Access Backhaul Integrated Communication Device and Method

Abstract

An embodiment of the present invention provides an integrated access backhaul (IAB) communication apparatus and method, which includes: a second donor distribution unit (target donor-DU) adding a tunnel-related header to uplink data and sending the uplink data to a first donor distribution unit (source donor-DU) through the TNL tunnel; and / or a first donor distribution unit (source donor-DU) adding a tunnel-related header to downlink data and sending the downlink data to a second donor distribution unit (target donor-DU) through the TNL tunnel.

Description

Technical Field

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

Background Art

[0002] The future deployment of seamless cellular networks requires the deployment of very flexible and ultra-high density NR cells. Ultra-high density networks are one of the goals of 5G, and the deployment of a new radio (NR) network that does not require a wired backhaul is important for realizing the 5G ultra-high density network. Since 5G millimeter waves narrow the cell coverage, a wireless self-backhaul system requires multi-hop to meet the deployment needs. 5G's high bandwidth, large-scale multiple input multiple output (MIMO) and beam systems make it easier to develop a wireless self-backhaul system for ultra-high density NR cells in 5G than in LTE. To develop such a multi-hop system with a wireless self-backhaul, 3GPP (registered trademark) initiated the research and standardization of the Integrated access and backhaul (IAB) project in R16.

[0003] FIG. 1 is a schematic diagram of an example of an IAB system. As shown in FIG. 1, in the IAB system, the relay node supports both access and backhaul functions, and the wireless transmission link of 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 utilize the same frequency band or different frequency bands.

[0004] In the IAB network architecture, the relay node means an IAB-node (IAB node) and supports both access and backhaul. The access node at the last hop on the network side is called an IAB-donnor (IAB donor), supports the gNB function, and supports IAB-node access. All UE data can be backhauled to the IAB-Donor via one or more hops through the IAB-node.

[0005] The IAB-node function is divided into two parts: the gNB-DU function called IAB-DU (Distributed Unit) and the UE function called IAB-MT (Mobile Terminal). The IAB-DU realizes the function of the network-side device, is connected to the downstream child IAB-node (child IAB node), provides NR air interface access to the UE and the downstream child IAB-node, and establishes an F1 connection with the IAB Donor-CU. The IAB-MT realizes a part of the function of the terminal device and is connected to the upstream parent IAB-node (parent IAB node) or the IAB-Donor DU. The IAB-MT 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, the IAB-node can access the network in the standalone (SA: Standalone) mode or the non-standalone (EN-DC, E-UTRA-NR Dual Connectivity) mode. Figure 2 is a schematic diagram of an example of the IAB architecture in the SA mode. Figure 3 is a schematic diagram of an example of the IAB architecture in the EN-DC mode.

[0007] FIG. 4 is a schematic diagram of an example of an IAB node, a parent IAB-node, and a child IAB-node. As shown in FIG. 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] FIG. 5 is a schematic diagram of an example of an F1 user plane (F1-U) protocol stack between an IAB-DU and an IAB-Donor CU. FIG. 6 is a schematic diagram of an example of an F1 control plane (F1-C) protocol stack between an IAB-DU and an IAB-Donor CU. As shown in FIGS. 5 and 6, F1-U and F1-C are established on the transport (IP) layer between the IAB-DU and the IAB-Donor-CU, and FIGS. 5 and 6 show a two-hop wireless backhaul and a one-hop wired backhaul.

[0009] In the backhaul link, the transport (IP) layer is carried by the Backhaul Adaptation Protocol (BAP) sublayer, and the BAP entity in the IAB-node realizes the routing function of the IAB system, and the IAB-Donor CU provides a routing table. The BAP PDU (Protocol Data Unit) is transmitted 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 services with different priorities and QoS (Quality of Service), and the BAP entity maps the BAP PDU to different backhaul RLC channels.

[0010] When the connection of the IAB-node in the IAB network with the original parent IAB-node is disconnected and connected to a new parent IAB-node, or when the IAB-node maintains the connection with the original parent node and adds a connection with a new parent node to form a dual connection, a change in the IAB network topology occurs.

[0011] FIG. 7 is a schematic diagram of an example of a change in network topology. As shown in FIG. 7, when IAB-node5 is switched from the cell under IAB-node3 to the cell under IAB-node4, the F1 transmission path from IAB-node5 and its downstream child node IAB-node6 to the Donor-CU is changed from the path via IAB-node1 and IAB-node2 to the path via IAB-node2 and IAB-node4, and the network topology is changed. Alternatively, when IAB-node5 adds a connection to IAB-node4 to become a dual connection, the F1 transmission path from IAB-node5 and its downstream child node IAB-node6 to the Donor-CU has an additional path via IAB-node1 and IAB-node2, and the network topology is changed.

[0012] Note that the above description of the background art is merely for more clearly and completely explaining the configuration of the present invention and is for the purpose of making those skilled in the art understand. It should not be construed that these configurations are well-known technologies to those skilled in the art just because they are described in the background art part of the present invention.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0013] According to the discovery of the inventor of the present invention, in some cases after the network topology is changed, the IAB-node and its descendant nodes may not have a Transmission Network Layer (TNL) address that can be routed through the target Donor-DU (target Donor-DU). There is a possibility that the uplink data is discarded by the Donor-DU and the downlink data is discarded by the source Donor-DU (source Donor-DU).

[0014] To solve at least one of the above problems, embodiments of the present invention provide an IAB communication device and method.

MEANS FOR SOLVING THE PROBLEM

[0015] In one aspect of an embodiment of the present invention, there is provided an IAB communication method, including steps of: a second donor distributed unit receiving uplink data transmitted by an IAB node; adding a header related to a transport network layer (TNL) tunnel to the uplink data; and transmitting the uplink data to the first donor distributed unit via the transport network layer tunnel.

[0016] In another aspect of an embodiment of the present invention, there is provided an IAB communication apparatus, including: a receiving unit configured to receive uplink data transmitted by an IAB node; a processing unit configured to add a header related to a transport network layer (TNL) tunnel to the uplink data; and a transmitting unit configured to transmit the uplink data to a first donor distributed unit via the transport network layer tunnel.

[0017] In another aspect of an embodiment of the present invention, there is provided an IAB communication method, including steps of: a first donor distributed unit receiving downlink data transmitted to the IAB node; adding a header related to a transport network layer (TNL) to the downlink data; and transmitting the downlink data to the second donor distributed unit via the transport network layer tunnel.

[0018] In another aspect of an embodiment of the present invention, there is provided an IAB communication apparatus, including: a receiving unit configured to receive downlink data transmitted to the IAB node; a processing unit configured to add a header related to a transport network layer (TNL) tunnel to the downlink data; and a transmitting unit configured to transmit the downlink data to a second donor distributed unit via the transport network layer tunnel.

[0019] One of the advantageous effects of the embodiments of the present invention is as follows. The second donor dispersion unit (target donor-DU) adds a tunnel-related header to the uplink data, transmits the uplink data to the first donor dispersion unit (source donor-DU) via the TNL tunnel, and / or the first donor dispersion unit (source donor-DU) adds a tunnel-related header to the downlink data and transmits the downlink data to the second donor dispersion unit (target donor-DU) via the TNL tunnel. By establishing a TNL tunnel between the source donor-DU and the target donor-DU during the IAB-node migration, the problem that uplink data or downlink data is discarded can be solved.

[0020] As shown in the following description and drawings, specific embodiments of the present invention are disclosed in detail, and the ways in which the principles of the present invention can be adopted are shown. It should be noted that the scope of the embodiments of the present invention is not limited thereto. The embodiments of the present invention include those that are changed, modified, and equivalent within the gist and scope of the appended claims.

[0021] The features described and / or shown in one embodiment may be used in one or more other embodiments in the same or similar manner, or may be combined with the features in other embodiments, or may replace the features in other embodiments.

[0022] It should be noted that in this text, the term "comprising / having" means that a feature, member, step, or component exists, and does not exclude the existence or addition of one or more other features, members, steps, or components.

Brief Description of the Drawings

[0023] The elements and features described in one drawing and one embodiment of an example of the present invention may be combined with the elements and features shown in one or more additional drawings or embodiments. Also, in the drawings, like reference numerals denote corresponding elements in a plurality of drawings and may denote corresponding elements used in one or more embodiments.

[0024] The included drawings are used to further understand the examples of the present invention, form part of the specification, are used to illustrate the embodiments of the present invention, and explain the principles of the present invention together with the written description. Note that the drawings described below are merely some examples of the present invention, and those skilled in the art can easily conceive of other drawings based on these drawings.

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Embodiments for Carrying Out the Invention

[0025] The above and other features of the present invention will become apparent from the following description. In the specification and drawings, specific embodiments of the present invention are disclosed in detail, and some embodiments in which the principles of the present invention can be adopted are shown. It should be noted that the present invention is not limited to the described embodiments. The present invention includes all modified, deformed, and equivalent ones within the scope of the appended claims.

[0026] In the embodiments of the present invention, terms such as "first" and "second" are used to distinguish different elements in the title, but do not represent the spatial arrangement or temporal order of these elements, and these elements are not limited by these terms. The term "and / or" includes any one and all combinations of one or more of the terms listed in the related list. Terms such as "include", "comprise", "have", etc. mean the existence of the recited features, elements, elements or components, but do not exclude the existence or addition of one or more other features, elements, elements or components.

[0027] In the embodiments of the present invention, singular forms such as "one" and "the" include the plural form and should be understood broadly as "one type" or "one category", and are not limited to "one". Also, the term "the foregoing" should be understood to include both singular and plural forms unless the context clearly indicates otherwise. Also, unless the context clearly indicates otherwise, the term "described in" should be understood as "described in at least part", and the term "based on" should be understood as "based on at least part".

[0028] In the embodiments of the present invention, the term "communication network" or "wireless communication network" may mean a network that conforms to any communication standard such as, for example, new radio (NR), Long Term Evolution (LTE), Long Term Evolution - Advanced (LTE - A), Wideband Code Division Multiple Access (WCDMA (registered trademark)), High - Speed Packet Access (HSPA), etc.

[0029] Also, the communication between devices in the communication system may be performed according to the communication protocol at any stage, and the communication protocol may include, for example, 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, and future 5G, 6G, etc., and / or other current known communication protocols or other communication protocols to be developed in the future, but is not limited thereto.

[0030] In an embodiment of the present invention, the term "network device" means, for example, a device in a communication system that allows a terminal device to access the communication system and provides services to the terminal device. The network device may include, but is not limited to, a base station (BS: Base Station), an access point (AP: Access Point), a transmission reception point (TRP: Transmission Reception Point), a broadcast transmitter, a mobility management entity (MME: Mobile Management Entity), a gateway, a server, a radio network controller (RNC: Radio Network Controller), a base station controller (BSC: Base Station Controller), etc.

[0031] Among them, the base station may include, but is not limited to, a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), and a 5G base station (gNB), etc., and also include a remote radio head (RRH: Remote Radio Head), a remote radio unit (RRU: Remote Radio Unit), a relay device (relay), or a low-power node (e.g., femto, pico, etc.). Also, the term "base station" may include some or all of their functions, and each base station may provide communication coverage for a specific geographical area. The term "cell" may mean a base station and / or its coverage area depending on the context in which the term is used.

[0032] In an embodiment of the present invention, the term "user equipment" (UE) or the term "terminal equipment" (TE) means a device that accesses a communication network via a network device, for example, and receives network services. The terminal equipment may be fixed or mobile, and may be referred to as a mobile station (MS), a terminal, a subscriber station (SS), an access terminal (AT), a station, etc.

[0033] Among them, the terminal equipment may include, but is not limited to, a cellular phone, a personal digital assistant (PDA), a radio transceiver, a wireless communication device, a handheld device, a machine type communication device, a laptop computer, a cordless phone, a smartphone, a smartwatch, a digital camera, etc.

[0034] For example, in a scenario such as the Internet of Things (IoT), the user equipment may be a device or apparatus that performs monitoring or measurement, and may include, but is not limited to, a machine type communication (MTC) terminal, a vehicle-mounted communication terminal, a device-to-device (D2D) terminal, a machine-to-machine (M2M) terminal, etc.

[0035] Rel-16 NR standardized the network topology adaptation procedure when an IAB-node moves in the same donor-CU. When the parent node of the IAB-node is changed, the Donor-CU configures the configuration related to the network topology update for the IAB-node using the RRC reconfiguration message so that the IAB-node migrates the F1 transmission path.

[0036] The configurations related to network topology update include the update of the BAP address of the IAB-node, uplink F1-C, F1-U, and the backhaul RLC channel for non-F1 data (BH RLC channel), and the update of the BAP routing identifier (the BAP address and path identifier of the Donor-DU). When the target Donor-DU is different from the source donor-DU after migration, it is necessary to update the source TNL address that can be routed through the Donor-DU, and the TNL address is assigned by the target Donor-DU.

[0037] When the IAB-node accesses the new parent node, the application of the configurations related to the above network topology update starts. That is, the IAB-node begins to use the new BAP address, and the uplink F1 transmission and non-F1 transmission of the IAB-node begin to use the configured BAP routing identifier and source TNL address. For the downstream descendant nodes of the IAB-node, the configurations related to the network topology update are also performed in the same way.

[0038] FIG. 8 is a schematic diagram of an example of the intra-CU topology adaptation process, showing the currently standardized intra-CU topology adaptation including the switching of the IAB-MT migrating the IAB-node and the migration process of the F1 connection between the IAB-DU and the donor-CU.

[0039] In FIG. 8, for simplicity, some of the entities are omitted. For example, the source path may include at least one of a source parent IAB-node, an intermediate hop IAB-node on the source path, and a source IAB-donor-DU, and the target path may include at least one of a target parent IAB-node, an intermediate hop IAB-node on the target path, and a target IAB-donor-DU. Although FIG. 8 schematically shows only that the IAB node performs Intra-CU topology adaptation, the present invention is not limited thereto, and details may refer to related technologies.

[0040] In an existing topology redundancy process, the IAB-node and its descendant nodes may not have a TNL address that can be routed through the target Donor-DU. When the IAB-node accesses a new parent node, the source TNL address of the uplink data still adopts a TNL address that can be routed through the source Donor-DU, that is, the TNL address assigned by the source Donor-DU.

[0041] When the target Donor-DU after the migration of the IAB-node is different from the source Donor-DU, that is, when performing intra-donor CU topology redundancy or inter-donor CU toplogy redundancy, the uplink data whose source TNL addresses are the TNL addresses assigned by the source Donor-DU is transmitted to the target donor-DU through the post-migration path. Since these data do not have the TNL address assigned by the target Donor-DU, they are discarded by the filtering function of the source TNL address of the target Donor-DU.

[0042] Accordingly, the target TNL address of the downlink data still adopts the TNL address that can be routed by the source Donor-DU, that is, the TNL address assigned by the source Donor-DU. When the target Donor-DU after the IAB-node migration is different from the source Donor-DU, the downlink data whose target TNL addresses are the TNL addresses assigned by the source Donor-DU cannot be routed to the target Donor-DU, so it is discarded by the source Donor-DU.

[0043] Also, even if a TNL address that can be routed via the target Donor-DU is configured for the IAB-node and its descendant nodes, when the migrating IAB-node accesses the new parent node, some uplink data (UL data inflight) whose source TNL address adopts the TNL address that can be routed by the source Donor-DU, that is, the uplink data whose source TNL address is the TNL address assigned by the source Donor-DU, may exist in the IAB-node and each of its descendant nodes. When the target Donor-DU after the IAB-node migration is different from the source Donor-DU, the uplink data whose source TNL addresses are the TNL addresses assigned by the source Donor-DU is discarded by the source TNL address filtering function of the target Donor-DU.

[0044] Accordingly, when the migrating IAB-node accesses the new parent node, the source Donor-DU may have some downlink data (DL data inflight) whose target TNL address is a TNL address that can be routed through the source Donor-DU before migration, that is, downlink data whose target TNL address is the TNL address assigned by the source Donor-DU. If the target Donor-DU after IAB-node migration is different from the source Donor-DU, the downlink data whose target TNL addresses are the TNL addresses assigned by the source Donor-DU is discarded by the source Donor-DU.

[0045] Regarding the above problems or similar problems, embodiments of the present invention provide a TNL tunnel between donor-DUs, which will be described in detail below. In the embodiments of the present invention, unless otherwise specified, the IAB node includes a migrating IAB node or its descendant nodes.

[0046] <Example 1> Embodiments of the present invention provide an IAB communication method, which describes the transmission of uplink data by a second donor distributed unit. Here, the IAB node migrates from a first donor distributed unit (source donor-DU) to a second donor distributed unit (target donor-DU), and a transmission network layer (TNL) tunnel is established between the first donor distributed unit and the second donor distributed unit.

[0047] FIG. 9 is a schematic diagram of an example of the IAB communication method according to an embodiment of the present invention. As shown in FIG. 9, the method includes the following steps.

[0048] Step 901: The second donor distributed unit receives uplink data sent by the IAB node.

[0049] Step 902: The second donor distributed unit adds a header related to the TNL tunnel to the uplink data.

[0050] Step 903: The second donor distribution unit transmits uplink data to the first donor distribution unit via the TNL tunnel.

[0051] Note that the above FIG. 9 only schematically shows an embodiment of the present invention, but the present invention is not limited thereto. For example, the execution order between various steps may be appropriately adjusted, or several other steps may be added, or several steps may be reduced. Those skilled in the art can make appropriate modifications based on the above content and are not limited to the description of FIG. 9 above.

[0052] In some aspects, the header (also referred to as a head) includes at least one of an Internet Protocol (IP) header, a General Packet Radio Service (GPRS) tunneling protocol (GTP) header, a User Datagram Protocol (UDP) header, or a Transmission Control Protocol (TCP) header.

[0053] In some aspects, the source transmission network layer (TNL) address of the header is the TNL address of the second donor distribution unit or a TNL address routable by the second donor distribution unit, and the target TNL address of the header is the TNL address of the first donor distribution unit.

[0054] For example, uplink data whose source TNL address is a TNL address routable by the source Donor-DU has an IP header added by the target donor-DU, or a GTP / UDP or TCP header is further added. The source TNL address in the added IP header and GTP / UDP or TCP header is the TNL address of the target donor-DU or a TNL address routable by the target Donor-DU, and the target TNL address is the TNL address of the source donor-DU side tunnel endpoint (i.e., the TNL address of the source donor-DU).

[0055] In this way, a TNL tunnel is established between the source donor-DU and the target donor-DU of the IAB-node migration. Therefore, when the IAB-node migrates across the donor distributed unit, the uplink data whose source TNL address is a TNL address routable via the source Donor-DU is transmitted from the target donor-DU to the source donor-DU via the TNL tunnel and routed to the donor-CU via the source donor-DU, thus solving the problem that these uplink data are discarded by the target donor-DU.

[0056] The following further describes embodiments of the present invention with reference to the transmission of uplink data in different scenarios.

[0057] First, the uplink data transmission in the scenario of intra-donor CU migration (for example, referred to as Scenario 1) will be described.

[0058] In some aspects, after the migrating IAB node is switched from the first donor distributed unit to the second donor distributed unit, or after the radio link from the migrating IAB node to the first donor distributed unit fails (RLF), the radio resource control (RRC) is re-established to the second donor distributed unit. Here, the first donor distributed unit and the second donor distributed unit belong to the same donor aggregation unit (donor-CU).

[0059] In other words, when the IAB-node performs intra-donor CU migration, TNL tunnel transmission is performed between the source donor-DU and the target donor-DU. For example, when the migrating IAB-node migrates to a new parent node, the transmission path of all data migrates from the original parent node of the IAB-node to the new parent node, and the donor-DU is changed from the source donor-DU to the target donor-DU. Whether or not the migrating IAB-node and its descendant nodes are configured with the TNL addresses assigned by the target donor-DU, uplink and downlink data discarding occurs, and it is necessary to perform TNL tunnel transmission between the target donor-DU and the source Donor-DU.

[0060] In some aspects, the second donor distributed unit receives a TNL tunnel transmission establishment request sent by the donor aggregation unit. The TNL tunnel transmission establishment request includes the end-point TNL address of the TNL tunnel of the first donor distributed unit, where the TNL tunnel transmission establishment request is used to request the second donor distributed unit to establish a TNL tunnel or activate the TNL tunnel transmission of uplink data.

[0061] For example, after the donor aggregation unit receives the switching completion message of the migrating IAB node, or after the donor aggregation unit receives the RRC re-establishment completion message of the migrating IAB node, or when the donor aggregation unit has not configured the TNL address assigned by the second donor distributed unit for the migrating IAB node, the second donor distributed unit receives the TNL tunnel transmission establishment request sent by the donor aggregation unit.

[0062] In some aspects, the TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to activate the TNL tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to activate the TNL tunnel transmission.

[0063] For example, the donor-CU sends a TNL tunnel transmission establishment request to the target donor-DU. For example, the TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Also, the TNL tunnel transmission establishment request may further include the source TNL address of the uplink F1 user plane, the source TNL address of the uplink F1 control plane, and the source TNL address of the uplink non-F1 data. Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes.

[0064] In some aspects, the second donor distributed unit sends a TNL tunnel transmission establishment response to the donor aggregation unit. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit.

[0065] In some aspects, the TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane where the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane where the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data where the activation of the TNL tunnel transmission is successful, or the source TNL address where the activation fails.

[0066] For example, the target donor-DU sends a TNL tunnel transmission establishment response to the donor-CU. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission establishment response may further include the source TNL address of the uplink F1 user plane transmitted via a normally activated tunnel, the source TNL address of the uplink F1 control plane, the source TNL address of the uplink non-F1 data, and the source TNL address for which activation has failed.

[0067] FIG. 10 is a diagram showing an example of activation of a TNL tunnel according to an embodiment of the present invention. As shown in FIG. 10, after the TNL tunnel transmission of the target donor-DU is established, the target donor-DU transmits uplink data (the source TNL address is the TNL address assigned by the source Donor-DU) configured by a TNL tunnel transmission establishment request to the source donor-DU via the TNL tunnel, and then it is routed to the source donor-CU by the source donor-DU.

[0068] In some aspects, the second donor distribution unit further receives service mapping information transmitted by the donor aggregation unit. The service mapping information is used to configure the backhaul adaptation protocol (BAP) routing identifier of the downlink data transmitted via the TNL tunnel and the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop.

[0069] For example, for the target donor-DU, the donor-CU further configures service mapping information for the downlink data transmitted via the activated TNL tunnel. In order for the target Donor-DU to send the downlink data transmitted via these TNL tunnels to the migration IaB-node or its descendant nodes, the service mapping information includes the TNL address of the downlink data and the BAP target address and route identifier corresponding to the DSCP (Differentiated Services Code Point), and the identifier of the backhaul RLC channel where the TNL address and DSCP of the downlink data are mapped to the target donor-DU and the next-hop IAB-node.

[0070] After the donor-CU configures the TNL address assigned by the target donor-DU (i.e., the TNL address routable via the target donor-DU) for the IAB-node, the uplink data carrying the TNL address assigned by the target donor-DU is not discarded by the target donor-DU. That is, it can be normally transmitted to the donor-CU without TNL tunnel transmission, and the donor-CU may trigger an update for the relevant update or release the TNL tunnel transmission. The IAB-node includes the migration IAB-node or its descendant nodes.

[0071] In some aspects, the second donor distributed unit receives a TNL tunnel transmission update or release request sent by the donor aggregation unit. The TNL tunnel transmission update or release request includes the end-point TNL address of the TNL tunnel of the first donor distributed unit, and the TNL tunnel transmission update or release request is used to request the second donor distributed unit to deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel.

[0072] In some embodiments, after the donor aggregation unit constructs the TNL address assigned by the second donor disaggregation unit for the IAB node, or after a predetermined time after the handover by the IAB node is completed, or after a predetermined time after the re-establishment by the migrating IAB node is completed, the second donor disaggregation unit receives the TNL tunnel transmission update or release request sent by the donor aggregation unit.

[0073] For example, when the migrating IAB-node is handed over, if the donor-CU configures the TNL address for the F1-C data and non-F1 data that can be routed via the target donor-DU to the migrating IAB-node, after a predetermined time after the handover is completed, the donor-CU deactivates the TNL tunnel transmission of the F1-C data and non-F1 data of the migrating IAB-node.

[0074] As another example, after the handover is completed, if the donor-CU configures the TNL address of the F1-U data that can be routed via the target donor-DU to the migrating IAB-node via the RRC reconfiguration message, after a predetermined time after the RRC reconfiguration is completed, the donor-CU deactivates the TNL tunnel transmission of F1-U of the migrating IAB-node.

[0075] In order to successfully route the uplink inflight data to the donor-CU via the TNL tunnel, when a predetermined time elapses after the TNL address assigned by the target donor-DU is configured by the donor-CU for the IAB-node, it triggers the update or release of the TNL tunnel transmission.

[0076] In some aspects, the TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission.

[0077] For example, the donor-CU sends a TNL tunnel transmission update or release request to the target donor-DU. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Further, the TNL tunnel transmission update or release request may further include the source TNL address of the uplink F1 user plane that needs to deactivate the tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to deactivate the tunnel transmission. Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes.

[0078] In some aspects, the second donor distributed unit further sends a TNL tunnel transmission update or release response to the donor aggregation unit. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit.

[0079] In some aspects, the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane where the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane where the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data where the deactivation of the TNL tunnel transmission is successful, or the source TNL address where the deactivation fails.

[0080] For example, the target donor-DU sends a TNL tunnel transmission update or release response to the donor-CU. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission update or release response may further include the source TNL address of the uplink F1 user plane for which the deactivation of the tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the deactivation of the tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the deactivation of the tunnel transmission has succeeded, or the source TNL address for which the deactivation has failed.

[0081] FIG. 11 is a diagram showing an example of deactivation of a TNL tunnel according to an embodiment of the present invention. As shown in FIG. 11, after the TNL tunnel transmission of the target donor-DU is updated or released, the target donor-DU does not transmit, via the TNL tunnel, the uplink data (the source TNL address is the TNL address assigned by the source Donor-DU) deleted from the TNL tunnel transmission configured in the TNL tunnel transmission update or release request, but directly discards it.

[0082] In some aspects, the second donor distributed unit further receives a service mapping information release instruction sent by the donor aggregation unit. The service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data for which the TNL tunnel transmission has been deactivated and the configuration of the backhaul RLC channel between the second donor distributed unit and the descendant node of the next hop.

[0083] For example, after the TNL address configured by the target donor-DU is allocated, the IAB-node may send the TNL addresses of the applied uplink and downlink data to the donor-CU via F1 connection control plane signaling (F1AP). For example, the donor-CU may be sent the TNL addresses allocated by the target donor-DU applied to each of the F1 user plane, F1 control plane, and non-F1 data, as well as the TNL addresses previously used by this data (the TNL addresses allocated to the source donor-DU). Thereby, the donor-CU is triggered to request the target donor-DU and the source donor-DU to remove this data from the TNL tunnel transmission.

[0084] Also, in the target donor-DU, the donor-CU needs to reconfigure the service mapping information for the downlink data for which the TNL address allocated by the target donor-DU is already configured. For example, configure the BAP target address and route identifier corresponding to the new TNL address and DSCP of the downlink data, and the identifier for which the TNL address and DSCP of the downlink data are mapped to the backhaul RLC channel between the target donor-DU and the next-hop IAB-node. Also, the donor-CU deletes the previous service mapping information.

[0085] Next, the uplink data transmission in the scenario of the dual connection in the intra-donor CU (which may also be referred to as Scenario 2) will be described.

[0086] In some aspects, the IAB node performs multi-path distribution within the donor aggregation unit (intra-donor CU), and the first donor distributed unit and the second donor distributed unit belong to the same donor aggregation unit (donor-CU).

[0087] In other words, when the IAB-node performs multi-path delivery (intra-donor CU topology redundancy) of the intra-donor CU, TNL tunnel transmission is performed between the source donor-DU and the target donor-DU. For example, when the migrating IAB-node accesses a new parent node, the transmission path of some data migrates from the original parent node of the IAB-node to the new parent node, and the donor-DU changes from the source donor-DU to the target donor-DU. Also, the transmission path of some data is still transmitted via the original parent node and the source donor-DU. For the data whose transmission path has migrated to the target donor-DU, if the TNL address assigned to the target donor-DU is not configured, uplink and downlink data discard will occur, and it is necessary to perform TNL tunnel transmission between the target donor-DU and the source Donor-DU.

[0088] In some aspects, the second donor distributed unit receives a TNL tunnel transmission establishment request sent by the donor aggregation unit. The TNL tunnel transmission establishment request includes the end-point TNL address of the TNL tunnel of the first donor distributed unit, where the TNL tunnel transmission establishment request is used to request the second donor distributed unit to establish a TNL tunnel or activate the TNL tunnel transmission of the uplink data.

[0089] In some aspects, when the donor aggregation unit configures the backhaul adaptation protocol (BAP) routing of the IAB node as the BAP routing identifier of the second donor distributed unit and does not configure the TNL address assigned by the second donor distributed unit, the second donor distributed unit receives a TNL tunnel transmission establishment request sent by the donor aggregation unit. The IAB node includes a migrating IAB node or its descendant nodes.

[0090] For example, when the donor-CU configures the uplink F1 control plane of the IAB node and the BAP routing of non-F1 data with the BAP address and path identifier of the target donor-DU, or when the donor-CU configures a BAP address that can be routed by the target donor-DU for the IAB-node, routes the downlink F1 control plane and non-F1 data of the IAB-node from the target donor-DU to the IAB-node, and does not configure the TNL address assigned by the target donor-DU for the IAB node, the donor-CU triggers to establish a TNL tunnel transmission.

[0091] In some aspects, the TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to activate the TNL tunnel transmission, or the GTP tunnel endpoint identifier (TEID: Tunnel Endpoint Identifier) of the uplink F1 user plane that needs to activate the TNL tunnel transmission.

[0092] For example, the donor-CU sends a TNL tunnel transmission establishment request to the target donor-DU. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Further, the TNL tunnel transmission establishment request may further include the source TNL address of the uplink F1 user plane that needs to be transmitted through the tunnel, the source TNL address of the uplink F1 control plane that needs to be transmitted through the tunnel, and the source TNL address of the uplink non-F1 data that needs to be transmitted through the tunnel.

[0093] Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes. Note that the minimum granularity of the uplink F1 user plane path distribution is the UE bearer. Since different UE bearers use different GTP-U tunnels, when requesting the TNL tunnel transmission of the uplink F1 user plane, in addition to indicating the source TNL address, it is also necessary to further indicate the UL GTP TEID.

[0094] In some aspects, the second donor distributed unit sends a TNL tunnel transmission establishment response to the donor aggregation unit. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit.

[0095] In some aspects, the TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane for which the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane for which the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data for which the activation of the TNL tunnel transmission is successful, or the source TNL address for which the activation fails.

[0096] For example, the target donor-DU sends a TNL tunnel transmission establishment response to the donor-CU. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission establishment response may further include the source TNL address of the uplink F1 user plane for which the activation of the tunnel transmission is successful, the source TNL address of the uplink F1 control plane for which the activation of the tunnel transmission is successful, the source TNL address of the uplink non-F1 data for which the activation of the tunnel transmission is successful, or the source TNL address for which the activation fails.

[0097] FIG. 12 is a diagram showing another example of activation of the TNL tunnel according to an embodiment of the present invention. As shown in FIG. 12, after the TNL tunnel of the target donor-DU is established, the target donor-DU transmits uplink data (the source TNL address is the TNL address assigned by the source Donor-DU) configured with a TNL tunnel transmission establishment request to the source donor-DU via the TNL tunnel, and then may be routed to the donor-CU by the source donor-DU.

[0098] In some aspects, the second donor distributed unit further receives service mapping information configured by the donor aggregation unit. The service mapping information is used to configure the BAP routing identifier of the downlink data transmitted via the TNL tunnel and the backhaul RLC channel between the second donor distributed unit and the descendant nodes of the next hop.

[0099] For example, for the target donor-DU, the donor-CU further configures service mapping information of the downlink data whose target TNL address configured with the TNL tunnel transmission establishment request is the TNL address assigned to the source Donor-DU. For example, it includes the BAP target address and path identifier corresponding to the TNL address and DSCP of the downlink data, and the identifier of the backhaul RLC channel where the TNL address and DSCP of the downlink data are mapped between the target donor-DU and the IAB-node of the next hop. Thereby, the target Donor-DU can transmit the downlink data of these TNL tunnel transmissions to the migrating IAB-node or its descendant nodes.

[0100] In some aspects, the second donor distribution unit receives a TNL tunnel transmission update or release request sent by the donor aggregation unit. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission update or release request is used to request the second donor distribution unit to deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel.

[0101] In some aspects, after the donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, the second donor distribution unit receives a TNL tunnel transmission update or release request sent by the donor aggregation unit.

[0102] For example, after the TNL address (a TNL address routable from the target donor-DU) assigned by the target donor-DU for the data migrated to the target donor-CU side by the IAB node is configured, if the uplink and downlink data carrying the TNL address assigned by the target donor-DU can be normally sent to the donor-CU or the IAB-node without TNL transmission, the donor-CU may trigger to update or release the TNL tunnel transmission for the relevant uplink and downlink data.

[0103] As another example, when the migrated IAB-node is connected to a new parent node and a dual connection with the new parent node is established, and then its F1 control plane and non-F1 data are migrated to the target donor-DU, when the donor-CU configures the TNL address assigned by the target donor-DU for the F1 control plane and non-F1 data of the migrated IAB-node, the donor-CU deactivates the TNL tunnel transmission to the F1-C and non-F1 data of the migrated IAB-node.

[0104] In some aspects, the TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission, or the GTP TEID of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission.

[0105] For example, the donor-CU sends a TNL tunnel transmission update or release request to the target donor-DU. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. The TNL tunnel transmission update or release request may further include the source TNL address of the uplink F1 user plane that needs to deactivate the tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to deactivate the tunnel transmission. Here, F1 includes the F1 connection of the migrating IAB-node and its descendant nodes.

[0106] In some aspects, the second donor distributed unit sends a TNL tunnel transmission update or release response to the donor aggregation unit. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit.

[0107] In some aspects, the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane for which the deactivation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the deactivation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the deactivation of the TNL tunnel transmission has succeeded, or the source TNL address for which the deactivation has failed.

[0108] For example, the target donor-DU sends a TNL tunnel transmission update or release response to the donor-CU. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission update or release response may further include the source TNL address of the uplink F1 user plane for which the deactivation of the tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the deactivation of the tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the deactivation of the tunnel transmission has succeeded, or the source TNL address for which the deactivation has failed.

[0109] FIG. 13 is a diagram showing another example of the deactivation of the TNL tunnel according to an embodiment of the present invention. As shown in FIG. 13, after the TNL tunnel transmission of the target donor-DU is updated or released, the target donor-DU does not send the uplink data deleted from the TNL tunnel transmission to the source donor-DU and directly discards it.

[0110] In some aspects, the second donor distributed unit further receives a service mapping information release instruction sent by the donor aggregation unit. The service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data for which the TNL tunnel transmission has been deactivated and the configuration of the backhaul RLC channel between the second donor distributed unit and the descendant node of the next hop.

[0111] For example, after the TNL address assigned by the target donor-DU is configured, the IAB node may send the TNL addresses of the applied uplink and downlink data to the donor-CU via F1 connection control plane signaling (F1AP). For example, the donor-CU may be sent the TNL address assigned by the target donor-DU applied to each of the F1 user plane, F1 control plane, and non-F1 data, as well as the TNL address previously used for these data (the TNL address assigned to the source donor-DU). Thereby, the donor-CU is triggered to request the target donor-DU and the source donor-DU to delete these data from TNL tunnel transmission.

[0112] Also, in the target donor-DU, the donor-DU reconstructs the service mapping information for the downlink data for which the TNL address assigned by the target donor-DU is configured. For example, it configures the BAP target address and route identifier corresponding to the new TNL address and DSCP of the downlink data, and the identifier for which the TNL address and DSCP of the downlink data are mapped to the backhaul RLC channel between the target donor-DU and the next-hop IAB-node. Also, the donor-CU further deletes the service mapping information before these downlink data (i.e., when transmitted via the TNL tunnel).

[0113] Next, the uplink data transmission in the scenario of inter-donor CU migration (for example, referred to as Scenario 3) will be described.

[0114] In some aspects, after the IAB node is switched from a first donor distributed unit to a second donor distributed unit, or after the radio link from the IAB node to the first donor distributed unit fails (RLF), the RRC is re-established to the second donor distributed unit, the first donor distributed unit belongs to the first donor aggregation unit, and the second donor distributed unit belongs to the second donor aggregation unit.

[0115] In other words, when the IAB-node performs an inter-donor CU migration, TNL tunnel transmission is performed between the source donor-DU and the target donor-DU. Here, the source donor-DU is controlled by the source donor-CU, and the target donor-DU is controlled by the target donor-CU.

[0116] For example, when the migrating IAB-node switches to the target donor-CU, all data transmission paths migrate from the source donor-CU side of the IAB-node to the target donor-CU side. When the donor-DU is changed from the source donor-DU to the target donor-DU, whether or not the TNL address assigned by the target donor-DU is configured for the migrating IAB-node and descendant nodes, uplink and downlink data discard occurs, and it is necessary to perform TNL tunnel transmission between the target donor-DU and the source Donor-DU.

[0117] In some aspects, the second donor distributed unit receives a TNL tunnel transmission establishment request sent by the second donor aggregation unit. The TNL tunnel transmission establishment request includes the end-point TNL address of the TNL tunnel of the first donor distributed unit. Here, the TNL tunnel transmission establishment request is used to request the second donor distributed unit to establish the TNL tunnel or activate the TNL tunnel transmission of the uplink data.

[0118] In some embodiments, after the second donor aggregation unit receives the switching completion message of the IAB node, or after the second donor aggregation unit receives the RRC re-establishment completion message of the IAB node, or when the second donor aggregation unit does not configure the TNL address assigned by the second donor distribution unit for the IAB node, the second donor distribution unit receives the TNL tunnel transmission establishment request sent by the second donor aggregation unit.

[0119] For example, the Handover Request message for the migrating IAB-node sent by the source donor-CU to the target donor-CU includes the TNL address of the endpoint of the TNL tunnel on the source donor-DU side, the F1 user plane of the migrating IAB-node assigned by the source donor-DU, the TNL addresses used by the F1 control plane and non-F1 data, or further includes the TNL addresses used by the F1 user plane, the F1 control plane and non-F1 data of the descendant nodes of the migrating IAB-node assigned by the source donor-DU. For example, the Handover Response message for the migrating IAB-node sent by the target donor-CU to the source donor-CU includes the TNL address of the endpoint of the TNL tunnel on the target donor-DU side.

[0120] In some embodiments, the TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane for which TNL tunnel transmission needs to be activated, the source TNL address of the uplink F1 control plane for which TNL tunnel transmission needs to be activated, or the source TNL address of the uplink non-F1 data for which TNL tunnel transmission needs to be activated, according to the method described in Annex 31.

[0121] For example, the target donor-CU receives a handover completion message from the migrating IAB-node and sends a TNL tunnel transmission establishment request to the target donor-DU. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Here, the TNL tunnel transmission establishment request may further include the source TNL address of the uplink F1 user plane, the source TNL address of the uplink F1 control plane, and the source TNL address of the uplink non-F1 data. Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes.

[0122] In some aspects, the second donor distributed unit sends a TNL tunnel transmission establishment response to the second donor centralized unit. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit.

[0123] In some aspects, the TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the source TNL address for which the activation has failed.

[0124] For example, the target donor-DU sends a TNL tunnel transmission establishment response to the target donor-CU. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission establishment response may further include the source TNL address of the uplink F1 user plane for which the activation of tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the activation of tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the activation of tunnel transmission has succeeded, or the source TNL address for which the activation has failed.

[0125] FIG. 14 is a diagram showing another example of the activation of a TNL tunnel according to an embodiment of the present invention. As shown in FIG. 14, after the TNL tunnel transmission of the target donor-DU is established, the target donor-DU transmits uplink data (the source TNL address is the TNL address assigned from the source Donor-DU) configured by a TNL tunnel transmission establishment request to the source donor-DU via the TNL tunnel, and then it is routed to the source donor-CU by the source donor-DU.

[0126] In some aspects, the second donor distributed unit further receives service mapping information transmitted by the donor aggregation unit. The service mapping information is used to configure the BAP routing identifier of the downlink data transmitted via the TNL tunnel and the backhaul RLC channel between the second donor distributed unit and the descendant node of the next hop.

[0127] For example, for the target donor-DU, the target donor-CU needs to configure service mapping information for downlink data where the target TNL address composed of the TNL tunnel transmission establishment request is the TNL address assigned by the source Donor-DU. This includes the BAP target address and route identifier corresponding to the TNL address and DSCP of the downlink data, and the identifier for mapping the TNL address and DSCP of the downlink data to the backhaul RLC channel between the target donor-DU and the next-hop IAB-node. Thereby, the target Donor-DU can send the downlink data of these TNL tunnel transmissions to the migrating IaB-node or its descendant nodes. Therefore, the source donor-CU needs to send the DSCP of the downlink service of the migrating IAB-node or its descendant nodes to the target donor-CU, for example, via a Handover Request message.

[0128] After the IAB-node configures the TNL address assigned by the target donor-DU for the target donor-CU (the TNL address that can be routed via the target donor-DU), the uplink and downlink data carrying the TNL address assigned by the target donor-DU do not need to pass through TNL transmission and are successfully sent to the source donor-CU or the IAB-node. The target donor-CU can trigger an update for the relevant uplink and downlink data or release the TNL tunnel transmission, and the source donor-CU can trigger an update for the relevant downlink data or release the TNL tunnel transmission.

[0129] In some aspects, the second donor distribution unit receives a TNL tunnel transmission update or release request sent by the second donor aggregation unit. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission update or release request is used to request the second donor distribution unit to deactivate the TNL tunnel transmission of uplink data or to release the TNL tunnel.

[0130] In some aspects, after the second donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the migrating IAB node or its descendant nodes, or after a predetermined time after the switching by the migrating IAB node is completed, or after a predetermined time after the re-establishment by the migrating IAB node is completed, the second donor distribution unit receives a TNL tunnel transmission update or release request sent by the second donor aggregation unit.

[0131] For example, when the migrating IAB-node switches, if the target donor-CU configures the TNL address for the F1-C data and non-F1 data that can be routed through the target donor-DU for the migrating IAB-node, after a predetermined time after the switching is completed, the target donor-CU and the source donor-CU deactivate the TNL tunnel transmission for the F1-C data and non-F1 data of the migrating IAB-node.

[0132] Also, for example, after the switching is completed, the migrating donor-CU configures the TNL address for the F1-U data that can be routed through the target donor-DU for the migrating IAB-node via a reconfiguration message. After a predetermined time of RRC reconfiguration completion, the target donor-CU and the source donor-CU deactivate the TNL tunnel transmission of F1-U of the migrating IAB-node.

[0133] To normally route the uplink in-flight data to the source donor-CU via TNL tunnel transmission, after a predetermined time after the target donor-CU configures the TNL address assigned by the target donor-DU to the IAB-node, it triggers to update or release the TNL tunnel transmission.

[0134] In some aspects, the TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission.

[0135] For example, the target donor-CU sends a TNL tunnel transmission update or release request to the target donor-DU. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Also, the update or release request of the target TNL tunnel may further include the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission. Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes.

[0136] In some aspects, the second donor distributed unit sends a TNL tunnel transmission update or release response to the second donor centralized unit. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit.

[0137] In some aspects, the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane for which the deactivation of the TNL tunnel transmission was successful, the source TNL address of the uplink F1 control plane for which the deactivation of the TNL tunnel transmission was successful, the source TNL address of the uplink non-F1 data for which the deactivation of the TNL tunnel transmission was successful, or the source TNL address for which the deactivation failed.

[0138] For example, the target donor-DU sends a TNL tunnel transmission update or release response to the target donor-CU. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission update or release response may further include the source TNL address of the uplink F1 user plane for which the deactivation of the tunnel transmission was successful, the source TNL address of the uplink F1 control plane for which the deactivation of the tunnel transmission was successful, the source TNL address of the uplink non-F1 data for which the deactivation of the tunnel transmission was successful, or the source TNL address for which the deactivation failed.

[0139] FIG. 15 is a diagram showing another example of the deactivation of the TNL tunnel according to an embodiment of the present invention. As shown in FIG. 15, after the TNL tunnel transmission of the target donor-DU is updated or released, the target donor-DU does not send the uplink data (the source TNL address is the TNL address assigned by the source Donor-DU) for which the transmission via the TNL tunnel has been deactivated to the source donor-DU, but directly discards it.

[0140] In some aspects, the second donor distribution unit further receives a service mapping information release instruction sent by the donor aggregation unit. The service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data with TNL tunnel transmission deactivated and the configuration of the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop.

[0141] For example, after the TNL address assigned by the target donor-DU is configured, the IAB-node may further send the TNL addresses of the applied uplink and downlink data to the source donor-CU via the F1 connection control plane signaling (F1AP). For example, the source donor-CU may be sent the TNL address assigned by the target donor-DU applied to each of the F1 user plane, F1 control plane, and non-F1 data, as well as the TNL address used before for these data (the TNL address assigned by the source donor-DU). This triggers the source donor-CU and the target donor-DU to respectively request the source donor-DU and the target donor-DU to remove these data from TNL tunnel transmission.

[0142] Also, at the target donor-DU, the target donor-CU needs to reconfigure the service mapping information for the downlink data with the TNL address assigned by the target donor-DU. For example, it includes the configuration of the BAP target address and path identifier corresponding to the new TNL address and DSCP of the downlink data, and the configuration of the identifier that maps the new TNL address and DSCP of the downlink data to the backhaul RLC channel between the target donor-DU and the next hop IAB-node. The target donor-CU further deletes the previous service mapping information of these downlink data.

[0143] Next, the uplink data transmission in the scenario of inter-donor CU dual connection (for example, referred to as Scenario 4) will be described.

[0144] In some aspects, the IAB node performs multipath distribution between inter-donor CUs, where the first donor distributed unit belongs to the first donor aggregated unit and the second donor distributed unit belongs to the second donor aggregated unit.

[0145] In other words, when the migrating IAB-node performs multipath distribution of inter-donor CU (inter-donor-CU topology redundancy), TNL tunnel transmission is performed between the source donor-DU and the target donor-DU. For example, when the migrating IAB-node accesses the target donor-CU, the transmission path of some data migrates from the source donor-CU side of the IAB-node to the target donor-CU side, and the donor-DU changes from the source donor-DU to the target donor-DU, and the transmission path of some other data is still transmitted via the original parent node, the source donor-DU. For the data whose transmission path has migrated to the target donor-DU, if the TNL address assigned by the target donor-DU is not configured, uplink and downlink data discard will occur, and it is necessary to perform TNL tunnel transmission between the target donor-DU and the source Donor-DU.

[0146] In some aspects, the second donor distributed unit receives a TNL tunnel transmission establishment request sent by the second donor aggregated unit. The TNL tunnel transmission establishment request includes the end-point TNL address of the TNL tunnel of the first donor distributed unit, where the TNL tunnel transmission establishment request is used to request the second donor distributed unit to establish a TNL tunnel or activate the TNL tunnel transmission of uplink data.

[0147] In some aspects, when the second donor distribution unit configures the backhaul adaptation protocol (BAP) routing of the IAB node as the BAP routing identifier of the second donor distribution unit and does not configure the TNL address assigned by the second donor distribution unit, the second donor distribution unit receives the TNL tunnel transmission establishment request sent by the second donor aggregation unit.

[0148] For example, the source donor-CU sends to the target donor-CU the endpoint TNL address of the TNL tunnel on the source donor-DU side, the uplink F1 user plane, F1 control plane or non-F1 data requesting the transition to the migrating IAB-node or descendant node on the target donor-CU side, and the TNL address assigned to these data by the source donor-DU.

[0149] For example, it is performed by an SgNB node addition request message or an SgNB node modification request for the migrating IAB-node. The target donor-CU sends the endpoint TNL address of the TNL tunnel on the target donor-DU side to the source donor-CU by, for example, an SgNB node addition response message or an SgNB node modification response message for the migrating IAB-node.

[0150] When the transmission path of IAB-node data migrates to the target donor-CU side, that is, when the target donor-CU configures the uplink F1 control plane of the IAB-node and the BAP routing of non-F1 data with the BAP address and path identifier of the target donor-DU, and does not configure the TNL address assigned by the target donor-DU for the uplink F1 control data and non-F1 data, the target donor-CU and the source donor-CU trigger to establish TNL tunnel transmission.

[0151] In some aspects, the TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to activate the TNL tunnel transmission, or the GTP TEID of the uplink F1 user plane that needs to activate the TNL tunnel transmission.

[0152] For example, the target donor-CU sends a TNL tunnel transmission establishment request to the target donor-DU. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission establishment request may further include the source TNL address of the uplink F1 user plane, the source TNL address of the uplink F1 control plane, and the source TNL address of the uplink non-F1 data.

[0153] Here, F1 includes the F1 connection of the migrating IAB-node and its descendant nodes. Since the minimum granularity of the uplink F1 user plane path distribution is the UE bearer, when requesting uplink F1 user plane tunnel transmission, in addition to the source TNL address, it is necessary to further indicate the UL GTP TEID.

[0154] In some embodiments, the second donor distribution unit transmits a TNL tunnel transmission establishment response to the second donor aggregation unit. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit.

[0155] In some embodiments, the TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the source TNL address for which the activation has failed.

[0156] For example, the target donor-DU transmits a TNL tunnel transmission establishment response to the target donor-CU. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission establishment response may further include the source TNL address of the uplink F1 user plane for which the activation of the tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the activation of the tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the activation of the tunnel transmission has succeeded, or the source TNL address for which the activation has failed.

[0157] FIG. 16 is a diagram showing another example of the activation of a TNL tunnel according to an embodiment of the present invention. As shown in FIG. 16, after the TNL tunnel transmission of the target donor-DU is established, the target donor-DU transmits uplink data (the source TNL address is the TNL address assigned from the source Donor-DU) configured with a TNL tunnel transmission establishment request to the source donor-DU via the TNL tunnel, and then it is routed to the source donor-CU by the source donor-DU.

[0158] In some aspects, the second donor distribution unit further receives service mapping information constituted by the donor aggregation unit. The service mapping information is used to configure the BAP routing identifier of the downlink data transmitted via the TNL tunnel and the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop.

[0159] For example, for the target donor-DU, the target donor-CU further configures service mapping information for activating the downlink data transmitted via the TNL tunnel, which includes the BAP target address and path identifier corresponding to the TNL address and DSCP of the downlink data, and the identifier of the backhaul RLC channel where the TNL address and DSCP of the downlink data are mapped between the target donor-DU and the next hop IAB-node. Thereby, the target Donor-DU transmits the downlink data transmitted via these TNL tunnels to the migration IaB-node or its descendant nodes. Therefore, the source donor-CU transmits the DSCP of the downlink service that requests migration to the target donor-CU side, for example, by means of an SgNB node addition response message or an SgNB node modification response message, to the target donor-CU.

[0160] In some aspects, the second donor distribution unit receives a TNL tunnel transmission update or release request transmitted by the second donor aggregation unit. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission update or release request is used to request the second donor distribution unit to deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel.

[0161] For example, after the target donor-CU configures the TNL address (TNL address routable via the target donor-DU) assigned by the target donor-DU in the IAB-node, the uplink and downlink data carrying the TNL address assigned by the target donor-DU can be successfully transmitted to the source donor-CU or the IAB-node without the need for TNL transmission. The target donor-CU can trigger an update for the relevant uplink data or release the TNL tunnel transmission. The source donor-CU can trigger an update for the relevant downlink data or release the TNL tunnel transmission.

[0162] In some aspects, after the second donor aggregation unit configures the TNL address assigned by the second donor disaggregation unit for the IAB node, the second donor disaggregation unit receives a TNL tunnel transmission update or release request sent by the second donor aggregation unit.

[0163] For example, when the migrating IAB-node is connected to a new parent node, after the dual connection with the new parent node is established, the F1 control plane data and non-F1 data are migrated to the target donor-DU. When the target donor-CU configures the TNL address assigned by the target donor-DU for the F1 control plane and non-F1 data of the migrating IAB-node, the target donor-CU and the source donor-CU deactivate the TNL tunnel transmission for the F1-C and non-F1 data of the migrating IAB-node.

[0164] In some aspects, the TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission, or the GTP TEID of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission.

[0165] For example, the target donor-CU sends a TNL tunnel transmission update or release request to the target donor-DU. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission update or release request may further include the source TNL address of the uplink F1 user plane that needs to deactivate the tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the tunnel transmission, and the source TNL address of the uplink non-F1 data that needs to deactivate the tunnel transmission.

[0166] Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes. Since the minimum granularity of F1 user plane path distribution is the UE bearer, when requesting to remove the uplink F1 user plane from the tunnel transmission, in addition to the source TNL address, it is necessary to further indicate the UL GTP TEID.

[0167] In some aspects, the second donor distributed unit sends a TNL tunnel transmission update or release response to the second donor centralized unit. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit.

[0168] In some aspects, the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane where the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane where the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data where the deactivation of the TNL tunnel transmission is successful, or the source TNL address where the deactivation fails.

[0169] For example, the target donor-DU sends a TNL tunnel transmission update or release response to the target donor-CU. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission update or release response may further include the source TNL address of the uplink F1 user plane where the deactivation of the tunnel transmission is successful, the source TNL address of the uplink F1 control plane where the deactivation of the tunnel transmission is successful, the source TNL address of the uplink non-F1 data where the deactivation of the tunnel transmission is successful, or the source TNL address where the deactivation fails.

[0170] FIG. 17 is a diagram showing another example of the deactivation of the TNL tunnel according to an embodiment of the present invention. As shown in FIG. 17, after the TNL tunnel transmission of the target donor-DU is updated or released, the target donor-DU does not send the uplink data (the source TNL address is the TNL address assigned from the source Donor-DU) whose transmission is deactivated via the TNL tunnel to the source donor-DU via the TNL tunnel, but directly discards it.

[0171] In some aspects, the second donor distribution unit further receives a service mapping information release instruction sent by the donor aggregation unit. The service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data in which the TNL tunnel transmission is deactivated and the configuration of the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop.

[0172] For example, after the TNL address assigned by the target donor-DU is configured, the IAB-node may send the TNL addresses of the applied uplink and downlink data to the source donor-CU via the F1 connection control plane signaling (F1AP). For example, the TNL addresses assigned by the target donor-DU applied to each of the F1 user plane, F1 control plane, and non-F1 data, as well as the previously used TNL addresses of these data (the TNL addresses assigned to the source donor-DU), may be sent to the source donor-CU. Thereby, the source donor-CU and the target donor-DU are triggered to request the source donor-DU and the target donor-DU to remove these data from the TNL tunnel transmission respectively.

[0173] Also, in the target donor-DU, the target donor-CU performs reconfiguration of service mapping information including the configuration of the BAP target address and the path identifier corresponding to the new TNL address and DSCP of the downlink data, and the configuration of the identifier that maps the TNL address and DSCP of the downlink data to the backhaul RLC channel between the target donor-DU and the next-hop IAB-node, for the downlink data in which the TNL address assigned by the target donor-DU is already configured. Also, the donor-CU removes the previous service mapping information of these downlink data.

[0174] Each of the above embodiments is merely an illustration of an embodiment of the present invention, and the present invention is not limited thereto, and appropriate modifications may be made based on each of the above embodiments. For example, each of the above embodiments may be used alone, or one or more of the above embodiments may be used in combination.

[0175] According to this embodiment, the second donor distribution unit (target donor-DU) adds a header related to the tunnel to the uplink data and transmits the uplink data to the first donor distribution unit (source donor-DU) via the TNL tunnel. By establishing a TNL tunnel between the source donor-DU and the target donor-DU during the IAB-node migration in this way, the problem that uplink data is discarded can be solved.

[0176] <Example 2> Embodiments of the present invention provide an IAB communication method and describe the transmission of downlink data by a first donor distribution unit. Here, the IAB node migrates from the first donor distribution unit (source donor-DU) to the second donor distribution unit (target donor-DU), and a transmission network layer (TNL) tunnel is established between the first donor distribution unit and the second donor distribution unit.

[0177] FIG. 18 is a schematic diagram of an example of an IAB communication method according to an embodiment of the present invention. As shown in FIG. 18, the method includes the following steps.

[0178] Step 1801: The first donor distribution unit receives the downlink data transmitted to the IAB node.

[0179] Step 1802: The first donor distribution unit adds a header related to the transmission network layer (TNL) tunnel to the downlink data.

[0180] Step 1803: The first donor distribution unit transmits downlink data to the second donor distribution unit via the TNL tunnel.

[0181] It should be noted that FIG. 18 above only schematically shows an embodiment of the present invention, but the present invention is not limited thereto. For example, the execution order between various steps may be appropriately adjusted, several other steps may be added, or several steps may be reduced. Those skilled in the art can make appropriate modifications based on the above content and are not limited to the description of FIG. 18 above.

[0182] In some aspects, the header includes at least one of an Internet Protocol (IP) header, a General Packet Radio Service (GPRS) Tunneling Protocol (GTP) header, a User Datagram Protocol (UDP) header, or a Transmission Control Protocol (TCP) header.

[0183] In some aspects, the source Transmission Network Layer (TNL) address of the header is the Transmission Network Layer (TNL) address of the first donor distribution unit or a TNL address routable by the first donor distribution unit, and the target Transmission Network Layer (TNL) address of the header is the Transmission Network Layer (TNL) address of the second donor distribution unit.

[0184] For example, for downlink data where the target TNL address is a TNL address routable by the source Donor-DU, an IP header is added by the source donor-DU, or a GTP / UDP or TCP header is further added. The source TNL address in the added IP header and GTP / UDP or TCP header is the TNL address of the source donor-DU, and the target TNL address is the TNL address of the target donor-DU side tunnel endpoint (i.e., the TNL address of the target donor-DU).

[0185] As a result, a TNL tunnel is established between the source donor-DU and the target donor-DU of the IAB-node migration. Therefore, when the IAB-node migrates across the donor distributed units, the downlink data with the target TNL address being a TNL address routable via the source Donor-DU is transmitted from the source donor-DU to the target donor-DU via the TNL tunnel, and is routed from the target donor-DU to the IAB-node or descendant nodes via the BAP layer. Thus, the problem that the downlink data cannot be routed to the target donor-DU and is discarded by the source donor-DU can be solved.

[0186] The following further describes embodiments of the present invention with reference to the transmission of downlink data in different scenarios.

[0187] First, the downlink data transmission in the scenario of intra-donor CU migration (for example, referred to as Scenario 1) will be described. Examples of the activation and deactivation of the TNL tunnel in Scenario 1 may be referred to FIG. 10 and FIG. 11.

[0188] In some aspects, after the migrating IAB node is switched from the first donor distributed unit to the second donor distributed unit, or after the radio link from the migrating IAB node to the first donor distributed unit fails, the RRC is re-established to the second donor distributed unit, and the first donor distributed unit and the second donor distributed unit belong to the same donor centralized unit (donor-CU).

[0189] In other words, when the IAB-node performs intra-donor CU migration, TNL tunnel transmission is performed between the source donor-DU and the target donor-DU. For example, when the migrating IAB-node switches to a new parent node, the transmission path of all data migrates from the original parent node of the IAB-node to the new parent node, the donor-DU is changed from the source donor-DU to the target donor-DU, and regardless of whether the TNL addresses assigned by the target donor-DU are configured for the migrating IAB-node and its descendant nodes, discard of downlink data occurs and it is necessary to perform TNL tunnel transmission between the target donor-DU and the source Donor-DU.

[0190] In some aspects, the first donor distributed unit receives a TNL tunnel transmission establishment request sent by the donor aggregation unit. The TNL tunnel transmission establishment request includes the end-point TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission establishment request is used to request the first donor distributed unit to establish a TNL tunnel or activate TNL tunnel transmission of downlink data.

[0191] In some aspects, after the donor aggregation unit receives the switching completion message of the migrating IAB node, or after the donor aggregation unit receives the RRC re-establishment completion message of the IAB node, or when the donor aggregation unit does not configure the TNL address assigned by the second donor distributed unit for the migrating IAB node, the first donor distributed unit receives a TNL tunnel transmission establishment request sent by the donor aggregation unit.

[0192] In some aspects, the TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane that needs to activate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane that needs to activate the TNL tunnel transmission, or the target TNL address of the downlink non-F1 data that needs to activate the TNL tunnel transmission.

[0193] For example, the donor-CU sends a TNL tunnel transmission establishment request to the source donor-DU. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission establishment request may further include the target TNL address of the downlink F1 user plane, the target TNL address of the downlink F1 control plane, or the target TNL address of the downlink non-F1 data. Here, F1 includes the F1 connection of the migrating IAB-node and its descendant nodes.

[0194] In some aspects, the first donor distributed unit sends a TNL tunnel transmission establishment response to the donor aggregation unit. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0195] In some aspects, the TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of the TNL tunnel transmission is successful, the target TNL address of the downlink F1 control plane for which the activation of the TNL tunnel transmission is successful, the target TNL address of the downlink non-F1 data for which the activation of the TNL tunnel transmission is successful, or the target TNL address for which the activation fails.

[0196] For example, the source donor-DU sends a TNL tunnel transmission establishment response to the donor-CU. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Further, the TNL tunnel transmission establishment response may further include the target TNL address of the downlink F1 user plane for which the activation of the tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the tunnel transmission has succeeded, or the target TNL address for which the activation has failed.

[0197] Thereby, after the TNL tunnel transmission of the source donor-DU is established, the source donor-DU sends downlink data (the target TNL address is the TNL address assigned to the source Donor-DU) configured by the TNL tunnel transmission establishment request to the target donor-DU, and then, after the BAP layer of the target donor-DU adds a BAP routing identifier, it may be sent to the destination IaB-node or its descendant nodes.

[0198] In some aspects, the first donor distributed unit receives a TNL tunnel transmission update or release request sent by the donor aggregation unit. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit, where the TNL tunnel transmission update or release request is used to request the first donor distributed unit to deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel.

[0199] For example, after the donor-CU constructs the TNL address (TNL address routable by the target donor-DU) assigned by the target donor-DU for the IAB-node, the data of the uplink and downlink that carries the TNL address assigned by the target donor-DU is normally transmitted to the donor-CU or the IAB-node without the need for TNL transmission, and the donor-CU can trigger the update or release of the TNL tunnel transmission for the relevant uplink and downlink data.

[0200] In some aspects, after the donor aggregation unit constructs the TNL address assigned by the second donor distribution unit for the migrating IAB node, or after a predetermined time after the switching by the migrating IAB node is completed, or after a predetermined time after the re-establishment by the migrating IAB node is completed, the first donor distribution unit receives the TNL tunnel transmission update or release request transmitted by the donor aggregation unit.

[0201] For example, when the migrating IAB-node is switching, if the donor-CU constructs the TNL address for the F1-C data and non-F1 data routable via the target donor-DU for the migrating IAB-node, after a predetermined time after the switching is completed, the donor-CU deactivates the TNL tunnel transmission of the F1-C data and non-F1 data of the migrating IAB-node.

[0202] Also, for example, after the switching is completed, if the migrating donor-CU constructs the TNL address for the F1-U data routable via the target donor-DU for the migrating IAB-node via the RRC reconfiguration message, after a predetermined time after the RRC reconfiguration is completed, the donor-CU deactivates the TNL tunnel transmission of the F1-U of the migrating IAB-node.

[0203] To properly route the uplink and downlink inflight data via TNL tunnel transmission to the donor-CU or IAB-node respectively, the donor-CU configures the TNL address assigned by the target donor-DU to the IAB-node and then, after a predetermined time, triggers an update or release of the TNL tunnel transmission.

[0204] In some aspects, the TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane that needs to deactivate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane that needs to deactivate the TNL tunnel transmission, or the target TNL address of the downlink non-F1 data that needs to deactivate the TNL tunnel transmission.

[0205] For example, the donor-CU sends a TNL tunnel transmission update or release request to the source donor-DU. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Also, the TNL tunnel transmission update or release request may further include the target TNL address of the downlink F1 user plane that needs to deactivate the tunnel transmission, the target TNL address of the downlink F1 control plane that needs to deactivate the tunnel transmission, or the target TNL address of the downlink non-F1 data that needs to deactivate the tunnel transmission. Here, F1 includes the F1 connection of the migrating IAB-node and its descendant nodes.

[0206] In some aspects, the first donor distributed unit sends a TNL tunnel transmission update or release response to the donor aggregation unit. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0207] In some aspects, the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission was successful, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission was successful, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission was successful, or the target TNL address for which the deactivation failed.

[0208] For example, the source donor-DU sends a TNL tunnel transmission update or release response to the donor-CU. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Further, the TNL tunnel transmission update or release response may further include the target TNL address of the downlink F1 user plane for which the deactivation of the tunnel transmission was successful, the target TNL address of the downlink F1 control plane for which the deactivation of the tunnel transmission was successful, the target TNL address of the downlink non-F1 data for which the deactivation of the tunnel transmission was successful, or the target TNL address for which the deactivation failed.

[0209] Thereby, after the TNL tunnel transmission of the source donor-DU is updated or released, the source donor-DU directly discards the deactivated downlink data (the target TNL address is the TNL address assigned to the source Donor-DU) transmitted via the TNL tunnel without sending it to the target donor-DU via the TNL tunnel transmission.

[0210] Next, the downlink data transmission in the scenario of intra-donor CU dual connection (for example, referred to as Scenario 2) will be described. Examples of the activation and deactivation of the TNL tunnel in Scenario 2 may be referred to Figures 12 and 13.

[0211] In some aspects, the IAB node performs multi-path delivery within an intra-donor CU, and the first donor distributed unit and the second donor distributed unit belong to the same donor aggregation unit (donor-CU).

[0212] In other words, when the IAB-node performs multi-path delivery within an intra-donor CU (intra-donor CU topology redundancy), TNL tunnel transmission is performed between the source donor-DU and the target donor-DU. For example, when the migrating IAB-node accesses a new parent node, the transmission path of some data migrates from the original parent node of the IAB-node to the new parent node, the donor-DU changes from the source donor-DU to the target donor-DU, and the transmission path of some other data is still transmitted via the original parent node and the source donor-DU. For the data whose transmission path has migrated to the target donor-DU, if the TNL address assigned by the target donor-DU is not configured, downlink data discard occurs, and it is necessary to perform TNL tunnel transmission between the target donor-DU and the source Donor-DU.

[0213] In some aspects, the first donor distributed unit receives a TNL tunnel transmission establishment request sent by the donor aggregation unit. The TNL tunnel transmission establishment request includes the end-point TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission establishment request is used to request the first donor distributed unit to establish a TNL tunnel or activate the TNL tunnel transmission of downlink data.

[0214] In some aspects, when the donor aggregation unit configures the IAB node's Backhaul Adaptation Protocol (BAP) routing as the BAP routing identifier of the second donor distribution unit and does not configure the TNL address assigned by the second donor distribution unit, the first donor distribution unit receives the TNL tunnel transmission establishment request sent by the donor aggregation unit.

[0215] For example, when the transmission path of IAB-node data switches to a new parent node and a target donor-DU, for example, the donor-CU configures a routable BAP address for the IAB-node via the target donor-DU, routes the downlink F1 control plane and non-F1 data of the IAB-node from the target donor-DU to the IAB-node, and does not configure the TNL address assigned by the target donor-DU for the IAB-node, the donor-CU triggers to establish TNL tunnel transmission.

[0216] In some aspects, the TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane that needs to activate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane that needs to activate the TNL tunnel transmission, the target TNL address of the downlink non-F1 data that needs to activate the TNL tunnel transmission, or the GTP TEID of the downlink F1 user plane that needs to activate the TNL tunnel transmission.

[0217] For example, the donor-CU sends a TNL tunnel transmission establishment request to the source donor-DU. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission establishment request may further include the target TNL address of the downlink F1 user plane that needs to be transmitted through the tunnel, the target TNL address of the downlink F1 control plane that needs to be transmitted through the tunnel, and the target TNL address of the downlink non-F1 data that needs to be transmitted through the tunnel.

[0218] Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes. Since the minimum granularity of the downlink F1 user plane path distribution is the UE bearer, when requesting downlink F1 user plane tunnel transmission, in addition to the target TNL address, it is necessary to further indicate the DL GTP TEID.

[0219] In some aspects, the first donor distributed unit sends a TNL tunnel transmission establishment response to the donor aggregation unit. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0220] In some aspects, the TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of the TNL tunnel transmission is successful, the target TNL address of the downlink F1 control plane for which the activation of the TNL tunnel transmission is successful, the target TNL address of the downlink non-F1 data for which the activation of the TNL tunnel transmission is successful, or the target TNL address for which the activation fails.

[0221] For example, the source donor-DU sends a TNL tunnel transmission establishment response to the donor-CU. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Further, the TNL tunnel transmission establishment response may further include the target TNL address of the downlink F1 user plane for which the activation of the tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the tunnel transmission has succeeded, or the target TNL address for which the activation has failed.

[0222] Thereby, after the TNL tunnel transmission of the source donor-DU is established, the source donor-DU transmits downlink data (the target TNL address is the TNL address assigned to the source Donor-DU) configured by the TNL tunnel transmission establishment request to the target donor-DU via the TNL tunnel, and then, after the BAP target address and the path identifier are added by the BAP layer of the target donor-DU, it may be transmitted to the migration IaB-node or its descendant nodes.

[0223] In some aspects, the first donor distributed unit receives a TNL tunnel transmission update or release request sent by the donor aggregation unit. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit, where the TNL tunnel transmission update or release request is used to request the first donor distributed unit to deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel.

[0224] In some aspects, after the donor aggregation unit configures the TNL address assigned to the second donor distributed unit for the IAB node, the first donor distributed unit receives a TNL tunnel transmission update or release request sent by the donor aggregation unit.

[0225] For example, after a TNL address (a TNL address routable via the target donor-DU) assigned by the target donor-DU is configured for the data of the IAB-node that has migrated to the target donor-CU side, the downlink data carrying the TNL address assigned by the target donor-DU can be normally transmitted to the IAB-node without TNL tunnel transmission, and the donor-CU can trigger an update for the relevant downlink data or release the TNL tunnel transmission.

[0226] For example, after the migrating IAB-node is connected to a new parent node and a dual connection with the new parent node is established, if the data of the F1 control plane and non-F1 data are migrated to the target donor-DU and the donor-CU configures a TNL address assigned by the target donor-DU for the F1 control plane and non-F1 data of the migrating IAB-node, the donor-CU deactivates the TNL tunnel transmission of the F1-C data and non-F1 data of the migrating IAB-node.

[0227] In some aspects, the TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be deactivated, or the GTP TEID of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated.

[0228] For example, the donor-CU sends a TNL tunnel transmission update or release request to the source donor-DU. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission update or release request may further include the target TNL address of the downlink F1 user plane that does not require tunnel transmission, the target TNL address of the downlink F1 control plane that does not require tunnel transmission, and the target TNL address of the downlink non-F1 data that does not require tunnel transmission.

[0229] Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes. Since the minimum granularity of the downlink of the F1 user plane path distribution is the UE bearer, when it is required to remove the downlink F1 user plane from tunnel transmission, in addition to the target TNL address, it is necessary to further indicate the DL GTP TEID.

[0230] In some aspects, the first donor distributed unit further sends a TNL tunnel transmission update or release response to the donor aggregation unit. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0231] In some aspects, the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission is successful, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission is successful, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission is successful, or the target TNL address for which the deactivation fails.

[0232] For example, the source donor-DU sends a TNL tunnel transmission establishment response to the donor-CU. The TNL tunnel transmission establishment response includes the TNL address of the endpoint of the TNL tunnel on the source donor-DU side. Further, the TNL tunnel transmission establishment response may further include the target TNL address of the downlink F1 user plane for which the deactivation of tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the deactivation of tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the deactivation of tunnel transmission has succeeded, or the target TNL address for which the deactivation has failed.

[0233] Thereby, after the TNL tunnel of the source donor-DU is updated or released, the source donor-DU directly discards the deactivated downlink data (the target TNL address is the TNL address assigned to the source Donor-DU) without sending it to the target donor-DU via the TNL tunnel.

[0234] Next, the downlink data transmission in the scenario of inter-donor CU migration (for example, referred to as Scenario 3) will be described. Examples of the activation and deactivation of the TNL tunnel in Scenario 3 may be referred to Figures 14 and 15.

[0235] In some aspects, after the IAB node is switched from the first donor distributed unit to the second donor distributed unit, or after the radio link from the IAB node to the first donor distributed unit fails (RLF), the RRC is re-established to the second donor distributed unit, the first donor distributed unit belongs to the first donor aggregation unit, and the second donor distributed unit belongs to the second donor aggregation unit.

[0236] In other words, when the IAB-node performs an inter-donor CU migration, a TNL tunnel transmission is performed between the source donor-DU and the target donor-DU. Here, the source donor-DU is controlled by the source donor-CU, and the target donor-DU is controlled by the target donor-CU.

[0237] For example, when the migrating IAB-node switches to a node controlled by the target donor-CU, the transmission path of all data migrates from the source donor-CU side of the IAB-node to the target donor-CU side, the donor-DU is changed from the source donor-DU to the target donor-DU, and regardless of whether the TNL address assigned from the target donor-DU is configured in the migrating IAB-node and its descendant nodes, discard of downlink data occurs, and it is necessary to perform a TNL tunnel transmission between the target donor-DU and the original Donor-DU.

[0238] In some aspects, the first donor distributed unit receives a TNL tunnel transmission establishment request sent by the first donor aggregation unit. The TNL tunnel transmission establishment request includes the end-point TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission establishment request is used to request the first donor distributed unit to establish the TNL tunnel or activate the TNL tunnel transmission of downlink data.

[0239] In some aspects, after the second donor aggregation unit receives the IAB node switch completion message, or after the second donor aggregation unit receives the IAB node RRC re-establishment completion message, or when the second donor aggregation unit does not configure the TNL address assigned by the second donor distributed unit for the IAB node, the first donor distributed unit receives a TNL tunnel transmission establishment request sent by the first donor aggregation unit.

[0240] For example, the Handover Request message for the migrating IAB-node sent from the source donor-CU to the target donor-CU includes the TNL address of the endpoint of the TNL tunnel on the source donor-DU side, the F1 user plane of the migrating IAB-node assigned by the source donor-DU, the F1 control plane, and the TNL address used for non-F1 data, or further includes the TNL addresses used for the F1 user plane, the F1 control plane, and non-F1 data of the descendant nodes of the migrating IAB-node assigned by the source donor-DU. The Handover Response message for the migrating IAB-node sent from the target donor-CU to the source donor-CU includes the TNL address of the endpoint of the TNL tunnel on the target donor-DU side.

[0241] In some aspects, the TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be activated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be activated, or the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be activated.

[0242] For example, when the source donor-CU receives the IAB-node context release instruction sent by the target donor-CU, it sends a TNL tunnel transmission establishment request to the source donor-DU. The TNL tunnel transmission establishment request includes the TNL address of the endpoint of the TNL tunnel on the target donor-DU side. The TNL tunnel transmission establishment request may further include the target TNL address of the downlink F1 user plane, the target TNL address of the downlink F1 control plane, and the target TNL address of the downlink non-F1 data. Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes.

[0243] In some embodiments, the first donor distribution unit transmits a TNL tunnel transmission establishment response to the first donor aggregation unit. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit.

[0244] In some embodiments, the TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the target TNL address for which the activation has failed.

[0245] For example, the source donor-DU transmits a TNL tunnel transmission establishment response to the source donor-CU. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Further, the TNL tunnel transmission establishment response may further include the target TNL address of the downlink F1 user plane for which the activation of the tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the tunnel transmission has succeeded, or the target TNL address for which the activation has failed.

[0246] Thereby, after the TNL tunnel transmission of the source donor-DU is established, the source donor-DU transmits the activated downlink data (the target TNL address is the TNL address assigned to the source Donor-DU) to the target donor-DU via the TNL tunnel transmission, and then, after the routing identifier is added by the BAP layer of the target donor-DU, it can be transmitted to the destination IaB-node or its descendant nodes.

[0247] In some embodiments, the first donor distribution unit receives a TNL tunnel transmission update or release request sent by the first donor aggregation unit. The TNL tunnel transmission update or release request includes the end-point TNL address of the TNL tunnel of the second donor distribution unit, where the TNL tunnel transmission update or release request is used to request the first donor distribution unit to deactivate the TNL tunnel transmission of downlink data or to release the TNL tunnel.

[0248] For example, after the target donor-CU configures the TNL address (the TNL address routable from the target donor-DU) assigned by the target donor-DU for the IAB-node, the uplink and downlink data carrying the TNL address assigned by the target donor-DU does not require TNL tunnel transmission and can be normally transmitted to the source donor-CU or the IAB-node. The target donor-CU can trigger an update for the relevant uplink data or release the TNL tunnel transmission. The source donor-CU can trigger an update for the relevant downlink data or release the TNL tunnel transmission.

[0249] In some embodiments, after the second donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, or after a predetermined time after the switching by the IAB node is completed, or after a predetermined time after the re-establishment by the IAB node is completed, the first donor distribution unit receives a TNL tunnel transmission update or release request sent by the first donor aggregation unit.

[0250] For example, when the migrating IAB-node switches, if the target donor-CU configures both the F1-C data and non-F1 data TNL addresses routable via the target donor-DU for the migrating IAB-node, after a predetermined time from the completion of the switch, the target donor-CU and the source donor-CU deactivate the TNL tunnel transmission of the F1-C data and non-F1 data of the migrating IAB-node.

[0251] As another example, after the switch is completed, the target donor-CU configures, for the migrating IAB-node via the RRC reconfiguration message, the TNL address of the F1-U data routable via the target donor-DU, and after a predetermined time has elapsed since the completion of the RRC reconfiguration, the target donor-CU and the source donor-CU deactivate the TNL tunnel transmission to F1-U of the migrating IAB-node.

[0252] To route the TNL tunnel transmission of the downlink inflight data to the IAB-node normally, after a predetermined time has elapsed since the target donor-CU configures the TNL address assigned by the target donor-DU for the IAB-node, the target donor-CU triggers the update or release of the TNL tunnel transmission.

[0253] In some aspects, the TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be deactivated, or the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be deactivated.

[0254] For example, the target donor-CU sends the source donor-CU the TNL address assigned by the target donor-DU for the F1 user plane or F1 control plane of the migrating IAB-node and non-F1 data, or further includes, for example, in a Handover Response message for the migrating IAB-node, the TNL address assigned by the target donor-DU for the F1 user plane or F1 control plane of the child node of the migrating IAB-node and non-F1 data.

[0255] For example, the source donor-CU sends a TNL tunnel transmission update or release request to the source donor-DU. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission update or release request may further include the target TNL address of the downlink F1 user plane that does not need to be tunnel-transmitted, the target TNL address of the downlink F1 control plane that does not need to be tunnel-transmitted, and the target TNL address of the downlink non-F1 data that does not need to be tunnel-transmitted. Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes.

[0256] In some aspects, the first donor distributed unit sends a TNL tunnel transmission update or release response to the first donor centralized unit. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0257] In some aspects, the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission has succeeded, or the target TNL address for which the deactivation has failed.

[0258] For example, the target donor-DU sends the TNL tunnel transmission update or release response to the target donor-CU. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Further, the TNL tunnel transmission update or release response may further include the target TNL address of the downlink F1 user plane for which the deactivation of the tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the deactivation of the tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the deactivation of the tunnel transmission has succeeded, or the target TNL address for which the deactivation has failed.

[0259] Thereby, after the TNL tunnel of the source donor-DU is updated or released, the source donor-DU directly discards the deactivated downlink data (the target TNL address is the TNL address assigned to the source Donor-DU) without sending it to the target donor-DU via the TNL tunnel.

[0260] Next, the downlink data transmission in the scenario of inter-donor CU dual connection (for example, referred to as Scenario 4) will be described. Examples of the activation and deactivation of the TNL tunnel in Scenario 4 may be referred to FIGS. 16 and 17.

[0261] In some aspects, the IAB node performs multipath delivery between inter-donor CUs, where a first donor distributed unit belongs to a first donor centralized unit and a second donor distributed unit belongs to a second donor centralized unit.

[0262] In other words, when the migrating IAB-node performs multipath delivery of inter-donor CUs (inter-donor CU topology redundancy), TNL tunnel transmission is performed between the source donor-DU and the target donor-DU. Here, the source donor-DU is controlled by the source donor-CU, and the target donor-DU is controlled by the target donor-CU.

[0263] For example, when the migrating IAB-node accesses a node under the control of the target donor-CU, the transmission path of some data moves from the source donor-CU side of the IAB-node to the target donor-CU side, and the donor-DU is changed from the source donor-DU to the target donor-DU. The transmission path of some other data is still transmitted via the original parent node, the source donor-DU. For the data whose transmission path has migrated to the target donor-DU, if the TNL address assigned from the target donor-DU is not configured, downlink data discard occurs, and it is necessary to perform TNL tunnel transmission between the target donor-DU and the source Donor-DU.

[0264] In some aspects, the first donor distributed unit receives a TNL tunnel transmission establishment request sent by the first donor centralized unit. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission establishment request is used to request the first donor distributed unit to establish the TNL tunnel or activate the TNL tunnel transmission of downlink data.

[0265] In some aspects, if the second donor aggregation unit configures the IAB node's Backhaul Adaptation Protocol (BAP) routing as the BAP routing identifier of the second donor distribution unit and does not configure the TNL address assigned by the second donor distribution unit for downlink data, the first donor distribution unit receives the TNL tunnel transmission establishment request sent by the first donor aggregation unit.

[0266] For example, the source donor-CU sends to the target donor-CU the TNL address of the end point of the TNL tunnel on the source donor-DU side, the downlink F1 user plane, F1 control plane or non-F1 data of the handover IAB-node or descendant node that requests handover to the target donor-CU side, and the TNL address assigned to these data by the source donor-DU. For example, it is performed by the SgNB node addition request message or SgNB node modification request of the handover IAB-node. For example, in response to the SgNB node addition response message or SgNB node modification response message for the handover IAB-node, the target donor-CU sends the TNL address of the end point of the TNL tunnel on the target donor-DU side to the source donor-CU.

[0267] For example, when the transmission path of IAB-node data migrates to the target donor-CU side, that is, when the target donor-CU configures for the IAB-node with a BAP address routable by the target donor-DU, and the downlink F1 control plane and non-F1 data of the IAB-node are routed to the IAB-node by the target donor-DU, and the TNL address assigned to the target donor-DU is not configured for the IAB-node, the target donor-CU and the source donor-CU trigger the establishment of TNL tunnel transmission.

[0268] In some aspects, the TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane that needs to activate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane that needs to activate the TNL tunnel transmission, the target TNL address of the downlink non-F1 data that needs to activate the TNL tunnel transmission, or the GTP TEID of the downlink F1 user plane that needs to activate the TNL tunnel transmission.

[0269] For example, the target donor-CU sends the uplink F1 user plane, F1 control plane, or non-F1 data of the migrated IAB-node or descendant node that has been successfully migrated to the target donor-CU side, the downlink F1 user plane, F1 control plane, or non-F1 data of the migrated IAB-node or child node to the source donor-CU, or further sends the TNL address assigned to these data by the target donor-DU. For example, this is done by an SgNB node addition response message or an SgNB node modification response message for the migrated IAB-node. If the TNL address assigned to these data by the target donor-DU is not included in the SgNB node addition response message or the SgNB node modification response message, the source donor-CU sends a TNL tunnel transmission establishment request to the source donor-DU.

[0270] For example, the TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. Further, the TNL tunnel transmission establishment request may further include the target TNL address of the downlink F1 user plane, the target TNL address of the downlink F1 control plane, and the target TNL address of the downlink non-F1 data.

[0271] Here, F1 includes the F1 connection between the migrated IAB-node and its descendant nodes. Since the minimum granularity of downlink F1 user plane path distribution is the UE bearer, when downlink F1 user plane tunnel transmission is required, in addition to the target TNL address, it is necessary to further indicate the DL GTP TEID.

[0272] In some aspects, the first donor distribution unit transmits a TNL tunnel transmission establishment response to the first donor aggregation unit. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit.

[0273] In some aspects, the TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the target TNL address for which the activation has failed.

[0274] For example, the source donor-DU transmits a TNL tunnel transmission establishment response to the source donor-CU. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. Further, the TNL tunnel transmission establishment response may further include the target TNL address of the downlink F1 user plane for which the activation of the tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the tunnel transmission has succeeded, or the target TNL address for which the activation has failed.

[0275] Thereby, after the TNL tunnel transmission of the source donor-DU is established, the source donor-DU transmits the activated downlink data (the target TNL address is the TNL address assigned to the source Donor-DU) to the target donor-DU via the TNL tunnel transmission, and then, after the BAP routing identifier is added by the BAP layer of the target donor-DU, it can be transmitted to the destination IaB-node or its descendant nodes.

[0276] In some aspects, the first donor distribution unit receives a TNL tunnel transmission update or release request sent by the first donor aggregation unit. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, and the TNL tunnel transmission update or release request further includes steps used to request the first donor distribution unit to deactivate the TNL tunnel transmission of downlink data or release the TNL tunnel.

[0277] In some aspects, after the second donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, the first donor distribution unit receives a TNL tunnel transmission update or release request sent by the first donor aggregation unit.

[0278] For example, after the target donor-CU configures the TNL address (the TNL address routable from the target donor-DU) assigned by the target donor-DU for the IAB-node, the downlink data carrying the TNL address assigned by the target donor-DU is normally sent to the source donor-CU or the IAB-node without the need for TNL tunnel transmission, and the source donor-CU can trigger an update for the relevant downlink data or release the TNL tunnel transmission.

[0279] For example, when the migrating IAB-node is connected to a new parent node and a dual connection with the new parent node is established, and the F1 control plane and non-F1 data are migrated to the target donor-DU, if the target donor-CU is configured with the TNL address assigned by the target donor-DU for the F1 control plane and non-F1 data of the migrating IAB-node, the target donor-CU, the source donor-CU deactivates the TNL tunnel transmission for both the F1-C data and the non-F1 data of the migrating IAB-node.

[0280] In some aspects, the TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane that needs to deactivate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane that needs to deactivate the TNL tunnel transmission, the target TNL address of the downlink non-F1 data that needs to deactivate the TNL tunnel transmission, or the GTP TEID of the downlink F1 user plane that needs to deactivate the TNL tunnel transmission.

[0281] For example, the target donor-CU sends the TNL address assigned by the target donor-DU for the F1 user plane or F1 control plane and non-F1 data of the migrated IAB-node migrated to the target donor-CU side to the source donor-CU, or further includes the TNL address assigned by the target donor-DU for the F1 user plane or F1 control plane and non-F1 data of the descendant nodes of the migrated IAB-node migrated to the target donor-CU side.

[0282] The source donor-CU sends a TNL tunnel transmission update or release request to the source donor-DU. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel on the target donor-DU side. The TNL tunnel transmission update or release request may further include the target TNL address of the downlink F1 user plane that does not require tunnel transmission, the target TNL address of the downlink F1 control plane that does not require tunnel transmission, and the target TNL address of the downlink non-F1 data that does not require tunnel transmission.

[0283] Here, F1 includes the F1 connections of the migrating IAB-node and its descendant nodes. Since the minimum granularity of downlink F1 user plane path delivery is the UE bearer, when it is required to remove the downlink F1 user plane from tunnel transmission, in addition to the target TNL address, it is necessary to further indicate the DL GTP TEID.

[0284] In some aspects, the first donor distributed unit sends a TNL tunnel transmission update or release response to the first donor centralized unit. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0285] In some aspects, the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of TNL tunnel transmission is successful, the target TNL address of the downlink F1 control plane for which the deactivation of TNL tunnel transmission is successful, the target TNL address of the downlink non-F1 data for which the deactivation of TNL tunnel transmission is successful, or the target TNL address for which the deactivation fails.

[0286] For example, the source donor-DU sends a TNL tunnel transmission update or release response to the source donor-CU. The TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel on the source donor-DU side. The TNL tunnel transmission update or release response may further include the target TNL address of the downlink F1 user plane for which the deactivation of tunnel transmission is successful, the target TNL address of the downlink F1 control plane for which the deactivation of tunnel transmission is successful, the target TNL address of the downlink non-F1 data for which the deactivation of tunnel transmission is successful, or the target TNL address for which the deactivation fails.

[0287] After the TNL tunnel transmission of the source donor-DU is updated or released accordingly, the source donor-DU directly discards the deactivated downlink data (the target TNL address is the TNL address assigned to the source Donor-DU) without transmitting it to the target donor-DU via the TNL tunnel.

[0288] Each of the above embodiments only illustrates the embodiments of the present invention, and the present invention is not limited thereto, and appropriate modifications may be made based on each of the above embodiments. For example, each of the above embodiments may be used alone, or one or more of the above embodiments may be used in combination.

[0289] According to this embodiment, the first donor distributed unit (source donor-DU) adds a tunnel-related header to the downlink data and transmits the downlink data to the second donor distributed unit (target donor-DU) via the TNL tunnel. Thereby, by establishing a TNL tunnel between the source donor-DU and the target donor-DU during the IAB-node migration, the problem that the downlink data is discarded can be solved.

[0290] <Example 3> The embodiments of the present invention provide an IAB communication method, which is described from the donor aggregation unit (donor-CU), and the description of the same content as in Embodiment 1 and Embodiment 2 is omitted.

[0291] In some aspects, the IAB node migrates from the first donor distributed unit to the second donor distributed unit. The first donor distributed unit and the second donor distributed unit belong to the same donor aggregation unit. The IAB node performs an intra-donor CU migration (scenario 1) or an intra-donor CU dual connection (scenario 2).

[0292] In some aspects, the donor aggregation unit receives uplink data transmitted by the second donor disaggregation unit to the IAB node and instructs the uplink data to be transmitted to the first donor disaggregation unit via a transport network layer (TNL) tunnel between the second donor disaggregation unit and the first donor disaggregation unit.

[0293] In some aspects, the donor aggregation unit receives downlink data transmitted by the first donor disaggregation unit to the IAB node and instructs the downlink data to be transmitted to the second donor disaggregation unit via a transport network layer (TNL) tunnel between the first donor disaggregation unit and the second donor disaggregation unit.

[0294] Here, the IAB node includes a migrating IAB node or its descendant nodes.

[0295] In some aspects, the IAB node migrates from the first donor disaggregation unit to the second donor disaggregation unit. The first donor disaggregation unit belongs to the first donor aggregation unit, and the second donor disaggregation unit belongs to the second donor aggregation unit. The IAB node performs an inter-donor CU migration (scenario 3) or an inter-donor CU dual connection (scenario 4).

[0296] In some aspects, the second donor aggregation unit receives uplink data transmitted by the second donor disaggregation unit to the IAB node and instructs the uplink data to be transmitted to the first donor disaggregation unit via a transport network layer (TNL) tunnel between the second donor disaggregation unit and the first donor disaggregation unit.

[0297] For example, the second donor aggregation unit sends a TNL tunnel transmission establishment request to the second donor aggregation unit. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the first donor aggregation unit, where the TNL tunnel transmission establishment request is used to request the second donor aggregation unit to establish a TNL tunnel or activate the TNL tunnel transmission of uplink data.

[0298] For example, the endpoint TNL address of the TNL tunnel of the first donor aggregation unit is sent from the first donor aggregation unit to the second donor aggregation unit.

[0299] Also, for example, after the second donor aggregation unit receives the IAB node handover completion message, or after the second donor aggregation unit receives the RRC re-establishment completion message of the IAB node, or when the second donor aggregation unit does not configure the TNL address assigned by the second donor distribution unit for the migrating IAB node or its descendant nodes, the second donor aggregation unit sends a TNL tunnel transmission establishment request to the second donor aggregation unit.

[0300] As another example, the second donor aggregation unit receives the TNL address assigned by the first donor distribution unit for the IAB node and sent by the first donor aggregation unit, so that the second donor aggregation unit sends a TNL tunnel transmission establishment request to the second donor distribution unit.

[0301] In some aspects, the first donor aggregation unit receives the downlink data sent by the first donor distribution unit to the IAB node, and instructs to send the downlink data to the second donor distribution unit via the transmission network layer (TNL) tunnel between the first donor distribution unit and the second donor distribution unit.

[0302] For example, the first donor aggregation unit further sends a TNL tunnel transmission update or release request to the first donor distribution unit. The TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, where the TNL tunnel transmission update or release request is used for the first donor distribution unit to deactivate the TNL tunnel transmission of downlink data or to request to release the TNL tunnel. Here, the IAB node includes a migrating IAB node or its descendant nodes.

[0303] For example, the endpoint TNL address of the TNL tunnel of the second donor distribution unit is sent by the second donor aggregation unit to the first donor aggregation unit.

[0304] For example, after the second donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, the first donor aggregation unit sends a TNL tunnel transmission update or release request to the first donor distribution unit.

[0305] Also, for example, the second donor aggregation unit further sends the TNL address assigned by the second donor distribution unit for the IAB node to the first donor aggregation unit, triggering the first donor aggregation unit to send a TNL tunnel transmission update or release request to the first donor distribution unit.

[0306] Each of the above embodiments only illustrates the embodiments of the present invention, and the present invention is not limited thereto. Appropriate modifications may be made based on each of the above embodiments. For example, each of the above embodiments may be used alone, or one or more of the above embodiments may be used in combination.

[0307] According to this embodiment, by establishing a TNL tunnel between a source donor-DU and a target donor-DU for the IAB-node to migrate based on the instruction of the donor-CU and / or the interaction between the target donor-CU and the source donor-CU, the problem that uplink and downlink data are discarded can be solved.

[0308] <Example 4> Embodiments of the present invention provide an IAB communication device. The device may be an IAB-donor device in the IAB system, or may be several components or components or modules configured within the IAB-donor device. For example, the IAB system includes an IAB-donor device and an IAB node. For example, the IAB-donor device may include an IAB-donor-CU and an IAB-donor-DU.

[0309] FIG. 19 is a schematic diagram of an example of an IAB communication device according to an embodiment of the present invention. As shown in FIG. 19, the IAB communication device 1900 includes a receiving unit 1901, a processing unit 1902, and a transmitting unit 1903.

[0310] In some aspects, the receiving unit 1901 receives uplink data transmitted by the IAB node. The processing unit 1902 adds a header related to the transmission network layer tunnel to the uplink data. The transmitting unit 1903 transmits the uplink data to a first donor distributed unit via the transmission network layer tunnel.

[0311] In some aspects, the header includes at least one of an Internet protocol header, a general packet radio service tunneling protocol header, a user datagram protocol header, or a transmission control protocol header.

[0312] In some aspects, the source transmission network layer address of the header is the TNL address of the second donor distribution unit or a TNL address that can be routed by the second donor distribution unit, and the target TNL address of the header is the TNL address of the first donor distribution unit.

[0313] In some aspects, after the IAB node is switched from the first donor distribution unit to the second donor distribution unit, or after the radio link from the IAB node to the first donor distribution unit fails, radio resource control is re-established with the second donor distribution unit, and the first donor distribution unit and the second donor distribution unit belong to the same donor aggregation unit.

[0314] In some aspects, the receiving unit 1901 further receives a TNL tunnel transmission establishment request sent by the donor aggregation unit, and the TNL tunnel transmission establishment request includes the end-point TNL address of the TNL tunnel of the first donor distribution unit, where the TNL tunnel transmission establishment request is used to request the second donor distribution unit to establish the TNL tunnel or activate the TNL tunnel transmission of the uplink data.

[0315] Here, the TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to activate the TNL tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to activate the TNL tunnel transmission.

[0316] In some aspects, the transmitting unit 1903 further sends a TNL tunnel transmission establishment response to the donor aggregation unit, and the TNL tunnel transmission establishment response includes the end-point TNL address of the TNL tunnel of the second donor distribution unit.

[0317] Here, the TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the source TNL address for which the activation has failed.

[0318] In some aspects, the receiving unit 1901 further receives service mapping information transmitted by the donor aggregation unit, and the service mapping information is used to configure the backhaul adaptation protocol (BAP) routing identifier of the downlink data transmitted via the TNL tunnel and the backhaul RLC channel between the second donor disaggregated unit and the descendant nodes of the next hop.

[0319] In some aspects, the receiving unit 1901 further receives a TNL tunnel transmission update or release request transmitted by the donor aggregation unit, the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor disaggregated unit, and the TNL tunnel transmission update or release request is used to request the second donor disaggregated unit to deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel.

[0320] Here, the TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane for which it is necessary to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane for which it is necessary to deactivate the TNL tunnel transmission, or the source TNL address of the uplink non-F1 data for which it is necessary to deactivate the TNL tunnel transmission.

[0321] In some aspects, the transmitting unit 1903 further transmits a TNL tunnel transmission update or release response to the donor aggregation unit, and the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit.

[0322] Here, the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane where the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane where the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data where the deactivation of the TNL tunnel transmission is successful, or the source TNL address where the deactivation fails.

[0323] In some aspects, the receiving unit 1901 further receives a service mapping information release instruction transmitted by the donor aggregation unit, and the service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data for which the TNL tunnel transmission is deactivated and the configuration of the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop.

[0324] In some aspects, the IAB node performs multipath distribution within the donor aggregation unit, and the first donor distribution unit and the second donor distribution unit belong to the same donor aggregation unit.

[0325] In some aspects, the receiving unit 1901 receives a TNL tunnel transmission establishment request transmitted by the donor aggregation unit, the TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and here, the TNL tunnel transmission establishment request is used to request the second donor distribution unit to establish the TNL tunnel or activate the TNL tunnel transmission of the uplink data.

[0326] In some aspects, the TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to activate the TNL tunnel transmission, or the GTP tunnel endpoint identifier of the uplink F1 user plane that needs to activate the TNL tunnel transmission.

[0327] In some aspects, the transmitter 1903 further transmits a TNL tunnel transmission establishment response to the donor aggregation unit, and the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor disaggregated unit.

[0328] Here, the TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane where the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane where the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data where the activation of the TNL tunnel transmission is successful, or the source TNL address where the activation fails.

[0329] In some aspects, the receiver 1901 further receives service mapping information configured by the donor aggregation unit, and the service mapping information is used to configure the BAP routing identifier of the downlink data transmitted through the TNL tunnel and the backhaul RLC channel between the second donor disaggregated unit and the descendant nodes of the next hop.

[0330] In some aspects, the receiving unit 1901 receives a TNL tunnel transmission update or release request transmitted by the donor aggregation unit, and the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission update or release request is used to request that the second donor distribution unit deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel.

[0331] Here, the TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission, or the GTP TEID of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission.

[0332] In some aspects, the transmitting unit 1903 further transmits a TNL tunnel transmission update or release response to the donor aggregation unit, and the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit.

[0333] Here, the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane where the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane where the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data where the deactivation of the TNL tunnel transmission is successful, or the source TNL address where the deactivation fails.

[0334] In some aspects, the receiving unit 1901 further receives a service mapping information release instruction transmitted by the donor aggregation unit, and the service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data with TNL tunnel transmission deactivated and the configuration of the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop.

[0335] In some aspects, after the IAB node is switched from the first donor distribution unit to the second donor distribution unit, or after the radio link between the IAB node and the first donor distribution unit fails, the RRC is re-established with the second donor distribution unit, the first donor distribution unit belongs to the first donor aggregation unit, and the second donor distribution unit belongs to the second donor aggregation unit.

[0336] In some aspects, the receiving unit 1901 further receives a TNL tunnel transmission establishment request transmitted by the second donor aggregation unit, the TNL tunnel transmission establishment request includes the end point TNL address of the TNL tunnel of the first donor distribution unit, where the TNL tunnel transmission establishment request is used to request the second donor distribution unit to establish the TNL tunnel or activate the TNL tunnel transmission of the uplink data.

[0337] Here, the TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane for which the TNL tunnel transmission needs to be activated, the source TNL address of the uplink F1 control plane for which the TNL tunnel transmission needs to be activated, or the source TNL address of the uplink non-F1 data for which the TNL tunnel transmission needs to be activated.

[0338] In some aspects, the transmitting unit 1903 further transmits a TNL tunnel transmission establishment response to the second donor aggregation unit, and the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit.

[0339] Here, the TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane where the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane where the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data where the activation of the TNL tunnel transmission is successful, or the source TNL address where the activation fails.

[0340] In some aspects, the receiving unit 1901 further receives service mapping information transmitted by the donor aggregation unit, and the service mapping information is used to configure the BAP routing identifier of the downlink data transmitted via the TNL tunnel and the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop.

[0341] In some aspects, the receiving unit 1901 further receives a TNL tunnel transmission update or release request transmitted by the second donor aggregation unit, the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission update or release request is used to request the second donor distribution unit to deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel.

[0342] Here, the TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission.

[0343] In some aspects, the transmitting unit 1903 further transmits a TNL tunnel transmission update or release response to the second donor aggregation unit, and the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit.

[0344] Here, the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane for which the deactivation of the TNL tunnel transmission was successful, the source TNL address of the uplink F1 control plane for which the deactivation of the TNL tunnel transmission was successful, the source TNL address of the uplink non-F1 data for which the deactivation of the TNL tunnel transmission was successful, or the source TNL address for which the deactivation failed.

[0345] In some aspects, the receiving unit 1901 further receives a service mapping information release instruction transmitted by the donor aggregation unit, and the service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data for which the TNL tunnel transmission was deactivated and the configuration of the backhaul RLC channel between the second donor distribution unit and the descendant node of the next hop.

[0346] In some aspects, the IAB node performs multi-path distribution between donor aggregation units, where the first donor distribution unit belongs to the first donor aggregation unit and the second donor distribution unit belongs to the second donor aggregation unit.

[0347] In some aspects, the receiving unit 1901 receives a TNL tunnel transmission establishment request transmitted by a second donor aggregation unit. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit. Here, the TNL tunnel transmission establishment request is used to request the second donor distribution unit to establish the TNL tunnel or activate the TNL tunnel transmission of uplink data.

[0348] Here, the TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane for which it is necessary to activate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane for which it is necessary to activate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data for which it is necessary to activate the TNL tunnel transmission, or the GTP TEID of the uplink F1 user plane for which it is necessary to activate the TNL tunnel transmission.

[0349] In some aspects, the transmitting unit 1903 further transmits a TNL tunnel transmission establishment response to the second donor aggregation unit. The TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit.

[0350] Here, the TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane for which the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane for which the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data for which the activation of the TNL tunnel transmission is successful, or the source TNL address for which the activation fails.

[0351] In some embodiments, the receiving unit 1901 further receives service mapping information constituted by a donor aggregation unit, and the service mapping information is used to configure the BAP routing identifier of downlink data transmitted via the TNL tunnel and the backhaul RLC channel between the second donor disaggregation unit and the descendant nodes of the next hop.

[0352] In some embodiments, the receiving unit 1901 receives a TNL tunnel transmission update or release request transmitted by a second donor aggregation unit, the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor disaggregation unit, and the TNL tunnel transmission update or release request is used to request that the second donor disaggregation unit deactivate the TNL tunnel transmission of uplink data or release the TNL tunnel.

[0353] Here, the TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission, or the GTP TEID of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission.

[0354] In some embodiments, the transmitting unit 1903 further transmits a TNL tunnel transmission update or release response to the second donor aggregation unit, and the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor disaggregation unit.

[0355] Here, the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane for which the deactivation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the deactivation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the deactivation of the TNL tunnel transmission has succeeded, or the source TNL address for which the deactivation has failed.

[0356] In some aspects, the receiving unit 1901 further receives a service mapping information release instruction transmitted by the donor aggregation unit, and the service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data for which the TNL tunnel transmission has been deactivated and the configuration of the backhaul RLC channel between the second donor disaggregation unit and the descendant nodes of the next hop.

[0357] In some aspects, the receiving unit 1901 receives downlink data transmitted by the IAB node. The processing unit 1902 adds a header related to the transmission network layer tunnel to the downlink data. The transmitting unit 1903 transmits the downlink data to the second donor disaggregation unit via the transmission network layer tunnel.

[0358] In some aspects, the header includes at least one of an Internet protocol header, a general packet radio service tunneling protocol header, a user datagram protocol header, or a transmission control protocol header.

[0359] In some aspects, the source transmission network layer address of the header is the transmission network layer address of the first donor disaggregation unit or a TNL address routable by the first donor disaggregation unit, and the target TNL address of the header is the transmission network layer address of the second donor disaggregation unit.

[0360] In some aspects, after the IAB node is switched from the first donor distributed unit to the second donor distributed unit, or after the radio link from the IAB node to the first donor distributed unit fails, the RRC is re-established to the second donor distributed unit, and the first donor distributed unit and the second donor distributed unit belong to the same donor aggregation unit.

[0361] In some aspects, the receiving unit 1901 further receives a TNL tunnel transmission establishment request sent by the donor aggregation unit. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission establishment request is used to request the first donor distributed unit to establish the TNL tunnel or activate the TNL tunnel transmission of downlink data.

[0362] Here, the TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be activated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be activated, or the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be activated.

[0363] In some aspects, the transmitting unit 1903 further sends a TNL tunnel transmission establishment response to the donor aggregation unit, and the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0364] Here, the TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the target TNL address for which the activation has failed.

[0365] In some aspects, the receiving unit 1901 further receives a TNL tunnel transmission update or release request sent by the donor aggregation unit, and the TNL tunnel transmission update or release request includes the end-point TNL address of the TNL tunnel of the second donor disaggregation unit, where the TNL tunnel transmission update or release request is used to request the first donor disaggregation unit to deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel.

[0366] Here, the TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be deactivated, or the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be deactivated.

[0367] In some aspects, the transmitting unit 1903 further sends a TNL tunnel transmission update or release response to the donor aggregation unit, and the TNL tunnel transmission update or release response includes the end-point TNL address of the TNL tunnel of the first donor disaggregation unit.

[0368] Here, the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission has succeeded, or the target TNL address for which the deactivation has failed.

[0369] In some aspects, the IAB node performs multi-path distribution within the donor aggregation unit, and the first donor distributed unit and the second donor distributed unit belong to the same donor aggregation unit.

[0370] In some aspects, the receiving unit 1901 receives a TNL tunnel transmission establishment request sent by the donor aggregation unit. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission establishment request is used to request the first donor distributed unit to establish the TNL tunnel or activate the TNL tunnel transmission of the downlink data.

[0371] Here, the TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane for which it is necessary to activate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane for which it is necessary to activate the TNL tunnel transmission, the target TNL address of the downlink non-F1 data for which it is necessary to activate the TNL tunnel transmission, or the GTP TEID of the downlink F1 user plane for which it is necessary to activate the TNL tunnel transmission.

[0372] In some aspects, the transmitting unit 1903 further sends a TNL tunnel transmission establishment response to the donor aggregation unit, and the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0373] Here, the TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the target TNL address for which the activation has failed.

[0374] In some aspects, the receiving unit 1901 receives a TNL tunnel transmission update or release request transmitted by the donor aggregation unit, the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission update or release request is used to request the first donor distributed unit to deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel.

[0375] Here, the TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane for which it is necessary to deactivate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane for which it is necessary to deactivate the TNL tunnel transmission, the target TNL address of the downlink non-F1 data for which it is necessary to deactivate the TNL tunnel transmission, or the GTP TEID of the downlink F1 user plane for which it is necessary to deactivate the TNL tunnel transmission.

[0376] In some aspects, the transmitting unit 1903 further transmits a TNL tunnel transmission update or release response to the donor aggregation unit, and the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0377] Here, the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission has succeeded, or the target TNL address for which the deactivation has failed.

[0378] In some aspects, after the IAB node is switched from the first donor distributed unit to the second donor distributed unit, or after the radio link from the IAB node to the first donor distributed unit fails, the RRC is re-established to the second donor distributed unit, the first donor distributed unit belongs to the first donor aggregation unit, and the second donor distributed unit belongs to the second donor aggregation unit.

[0379] In some aspects, the receiving unit 1901 further receives a TNL tunnel transmission establishment request sent by the first donor aggregation unit. The TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission establishment request is used to request the first donor distributed unit to establish the TNL tunnel or activate the TNL tunnel transmission of the downlink data.

[0380] Here, the TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be activated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be activated, or the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be activated.

[0381] In some aspects, the transmitting unit 1903 further transmits a TNL tunnel transmission establishment response to the first donor aggregation unit, and the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit.

[0382] Here, the TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the target TNL address for which the activation has failed.

[0383] In some aspects, the receiving unit 1901 further receives a TNL tunnel transmission update or release request transmitted by the first donor aggregation unit, the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, and the TNL tunnel transmission update or release request is used to request that the first donor distribution unit deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel.

[0384] Here, the TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be deactivated, or the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be deactivated.

[0385] In some aspects, the transmitting unit 1903 further transmits a TNL tunnel transmission update or release response to the first donor aggregation unit, and the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor disaggregation unit.

[0386] Here, the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission has succeeded, or the target TNL address for which the deactivation has failed.

[0387] In some aspects, the IAB node performs multipath delivery between donor aggregation units, the first donor disaggregation unit belongs to the first donor aggregation unit, and the second donor disaggregation unit belongs to the second donor aggregation unit.

[0388] In some aspects, the receiving unit 1901 receives a TNL tunnel transmission establishment request transmitted by the first donor aggregation unit, the TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the second donor disaggregation unit, and the TNL tunnel transmission establishment request is used to request that the first donor disaggregation unit establish the TNL tunnel or activate the TNL tunnel transmission of the downlink data.

[0389] Here, the TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane for which TNL tunnel transmission needs to be activated, the target TNL address of the downlink F1 control plane for which TNL tunnel transmission needs to be activated, the target TNL address of the downlink non-F1 data for which TNL tunnel transmission needs to be activated, or the GTP TEID of the downlink F1 user plane for which TNL tunnel transmission needs to be activated.

[0390] In some aspects, the transmitter 1903 further transmits a TNL tunnel transmission establishment response to the first donor aggregation unit, and the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0391] Here, the TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of TNL tunnel transmission is successful, the target TNL address of the downlink F1 control plane for which the activation of TNL tunnel transmission is successful, the target TNL address of the downlink non-F1 data for which the activation of TNL tunnel transmission is successful, or the target TNL address for which the activation fails.

[0392] In some aspects, the receiver 1901 receives a TNL tunnel transmission update or release request transmitted by the first donor aggregation unit, the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission update or release request is used to request the first donor distributed unit to deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel.

[0393] Here, the TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be deactivated, or the GTP TEID of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated.

[0394] In some aspects, the transmitter 1903 further transmits a TNL tunnel transmission update or release response to the first donor aggregation unit, and the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit.

[0395] Here, the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission is successful, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission is successful, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission is successful, or the target TNL address for which the deactivation fails.

[0396] Note that the above only describes the components or modules related to the present invention, but the present invention is not limited thereto. The IAB communication device 1900 may further include other components or modules. For the specific content of these components or modules, relevant technologies may be referred to.

[0397] Furthermore, for the convenience of description, FIG. 19 only exemplarily shows the connection relationships or signal directions between various components or modules, but it is obvious to those skilled in the art that various related technologies such as bus connections can be used. The above-mentioned various components or modules may be implemented by hardware devices such as processors, memories, transmitters, and receivers, and the present invention is not limited thereto.

[0398] Thereby, the second donor distribution unit (target donor-DU) adds a header related to the tunnel to the uplink data, transmits the uplink data to the first donor distribution unit (source donor-DU) via the TNL tunnel, and / or the first donor distribution unit (source donor-DU) adds a header related to the tunnel to the downlink data and transmits the downlink data to the second donor distribution unit (target donor-DU) via the TNL tunnel. Thereby, by establishing a TNL tunnel between the source donor-DU and the target donor-DU of the IAB-node migration, the problem that uplink data or downlink data is discarded can be solved.

[0399] <Example 5> Embodiments of the present invention provide a communication system including a donor device and an IAB node (IAB-node). Since the related art may be referred to for the network configurations of the donor device and the IAB node, the description thereof is omitted here.

[0400] Embodiments of the present invention further provide a donor device.

[0401] FIG. 20 is a schematic diagram of an example of a Donor device according to an embodiment of the present invention. As shown in FIG. 20, the Donor device 2000 may include a processor 2001 (e.g., a central processing unit (CPU)) and a memory 2002, and the memory 2002 is connected to the processor 2001. The memory 2002 may store various data, and may further store a program 2005 for information processing, and execute the program 2005 under the control of the processor 2001.

[0402] For example, the processor 2001 may execute a program to implement the IAB communication method described in Example 1. For example, the processor 2001 may be configured to receive uplink data transmitted by an IAB node, add a header related to a TNL tunnel to the uplink data, and transmit the uplink data to a first donor distribution unit via a transmission network layer (TNL) tunnel.

[0403] Also, for example, the processor 2001 may execute a program to implement the IAB communication method described in Example 2. For example, the processor 2001 may be configured to receive downlink data transmitted to an IAB node, add a header related to a TNL tunnel to the downlink data, and transmit the downlink data to a second donor distribution unit via a transmission network layer (TNL) tunnel.

[0404] Also, for example, the processor 2001 may execute a program to implement the IAB communication method described in Example 3. For example, the processor 2001 may be configured to receive uplink data transmitted by an IAB node by a second donor distribution unit, and instruct to transmit the uplink data to a first donor distribution unit via a transmission network layer (TNL) tunnel between the second donor distribution unit and the first donor distribution unit.

[0405] Alternatively, the processor 2001 may be configured to receive the downlink data transmitted by the first donor distribution unit to the IAB node and transmit the downlink data to the second donor distribution unit via a transmission network layer (TNL) tunnel between the first donor distribution unit and the second donor distribution unit.

[0406] Also, as shown in FIG. 20, the Donor device 2000 may further include a transceiver 2003, an antenna 2004, etc. The functions of the above members are similar to those of the prior art, and the description thereof is omitted here. Note that the Donor device 2000 does not necessarily include all the units shown in FIG. 20. Also, the Donor device 2000 may further include units not shown in FIG. 20, and reference may be made to the prior art.

[0407] In an embodiment of the present invention, there is further provided a computer-readable program which, when executed on a Donor device, causes the Donor device to execute the IAB communication method described in Embodiments 1 to 3.

[0408] An embodiment of the present invention further provides a storage medium storing a computer-readable program which, when executed, causes a Donor device to execute the IAB communication method described in Embodiments 1 to 3.

[0409] The above devices and methods of the present invention may be implemented by hardware, or may be implemented by combining hardware and software. The present invention relates to a computer-readable program which, when executed by a logic unit, causes the logic unit to implement the above-described device or component, or to implement the above-described various methods or steps. The present invention relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, etc.

[0410] Each processing method in each device described with reference to the embodiments of the present invention may be implemented by hardware, a software module executed by a processor, or a combination of both. For example, one or more of the functional block diagrams shown in the drawings, or one or more combinations of the functional block diagrams, may correspond to each software module of the computer program flow, or may correspond to each hardware module. These software modules may each correspond to each step shown in the drawings. These hardware modules may be realized, for example, by hardware-implementing these software modules using a field programmable gate array (FPGA).

[0411] The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile hard disk, a CD-ROM, or any other form of storage medium known to those skilled in the art. The storage medium may be connected to the processor so that the processor reads information from the storage medium or writes information to the storage medium, or the storage medium may be a component of the processor. The processor and the storage medium may be located in an ASIC. The software module may be stored in the memory of the mobile terminal or may be stored in a memory card inserted into the mobile terminal. For example, when a device (e.g., a mobile terminal) uses a relatively large-capacity MEGA-SIM card or a large-capacity flash memory device, the software module may be stored in the MEGA-SIM card or the large-capacity flash memory device.

[0412] One or more functional blocks and / or one or more combinations of functional blocks in the functional block diagrams described in the drawings may be implemented by a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof for performing the functions described in this application. One or more functional blocks and / or one or more combinations of functional blocks in the functional block diagrams described in the drawings may be implemented, for example, by 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 combination with DSP communication, or any other configuration.

[0413] Although the present invention has been described with reference to specific embodiments above, the above description is merely illustrative and does not limit the scope of protection of the present invention. Without departing from the spirit and principle of the present invention, various modifications and changes may be made to the present invention, and these modifications and changes are also within the scope of the present invention.

[0414] Regarding the embodiments including the above embodiments, the following additional remarks are disclosed. (Additional Remark 1) An access backhaul integration (IAB) communication method, wherein an IAB node migrates from a first donor distributed unit (donor-DU) to a second donor distributed unit, and a transmission network layer (TNL) tunnel is established between the first donor distributed unit and the second donor distributed unit, the step of the second donor distributed unit receiving uplink data transmitted by the IAB node, the step of the second donor distributed unit adding a header related to the tunnel to the uplink data, The step in which the second donor distribution unit transmits the uplink data to the first donor distribution unit via the transmission network layer (TNL) tunnel, and a method including the step. (Appendix 2) The method according to Appendix 1, wherein the header includes at least one of an Internet Protocol (IP) header, a General Packet Radio Service (GPRS) tunneling protocol (GTP) header, a User Datagram Protocol (UDP) header, or a Transmission Control Protocol (TCP) header. (Appendix 3) The method according to Appendix 1, wherein the source transmission network layer (TNL) address of the header is the TNL address of the second donor distribution unit or a TNL address routable by the second donor distribution unit, and the target TNL address of the header is the TNL address of the first donor distribution unit. (Appendix 4) After the IAB node is switched from the first donor distribution unit to the second donor distribution unit, or after a radio link failure (RLF) from the IAB node to the first donor distribution unit, radio resource control (RRC) is re-established with the second donor distribution unit, and the first donor distribution unit and the second donor distribution unit belong to the same donor aggregation unit (donor-CU). The method according to Appendix 1. (Appendix 5) The method according to Appendix 4, further including the step of the second donor distribution unit receiving a TNL tunnel transmission establishment request transmitted by the donor aggregation unit, where the TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission establishment request is used to request the second donor distribution unit to establish the TNL tunnel or activate the TNL tunnel transmission of the uplink data. (Appendix 6) After the donor aggregation unit receives the switching completion message of the IAB node, or after the donor aggregation unit receives the RRC reestablishment completion message of the IAB node, or when the donor aggregation unit does not configure the TNL address assigned by the second donor distribution unit for the IAB node, the second donor distribution unit receives the TNL tunnel transmission establishment request transmitted by the donor aggregation unit, according to the method described in Supplementary Note 5. (Supplementary Note 7) The TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to activate the TNL tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to activate the TNL tunnel transmission, according to the method described in Supplementary Note 5. (Supplementary Note 8) The step in which the second donor distribution unit transmits a TNL tunnel transmission establishment response to the donor aggregation unit, where the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, according to the method described in Supplementary Note 5. (Supplementary Note 9) The TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane for which the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane for which the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data for which the activation of the TNL tunnel transmission is successful, or the source TNL address for which the activation fails, according to the method described in Supplementary Note 8. (Supplementary Note 10) The second donor distribution unit further receives the service mapping information transmitted by the donor aggregation unit, and the service mapping information is the backhaul adaptation protocol (BAP) routing identifier of the downlink data transmitted via the TNL tunnel and the method described in Appendix 4 used to configure the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop. (Appendix 11) The step in which the second donor distribution unit receives the TNL tunnel transmission update or release request transmitted by the donor aggregation unit, where the TNL tunnel transmission update or release request includes the end-point TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission update or release request is used to request the second donor distribution unit to deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel, the method described in Appendix 4 further includes this step. (Appendix 12) After the donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, or after a predetermined time after the switching by the IAB node is completed, or after a predetermined time after the re-establishment by the IAB node is completed, the second donor distribution unit receives the TNL tunnel transmission update or release request transmitted by the donor aggregation unit, the method described in Appendix 11. (Appendix 13) The TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, or the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission, the method described in Appendix 11. (Appendix 14) The step in which the second donor distribution unit further transmits a TNL tunnel transmission update or release response to the donor aggregation unit, where the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, the method according to appendix 11 further comprising this step. (Appendix 15) The TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane for which the deactivation of the TNL tunnel transmission was successful, the source TNL address of the uplink F1 control plane for which the deactivation of the TNL tunnel transmission was successful, the source TNL address of the uplink non-F1 data for which the deactivation of the TNL tunnel transmission was successful, or the source TNL address for which the deactivation failed, the method according to appendix 14. (Appendix 16) The second donor distribution unit further receives a service mapping information release instruction transmitted by the donor aggregation unit, where the service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data for which the TNL tunnel transmission was deactivated and the configuration of the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop, the method according to appendix 4. (Appendix 17) The IAB node performs multi-path distribution within the donor aggregation unit (intra-donor CU), and the first donor distribution unit and the second donor distribution unit belong to the same donor aggregation unit (donor-CU), the method according to appendix 1. (Appendix 18) The step in which the second donor distribution unit receives the TNL tunnel transmission establishment request sent by the donor aggregation unit, wherein the TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission establishment request is used for the second donor distribution unit to establish the TNL tunnel or activate the TNL tunnel transmission of the uplink data, the method according to appendix 17, further comprising the step. (Appendix 19) If the donor aggregation unit configures the backhaul adaptation protocol (BAP) routing of the IAB node as the BAP routing identifier of the second donor distribution unit and does not configure the TNL address assigned by the second donor distribution unit, the second donor distribution unit receives the TNL tunnel transmission establishment request sent by the donor aggregation unit, the method according to appendix 18. (Appendix 20) The TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to activate the TNL tunnel transmission, or the GTP tunnel endpoint identifier (TEID) of the uplink F1 user plane that needs to activate the TNL tunnel transmission, the method according to appendix 18. (Appendix 21) The step in which the second donor distribution unit sends a TNL tunnel transmission establishment response to the donor aggregation unit, wherein the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, the method according to appendix 18, further comprising the step. (Appendix 22) The TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane in which the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane in which the activation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data in which the activation of the TNL tunnel transmission is successful, or the source TNL address in which the activation fails, and is the method described in Appendix 21. (Appendix 23) The second donor distributed unit further receives service mapping information constituted by the donor aggregation unit, and the service mapping information is the BAP routing identifier of the downlink data transmitted through the TNL tunnel and is used to configure the backhaul RLC channel between the second donor distributed unit and the descendant nodes of the next hop, and is the method described in Appendix 17. (Appendix 24) The step in which the second donor distributed unit receives a TNL tunnel transmission update or release request transmitted by the donor aggregation unit, the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit, and the TNL tunnel transmission update or release request is used to request the second donor distributed unit to deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel, and further includes this step, and is the method described in Appendix 17. (Appendix 25) After the donor aggregation unit configures the TNL address assigned by the second donor distributed unit for the IAB node, the second donor distributed unit receives the TNL tunnel transmission update or release request transmitted by the donor aggregation unit, and is the method described in Appendix 24. (Appendix 26) The method according to appendix 24, wherein the TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission, or the GTP TEID of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission. (Appendix 27) The method according to appendix 24, further including the step of the second donor distributed unit transmitting a TNL tunnel transmission update or release response to the donor aggregation unit, wherein the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit. (Appendix 28) The method according to appendix 27, wherein the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane for which the deactivation of the TNL tunnel transmission was successful, the source TNL address of the uplink F1 control plane for which the deactivation of the TNL tunnel transmission was successful, the source TNL address of the uplink non-F1 data for which the deactivation of the TNL tunnel transmission was successful, or the source TNL address for which the deactivation failed. (Appendix 29) The method according to appendix 17, wherein the second donor distributed unit further receives a service mapping information release instruction transmitted by the donor aggregation unit, and the service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data for which the TNL tunnel transmission was deactivated and the configuration of the backhaul RLC channel between the second donor distributed unit and the descendant node of the next hop. (Appendix 30) The method according to Appendix 1, wherein after the IAB node is switched from the first donor distributed unit to the second donor distributed unit, or after the radio link from the IAB node to the first donor distributed unit fails (RLF), RRC is re-established with the second donor distributed unit, the first donor distributed unit belongs to a first donor aggregation unit, and the second donor distributed unit belongs to a second donor aggregation unit. (Appendix 31) The method according to Appendix 30, further comprising the step of receiving, by the second donor distributed unit, a TNL tunnel transmission establishment request sent by the second donor aggregation unit, wherein the TNL tunnel transmission establishment request includes an end-point TNL address of a TNL tunnel of the first donor distributed unit, and the TNL tunnel transmission establishment request is used to request the second donor distributed unit to establish the TNL tunnel or activate the TNL tunnel transmission of the uplink data. (Appendix 32) The method according to Appendix 31, wherein after the second donor aggregation unit receives a switching completion message of the IAB node, or after the second donor aggregation unit receives an RRC re-establishment completion message of the IAB node, or when the second donor aggregation unit does not configure a TNL address assigned by the second donor distributed unit for the IAB node, the second donor distributed unit receives a TNL tunnel transmission establishment request sent by the second donor aggregation unit. (Appendix 33) The method according to Appendix 31, wherein the TNL tunnel transmission establishment request further includes at least one of a source TNL address of an uplink F1 user plane for which the TNL tunnel transmission needs to be activated, a source TNL address of an uplink F1 control plane for which the TNL tunnel transmission needs to be activated, or a source TNL address of uplink non-F1 data for which the TNL tunnel transmission needs to be activated. (Appendix 34) The step in which the second donor distribution unit further transmits a TNL tunnel transmission establishment response to the second donor aggregation unit, wherein the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, the method according to appendix 31, further comprising the step. (Appendix 35) The TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane in which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane in which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data in which the activation of the TNL tunnel transmission has succeeded, or the source TNL address in which the activation has failed, the method according to appendix 34. (Appendix 36) The second donor distribution unit further receives service mapping information transmitted by the donor aggregation unit, wherein the service mapping information is used to configure the BAP routing identifier of the downlink data transmitted via the TNL tunnel and the backhaul RLC channel between the second donor distribution unit and the descendant node of the next hop, the method according to appendix 30. (Appendix 37) The step in which the second donor distribution unit further receives a TNL tunnel transmission update or release request transmitted by the second donor aggregation unit, wherein the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission update or release request is used to request the second donor distribution unit to deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel, the method according to appendix 30, further comprising the step. (Appendix 38) After the second donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, or after a predetermined time has elapsed after the switching by the IAB node is completed, or after a predetermined time has elapsed after the reestablishment by the IAB node is completed, the second donor distribution unit receives the TNL tunnel transmission update or release request transmitted by the second donor aggregation unit, the method described in Appendix 37. (Appendix 39) The TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane for which the TNL tunnel transmission needs to be deactivated, the source TNL address of the uplink F1 control plane for which the TNL tunnel transmission needs to be deactivated, or the source TNL address of the uplink non-F1 data for which the TNL tunnel transmission needs to be deactivated, the method described in Appendix 37. (Appendix 40) The step in which the second donor distribution unit transmits a TNL tunnel transmission update or release response to the second donor aggregation unit, wherein the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, the method described in Appendix 37. (Appendix 41) The TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane for which the deactivation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the deactivation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the deactivation of the TNL tunnel transmission has succeeded, or the source TNL address for which the deactivation has failed, the method described in Appendix 40. (Appendix 42) The second donor distribution unit further receives the service mapping information release instruction transmitted by the donor aggregation unit, and the service mapping information release instruction is used to configure the BAP routing identifier of the downlink data in which the TNL tunnel transmission is deactivated and to release the configuration of the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop, as described in Appendix 30. (Appendix 43) The IAB node performs multi-path distribution among donor aggregation units (inter-donor CUs), where the first donor distribution unit belongs to the first donor aggregation unit and the second donor distribution unit belongs to the second donor aggregation unit, as described in Appendix 1. (Appendix 44) The step in which the second donor distribution unit receives the TNL tunnel transmission establishment request transmitted by the second donor aggregation unit, where the TNL tunnel transmission establishment request includes the end-point TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission establishment request is used to request the second donor distribution unit to establish the TNL tunnel or activate the TNL tunnel transmission of the uplink data, as further included in the method described in Appendix 43. (Appendix 45) If the second donor distribution unit configures the backhaul adaptation protocol (BAP) routing of the IAB node as the BAP routing identifier of the second donor distribution unit and does not configure the TNL address assigned by the second donor distribution unit, the second donor distribution unit receives the TNL tunnel transmission establishment request transmitted by the second donor aggregation unit, as described in Appendix 44. (Appendix 46) The method according to Supplementary Note 44, wherein the TNL tunnel transmission establishment request further includes at least one of the source TNL address of the uplink F1 user plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to activate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to activate the TNL tunnel transmission, or the GTP TEID of the uplink F1 user plane that needs to activate the TNL tunnel transmission. (Supplementary Note 47) The method according to Supplementary Note 44, further including the step of the second donor distributed unit transmitting a TNL tunnel transmission establishment response to the second donor aggregation unit, wherein the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit. (Supplementary Note 48) The method according to Supplementary Note 47, wherein the TNL tunnel transmission establishment response further includes at least one of the source TNL address of the uplink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the source TNL address of the uplink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the source TNL address for which the activation has failed. (Supplementary Note 49) The method according to Supplementary Note 43, wherein the second donor distributed unit further receives service mapping information configured by the donor aggregation unit, and the service mapping information is used to configure the BAP routing identifier of the downlink data transmitted via the TNL tunnel and the backhaul RLC channel between the second donor distributed unit and the descendant nodes of the next hop. (Supplementary Note 50) The step of the second donor distribution unit receiving the TNL tunnel transmission update or release request transmitted by the second donor aggregation unit, wherein the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, and the TNL tunnel transmission update or release request is used to request the second donor distribution unit to deactivate the TNL tunnel transmission of the uplink data or release the TNL tunnel, the method according to Supplementary Note 43, further comprising the step. (Supplementary Note 51) After the second donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, the second donor distribution unit receives the TNL tunnel transmission update or release request transmitted by the second donor aggregation unit, the method according to Supplementary Note 50. (Supplementary Note 52) The TNL tunnel transmission update or release request further includes at least one of the source TNL address of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink F1 control plane that needs to deactivate the TNL tunnel transmission, the source TNL address of the uplink non-F1 data that needs to deactivate the TNL tunnel transmission, or the GTP TEID of the uplink F1 user plane that needs to deactivate the TNL tunnel transmission, the method according to Supplementary Note 50. (Supplementary Note 53) The step of the second donor distribution unit transmitting a TNL tunnel transmission update or release response to the second donor aggregation unit, wherein the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, the method according to Supplementary Note 50, further comprising the step. (Supplementary Note 54) The method according to Appendix 53, wherein the TNL tunnel transmission update or release response further includes at least one of the source TNL address of the uplink F1 user plane in which the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink F1 control plane in which the deactivation of the TNL tunnel transmission is successful, the source TNL address of the uplink non-F1 data in which the deactivation of the TNL tunnel transmission is successful, or the source TNL address in which the deactivation fails. (Appendix 55) The second donor distribution unit further receives a service mapping information release instruction sent by the donor aggregation unit, and the service mapping information release instruction is used to release the configuration of the BAP routing identifier of the downlink data that deactivated the TNL tunnel transmission and the configuration of the backhaul RLC channel between the second donor distribution unit and the descendant nodes of the next hop, according to the method described in Appendix 43. (Appendix 56) An access backhaul integration (IAB) communication method, in which an IAB node migrates from a first donor distribution unit to a second donor distribution unit, and a transmission network layer (TNL) tunnel is established between the first donor distribution unit and the second donor distribution unit. Receiving, by the first donor distribution unit, downlink data sent by the IAB node; Adding, by the first donor distribution unit, a header related to the TNL tunnel to the downlink data; Transmitting, by the first donor distribution unit, the downlink data to the second donor distribution unit via the transmission network layer (TNL) tunnel. The method includes the steps. (Appendix 57) The method according to appendix 56, wherein the header includes at least one of an Internet Protocol (IP) header, a General Packet Radio Service (GPRS) Tunneling Protocol (GTP) header, a User Datagram Protocol (UDP) header, or a Transmission Control Protocol (TCP) header. (Appendix 58) The method according to appendix 56, wherein the source transport network layer (TNL) address of the header is the transport network layer (TNL) address of the first donor distribution unit or a TNL address routable by the first donor distribution unit, and the target transport network layer (TNL) address of the header is the transport network layer (TNL) address of the second donor distribution unit. (Appendix 59) The method according to appendix 56, wherein after the IAB node is switched from the first donor distribution unit to the second donor distribution unit, or after the radio link from the IAB node to the first donor distribution unit fails, RRC is re-established to the second donor distribution unit, and the first donor distribution unit and the second donor distribution unit belong to the same donor aggregation unit (donor-CU). (Appendix 60) The method according to appendix 59, further including the step of receiving, by the first donor distribution unit, a TNL tunnel transmission establishment request sent by the donor aggregation unit, wherein the TNL tunnel transmission establishment request includes an end-point TNL address of a TNL tunnel of the second donor distribution unit, and the TNL tunnel transmission establishment request is used to request the first donor distribution unit to establish the TNL tunnel or activate the TNL tunnel transmission of the downlink data. (Appendix 61) After the donor aggregation unit receives the switching completion message of the IAB node, or after the donor aggregation unit receives the RRC re-establishment completion message of the IAB node, or when the donor aggregation unit does not configure the TNL address assigned by the second donor distribution unit for the IAB node, the first donor distribution unit receives the TNL tunnel transmission establishment request transmitted by the donor aggregation unit, the method described in Appendix 60. (Appendix 62) The TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane that needs to activate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane that needs to activate the TNL tunnel transmission, or the target TNL address of the downlink non-F1 data that needs to activate the TNL tunnel transmission, the method described in Appendix 60. (Appendix 63) The step in which the first donor distribution unit transmits a TNL tunnel transmission establishment response to the donor aggregation unit, wherein the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, the method described in Appendix 60. (Appendix 64) The TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of the TNL tunnel transmission is successful, the target TNL address of the downlink F1 control plane for which the activation of the TNL tunnel transmission is successful, the target TNL address of the downlink non-F1 data for which the activation of the TNL tunnel transmission is successful, or the target TNL address for which the activation fails, the method described in Appendix 63. (Appendix 65) The step of the first donor distribution unit receiving the TNL tunnel transmission update or release request transmitted by the donor aggregation unit, wherein the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, and the TNL tunnel transmission update or release request is used to request the first donor distribution unit to deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel, the method according to supplementary note 60, further comprising the step. (Supplementary note 66) After the donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, or after a predetermined time after the switching by the IAB node is completed, or after a predetermined time after the re-establishment by the IAB node is completed, the first donor distribution unit receives the TNL tunnel transmission update or release request transmitted by the donor aggregation unit, the method according to supplementary note 65. (Supplementary note 67) The TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be deactivated, or the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be deactivated, the method according to supplementary note 65. (Supplementary note 68) The step of the first donor distribution unit transmitting a TNL tunnel transmission update or release response to the donor aggregation unit, wherein the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, the method according to supplementary note 65, further comprising the step. (Supplementary note 69) The method according to appendix 68, wherein the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission has been successful, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission has been successful, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission has been successful, or the target TNL address for which the deactivation has failed. (Appendix 70) The method according to appendix 56, wherein the IAB node performs multipath distribution within an intra-donor CU, and the first donor distributed unit and the second donor distributed unit belong to the same donor CU. (Appendix 71) The method according to appendix 70, further including the step of receiving, by the first donor distributed unit, a TNL tunnel transmission establishment request transmitted by the donor CU, wherein the TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission establishment request is used to request the first donor distributed unit to establish the TNL tunnel or activate the TNL tunnel transmission of the downlink data. (Appendix 72) The method according to appendix 71, wherein when the donor CU configures the backhaul adaptation protocol (BAP) routing of the IAB node as the BAP routing identifier of the second donor distributed unit and does not configure the TNL address assigned by the second donor distributed unit, the first donor distributed unit receives the TNL tunnel transmission establishment request transmitted by the donor CU. (Appendix 73) The method according to Supplementary Note 71, wherein the TNL tunnel transmission establishment request further includes at least one of a target TNL address of a downlink F1 user plane that needs to activate the TNL tunnel transmission, a target TNL address of a downlink F1 control plane that needs to activate the TNL tunnel transmission, a target TNL address of downlink non-F1 data that needs to activate the TNL tunnel transmission, or a GTP TEID of a downlink F1 user plane that needs to activate the TNL tunnel transmission. (Supplementary Note 74) The method according to Supplementary Note 71, further including a step in which the first donor distributed unit transmits a TNL tunnel transmission establishment response to the donor aggregation unit, wherein the TNL tunnel transmission establishment response includes an endpoint TNL address of a TNL tunnel of the first donor distributed unit. (Supplementary Note 75) The method according to Supplementary Note 74, wherein the TNL tunnel transmission establishment response further includes at least one of a target TNL address of a downlink F1 user plane for which activation of the TNL tunnel transmission has been successful, a target TNL address of a downlink F1 control plane for which activation of the TNL tunnel transmission has been successful, a target TNL address of downlink non-F1 data for which activation of the TNL tunnel transmission has been successful, or a target TNL address for which activation has failed. (Supplementary Note 76) The method according to Supplementary Note 70, further including a step in which the first donor distributed unit receives a TNL tunnel transmission update or release request transmitted by the donor aggregation unit, wherein the TNL tunnel transmission update or release request includes an endpoint TNL address of a TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission update or release request is used to request that the first donor distributed unit deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel. (Supplementary Note 77) After the donor aggregation unit constructs the TNL address assigned by the second donor distribution unit for the IAB node, the first donor distribution unit receives the TNL tunnel transmission update or release request sent by the donor aggregation unit, the method described in Appendix 76. (Appendix 78) The TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be deactivated, the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be deactivated, or the GTP TEID of the downlink F1 user plane for which the TNL tunnel transmission needs to be deactivated, the method described in Appendix 76. (Appendix 79) The step in which the first donor distribution unit further sends a TNL tunnel transmission update or release response to the donor aggregation unit, wherein the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, the method described in Appendix 76. (Appendix 80) The TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission is successful, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission is successful, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission is successful, or the target TNL address for which the deactivation fails, the method described in Appendix 79. (Appendix 81) The method according to appendix 56, wherein after the IAB node is switched from the first donor distribution unit to the second donor distribution unit, or after the radio link from the IAB node to the first donor distribution unit fails (RLF), RRC is re-established to the second donor distribution unit, the first donor distribution unit belongs to a first donor aggregation unit, and the second donor distribution unit belongs to a second donor aggregation unit. (Appendix 82) The method according to appendix 81, further comprising the step of receiving, by the first donor distribution unit, a TNL tunnel transmission establishment request sent by the first donor aggregation unit, wherein the TNL tunnel transmission establishment request includes an endpoint TNL address of a TNL tunnel of the second donor distribution unit, and the TNL tunnel transmission establishment request is used to request the first donor distribution unit to establish the TNL tunnel or activate the TNL tunnel transmission of the downlink data. (Appendix 83) The method according to appendix 82, wherein after the second donor aggregation unit receives a switching completion message of the IAB node, or after the second donor aggregation unit receives an RRC re-establishment completion message of the IAB node, or when the second donor aggregation unit does not configure a TNL address assigned by the second donor distribution unit for the IAB node, the first donor distribution unit receives the TNL tunnel transmission establishment request sent by the first donor aggregation unit. (Appendix 84) The method according to appendix 82, wherein the TNL tunnel transmission establishment request further includes at least one of a target TNL address of a downlink F1 user plane for which the TNL tunnel transmission needs to be activated, a target TNL address of a downlink F1 control plane for which the TNL tunnel transmission needs to be activated, or a target TNL address of downlink non-F1 data for which the TNL tunnel transmission needs to be activated. (Appendix 85) The step in which the first donor distribution unit transmits a TNL tunnel transmission establishment response to the first donor aggregation unit, wherein the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, the method according to Supplementary Note 82, further comprising the step. (Supplementary Note 86) The TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane in which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane in which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data in which the activation of the TNL tunnel transmission has succeeded, or the target TNL address in which the activation has failed, the method according to Supplementary Note 85. (Supplementary Note 87) The step in which the first donor distribution unit receives a TNL tunnel transmission update or release request transmitted by the first donor aggregation unit, wherein the TNL tunnel transmission update or release request includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, and the TNL tunnel transmission update or release request is used for the first donor distribution unit to deactivate the TNL tunnel transmission of the downlink data or to request to release the TNL tunnel, the method according to Supplementary Note 81, further comprising the step. (Supplementary Note 88) After the second donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, or after a predetermined time after the switching by the IAB node is completed, or after a predetermined time after the re-establishment by the IAB node is completed, the first donor distribution unit receives a TNL tunnel transmission update or release request transmitted by the first donor aggregation unit, the method according to Supplementary Note 87. (Supplementary Note 89) The method according to appendix 87, wherein the TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane that needs to deactivate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane that needs to deactivate the TNL tunnel transmission, or the target TNL address of the downlink non-F1 data that needs to deactivate the TNL tunnel transmission. (Appendix 90) The method according to appendix 87, further including the step of the first donor distributed unit sending a TNL tunnel transmission update or release response to the first donor aggregation unit, wherein the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distributed unit. (Appendix 91) The method according to appendix 90, wherein the TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane for which the deactivation of the TNL tunnel transmission was successful, the target TNL address of the downlink F1 control plane for which the deactivation of the TNL tunnel transmission was successful, the target TNL address of the downlink non-F1 data for which the deactivation of the TNL tunnel transmission was successful, or the target TNL address for which the deactivation failed. (Appendix 92) The method according to appendix 47, wherein the IAB node performs multi-path distribution between donor aggregation units (inter-donor CU), the first donor distributed unit belongs to the first donor aggregation unit, and the second donor distributed unit belongs to the second donor aggregation unit. (Appendix 93) The step of the first donor distribution unit receiving a TNL tunnel transmission establishment request transmitted by the first donor aggregation unit, wherein the TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the second donor distribution unit, and the TNL tunnel transmission establishment request is used for the first donor distribution unit to establish the TNL tunnel or to request to activate the TNL tunnel transmission of the downlink data, the method according to appendix 92, further comprising the step. (Appendix 94) If the second donor aggregation unit configures the backhaul adaptation protocol (BAP) routing of the IAB node as the BAP routing identifier of the second donor distribution unit and does not configure the TNL address assigned by the second donor distribution unit for the downlink data, the first donor distribution unit receives the TNL tunnel transmission establishment request transmitted by the first donor aggregation unit, the method according to appendix 93. (Appendix 95) The TNL tunnel transmission establishment request further includes at least one of the target TNL address of the downlink F1 user plane for which the TNL tunnel transmission needs to be activated, the target TNL address of the downlink F1 control plane for which the TNL tunnel transmission needs to be activated, the target TNL address of the downlink non-F1 data for which the TNL tunnel transmission needs to be activated, or the GTP TEID of the downlink F1 user plane for which the TNL tunnel transmission needs to be activated, the method according to appendix 93. (Appendix 96) The step of the first donor distribution unit transmitting a TNL tunnel transmission establishment response to the first donor aggregation unit, wherein the TNL tunnel transmission establishment response includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, the method according to appendix 93, further comprising the step. (Appendix 97) The TNL tunnel transmission establishment response further includes at least one of the target TNL address of the downlink F1 user plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane for which the activation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data for which the activation of the TNL tunnel transmission has succeeded, or the target TNL address for which the activation has failed, according to the method described in Appendix 96. (Appendix 98) The step of the first donor distributed unit receiving a TNL tunnel transmission update or release request sent by the first donor aggregation unit, where the TNL tunnel transmission update or release request includes the end-point TNL address of the TNL tunnel of the second donor distributed unit, and the TNL tunnel transmission update or release request is used to request the first donor distributed unit to deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel, according to the method described in Appendix 92. (Appendix 99) After the second donor aggregation unit configures the TNL address assigned by the second donor distributed unit for the IAB node, the first donor distributed unit receives the TNL tunnel transmission update or release request sent by the first donor aggregation unit, according to the method described in Appendix 98. (Appendix 100) The TNL tunnel transmission update or release request further includes at least one of the target TNL address of the downlink F1 user plane for which it is necessary to deactivate the TNL tunnel transmission, the target TNL address of the downlink F1 control plane for which it is necessary to deactivate the TNL tunnel transmission, the target TNL address of the downlink non-F1 data for which it is necessary to deactivate the TNL tunnel transmission, or the GTP TEID of the downlink F1 user plane for which it is necessary to deactivate the TNL tunnel transmission, according to the method described in Appendix 98. (Supplementary Note 101) The step in which the first donor distribution unit transmits a TNL tunnel transmission update or release response to the first donor aggregation unit, wherein the TNL tunnel transmission update or release response includes the endpoint TNL address of the TNL tunnel of the first donor distribution unit, the method according to Supplementary Note 98, further comprising the step. (Supplementary Note 102) The TNL tunnel transmission update or release response further includes at least one of the target TNL address of the downlink F1 user plane in which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink F1 control plane in which the deactivation of the TNL tunnel transmission has succeeded, the target TNL address of the downlink non-F1 data in which the deactivation of the TNL tunnel transmission has succeeded, or the target TNL address in which the deactivation has failed, the method according to Supplementary Note 101. (Supplementary Note 103) An access backhaul integration (IAB) communication method, wherein an IAB node migrates from a first donor distribution unit to a second donor distribution unit, The second donor aggregation unit receives uplink data transmitted by the second donor distribution unit by the IAB node, and instructs the first donor distribution unit to transmit the uplink data to the first donor distribution unit via a transmission network layer (TNL) tunnel between the second donor distribution unit and the first donor distribution unit, the method comprising the step. The first donor distribution unit belongs to the first donor aggregation unit, and the second donor distribution unit belongs to the second donor aggregation unit, the method. (Supplementary Note 104) The step in which the second donor aggregation unit transmits a TNL tunnel transmission establishment request to the second donor aggregation unit, where the TNL tunnel transmission establishment request includes the endpoint TNL address of the TNL tunnel of the first donor aggregation unit, and the TNL tunnel transmission establishment request is used to request that the second donor aggregation unit establish the TNL tunnel or activate the TNL tunnel transmission of the uplink data, the method according to supplementary note 103, further comprising. (Supplementary note 105) The method according to supplementary note 104, wherein the endpoint TNL address of the TNL tunnel of the first donor aggregation unit is transmitted by the first donor aggregation unit to the second donor aggregation unit. (Supplementary note 106) After the second donor aggregation unit receives the IAB node handover completion message, or After the second donor aggregation unit receives the RRC re-establishment completion message of the IAB node, or If the second donor aggregation unit does not configure the TNL address assigned by the second donor distribution unit for the IAB node, The method according to supplementary note 103, wherein the second donor aggregation unit transmits the TNL tunnel transmission establishment request to the second donor aggregation unit. (Supplementary note 107) The method according to supplementary note 104, further comprising the step of the second donor aggregation unit receiving the TNL address assigned by the first donor distribution unit for the IAB node and transmitted by the first donor aggregation unit, so that the second donor aggregation unit transmits a TNL tunnel transmission establishment request to the second donor distribution unit. (Supplementary note 108) An access backhaul integration (IAB) communication method, wherein an IAB node migrates from a first donor distribution unit to a second donor distribution unit, The first donor aggregation unit receives the downlink data transmitted by the first donor distribution unit to the IAB node, and instructs to transmit the downlink data to the second donor distribution unit via a transmission network layer (TNL) tunnel between the first donor distribution unit and the second donor distribution unit, including the step of A method in which the first donor distribution unit belongs to the first donor aggregation unit and the second donor distribution unit belongs to a second donor aggregation unit. (Appendix 109) The method according to Appendix 108, further including the step that the first donor aggregation unit further transmits a TNL tunnel transmission update or release request to the first donor distribution unit, where the TNL tunnel transmission update or release request includes an endpoint TNL address of the TNL tunnel of the second donor distribution unit, and the TNL tunnel transmission update or release request is used to request that the first donor distribution unit deactivate the TNL tunnel transmission of the downlink data or release the TNL tunnel. (Appendix 110) The method according to Appendix 109, where the endpoint TNL address of the TNL tunnel of the second donor distribution unit is transmitted by the second donor aggregation unit to the first donor aggregation unit. (Appendix 111) After the second donor aggregation unit configures the TNL address assigned by the second donor distribution unit for the IAB node, the first donor aggregation unit transmits the TNL tunnel transmission update or release request to the first donor distribution unit, according to the method described in Appendix 109. (Appendix 112) The second donor aggregation unit further transmits the TNL address assigned to the IAB node by the second donor distribution unit to the first donor aggregation unit, and triggers the first donor aggregation unit to transmit the TNL tunnel transmission update or release request to the first donor distribution unit, according to the method described in appendix 109. (Appendix 113) An access backhaul integration (IAB) communication method, wherein an IAB node migrates from a first donor distribution unit to a second donor distribution unit, The donor aggregation unit receives uplink data transmitted by the IAB node by the second donor distribution unit, and instructs to transmit the uplink data to the first donor distribution unit via a transmission network layer (TNL) tunnel between the second donor distribution unit and the first donor distribution unit, the method comprising: The first donor distribution unit and the second donor distribution unit belong to the donor aggregation unit. (Appendix 114) An access backhaul integration (IAB) communication method, wherein an IAB node migrates from a first donor distribution unit to a second donor distribution unit, The donor aggregation unit receives downlink data transmitted by the IAB node by the first donor distribution unit, and instructs to transmit the downlink data to the second donor distribution unit via a transmission network layer (TNL) tunnel between the first donor distribution unit and the second donor distribution unit, the method comprising: The first donor distribution unit and the second donor distribution unit belong to the donor aggregation unit. (Appendix 115) A donor device including a memory storing a computer program and a processor, wherein the processor is configured to implement the IAB communication method according to any one of appendices 1 to 114 by executing the computer program. (Appendix 116) A communication system including a donor device and an IAB node, wherein the donor device is configured to execute the IAB communication method described in any one of Appendices 1 to 114.

Claims

1. An IAB communication device configured as a second donor IAB-DU, comprising: a receiving unit that receives an uplink packet transmitted by an IAB node; a processing unit that adds a header related to a TNL tunnel to the uplink packet; a transmitting unit that transmits the uplink packet to a first donor IAB-DU via the TNL tunnel, wherein a source TNL address of the uplink packet is anchored to the first donor IAB-DU; a transmission path of the IAB node migrates from the first donor IAB-DU to the second donor IAB-DU; the receiving unit receives a configuration of a source TNL address of the uplink packet from the donor IAB-CU, the source TNL address is permitted to be transferred to the first donor IAB-DU, and is excluded from TNL addresses filtered by the second donor IAB-DU.

2. The IAB communication device according to claim 1, wherein the header includes at least one of an Internet protocol header, a general packet radio service tunneling protocol header, a user datagram protocol header, or a transmission control protocol header.

3. The IAB communication device according to claim 1, wherein after the IAB node is switched from the first donor IAB-DU to the second donor IAB-DU, or after a radio link from the IAB node to the first donor IAB-DU fails, radio resource control is re-established to the second donor IAB-DU, and the first donor IAB-DU and the second donor IAB-DU belong to the same donor IAB-CU.

4. The IAB communication device according to claim 1, wherein the first donor IAB-DU and the second donor IAB-DU belong to the same donor IAB-CU.

5. The IAB communication device according to claim 1, wherein the IAB node is switched from the first donor IAB-DU to the second donor IAB-DU, or after the radio link from the IAB node to the first donor IAB-DU fails, RRC is re-established with the second donor IAB-DU, the first donor IAB-DU belongs to the first donor IAB-CU, and the second donor IAB-DU belongs to the second donor IAB-CU.

6. The IAB communication device according to claim 1, wherein the first donor IAB-DU belongs to the first donor IAB-CU and the second donor IAB-DU belongs to the second donor IAB-CU.

7. An IAB communication device configured in a first donor IAB-DU, comprising: a receiving unit that receives a downlink packet transmitted to an IAB node; a processing unit that adds a header related to a TNL tunnel to the downlink packet; a transmitting unit that transmits the downlink packet to a second donor IAB-DU via the TNL tunnel, wherein the transmission path of the IAB node migrates from the first donor IAB-DU to the second donor IAB-DU, and the receiving unit receives a configuration of a source TNL address of the downlink packet from the donor IAB-CU, and the source TNL address is permitted to be transferred to the first donor IAB-DU and excluded from TNL addresses filtered by the second donor IAB-DU.

8. The IAB communication device according to claim 7, wherein the header includes at least one of an Internet protocol header, a general packet radio service tunneling protocol header, a user datagram protocol header, or a transmission control protocol header.

9. The IAB node is switched from the first donor IAB-DU to the second donor IAB-DU, or after the radio link from the IAB node to the first donor IAB-DU fails, RRC is re-established with the second donor IAB-DU, and the first donor IAB-DU and the second donor IAB-DU belong to the same donor IAB-CU, the IAB communication device according to claim 7.

10. The IAB communication device according to claim 7, wherein the first donor IAB-DU and the second donor IAB-DU belong to the same donor IAB-CU.

11. The IAB node is switched from the first donor IAB-DU to the second donor IAB-DU, or after the radio link from the IAB node to the first donor IAB-DU fails, RRC is re-established with the second donor IAB-DU, the first donor IAB-DU belongs to a first donor IAB-CU, and the second donor IAB-DU belongs to a second donor IAB-CU, the IAB communication device according to claim 7.

12. The IAB communication device according to claim 7, wherein the first donor IAB-DU belongs to a first donor IAB-CU and the second donor IAB-DU belongs to a second donor IAB-CU.

13. An IAB communication method executed by a second donor IAB-CU, wherein an IAB node migrates from a first donor IAB-DU to a second donor IAB-DU, and the IAB communication method includes: a step of instructing the second donor IAB-DU to receive an uplink packet from the IAB node and transmit the uplink packet to the first donor IAB-DU via a TNL tunnel between the first donor IAB-DU and the second donor IAB-DU, the first donor IAB-DU belongs to a first donor IAB-CU, and the second donor IAB-DU belongs to the second donor IAB-CU, A step of receiving a configuration of a source TNL address of the uplink packet transmitted by the first donor IAB-CU so that the second donor IAB-CU transmits the source TNL address of the uplink packet to the second donor IAB-DU, the IAB communication method further comprising this step.

14. A step of further including transmitting a TNL tunnel transmission establishment request to the second donor IAB-DU, The TNL tunnel transmission establishment request includes an endpoint TNL address of a TNL tunnel of the first donor IAB-DU, and the TNL tunnel transmission establishment request is used for the second donor IAB-DU to establish the TNL tunnel or to request to activate TNL tunnel transmission of uplink data. The IAB communication method according to claim 13.

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