths in donor-CU 1's topology, and configure routing tables and RLC channel mapping tables belonging to donor-CU 1's topology for the transition node.

[0086] In this way, the traffic transmission path can be transitioned to donor-CU 1's topology.

[0087] Donor-CU 1 needs to send a traffic flow indicator to be released for each request to donor-CU 2. After donor-CU 2 receives the first transmission transition release request, it releases the BH RLC channel and routing of the associated traffic on the path in the topology of donor-CU 2. As shown in Figure 11, donor-CU 2 does not need to send a transmission transition release response to donor-CU 1.

[0088] The above signaling process is only for illustrative purposes of the embodiment of the present invention, and the present invention is not limited thereto. For more specific content of the signaling, reference may be made to related art. In addition, for example, the execution order between each operation (step) can be appropriately adjusted, or some operations can be increased or decreased. Those skilled in the art can make appropriate modifications based on the above content without being limited to the description of FIG. 11 above.

[0089] In some embodiments, when the IAB-MT of an IAB node is switched from a first donor-CU to a second donor-CU and resources for serving one or more traffics of the IAB node (including transition nodes and child nodes) have already been established in the topology of the second donor-CU, the first donor-CU sends a first transmission transition release request for the one or more traffics.

[0090] For example, the transmission migration release process initiated by donor-CU 1 may be performed after the migration node is switched from a parent node under an F1-terminating CU to a parent node under a non-F1-terminating CU, and all traffic is migrated to the topology of the non-F1-terminating CU.

[0091] In some embodiments, when an IAB-MT of an IAB node is re-established from a first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node (including transition nodes and child nodes) have already been established in the topology of the second donor-CU, the first donor-CU sends a first transmission transition release request for one or more traffics.

[0092] For example, the transmission migration release process initiated by donor-CU 1 may occur after the migration node has been re-established from a parent node under an F1-terminating CU to a parent node under a non-F1-terminating CU, and all traffic has been migrated to the topology of the non-F1-terminating CU.

[0093] In some embodiments, when the IAB-MT of an IAB node establishes a dual connection with a first donor-CU and a second donor-CU, and resources for serving one or more traffics of the IAB node (including transition nodes and child nodes) have already been established in the topology of the second donor-CU, the first donor-CU sends a first transmission transition release request for one or more traffics.

[0094] For example, the transmission migration release process initiated by donor-CU 1 may be performed after the migration node establishes a dual connection with an F1-terminating CU and a non-F1-terminating CU, and the transmission path of some traffic has been migrated to the topology of the non-F1-terminating CU.

[0095] The above-mentioned embodiments are merely for illustrative purposes, and the present invention is not limited thereto, and appropriate modifications can be made based on the above-mentioned embodiments. For example, each of the above-mentioned embodiments may be used alone, or a combination of two or more of the above-mentioned embodiments may be used.

[0096] As can be seen from the above embodiment, the first donor-CU sends a first transmission transition release request for traffic to the second donor-CU, where the first transmission transition release request is used to request the second donor-CU to release resources for serving the traffic in the topology of the second donor-CU, so that the second donor-CU can release the transmission resources for serving the traffic, thereby allowing the traffic to be migrated to the topology of the first donor-CU or the traffic transmission to be terminated, thereby improving system efficiency and performance.

[0097] <Example of the second aspect> In an embodiment of the present invention, a transmission transition management method is provided, which is described starting from the second donor-CU. Here, the description of the same contents as in the embodiment of the first aspect is omitted. Wherein, the IAB-DU of the IAB node maintains an F1 connection with the first donor-CU, and resources for serving the traffic of the IAB node in the topology of the second donor-CU have been established.

[0098] 12 is a diagram showing another transmission transition management method in an embodiment of the present invention. As shown in FIG. 12, the method includes the following steps:

[0099] 1201: A second donor-CU receives a first transmission transition release request for the traffic sent by a first donor-CU, in which the first transmission transition release request is used to request to release resources for serving the traffic in the topology of the second donor-CU.

[0100] It should be noted that the above-mentioned FIG. 12 is only for illustrative purposes of the embodiment of the present invention, and the present invention is not limited thereto. For example, the execution order between each operation (step) can be appropriately adjusted, or some operations can be increased or decreased. Those skilled in the art can make appropriate modifications based on the above-mentioned contents without being limited to the description of the above-mentioned FIG. 12.

[0101] In some embodiments, an IAB-MT of the IAB node maintains an RRC connection with the second donor-CU, or an IAB-MT of the IAB node maintains an RRC connection with the first donor-CU.

[0102] In some embodiments, the traffic includes one or a combination of the following: F1 control plane (F1-C) traffic, F1 user plane (F1-U) traffic, and non-F1 traffic.

[0103] In some embodiments, the second donor-CU receives a first transmission transition release request for the traffic transmitted by the first donor-CU when the traffic transitions from the topology of the second donor-CU to the topology of the first donor-CU or when the traffic terminates.

[0104] In some embodiments, the second donor-CU receives the first transport migration release request through first transport migration management request information.

[0105] In some embodiments, the first transmission transition release request includes an indication of the traffic that needs to be released.

[0106] In some embodiments, after receiving the first transmission transition release request, the second donor-CU releases the BAP sublayer routing and / or BH RLC channels that the traffic uses on a path in the topology of the second donor-CU.

[0107] The above-mentioned embodiments are merely for illustrative purposes, and the present invention is not limited thereto, and appropriate modifications can be made based on the above-mentioned embodiments. For example, each of the above-mentioned embodiments may be used alone, or a combination of two or more of the above-mentioned embodiments may be used.

[0108] As can be seen from the above embodiment, the first donor-CU sends a first transmission transition release request for traffic to the second donor-CU, where the first transmission transition release request is used to request the second donor-CU to release resources for serving the traffic in the topology of the second donor-CU, so that the second donor-CU can release the transmission resources for serving the traffic, thereby allowing the traffic to be migrated to the topology of the first donor-CU or the traffic transmission to be terminated, thereby improving system efficiency and performance.

[0109] <Example of the third aspect> In an embodiment of the present invention, a transmission transition management method is provided, which is described from a second donor concentration unit (donor-CU), in which an IAB-DU of an IAB node maintains an F1 connection with a first donor concentration unit (donor-CU), and resources for serving the traffic of the IAB node in the topology of the second donor-CU have been established.

[0110] 13 is a diagram showing a transmission transition management method in an embodiment of the present invention. As shown in FIG. 13, the method includes the following steps:

[0111] 1301: A second donor-CU sends a second transmission transition release request for the traffic to a first donor-CU; and 1302: The second donor-CU releases resources for serving the traffic in the topology of the second donor-CU.

[0112] It should be noted that the above-mentioned FIG. 13 is only for illustrative purposes of the embodiment of the present invention, and the present invention is not limited thereto. For example, the execution order between each operation (step) can be appropriately adjusted, or some operations can be increased or decreased. Those skilled in the art can make appropriate modifications based on the above-mentioned contents without being limited to the description of the above-mentioned FIG. 13.

[0113] In some embodiments, when transitioning the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the second donor-CU sends a second transmission transition release request for the traffic to the first donor-CU.

[0114] In some embodiments, the second donor-CU sends the second transport migration release request through a second transport migration management request (TRANSPORT MIGRATION MANAGEMENT REQUEST) information, although the present invention is not limited thereto and the second transport migration release request may be carried by other information.

[0115] In some embodiments, the second transmission transition release request includes an indication of the traffic that needs to be released.

[0116] In some embodiments, the second donor-CU receives the transmission transition release response sent by the first donor-CU.

[0117] In some embodiments, the second donor-CU receives the transport migration release response sent by the first donor-CU through TRANSPORT MIGRATION MANAGEMENT RESPONSE information, although the present invention is not limited thereto and the transport migration release response may carry other information.

[0118] Optionally, the transport transition release response includes an indication of successful release of traffic.

[0119] In some embodiments, after receiving the transmission transition release response, the second donor-CU releases the BAP sublayer routing and / or BH RLC channels that the traffic uses on the path in the topology of the second donor-CU.

[0120] Thus, when the second donor-CU needs to migrate traffic to the topology of the first donor-CU, for example when the load on the topology of the second donor-CU is relatively high, the second donor-CU can send a second transmission transition release request to the first donor-CU and release resources for serving traffic in the topology of the second donor-CU, thereby allowing the traffic to be migrated to the topology of the first donor-CU and the traffic to continue being transmitted in the topology of the first donor-CU, thereby avoiding traffic interruption.

[0121] The following describes an example of a case where a traffic transmission transition release request fails.

[0122] In some embodiments, the second donor-CU receives a transmission transition release response to deny the first donor-CU's second transmission transition release request for the traffic.

[0123] In some embodiments, the second donor-CU receives the transport migration release response via TRANSPORT MIGRATION MANAGEMENT RESPONSE information.

[0124] In some embodiments, the transmission transition release response includes a traffic indicator for the traffic.

[0125] The following is an exemplary description of a transmission transition release process initiated by the second donor-CU through signaling interaction.

[0126] 14 illustrates a signaling flow of a transmission migration release in an embodiment of the present invention. For example, when the network load of donor-CU 2 is relatively large and traffic that has already been migrated to donor-CU 2's topology needs to be migrated to donor-CU 1's topology, donor-CU 2 initiates a second transmission migration release request to donor-CU 1 through TRANSPORT MIGRATION MANAGEMENT REQUEST information or TRANSPORT MIGRATION RELEASE information.

[0127] Donor-CU 2 can send to donor-CU 1 a traffic flow indicator to release for each request.

[0128] When donor-CU1 receives the transmission transition release request, donor-CU1 transitions the associated traffic to donor-CU1's topology, and the transition node redirects the traffic to donor-CU2's topology (path 1 in FIG. 14).

[0129] - donor-CU 1 needs to establish resources that traffic uses in the topology of donor-CU 1. For example, for the child node traffic that is requested to be released, configure the transition node to release the BAP header rewrite information between the topologies for the traffic, the routing information belonging to the topology of donor-CU 2, and the BH RLC channel mapping information between the two topologies, and for the transition node traffic that is requested to be released, configure the transition node to release the uplink BH information in the topology of donor-CU 1 (including the routing ID, BH RLC channel ID, and next hop node address belonging to the topology of the first donor-CU).

[0130] Optionally, configure BH RLC channels and routing for traffic on paths in the topology of donor-CU 1, and configure routing information and BH RLC channel mapping information belonging to the topology of donor-CU 1 for transition.

[0131] In addition, donor-CU1 can configure IP addresses anchored to donor-DU of donor-CU1 for the transition node and child node through the RRC reconfiguration information (because traffic transitioned to donor-CU1 needs to use donor-DU of donor-CU1).

[0132] In this way, the traffic path can be migrated to the topology of donor-CU 1. Donor-CU 1 sends a response to donor-CU 2 indicating that the migrated traffic has been successfully released, and includes a traffic release success indicator.

[0133] If donor-CU 1 is under relatively heavy load and the QoS requirements cannot be met after the traffic is migrated to donor-CU 1's topology, donor-CU 1 can reject the second transmission transition release request, and donor-CU 1 sends a release reject traffic indication to donor-CU 2.

[0134] When donor-CU 1 sends a response of successful release of transition traffic to donor-CU 2, donor-CU 2 releases the BH RLC channel and routing of the associated traffic on the path in donor-CU 2's topology.

[0135] The above signaling process is only for illustrative purposes of the embodiment of the present invention, and the present invention is not limited thereto. For more specific content of the signaling, reference may be made to related art. For example, the execution order between each operation (step) may be appropriately adjusted, or some operations may be added or removed. Those skilled in the art may make appropriate modifications based on the above content without being limited to the description of FIG. 14 above.

[0136] In some embodiments, when the IAB-MT of an IAB node is switched from a first donor-CU to a second donor-CU and resources for serving one or more traffics of the IAB node (including transition nodes and child nodes) have already been established in the topology of the second donor-CU, the second donor-CU sends a second transmission transition release request for the one or more traffics.

[0137] For example, the transmission migration release process initiated by donor-CU 2 may be performed after the migration node has been switched from a parent node under an F1-terminating CU to a parent node under a non-F1-terminating CU, and all traffic has been migrated to the topology of the non-F1-terminating CU.

[0138] In some embodiments, when the IAB-MT of an IAB node is re-established from a first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node (including transition nodes and child nodes) have already been established in the topology of the second donor-CU, the second donor-CU sends a second transmission transition release request for the one or more traffics.

[0139] For example, the transmission migration release process initiated by donor-CU 2 may occur after the migration node has been re-established from the parent node under the F1-terminating CU to the parent node under the non-F1-terminating CU, and all traffic has been migrated to the topology of the non-F1-terminating CU.

[0140] In some embodiments, when the IAB-MT of an IAB node establishes a dual connection with a first donor-CU and a second donor-CU, and resources for serving one or more traffics of the IAB node (including transition nodes and child nodes) have already been established in the topology of the second donor-CU, the second donor-CU sends a second transmission transition release request for the one or more traffics.

[0141] For example, the transmission migration release process initiated by donor-CU 2 may be performed after the migration node establishes a dual connection with an F1-terminating CU and a non-F1-terminating CU, and the transmission path of some traffic has been migrated to the topology of the non-F1-terminating CU.

[0142] The above-mentioned embodiments are merely for illustrative purposes, and the present invention is not limited thereto, and appropriate modifications can be made based on the above-mentioned embodiments. For example, each of the above-mentioned embodiments may be used alone, or a combination of two or more of the above-mentioned embodiments may be used.

[0143] As can be seen from the above embodiment, the second donor-CU sends a second transmission transition release request for the traffic to the first donor-CU, and the second donor-CU releases resources for serving the traffic in the topology of the second donor-CU, so that the traffic can be transitioned to the topology of the first donor-CU by releasing the transmission resources for serving the traffic, and the traffic can be continuously transmitted in the topology of the first donor-CU, thereby avoiding traffic interruption.

[0144] <Example of the fourth aspect> In the embodiment of the present invention, a transmission transition management method is provided, which is described starting from a first donor-CU. Here, the description of the same contents as in the embodiment of the third aspect is omitted. In this case, the IAB-DU of the IAB node maintains an F1 connection with the first donor-CU, and resources for serving the traffic of the IAB node in the topology of the second donor-CU have been established.

[0145] 15 is a diagram showing another transmission transition management method in an embodiment of the present invention. As shown in FIG. 15, the method includes the following steps:

[0146] 1501: A first donor-CU receives a second transmission transition release request for the traffic of a second donor-CU, in which the second donor-CU releases resources for serving the traffic in the topology of the second donor-CU.

[0147] It should be noted that the above-mentioned FIG. 15 is only for illustrative purposes of the embodiment of the present invention, and the present invention is not limited thereto. For example, the execution order between each operation (step) can be appropriately adjusted, or some operations can be increased or decreased. Those skilled in the art can make appropriate modifications based on the above-mentioned contents without being limited to the description of the above-mentioned FIG. 15.

[0148] In some embodiments, when transitioning the traffic from a topology of a second donor-CU to a topology of the first donor-CU, the first donor-CU receives a second transmission transition release request for the traffic transmitted by the second donor-CU.

[0149] In some embodiments, the first donor-CU receives the second transport migration release request via second transport migration management request information.

[0150] In some embodiments, the second transmission transition release request includes an indication of the traffic that needs to be released.

[0151] In some embodiments, when the traffic is transferred from the topology of the second donor-CU to the topology of the first donor-CU, the first donor-CU configures the IAB node to update uplink BH information of the traffic.

[0152] In some embodiments, when migrating the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the first donor-CU configures the IAB node to release at least one of the following: BAP header rewrite information between the topology of the first donor-CU and the topology of the second donor-CU, routing information in the topology of the second donor-CU, and BH RLC channel mapping information between the topology of the first donor-CU and the topology of the second donor-CU.

[0153] In some embodiments, when transitioning the traffic from the second donor-CU's topology to the first donor-CU's topology, the first donor-CU configures the IAB node with an augmentation of routing information in the first donor-CU's topology and / or BH RLC channel mapping information in the first donor-CU's topology.

[0154] In some embodiments, the first donor-CU configures an IP address for the IAB node that is anchored to a donor-DU of the first donor-CU.

[0155] In some embodiments, the first donor-CU configures BAP sublayer routing and / or backhaul (BH) radio link control (RLC) channels that the traffic uses on paths in the first donor-CU's topology.

[0156] In some embodiments, the first donor-CU sends a transmission transition release response to the second donor-CU.

[0157] In some embodiments, the first donor-CU sends the transport migration release response via TRANSPORT MIGRATION MANAGEMENT RESPONSE information.

[0158] In some embodiments, the transport transition release response includes an indication of successful release of traffic.

[0159] In some embodiments, after receiving the second transmission transition release request, the first donor-CU rejects the second transmission transition release request for the traffic.

[0160] For example, if the Quality of Service (QoS) of the traffic cannot be satisfied, the first donor-CU rejects the second transmission transition release request for the traffic.

[0161] In some embodiments, the first donor-CU sends a transmission transition release response to the second donor-CU to deny the second transmission transition release request for the traffic.

[0162] In some embodiments, the first donor-CU sends the transmission transition release response with transmission transition management response information.

[0163] In some embodiments, the transmission transition release response includes a traffic indicator for the traffic.

[0164] The above-mentioned embodiments are merely for illustrative purposes, and the present invention is not limited thereto, and appropriate modifications can be made based on the above-mentioned embodiments. For example, each of the above-mentioned embodiments may be used alone, or a combination of two or more of the above-mentioned embodiments may be used.

[0165] As can be seen from the above embodiment, the second donor-CU sends a second transmission transition release request for the traffic to the first donor-CU, and the second donor-CU releases resources for serving the traffic in the topology of the second donor-CU, so that the traffic can be transitioned to the topology of the first donor-CU by releasing the transmission resources for serving the traffic, and the traffic can be continuously transmitted in the topology of the first donor-CU, thereby avoiding traffic interruption.

[0166] <Example of the fifth aspect> In the embodiment of the present invention, an IAB donor device is provided, and the description of the same contents as in the embodiment of the first aspect will be omitted. The device may be, for example, an IAB donor-CU in an IAB system (e.g., the first donor-CU in the embodiments of the first and second aspects), or may be one or more parts, assemblies, or modules disposed in the IAB donor-CU.

[0167] 16 is a diagram illustrating an IAB donor device according to an embodiment of the present invention, in which an IAB node's IAB-DU maintains an F1 connection with a first donor concentration unit (donor-CU), and resources have been established to serve the traffic of the IAB node in the topology of a second donor-CU.

[0168] As shown in FIG. 16, the IAB donor device 1600 includes:

[0169] Transmitter 1601: Send a first transmission transition release request for the traffic to a second donor-CU, in which the first transmission transition release request is used to request the release of resources for serving the traffic in the topology of the second donor-CU.

[0170] In some embodiments, an IAB-MT of the IAB node maintains an RRC connection with the second donor-CU, or an IAB-MT of the IAB node maintains an RRC connection with the first donor-CU.

[0171] In some embodiments, the traffic includes one or a combination of the following: F1 control plane traffic, F1 user plane traffic, and non-F1 traffic.

[0172] In some embodiments, when the traffic is transitioned from the topology of the second donor-CU to the topology of the first donor-CU, or when the traffic is terminated, the transmitter 1601 sends a first transmission transition release request for the traffic to the second donor-CU.

[0173] In some embodiments, the first transmission transition management request information is used to send a first transmission transition release request.

[0174] In some embodiments, as shown in FIG. 16, the IAB donor device 1600 further includes:

[0175] Processing unit 1602: Configures updating of uplink BH information of the traffic in the IAB node.

[0176] In some embodiments, the processing unit 1602 configures the IAB node to release at least one of the following: BAP header rewrite information between the topology of the first donor-CU and the topology of the second donor-CU, routing information in the topology of the second donor-CU, and BH RLC channel mapping information between the topology of the first donor-CU and the topology of the second donor-CU.

[0177] In some embodiments, the processing unit 1602 configures the IAB node with an augmentation of routing information in the topology of the first donor-CU and / or BH RLC channel mapping information in the topology of the first donor-CU.

[0178] In some embodiments, the processing unit 1602 configures an IP address for the IAB node that is anchored to a donor-DU of the first donor-CU.

[0179] In some embodiments, the processing unit 1602 configures BAP sublayer routing and / or backhaul (BH) radio link control (RLC) channels that the traffic uses on a path in the topology of the first donor-CU.

[0180] In some embodiments, the first transmission transition release request includes an indication of the traffic that needs to be released.

[0181] In some embodiments, when the IAB-MT of the IAB node is switched from the first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the transmitter 1601 sends a first transmission transition release request for the one or more traffics.

[0182] In some embodiments, when the IAB-MT of the IAB node is re-established from the first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the transmitter 1601 sends a first transmission transition release request for the one or more traffics.

[0183] In some embodiments, when the IAB-MT of the IAB node establishes a dual connection with the first donor-CU and the second donor-CU, and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the transmitter 1601 sends a first transmission transition release request for the one or more traffics.

[0184] The above-mentioned embodiments are merely for illustrative purposes, and the present invention is not limited thereto, and appropriate modifications can be made based on the above-mentioned embodiments. For example, each of the above-mentioned embodiments may be used alone, or a combination of two or more of the above-mentioned embodiments may be used.

[0185] Although the components or modules according to the present invention have been described above, the present invention is not limited thereto. The IAB donor device 1600 according to the embodiment of the present invention may further include other components or modules, and the specific contents of these components or modules can be found in the related art.

[0186] For convenience, Fig. 16 shows only the connection relationships or signal directions between each component or module, but various techniques such as bus connection may be adopted as understood by those skilled in the art. Each of the above-mentioned components or modules may be realized by hardware such as a processor, a memory, a transmitter, a receiver, etc., but the implementation of the present invention is not limited thereto.

[0187] As can be seen from the above embodiment, the first donor-CU sends a first transmission transition release request for traffic to the second donor-CU, where the first transmission transition release request is used to request the second donor-CU to release resources for serving the traffic in the topology of the second donor-CU, so that the second donor-CU can release the transmission resources for serving the traffic, thereby allowing the traffic to be migrated to the topology of the first donor-CU or the traffic transmission to be terminated, thereby improving system efficiency and performance.

[0188] <Example of the sixth aspect> In the embodiment of the present invention, an IAB donor device is provided, and the description of the same contents as in the embodiment of the second aspect will be omitted. The device may be, for example, an IAB donor-CU in an IAB system (e.g., the second donor-CU in the embodiments of the first and second aspects), or may be one or more parts, assemblies, or modules disposed in the IAB donor-CU.

[0189] 17 is a diagram illustrating an IAB donor device according to an embodiment of the present invention, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor-CU, and resources have been established to serve the traffic of the IAB node in the topology of a second donor-CU.

[0190] As shown in FIG. 17, the IAB donor device 1700 includes:

[0191] Receiving unit 1701: Receive a first transmission transition release request for the traffic transmitted by the first donor-CU, in which the first transmission transition release request is used to request the release of resources for serving the traffic in the topology of a second donor-CU.

[0192] In some embodiments, an IAB-MT of the IAB node maintains an RRC connection with the second donor-CU, or an IAB-MT of the IAB node maintains an RRC connection with the first donor-CU.

[0193] In some embodiments, the traffic includes one or a combination of the following: F1 control plane (F1-C) traffic, F1 user plane (F1-U) traffic, and non-F1 traffic.

[0194] In some embodiments, the receiver 1701 receives a first transmission transition release request for the traffic of the first donor-CU transmission when the traffic transitions from the topology of the second donor-CU to the topology of the first donor-CU or when the traffic terminates.

[0195] In some embodiments, the first transmission transition release request is received according to the first transmission transition management request information.

[0196] In some embodiments, the first transmission transition release request includes an indication of the traffic that needs to be released.

[0197] In some embodiments, as shown in FIG. 17, the IAB donor device 1700 further includes:

[0198] Processing unit 1702: After receiving the first transmission transition release request, releases a BAP sublayer routing and / or BH RLC channel that the traffic uses on a path in the topology of the second donor-CU.

[0199] The above-mentioned embodiments are merely for illustrative purposes, and the present invention is not limited thereto, and appropriate modifications can be made based on the above-mentioned embodiments. For example, each of the above-mentioned embodiments may be used alone, or a combination of two or more of the above-mentioned embodiments may be used.

[0200] It should be noted that, although only the components or modules according to the present invention have been described above, the present invention is not limited thereto. The IAB donor device 1700 in the embodiment of the present invention may further include other components or modules, and the specific contents of these components or modules can be referred to in the related art.

[0201] For convenience, Fig. 17 shows only the connection relationships or signal directions between each component or module, but various techniques such as bus connection may be adopted as understood by those skilled in the art. Each of the above-mentioned components or modules may be realized by hardware such as a processor, a memory, a transmitter, a receiver, etc., but the implementation of the present invention is not limited thereto. As can be seen from the above embodiment, the first donor-CU sends a first transmission transition release request for traffic to the second donor-CU, where the first transmission transition release request is used to request the second donor-CU to release resources for serving the traffic in the topology of the second donor-CU, so that the second donor-CU can release the transmission resources for serving the traffic, thereby allowing the traffic to be migrated to the topology of the first donor-CU or the traffic transmission to be terminated, thereby improving system efficiency and performance.

[0202] <Example of the seventh aspect> In the embodiment of the present invention, an IAB donor device is provided, and the description of the same contents as in the embodiment of the third aspect will be omitted. The device may be, for example, an IAB donor-CU in an IAB system (e.g., the second donor-CU in the embodiments of the third and fourth aspects), or may be one or more parts, assemblies, or modules disposed in the IAB donor-CU.

[0203] 18 is a diagram illustrating an IAB donor device according to an embodiment of the present invention, in which an IAB node's IAB-DU maintains an F1 connection with a first donor concentration unit (donor-CU), and resources have been established to serve the traffic of the IAB node in the topology of a second donor-CU.

[0204] As shown in FIG. 18, the IAB donor device 1800 includes:

[0205] A sending unit 1801: sending a second transmission transition release request for the traffic to the first donor-CU; and Processing unit 1802: Releases resources for serving the traffic in the topology of the second donor-CU.

[0206] In some embodiments, when transitioning the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the sending unit 1801 sends a second transmission transition release request for the traffic to the first donor-CU.

[0207] In some embodiments, the second transport migration release request is sent using second transport migration management request information.

[0208] In some embodiments, the second transmission transition release request includes an indication of the traffic that needs to be released.

[0209] In some embodiments, as shown in FIG. 18, the IAB donor device 1800 further includes:

[0210] A receiving unit 1803: receives a transmission transition release response to the first donor-CU transmission.

[0211] In some embodiments, a TRANSPORT MIGRATION MANAGEMENT RESPONSE information message is sent to receive a TRANSPORT MIGRATION MANAGEMENT RESPONSE message from the first donor-CU.

[0212] In some embodiments, the receiver 1803 further receives a transmission transition release response to reject a second transmission transition release request for the traffic of the first donor-CU transmission.

[0213] In some embodiments, the transport migration release response is received via TRANSPORT MIGRATION MANAGEMENT RESPONSE information.

[0214] In some embodiments, the transmission transition release response includes a traffic indicator for the traffic.

[0215] In some embodiments, when the IAB-MT of the IAB node is switched from the first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the transmitter 1801 sends a second transmission transition release request for the one or more traffics.

[0216] In some embodiments, when the IAB-MT of the IAB node is re-established from the first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the transmitter 1801 sends a second transmission transition release request for the one or more traffics.

[0217] In some embodiments, when the IAB-MT of the IAB node establishes a dual connection with the first donor-CU and the second donor-CU, and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the transmitter 1801 sends a second transmission transition release request for the one or more traffics.

[0218] The above-mentioned embodiments are merely for illustrative purposes, and the present invention is not limited thereto, and appropriate modifications can be made based on the above-mentioned embodiments. For example, each of the above-mentioned embodiments may be used alone, or a combination of two or more of the above-mentioned embodiments may be used.

[0219] It should be noted that, although only the components or modules according to the present invention have been described above, the present invention is not limited thereto. The IAB donor device 1800 in the embodiment of the present invention may further include other components or modules, and the specific contents of these components or modules can be referred to in the related art.

[0220] For convenience, Fig. 18 shows only the connection relationships or signal directions between each component or module, but various techniques such as bus connection may be adopted as understood by those skilled in the art. Each of the above-mentioned components or modules may be realized by hardware such as a processor, a memory, a transmitter, a receiver, etc., but the implementation of the present invention is not limited thereto.

[0221] As can be seen from the above embodiment, the second donor-CU sends a second transmission transition release request for the traffic to the first donor-CU, and the second donor-CU releases resources for serving the traffic in the topology of the second donor-CU, so that the traffic can be transitioned to the topology of the first donor-CU by releasing the transmission resources for serving the traffic, and the traffic can be continuously transmitted in the topology of the first donor-CU, thereby avoiding traffic interruption.

[0222] <Example of the eighth aspect> In an embodiment of the present invention, an IAB donor device is provided, and description of the same contents as in the embodiment of the fourth aspect will be omitted. The device may be, for example, an IAB donor-CU in an IAB system (e.g., the first donor-CU in the embodiments of the third and fourth aspects), or may be one or more parts, assemblies, or modules disposed in the IAB donor-CU.

[0223] 19 is a diagram illustrating an IAB donor device according to an embodiment of the present invention, in which an IAB-DU of an IAB node maintains an F1 connection with a first donor-CU, and resources for serving the traffic of the IAB node in the topology of a second donor-CU have been established.

[0224] As shown in FIG. 19, the IAB donor device 1900 includes: A receiving unit 1901: receives a second transmission transition release request for the traffic of the second donor-CU, in which the second donor-CU releases resources for serving the traffic in the topology of the second donor-CU.

[0225] In some embodiments, when transitioning the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the receiver 1901 receives a second transmission transition release request for the traffic transmitted by the second donor-CU.

[0226] In some embodiments, the second transmission transition release request is received according to the second transmission transition management request information.

[0227] In some embodiments, the second transmission transition release request includes an indication of the traffic that needs to be released.

[0228] In some embodiments, as shown in FIG. 19, the IAB donor device 1900 further includes:

[0229] Processing unit 1902: Sets the IAB node to update the uplink BH information of the traffic.

[0230] In some embodiments, the processing unit 1902 configures at least one of the following releases to the IAB node: BAP header rewrite information between the topology of the first donor-CU and the topology of the second donor-CU, routing information in the topology of the second donor-CU, and BH RLC channel mapping information between the topology of the first donor-CU and the topology of the second donor-CU.

[0231] In some embodiments, the processing unit 1902 configures the IAB node with augmented routing information in the topology of the first donor-CU and / or BH RLC channel mapping information in the topology of the first donor-CU.

[0232] In some embodiments, the processing unit 1902 configures an IP address for the IAB node that is anchored to a donor-DU of the first donor-CU.

[0233] In some embodiments, the processing unit 1902 configures BAP sublayer routing and / or backhaul (BH) radio link control (RLC) channels that the traffic uses on a path in the topology of the first donor-CU.

[0234] In some embodiments, as shown in FIG. 19, the IAB donor device 1900 further includes:

[0235] Transmitting unit 1903: Transmits a transmission transition release response to the second donor-CU.

[0236] In some embodiments, the transport migration release response is sent via TRANSPORT MIGRATION MANAGEMENT RESPONSE information.

[0237] In some embodiments, after receiving the second transmission transition release request, the processing unit 1902 rejects the second transmission transition release request for the traffic.

[0238] For example, if the quality of service (QoS) of the traffic cannot be satisfied, the processing unit 1902 rejects the second transmission transition release request for the traffic.

[0239] In some embodiments, the sending unit 1903 further sends a transmission transition release response to the second donor-CU to reject the second transmission transition release request for the traffic.

[0240] In some embodiments, the transmission transition release response is sent via transmission transition management response information.

[0241] In some embodiments, the transmission transition release response includes a traffic indicator for the traffic.

[0242] The above-mentioned embodiments are merely for illustrative purposes, and the present invention is not limited thereto, and appropriate modifications can be made based on the above-mentioned embodiments. For example, each of the above-mentioned embodiments may be used alone, or a combination of two or more of the above-mentioned embodiments may be used.

[0243] It should be noted that, although only the components or modules according to the present invention have been described above, the present invention is not limited thereto. The IAB donor device 1900 in the embodiment of the present invention may further include other components or modules, and the specific contents of these components or modules can be referred to in the related art.

[0244] For convenience, only the connection relationships or signal directions between each component or module are shown in Fig. 19, but various techniques such as bus connection may be adopted as understood by those skilled in the art. Each of the above-mentioned components or modules may be realized by hardware such as a processor, a memory, a transmitter, a receiver, etc., but the implementation of the present invention is not limited thereto.

[0245] As can be seen from the above embodiment, the second donor-CU sends a second transmission transition release request for the traffic to the first donor-CU, and the second donor-CU releases resources for serving the traffic in the topology of the second donor-CU, so that the traffic can be transitioned to the topology of the first donor-CU by releasing the transmission resources for serving the traffic, and the traffic can be continuously transmitted in the topology of the first donor-CU, thereby avoiding traffic interruption.

[0246] <Example of the ninth aspect> In an embodiment of the present invention, a communication system is provided, which includes a donor device and an IAB node. The network architecture of the donor device and the IAB node can be further referred to in the related art, and detailed description thereof will be omitted here.

[0247] In some embodiments, the IAB system includes:

[0248] A first donor concentration unit (first donor-CU): sending a first transmission transition release request for the traffic, in which the first transmission transition release request is used to request to release resources for serving the traffic in the topology of a second donor-CU; and A second donor centralization unit (second donor-CU): receives the first transmission transition release request.

[0249] In some embodiments, the IAB system includes:

[0250] A second donor concentration unit (second donor-CU): sending a second transmission transition release request for the traffic and releasing resources for serving the traffic in the topology of the second donor-CU; and First donor centralization unit (first donor-CU): receives the second transmission transition release request.

[0251] In an embodiment of the present invention, an IAB device is further provided, which may be an IAB donor device or an IAB node device (a transition node or a child node).

[0252] 20 is a diagram showing an IAB device according to an embodiment of the present invention. As shown in FIG. 20, the IAB device 2000 may include a processor (e.g., a central processing unit CPU) 2001 and a memory 2002, and the memory 2002 is connected to the processor 2001. The memory 2002 can store various data, and can further store a program 2005 for information processing, and can execute the program 2005 under the control of the central processing unit 2001.

[0253] For example, the processor 2001 may be configured to execute a program to realize a transmission transition management method in an embodiment of the first aspect. For example, the processor 2001 may be configured to perform the following control: sending a first transmission transition release request for the traffic to a second donor-CU, in which the first transmission transition release request is used to request the release of resources for serving the traffic in the topology of the second donor-CU.

[0254] Also, for example, the processor 2001 may be configured to execute a program to realize the transmission transition management method in the embodiment of the second aspect. For example, the processor 2001 may be configured to perform the following control: receive a first transmission transition release request for the traffic sent by a first donor-CU, in which the first transmission transition release request is used to request the release of resources for serving the traffic in the topology of a second donor-CU.

[0255] Also, for example, the processor 2001 may be configured to execute a program to realize a transmission transition management method in an embodiment of the third aspect. For example, the processor 2001 may be configured to perform the following control: sending a second transmission transition release request for the traffic to a first donor-CU; and releasing resources for serving the traffic in the topology of the second donor-CU.

[0256] Also, for example, the processor 2001 may be configured to execute a program to realize the transmission transition management method in the embodiment of the fourth aspect. For example, the processor 2001 may be configured to perform the following control: receive a second transmission transition release request for the traffic sent by a second donor-CU, in which the second donor-CU releases resources for serving the traffic in the topology of the second donor-CU.

[0257] 20, the IAB device 2000 may further include a transceiver 2003, an antenna 2004, etc., among which the functions of these components are similar to those of the prior art, and therefore detailed description thereof will be omitted here. Note that the IAB device 2000 does not need to include all the components shown in Fig. 20. The IAB device 2000 may further include components not shown in Fig. 20, and for this, reference can be made to the prior art.

[0258] In an embodiment of the present invention, a computer readable program is provided, which, when executed by an IAB device, causes a computer to perform a transmission transition management method according to any of the embodiments of the first to fourth aspects on the IAB device.

[0259] An embodiment of the present invention further provides a storage medium having a computer readable program stored thereon, wherein the computer readable program causes a computer to execute the transmission transition management method according to the embodiment of the first to fourth aspects in an IAB device.

[0260] The above-mentioned devices and methods may be realized by software or hardware, or may be realized by a combination of hardware and software. The present invention further relates to a computer-readable program, which, when executed by a logic component, causes the logic component to realize the above-mentioned device or component, or causes the logic component to realize each of the above-mentioned methods or steps. The logic component may be, for example, a Field Programmable Gate Array (FPGA), a microprocessor, a processor for use in a computer, etc. The present invention also relates to a storage medium, such as a hard disk, a magnetic disk, an optical hard disk, a DVD, a flash memory, etc., storing the above-mentioned program.

[0261] Additionally, one or more combinations of the functional blocks illustrated in the figures and / or one or more combinations of the functional blocks may be implemented as a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic component, a discrete gate or transistor logic component, a discrete hardware assembly, or any other suitable combination for performing the functions described herein. Also, one or more combinations of the functional blocks illustrated in the figures and / or one or more combinations of the functional blocks may be further configured as a combination of computing devices, such as a combination of a DSP and a microprocessor, a combination of multiple microprocessors, one or more microprocessors in communication with a DSP, or any other configuration.

[0262] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and any modifications to the present invention that do not depart from the spirit of the present invention belong to the technical scope of the present invention.

[0263] Furthermore, with respect to the above-mentioned embodiments, the following supplementary notes are disclosed.

[0264] (Appendix 1) 1. A method for managing transmission transitions, comprising: An IAB-DU of an IAB node maintains an F1 connection with a first donor concentration unit (donor-CU), and resources for serving traffic of the IAB node in a topology of a second donor-CU have already been established, and the method includes: the first donor-CU sending a first transmission transition release request for the traffic to the second donor-CU; wherein the first transmission transition release request is used to request to release resources for serving the traffic in the topology of a second donor-CU.

[0265] (Appendix 2) 2. The method according to claim 1, comprising: The method, wherein an IAB-MT of the IAB node maintains an RRC connection with the second donor-CU, or an IAB-MT of the IAB node maintains an RRC connection with the first donor-CU.

[0266] (Appendix 3) 3. The method according to claim 1 or 2, The method, wherein the traffic includes one or a combination of the following: F1 control plane (F1-C) traffic, F1 user plane (F1-U) traffic, and non-F1 traffic.

[0267] (Appendix 4) 4. The method according to any one of claims 1 to 3, comprising: The method of claim 1, wherein the first donor-CU sends a first transmission transition release request for the traffic to the second donor-CU when the traffic is transitioned from a topology of a second donor-CU to a topology of the first donor-CU or when the traffic is terminated.

[0268] (Appendix 5) 5. The method according to any one of claims 1 to 4, comprising: The first donor-CU sends the first transport migration release request by using first transport migration management request information.

[0269] (Appendix 6) 6. The method according to any one of claims 1 to 5, comprising: When migrating the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the method further includes: The method includes the first donor-CU configuring the IAB node to update uplink BH information of the traffic.

[0270] (Appendix 7) 7. The method according to any one of claims 1 to 6, comprising: When migrating the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the method further includes: The method includes the first donor-CU configuring at least one of the following releases in the IAB node: BAP header rewrite information between the topology of the first donor-CU and the topology of the second donor-CU, routing information in the topology of the second donor-CU, and BH RLC channel mapping information between the topology of the first donor-CU and the topology of the second donor-CU.

[0271] (Appendix 8) 8. The method according to any one of claims 1 to 7, comprising: When migrating the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the method further includes: The method includes the first donor-CU configuring, in the IAB node, augmentation of routing information in the topology of the first donor-CU and / or augmentation of BH RLC channel mapping information in the topology of the first donor-CU.

[0272] (Appendix 9) The method according to any one of claims 1 to 8, further comprising: The method includes the first donor-CU configuring an IP address for the IAB node that is anchored to a donor-DU of the first donor-CU.

[0273] (Appendix 10) The method according to any one of claims 1 to 9, further comprising: The method includes the first donor-CU configuring a BAP sublayer routing and / or a backhaul (BH) radio link control (RLC) channel to be used by the traffic on a path in the topology of the first donor-CU.

[0274] (Appendix 11) 11. The method according to any one of claims 1 to 10, comprising: The first transmission transition release request includes a traffic indicator that needs to be released.

[0275] (Appendix 12) 12. The method according to any one of claims 1 to 11, comprising: A method in which, when an IAB-MT of the IAB node is switched from the first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the first donor-CU sends a first transmission transition release request for the one or more traffics.

[0276] (Appendix 13) 12. The method according to any one of claims 1 to 11, comprising: When an IAB-MT of the IAB node is re-established from the first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the first donor-CU sends a first transmission transition release request for the one or more traffics.

[0277] (Appendix 14) 12. The method according to any one of claims 1 to 11, comprising: a first donor-CU sending a first transmission transition release request for one or more traffics when resources for serving one or more traffics of the IAB node in the topology of the second donor-CU have already been established, and an IAB-MT of the IAB node establishes a dual connection with the first donor-CU and the second donor-CU;

[0278] (Appendix 15) 1. A method for managing transmission transitions, comprising: An IAB-DU of an IAB node maintains an F1 connection with a first donor concentration unit (donor-CU), and resources for serving traffic of the IAB node in a topology of a second donor-CU have already been established, and the method includes: the second donor-CU receiving a first transmission transition release request for the traffic of the first donor-CU; wherein the first transmission transition release request is used to request to release resources for serving the traffic in the topology of a second donor-CU.

[0279] (Appendix 16) 16. The method according to claim 15, The method, wherein an IAB-MT of the IAB node maintains an RRC connection with the second donor-CU, or an IAB-MT of the IAB node maintains an RRC connection with the first donor-CU.

[0280] (Appendix 17) 17. The method according to claim 15 or 16, The method, wherein the traffic includes one or a combination of the following: F1 control plane (F1-C) traffic, F1 user plane (F1-U) traffic, and non-F1 traffic.

[0281] (Appendix 18) 18. The method according to any one of claims 15 to 17, comprising: The method of claim 1, wherein the second donor-CU receives a first transmission transition release request for the traffic transmitted by the first donor-CU when the traffic transitions from a topology of a second donor-CU to a topology of the first donor-CU or when the traffic terminates.

[0282] (Appendix 19) 19. The method according to any one of claims 15 to 18, comprising: The second donor-CU receives the first transport migration release request through first transport migration management request information.

[0283] (Appendix 20) 20. The method according to any one of claims 15 to 19, comprising: The first transmission transition release request includes a traffic indicator that needs to be released.

[0284] (Appendix 21) 21. The method according to any one of claims 15 to 20, comprising: The method of the present invention, wherein after the second donor-CU receives the first transmission transition release request, the second donor-CU releases a BAP sublayer routing and / or BH RLC channel that the traffic uses on a path in the topology of the second donor-CU.

[0285] (Appendix 22) 1. A method for managing transmission transitions, comprising: An IAB-DU of an IAB node maintains an F1 connection with a first donor-CU, and resources for serving traffic of the IAB node in a topology of a second donor-CU have already been established, and the method includes: the second donor-CU sends a second transmission transition release request for the traffic to the first donor-CU; and the second donor-CU releasing resources for serving the traffic in the second donor-CU's topology.

[0286] (Appendix 23) 23. The method of claim 22, The method, wherein an IAB-MT of the IAB node maintains an RRC connection with the second donor-CU, or an IAB-MT of the IAB node maintains an RRC connection with the first donor-CU.

[0287] (Appendix 24) 23. The method according to claim 21 or 22, The method, wherein the traffic includes one or a combination of the following: F1 control plane (F1-C) traffic, F1 user plane (F1-U) traffic, and non-F1 traffic.

[0288] (Appendix 25) 25. The method according to any one of claims 22 to 24, comprising: The method of claim 1, wherein when the traffic is transitioned from a topology of a second donor-CU to a topology of the first donor-CU, the second donor-CU sends a second transmission transition release request for the traffic to the first donor-CU.

[0289] (Appendix 26) 26. The method according to any one of claims 22 to 25, comprising: The second donor-CU sends the second transmission transition release request according to second transmission transition management request information.

[0290] (Appendix 27) 27. The method according to any one of claims 22 to 26, comprising: The second transmission transition release request includes a traffic indicator that needs to be released.

[0291] (Appendix 28) 28. The method of any one of claims 22 to 27, further comprising: The method includes the second donor-CU receiving a transmission transition release response of the first donor-CU transmission.

[0292] (Appendix 29) 29. The method according to claim 28, comprising: The second donor-CU receives a transport migration release response of the first donor-CU transmission by transport migration management response information.

[0293] (Appendix 30) 29. The method according to claim 28, further comprising: The transport transition release response includes an indication of successful release of traffic.

[0294] (Appendix 31) 29. The method according to claim 29, Releasing resources for serving the traffic in the topology of the second donor-CU by the second donor-CU, The method includes, after the second donor-CU receives the transmission transition release response, releasing a BAP sublayer routing and / or BH RLC channel used by the traffic on a path in the topology of the second donor-CU.

[0295] (Appendix 32) 28. The method according to any one of claims 22 to 27, comprising: The second donor-CU receives a transmission transition release response to deny a second transmission transition release request for the traffic transmitted by the first donor-CU.

[0296] (Appendix 33) 33. The method of claim 32, The second donor-CU receives the transport migration release response through transport migration management response information.

[0297] (Appendix 34) 33. The method of claim 32, The transmission transition release response includes a traffic indication for the traffic.

[0298] (Appendix 35) 35. The method according to any one of claims 22 to 34, comprising: When an IAB-MT of the IAB node is switched from the first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the second donor-CU sends a second transmission transition release request for the one or more traffics.

[0299] (Appendix 36) 35. The method according to any one of claims 22 to 34, comprising: When an IAB-MT of the IAB node is re-established from the first donor-CU to the second donor-CU and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor-CU, the second donor-CU sends a second transmission transition release request for the one or more traffics.

[0300] (Appendix 37) 35. The method according to any one of claims 22 to 34, comprising: a second donor-CU sending a second transmission transition release request for one or more traffics when resources for serving one or more traffics of the IAB node in the topology of the second donor-CU have already been established, said second donor-CU receiving a second transmission transition release request for the one or more traffics of the IAB node;

[0301] (Appendix 38) 1. A method for managing transmission transitions, comprising: An IAB-DU of an IAB node maintains an F1 connection with a first donor-CU, and resources for serving traffic of the IAB node in a topology of a second donor-CU have already been established, and the method includes: the first donor-CU receiving a second transmission transition release request for the traffic of the second donor-CU; wherein the second donor-CU releases resources for serving the traffic in the topology of the second donor-CU.

[0302] (Appendix 39) 39. The method according to claim 38, comprising: The method, wherein an IAB-MT of the IAB node maintains an RRC connection with the second donor-CU, or an IAB-MT of the IAB node maintains an RRC connection with the first donor-CU.

[0303] (Appendix 40) 39. The method according to claim 38, further comprising: The method, wherein the traffic includes one or a combination of the following: F1 control plane (F1-C) traffic, F1 user plane (F1-U) traffic, and non-F1 traffic.

[0304] (Appendix 41) 41. The method according to any one of claims 38 to 40, comprising: The method of claim 1, wherein the first donor-CU receives a second transmission transition release request for the traffic transmitted by the second donor-CU when transitioning the traffic from a topology of a second donor-CU to a topology of the first donor-CU.

[0305] (Appendix 42) 42. The method according to any one of claims 38 to 41, comprising: The first donor-CU receives the second transmission transition release request through second transmission transition management request information.

[0306] (Appendix 43) 43. The method according to any one of claims 38 to 42, comprising: The second transmission transition release request includes a traffic indicator that needs to be released.

[0307] (Appendix 44) 44. The method according to any one of claims 38 to 43, comprising: When migrating the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the method further includes: The method includes the first donor-CU configuring the IAB node to update uplink BH information of the traffic.

[0308] (Appendix 45) 45. The method according to any one of claims 38 to 44, comprising: When migrating the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the method further includes: The method includes the first donor-CU configuring at least one of the following releases in the IAB node: BAP header rewrite information between the topology of the first donor-CU and the topology of the second donor-CU, routing information in the topology of the second donor-CU, and BH RLC channel mapping information between the topology of the first donor-CU and the topology of the second donor-CU.

[0309] (Appendix 46) 46. ​​The method according to any one of claims 38 to 45, comprising: When migrating the traffic from the topology of the second donor-CU to the topology of the first donor-CU, the method further includes: The method includes the first donor-CU configuring, in the IAB node, augmentation of routing information in the topology of the first donor-CU and / or augmentation of BH RLC channel mapping information in the topology of the first donor-CU.

[0310] (Appendix 47) 47. The method of any one of claims 38 to 46, further comprising: The method includes the first donor-CU configuring an IP address for the IAB node that is anchored to a donor-DU of the first donor-CU.

[0311] (Appendix 48) 48. The method of any one of claims 38 to 47, further comprising: The method includes the first donor-CU configuring a BAP sublayer routing and / or a backhaul (BH) radio link control (RLC) channel to be used by the traffic on a path in the topology of the first donor-CU.

[0312] (Appendix 49) 49. The method of any one of claims 38 to 48, further comprising: The method includes the first donor-CU sending a transmission transition release response to the second donor-CU.

[0313] (Appendix 50) 49. The method of claim 49, The first donor-CU sends the transport migration release response by using transport migration management response information.

[0314] (Appendix 51) 51. The method according to claim 49 or 50, The transport transition release response includes an indication of successful release of traffic.

[0315] (Appendix 52) 49. The method of any one of claims 38 to 48, comprising: The method, wherein the first donor-CU rejects the second transmission transition release request for the traffic after receiving the second transmission transition release request.

[0316] (Appendix 53) 53. The method of claim 52, comprising: The first donor-CU sends a transmission transition release response to the second donor-CU to deny a second transmission transition release request for the traffic.

[0317] (Appendix 54) 54. The method of claim 53, comprising: The first donor-CU sends the transmission transition release response according to transmission transition management response information.

[0318] (Appendix 55) 54. The method of claim 53, comprising: The transmission transition release response includes a traffic indication for the traffic.

[0319] (Appendix 56) An IAB donor device, A memory and a processor are included, The storage device stores a computer program, The processor is configured to execute the computer program to implement the transmission transition management method described in any one of claims 1 to 55.

Claims

1. 1. An IAB donor device comprising: The IAB-DU of the IAB node maintains an F1 connection with the first donor concentration unit, and resources for serving the traffic of the IAB node in the topology of the second donor concentration unit have already been established, and the device a transmitter for transmitting a first transmission transition release request for the traffic to the second donor concentration unit; Wherein, the first transmission transition release request is used to request the release of resources for serving the traffic in the topology of a second donor concentration unit.

2. 2. The device of claim 1, An IAB-MT of the IAB node maintains a radio resource control connection with the second donor concentration unit, or an IAB-MT of the IAB node maintains a radio resource control connection with the first donor concentration unit.

3. 2. The device of claim 1, The traffic may include one or a combination of the following: F1 control plane traffic, F1 user plane traffic, and non-F1 traffic.

4. 2. The device of claim 1, When the traffic is transitioned from the topology of the second donor concentration unit to the topology of the first donor concentration unit or when the traffic is terminated, the transmitter sends a first transmission transition release request for the traffic to the second donor concentration unit.

5. 5. The device of claim 4, The device sends the first transmission transition release request according to first transmission transition management request information.

6. 2. The device of claim 1, The method further includes a processing unit, which performs at least one operation, such as: Configuring the IAB node to update uplink BH information of the traffic; Configure the IAB node to release at least one of the following: backhaul adaptation protocol header rewrite information between the topology of the first donor concentration unit and the topology of the second donor concentration unit, routing information in the topology of the second donor concentration unit, and backhaul radio link control channel mapping information between the topology of the first donor concentration unit and the topology of the second donor concentration unit; Configure the IAB node with routing information in the first donor centralization unit topology and / or augmentation of backhaul radio link control channel mapping information in the first donor centralization unit topology; Setting an IP address for the IAB node that is anchored to a donor distribution unit of the first donor centralization unit; and The device is operable to configure backhaul adaptation protocol sublayer routing and / or backhaul radio link control channels for use by the traffic on paths in the topology of the first donor concentration unit.

7. 2. The device of claim 1, The first transmission transition release request includes a traffic indicator that needs to be released.

8. 2. The device of claim 1, When an IAB-MT of the IAB node is switched from the first donor concentration unit to the second donor concentration unit and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor concentration unit, the transmitter sends a first transmission transition release request for the one or more traffics; or When an IAB-MT of the IAB node is re-established from the first donor concentration unit to the second donor concentration unit and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor concentration unit, the transmitter sends a first transmission transition release request for the one or more traffics; or When an IAB-MT of the IAB node has established a dual connection with the first donor concentration unit and the second donor concentration unit, and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor concentration unit, the transmitter sends a first transmission transition release request for the one or more traffics.

9. 1. An IAB donor device comprising: The IAB-DU of the IAB node maintains an F1 connection with the first donor concentration unit, and resources for serving the traffic of the IAB node in the topology of the second donor concentration unit have already been established, and the device a transmitter for transmitting a second transmission transition release request for the traffic to the first donor concentration unit; and and a processor for releasing resources for serving said traffic in the topology of a second donor concentration unit.

10. 10. The device of claim 9, When the traffic is transitioned from the topology of the second donor concentration unit to the topology of the first donor concentration unit, the transmitter transmits a second transmission transition release request for the traffic to the first donor concentration unit.

11. 11. The apparatus of claim 10, The device sends the second transmission transition release request according to second transmission transition management request information.

12. 10. The device of claim 9, The second transmission transition release request includes a traffic indicator that needs to be released.

13. 10. The device of claim 9, The apparatus further includes a receiver that receives a transmission transition release response of the first donor concentration unit transmission.

14. 14. The apparatus of claim 13, receiving the transmission transition release response according to transmission transition management response information; The transmission transition release response includes an indication of a successful release of traffic, the device.

15. 10. The device of claim 9, After receiving the transmission transition release response, the processing unit releases the backhaul adaptation protocol sublayer routing and / or backhaul radio link control channel that the traffic uses on the path in the topology of the second donor concentration unit, the device.

16. 14. The apparatus of claim 13, The receiving unit further receives a transmission transition release response to reject a second transmission transition release request for the traffic of the first donor concentration unit transmission.

17. 17. The apparatus of claim 16, The device receives the transmission transition release response according to transmission transition management response information.

18. 17. The apparatus of claim 16, The transmission transition release response includes a traffic indication for the traffic.

19. 10. The device of claim 9, When an IAB-MT of the IAB node is switched from the first donor concentration unit to the second donor concentration unit and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor concentration unit, the transmitter sends a second transmission transition release request for the one or more traffics; or When an IAB-MT of the IAB node is re-established from the first donor concentration unit to the second donor concentration unit and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor concentration unit, the transmitter sends a second transmission transition release request for the one or more traffics; or When an IAB-MT of the IAB node has established a dual connection with the first donor concentration unit and the second donor concentration unit, and resources for serving one or more traffics of the IAB node have already been established in the topology of the second donor concentration unit, the transmitter sends a second transmission transition release request for the one or more traffics.

20. 1. An IAB system comprising: A first donor concentration unit and a second donor concentration unit, The first donor concentration unit sends a first transmission transition release request for traffic, in which the first transmission transition release request is used to request the release of resources for serving the traffic in the topology of the second donor concentration unit, and the second donor concentration unit receives the first transmission transition release request; or The second donor concentration unit sends a second transmission transition release request for the traffic and releases resources for serving the traffic in the topology of the second donor concentration unit, and the first donor concentration unit receives the second transmission transition release request.

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