Network node communication method, mobile node communication method, mobile node and donor device

Abstract

In some embodiments of the present invention, there are provided a communication method for a network node, a communication method for a mobile node, a mobile node, and a donor device, the method including: a first donor-CU receiving first instruction information, the first instruction information including identification information for a third donor-CU; and the first donor-CU sending second instruction information to the third donor-CU to indicate a traffic context.

Description

[Technical Field]

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

[0002] Future seamless cellular network deployment requires highly flexible and ultra-dense new radio (NR) cell deployment, and ultra-dense networks are one of the goals of 5G. The deployment of a single NR network without wired backhaul is crucial for realizing 5G's ultra-dense networks. Because 5G millimeter wave reduces cell coverage, wireless self-backhaul systems require multi-hop operation to meet deployment needs. 5G's high bandwidth, massive multiple-input multiple-output (MIMO), and beam systems make it easier to develop wireless self-backhaul systems with ultra-dense NR cells than LTE. To develop such multi-hop systems with wireless self-backhaul, 3GPP (registered trademark) has initiated research and standardization of the Integrated Access and Backhaul (IAB) project in Rel-16.

[0003] In the IAB system, access and backhaul adopt wireless transmission over the NR Uu air interface, relay nodes simultaneously support access and backhaul functions, relay nodes multiplex the access link and backhaul link in the time domain, frequency domain or spatial domain, and the access link and backhaul link can use the same or different frequency bands.

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

[0005] The IAB-node functions are divided into two parts: one part is the gNB-DU function and is called IAB-DU (Distributed Unit), and the other part is the UE function and is called IAB-MT (Mobile Terminal). The IAB-DU realizes the network side equipment function, serves one or more cells, and is connected to a downstream child IAB-node (child IAB node (or simply referred to as child node)). It provides NR air interface access for UEs and downstream child IAB-nodes, and establishes F1 connection with an IAB donor-CU (Donor Centralized Unit). The IAB-MT implements some terminal device functions and is connected to the upstream parent IAB-node (or simply referred to as parent node) or 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 (CN).

[0006] Figure 1 shows the IAB architecture in SA mode. Figure 2 shows the IAB architecture in EN-DC mode. In an IAB system, an IAB-node can access the network through either Standalone (SA) mode or Dual Connectivity (EN-DC) mode.

[0007] Figure 3 shows one IAB node (IAB-node), its parent node (parent IAB-node), and its child node (child IAB-node). As shown in Figure 3, the IAB node's IAB-DU is connected to the child node IAB-MT as the network side, and the IAB node's IAB-MT is connected to the parent node IAB-DU as the terminal side.

[0008] Figure 4 shows the F1 user plane (F1-U) protocol stack between the IAB-DU and the IAB donor-CU. Figure 5 shows the F1 control plane (F1-C) protocol stack between the IAB-DU and the IAB donor-CU. As shown in Figures 4 and 5, F1-U and F1-C are established on the transport (IP) layer between the IAB-DU and the IAB donor-CU, and Figures 4 and 5 include two-hop wireless backhaul and one-hop wired backhaul.

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

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

[0011] The inventors have found that, although it has been proposed that a mobile node can move within a donor-CU, how to specifically perform migration, handover, and / or radio link failure (RLF) recovery has not been defined or supported.

[0012] To solve at least one of the above problems, embodiments of the present invention provide a communication method for a network node, a communication method for a mobile node, a mobile node, and a donor device. [Means for solving the problem]

[0013] According to one aspect of an embodiment of the present invention, there is provided a communication method for network nodes, wherein a first donor-CU is an F1 terminating donor-CU of a mobile node, a second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and a third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery; The method comprises: The first donor-CU receives first instruction information, the first instruction information including identification (ID) information regarding the third donor-CU; and The first donor-CU sends second instruction information to the third donor-CU to indicate a traffic context.

[0014] According to another aspect of an embodiment of the present invention, there is provided a donor device, wherein the donor device is an F1 terminating donor-CU of a mobile node, a second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and a third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery; The donor device comprises: a receiving unit for receiving first instruction information, the first instruction information including identification information regarding the third donor-CU; and A transmitter for transmitting second instruction information for instructing the third donor-CU about a traffic context is also included.

[0015] According to another aspect of an embodiment of the present invention, there is provided a communication method for network nodes, in which a first donor-CU is an F1 terminating donor-CU of a mobile node, a second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and a third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery; The method comprises: the second donor-CU sending first instruction information to the first donor-CU; The first instruction information includes the identification information of the third donor-CU.

[0016] According to another aspect of an embodiment of the present invention, there is provided a donor device, wherein a first donor-CU is an F1 terminating donor-CU of a mobile node, the donor device is a non-F1 terminating donor-CU before a transition or radio link failure (RLF) recovery of the mobile node, and a third donor-CU is a non-F1 terminating donor-CU after a transition or RLF recovery of the mobile node; The donor device comprises: a transmitter for transmitting first instruction information to the first donor-CU; The first instruction information includes the identification information of the third donor-CU.

[0017] According to another aspect of an embodiment of the present invention, there is provided a communication method for network nodes, in which a first donor-CU is an F1 terminating donor-CU of a mobile node, a second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and a third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery; The method comprises: receiving, by the third donor-CU, second indication information for indicating a traffic context, the second indication information being transmitted by the first donor-CU based on the indicator information; Wherein, the indicator information relates to the third donor-CU and is included in the first instruction information received by the first donor-CU.

[0018] According to another aspect of an embodiment of the present invention, there is provided a donor device, wherein a first donor-CU is an F1 terminating donor-CU of a mobile node, a second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and the donor device is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery; The donor device comprises: a receiving unit for receiving second indication information for indicating a traffic context, the second indication information being transmitted by the first donor-CU based on the indication information; Wherein, the indicator information relates to the third donor-CU and is included in the first instruction information received by the first donor-CU. [Effects of the Invention]

[0019] The advantageous effects of the embodiment of the present invention are at least as follows: a first donor-CU receives first indication information, the first indication information includes indicator information for a third donor-CU, and the first donor-CU sends second indication information to the third donor-CU based on the indicator information to indicate traffic context, thereby supporting mobile nodes to move within a control domain without service interruption, and thus ensuring the service quality of the mobile nodes for user equipment.

[0020] The following description and reference to the drawings disclose in detail particular embodiments of the present invention, illustrating ways in which the principles of the present invention may be employed, but the scope of the present invention is not limited thereto, and various changes, modifications, and alternatives may be included within the scope of the appended claims.

[0021] Additionally, features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, may be combined with features in the other embodiments, or may be substituted for features in the other embodiments.

[0022] It should be noted that when used in this specification, terms such as "comprise / have" refer to the presence of a feature, element, step, or assembly, but do not exclude the presence or addition of one or more other features, elements, steps, or assemblies. [Brief explanation of the drawings]

[0023] Elements and features described in one drawing or one embodiment of the invention may be combined with elements and features shown in one or more other drawings or embodiments, and in the drawings, like reference numerals are used to indicate corresponding parts in several drawings and to indicate corresponding parts used in multiple embodiments.

[0024] The included drawings are used to provide a further understanding of the embodiments of the present invention, and these drawings constitute a part of this specification, illustrate embodiments of the present invention, and together with the written description, serve to explain the principles of the present invention. Also, it is apparent that the drawings described below are only for illustrating some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without any creative effort. [Figure 1] FIG. 1 illustrates the IAB architecture in SA mode. [Figure 2] FIG. 1 illustrates an IAB architecture in EN-DC mode. [Figure 3] FIG. 1 is a diagram showing a parent node (parent IAB-node) and a child node (child IAB-node). [Figure 4] FIG. 1 illustrates the F1-U protocol stack of the IAB system. [Figure 5] FIG. 1 illustrates the F1-C protocol stack of the IAB system. [Figure 6] FIG. 1 illustrates a mobility scenario according to an embodiment of the present invention. [Figure 7] FIG. 10 is a diagram illustrating intra-m-CU topology adaptation in an embodiment of the present invention. [Figure 8] FIG. 2 is a diagram illustrating a communication method of a network node in an embodiment of the present invention. [Figure 9] 1 is a signaling flowchart of topology adaptation in an embodiment of the present invention; [Figure 10] 10 is another signaling flowchart of topology adaptation in an embodiment of the present invention; [Figure 11] 10 is yet another signaling flowchart of topology adaptation in an embodiment of the present invention; [Figure 12] 1 is a signaling flowchart of RLF recovery in an embodiment of the present invention; [Figure 13] FIG. 2 is a diagram illustrating a communication method of a network node in an embodiment of the present invention. [Figure 14]FIG. 2 is a diagram illustrating a communication method of a network node in an embodiment of the present invention. [Figure 15] FIG. 2 is a diagram illustrating a communication method of a mobile node in an embodiment of the present invention. [Figure 16] FIG. 1 illustrates a donor device in accordance with an embodiment of the present invention. [Figure 17] FIG. 1 illustrates a donor device in accordance with an embodiment of the present invention. [Figure 18] FIG. 1 illustrates a donor device in accordance with an embodiment of the present invention. [Figure 19] FIG. 2 illustrates a mobile node in an embodiment of the present invention. [Figure 20] FIG. 1 illustrates an IAB device in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The foregoing and other features of the present invention will become more apparent from a consideration of the accompanying drawings and the following description. While the specification and drawings disclose particular embodiments of the present invention, they illustrate only some of the embodiments which may employ the principles of the present invention, and it is to be understood that the present invention is not limited to the described embodiments, but rather includes all modifications, variations, and alternatives which fall within the scope of the appended claims.

[0026] In embodiments of the present invention, the term "communication network" or "wireless communication network" may refer to a network conforming to any communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), etc.

[0027] Additionally, communications between devices in a communications system may be performed according to any level of communications protocol, including, but not limited to, 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G, New Radio (NR), and / or other conventional or future-developed communications protocols.

[0028] In an embodiment of the present invention, the term "network equipment" refers to, for example, a device in a communication system that connects a terminal device to a communication network and provides services to the terminal device. The network equipment may include, but is not limited to, a "node" and / or a "donor" in the IAB architecture, a base station (BS), an access point (AP), a transmission reception point (TRP), a broadcast transmitter, a mobile management entity (MME), a network gateway, a server, a radio network controller (RNC), a base station controller (BSC), etc.

[0029] The base station may include, but is not limited to, a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a 5G base station (gNB), etc., and may further include a Remote Radio Head (RRH), a Remote Radio Unit (RRU), a relay, or a low-power node (e.g., femto, pico, etc.). The term "base station" may include some or all of these functions, and each base station can provide communication coverage for a specific geographical area. For example, a 5G base station gNB may include one gNB CU and one or more gNB DUs, where a CU / DU is a logical node of the gNB that has some of the functions of the gNB. The term "cell" may refer to a base station and / or the area it covers, depending on the context in which the term is used.

[0030] In the embodiments of the present invention, the term "user equipment" (UE) or "terminal equipment" (TE) refers to a device that accesses a communication network and receives services from the network, for example, via network equipment. The user equipment may be fixed or mobile, and may also be referred to as a mobile station (MS), terminal, subscriber station (SS), access terminal (AT), station, etc. For example, it is a terminal equipment served by an IAB node or an IAB donor under the IAB architecture.

[0031] Among these, user equipment may include, but is not limited to, cellular phones, personal digital assistants (PDAs), wireless modems, wireless communication devices, mobile devices, machine-type communication devices, laptop computers, cordless phones, smartphones, smart watches, digital cameras, etc.

[0032] Furthermore, for example, in a scenario such as the Internet of Things (IoT), the user equipment may also be a monitoring or measuring device or apparatus, for example, including but not limited to, a Machine Type Communication (MTC) terminal, an in-vehicle communication terminal, a Device to Device (D2D) terminal, a Machine to Machine (M2M) terminal, etc.

[0033] Furthermore, the term "network side" or "network equipment side" refers to the network side, or may be a base station, and may include one or more network equipment as described above. The term "user side" or "terminal side" or "terminal equipment side" refers to the user or terminal side, or may be a UE, and may include one or more terminal equipment as described above.

[0034] Currently, there is a growing demand for improved 5G cellular coverage and connectivity performance, which is particularly challenging in many outdoor and mobile scenarios. In some outdoor environments, vehicles equipped with mobile base station relays (e.g., mobile IABs) can provide significant opportunity improvements in cellular coverage and capacity when or where needed. These vehicles follow some known or predictable routes, such as buses, trains, etc., or are located in convenient locations, such as outside stadiums, hot spots, or emergency sites.

[0035] These relays can use 5G wireless backhaul to the macro network to provide better 5G coverage and connectivity to nearby UEs. Vehicular relays are also well suited to improving the connectivity performance of users or devices within their own vehicles, including scenarios such as passengers, temporary / professional personnel, or devices in buses, cars, taxis, and trains. Other target scenarios include vehicular relays being used to serve user equipment with no or very poor macro coverage. Small in-vehicle base station relays are installed in moving vehicles to provide 5G coverage and communication to nearby UEs inside and / or outside the vehicle, and are wirelessly connected to the 5G network by a RAN (donor) node.

[0036] Taking an IAB node as an example, the IAB-MT can migrate to a parent node under a different IAB-donor-CU. In this case, the collocated IAB-DU and the descendant IAB-DUs maintain F1 connectivity with the original IAB-donor-CU. This type of migration is called inter-donor partial migration. The IAB node of the new IAB-donor-CU to which the IAB-MT migrates is a border IAB node. After inter-donor partial migration, the F1 traffic of the IAB-DU and descendant nodes is routed via the BAP layer of the IAB topology to which the IAB-MT migrated.

[0037] When an IAB node in SA mode declares backhaul link RLF, it can perform RLF recovery at a parent node under a different IAB-donor-CU. Similar to inter-donor partial migration, the collocated IAB-DU and the descendant IAB-DU can maintain F1 connectivity with the original IAB-donor-CU.

[0038] A mobile IAB (mIAB) or mobile relay faces a challenge of mobility in a relatively large area: when it changes IAB donors, all of the PDCP (packet data convergence protocol) and RRC connections of its serving UEs may be affected. Thus, a UE in a vehicle, even if stationary, may experience a relatively large signaling overhead due to mobility in idle state (because it needs to adjust the TA value to the value assigned by the new gNB and change the PDCP termination and security for the user plane) and connected state.

[0039] FIG. 6 illustrates a mobility scenario according to an embodiment of the present invention. As shown in FIG. 6, if the DUs of an mIAB are served by a single CU covering a larger area, the root cause of these mobility-related signaling issues can be eliminated. Simply put, providing a dedicated mobility control unit (m-CU) for the mIAB donor function to control UEs connected to the mIAB is an advanced approach. This allows the mIAB to move within a fairly large RAN coverage area without changing the m-CU. Therefore, the movement of the mIAB between IAB donors can be invisible to UEs connected to the mIAB as long as the controller is in the same m-CU.

[0040] However, how to achieve intra-m-CU IAB mobility when the m-CU does not change, i.e., mIAB migration and RLF recovery, has not yet been defined and supported. An embodiment of the present invention relates to a partial migration process of mIAB within an m-CU, i.e., a topology adaptation process within an m-CU.

[0041] In an embodiment of the present invention, the m-CU may be a dedicated IAB-donor-CU, i.e., an F1-terminating donor-CU of an IAB node or an IAB-DU. Partial migration within an m-CU of an IAB node refers to the ability of an IAB-MT to migrate to a different IAB-donor-CU or its subordinate parent node. In such a case, the RRC connection of the IAB-MT is migrated from the source IAB-donor-CU to the target IAB-donor-CU, and the collocated IAB-DU maintains its F1 connection with the original IAB-donor-CU (i.e., the m-CU).

[0042] During the mIAB migration process, the IAB-MT can always be migrated to a different IAB-donor-CU or its parent node. The F1 traffic of the IAB-DU is routed through the BAP layer of the IAB topology to which the IAB-MT has migrated. Similarly, when an mIAB node declares backhaul link RLF, it can perform RLF recovery at a parent node under a different IAB-donor-CU. Similar to partial migration within an m-CU, the collocated IAB-DU can maintain F1 connectivity with the original m-CU. When the source IAB-donor-CU of the mIAB-MT is an m-CU, the migration process within the mIAB is the partial migration / RLF recovery process defined in Rel-17.

[0043] 7 is a diagram illustrating intra-m-CU topology adaptation in an embodiment of the present invention. As shown in FIG. 7, when the source IAB-donor-CU of an mIAB is not an m-CU, the intra-m-CU migration process of the mIAB can be regarded as a partial migration process between non-F1 terminal donors, i.e., a process of changing the non-F1 terminal donor.

[0044] In the embodiments of the present invention, unless otherwise specified, the IAB node device includes a transition node or its child node. Also, the mobile node is not limited to an IAB node, and can be, for example, a network-controlled repeater (NCR) in the case of a relay.

[0045] The following describes in more detail the embodiments of the present invention.

[0046] <Example of the first aspect> In an embodiment of the present invention, a communication method of a network node is provided, which is described from the perspective of a first donor-CU, where the first donor-CU is an F1 terminating donor-CU of a mobile node, the second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery and may be referred to as a source donor-CU or initial donor-CU, and the third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery and may be referred to as a target donor-CU or new donor-CU.

[0047] FIG. 8 illustrates a communication method for a network node according to an embodiment of the present invention. As shown in FIG. 8, the method includes the following steps (operations): 801: A first donor-CU receives first instruction information, the first instruction information including indicator information regarding the third donor-CU; and 802: The first donor-CU sends second instruction information to the third donor-CU to instruct the traffic context.

[0048] Note that, although the above-mentioned FIG. 8 is used to exemplify an embodiment of the present invention, the present invention is not limited thereto. For example, the execution order of each operation may be appropriately adjusted, or some operations may be appropriately increased or decreased. Those skilled in the art may make appropriate modifications based on the above content without being limited to the description of the above-mentioned FIG. 8.

[0049] In some embodiments, the first donor-CU is an F1 terminating donor-CU for multiple mobile nodes within a designated (predetermined) area, and the F1 connections of the multiple mobile nodes are always terminated at the first donor-CU, i.e., the first donor-CU is the m-CU shown in FIG.

[0050] Taking Figure 7 as an example, in the topology adaptation process within the m-CU, IAB node 3 (mobile node) performs topology adaptation within the m-CU. In the topology diagram on the left side of Figure 7, IAB node 3 is connected to IAB-donor 1 (a collective term for donor-CU 1 and donor-DU 1 in Figure 7; Figure 7 shows a case where CU and DU are separated (distributed), but a centralized case is also possible, i.e., CU and DU are in one node) via parent node IAB node 1 (note that parent node IAB node 1 is not required and can be directly connected to IAB-donor). In other words, the source IAB-donor of IAB-MT 3 is IAB-donor 1 (second donor-CU), i.e., the endpoint of the RRC connection of IAB-MT 3 is IAB-donor 1. IAB-donor 1 is also referred to as the non-F1 terminating donor of IAB node 3. The F1 terminating donor of IAB node 3 is m-CU (first donor-CU) in Figure 7. All F1 traffic of IAB-DU 3, i.e., traffic of UEs of IAB node 3, reaches m-CU via IAB-MT 3 and IAB-donor 1.

[0051] In the mobility process of IAB node 3, IAB node 3 can be migrated to the topology diagram on the right side of Figure 7. IAB node 3 is connected to IAB-donor 2 (a collective term for donor-CU 2 and donor-DU 2 in Figure 7) by node IAB node 2 (note that the parent node IAB node 2 is not required, and it may be directly connected to the IAB-donor). In other words, the target IAB-donor of IAB-MT 3 is IAB-donor 2 (third donor-CU), that is, the endpoint of the RRC connection of IAB-MT 3 is IAB-donor 2. IAB-donor 2 becomes the non-F1 terminating donor of IAB node 3. The F1 terminating donor of IAB node 3 remains m-CU in Figure 7. All F1 traffic of IAB-DU 3, i.e., traffic of UEs on IAB node 3, reaches m-CU via IAB-MT 3 and IAB-donor 2.

[0052] In some embodiments, the first donor-CU receives address information sent by the mobile node, which anchors the mobile node to a donor-DU of the third donor-CU (e.g., donor-DU 2 in FIG. 7).

[0053] In some embodiments, the second instruction information is sent by a transmission transition management request message, and the second instruction information includes downlink address information to allow the third donor-CU to configure or change downlink mapping.

[0054] In some embodiments, the first donor-CU receives a transmission transition management response message sent by the third donor-CU, and the transmission transition management response message includes mapping information for offloaded traffic and / or Layer 2 information on the topology of the third donor-CU.

[0055] In some embodiments, the first donor-CU transmits uplink backhaul information of traffic to the mobile node.

[0056] The inter-donor partial transfer has been described above as an example, and the first instruction information will now be described.

[0057] In some implementations, the first instruction information is sent by the second donor-CU in a transmission transition change request message, and the first donor-CU sends a transmission transition change response message to the second donor-CU.

[0058] Wherein, the transmission transition change request message includes a target cell global identifier of the mobile node or a global node identifier of the target donor node, for example, the target cell global identifier of the mobile node or the global node identifier of the target donor node is included in a traffic release information element carried by the transmission transition change request message.

[0059] The transmission transition change request message may further include a traffic release cause, which may include that the mobile node has performed an inter-donor handover or that the mobile node has performed an inter-donor Radio Link Failure (RLF) recovery.

[0060] The topology adaptation process in the embodiment of the present invention will be further explained below through signaling interactions.

[0061] FIG. 9 is a signaling flowchart of topology adaptation in an embodiment of the present invention.

[0062] As shown in Figure 9, the transition IAB node (IAB node 3 mentioned above) changes the non-F1 terminating donor and keeps the F1 terminating donor. In Figure 9, the transition node assumes that both the source path and the target path have a parent node and intermediate nodes between the parent node and the IAB-donor. These nodes may not exist, in which case the parent node of the transition node is the IAB-donor.

[0063] As shown in FIG. 9, the flow includes:

[0064] 901: The source IAB-donor-CU sends an Xn HANDOVER REQUEST message to the target IAB-donor-CU, which may include the TNL (transport network layer) address information of the transition IAB node in an RRC container.

[0065] 902: The target IAB-donor-CU sends a UE CONTEXT SETUP REQUEST message to the IAB-DU of the target parent node, which is used to create a UE context for the transition IAB-MT and establish a bearer for signaling and optionally data traffic for the transition IAB-MT.

[0066] 903: The target parent node IAB-DU replies with a UE CONTEXT SETUP RESPONSE message to the target IAB-donor-CU.

[0067] 904: The target IAB-donor-CU performs admission control and provides new RRC configurations according to the contents of the HANDOVER REQUEST ACKNOWLEDGE message. The RRC configurations include the BAP address in the topology of the target IAB-donor-CU of the transition node, the default BH RLC channel, and the default BAP routing indicator configuration for uplink F1-C / non-F1 traffic mapping on the target path. The RRC configurations may also include new TNL address(es) where the transition node will be anchored to the target IAB-donor-DU.

[0068] 905: The source IAB-donor-CU sends a UE CONTEXT MODIFICATION REQUEST message to the source parent node IAB-DU, containing the RRCReconfiguration message received from the target IAB-donor-CU.

[0069] 906: The source parent node IAB-DU forwards the received RRCReconfiguration message to the transition IAB-MT.

[0070] 907: The source parent node IAB-DU returns a UE CONTEXT MODIFICATION RESPONSE message to the source IAB-donor-CU.

[0071] 908: The migration IAB-MT performs a random access process to the target parent node IAB-DU.

[0072] 909: The transition IAB-MT responds (returns) an RRCReconfigurationComplete message to the target parent node IAB-DU.

[0073] 910: The target parent node IAB-DU sends a UL RRC MESSAGE TRANSFER message to the target IAB-donor-CU, carrying the received RRCReconfigurationComplete message.

[0074] 911: If necessary, the target IAB-donor-CU triggers a route handover process for the transition IAB-MT.

[0075] 912: The target IAB-donor-CU sends a UE CONTEXT RELEASE message to the source IAB-donor-CU.

[0076] If the source IAB-donor-CU is an m-CU, as long as the target route is used to transmit traffic between the transition node and the source IAB-donor-CU, both the source IAB-donor-CU and the target IAB-donor-CU need to preserve the XnAP UE ID of the transition node. If the source IAB-donor-CU is not an m-CU, the target route does not need to transmit traffic between the transition node and the source IAB-donor-CU (i.e., the transition node's traffic does not pass through the source IAB-donor-CU), and the source IAB-donor-CU can release the XnAP UE ID of the transition node.

[0077] 913: The source IAB-donor-CU may release the BH RLC channel and the routing entry of the BAP sublayer on the source path from the source parent node of the transition IAB node to the source IAB-donor-DU.

[0078] 914: The target IAB-donor-CU configures a BH RLC channel and routing entries for the BAP sublayer on the target route from the transition IAB node to the target IAB-donor-DU, and downlink mapping for the target route of the transition IAB node on the target IAB-donor-DU, which supports the transmission of F1-C traffic on the target route.

[0079] 915: The F1-C connection between the transition IAB node and the m-CU is handed over to the target route using the transition IAB node's new TNL address information. The transition IAB node can report the new TNL address it wants to use for F1-U traffic to the m-CU via a gNB-DU CONFIGURATION UPDATE message.

[0080] Assuming TNL protection is provided using IPsec tunnels, the transition IAB node can use MOBIKE (IETF RFC 4555) to transition the IPsec tunnels to new IP external addresses. After the MOBIKE process is complete, the transition IAB-DU initiates the gNB-DU Configuration Update process for the F1AP, during which the IAB-donor-CU can determine whether the existing internal IP address (e.g., for stream control transmission protocol (SCTP) association) and downlink F-TEID (Fully Qualified Tunnel Endpoint Identifier) ​​can be reused.

[0081] When a new TNL address is configured for F1-C traffic, a new SCTP association between the transition IAB node and the F1 terminating IAB-donor-CU can be formed using the transition IAB's new TNL address information. The transition IAB node sends a gNB-DU CONFIGURATION UPDATE message of the F1 AP to the F1 terminating IAB-donor-CU (m-CU), and the message may include a new (external) IP address and a corresponding new (internal) IP address for handing over F1-U traffic to the target path.

[0082] 916: The source IAB-donor-CU requests the m-CU to release all offloaded traffic by sending an IAB TRANSPORT MIGRATION MODIFICATION REQUEST message, which may include the node identifier (or target cell identifier) ​​of the target IAB-donor-CU, the reason for offloading and releasing the traffic, etc.

[0083] 917: The m-CU returns an IAB TRANSPORT MIGRATION MODIFICATION RESPONSE message to the source IAB-donor-CU.

[0084] 918: The m-CU sends an IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message to the target IAB-donor-CU, which is used to provide the context of the traffic that needs to be offloaded. The message may include new downlink TNL address information, which the target IAB-donor-CU uses to set or change downlink mapping with the IAB-donor-DU.

[0085] 919: The target IAB-donor-CU may configure or modify the BH RLC channel and BAP sublayer routing entries from the transition IAB node to the target IAB-donor-CU on the target route, and the downlink mapping for the target route of the transition IAB node on the target IAB-donor-DU. These configurations can support user plane and non-user plane traffic transmission on the target route.

[0086] 920: The target IAB-donor-CU returns an IAB Transport Migration Management Response message to the m-CU, providing mapping information for the offloaded traffic. The message includes Layer 2 information on the topology for the target IAB-donor-CU, which is necessary for the migration IAB node to configure uplink mapping for the traffic indicated in 918. The message includes a Differentiated Services Code Point (DSCP) / IPv6 flow label value for configuring downlink mapping for the traffic indicated in 918.

[0087] 921: The F1-U connection from the transition IAB node to the m-CU is handed over using the new TNL address of the transition IAB node. Based on the uplink backhaul information received from the target IAB-donor-CU in 1020, the m-CU provides the IAB-DU of the transition IAB node with updated uplink backhaul information for the traffic indicated in 918. The m-CU may also update uplink backhaul information associated with non-user plane traffic. This step may use UE-associated signaling or non-UE-associated signaling on the E1 and / or F1 interfaces. Possible conflict avoidance must be guaranteed in the implementation, i.e., conflicting configurations cannot be performed simultaneously during the use of UE-associated and non-UE-associated processes.

[0088] 922: If necessary, steps 918 to 921 can be repeated. In this way, the m-CU can request more traffic offload, or request a change or release of offloaded traffic. The target IAB-donor-CU can reject the m-CU's request to increase or change its traffic offload, in whole or in part.

[0089] The target IAB-donor-CU can use the TRANSPORT MIGRATION MODIFICATION REQUEST message to request changes to the Layer 2 transmission of traffic offloaded in the target IAB-donor-CU's topology. The m-CU reconfigures the uplink backhaul mapping based on the request and acknowledges the changes with an IAB TRANSPORT MIGRATION MODIFICATION RESPONSE message. The target IAB-donor-CU can further reconfigure the TNL address for the migration IAB node via RRC.

[0090] The above signaling process is provided for illustrative purposes only to explain an embodiment of the present invention, but the present invention is not limited thereto. For more specific details of the signaling process, please refer to the related art. For example, the execution order of each operation may be appropriately adjusted, or some operations may be appropriately increased or decreased. Those skilled in the art can make appropriate modifications based on the above content, without being limited to the description of FIG. 9.

[0091] In an embodiment of the present invention, 916 enhances the existing IAB TRANSPORT MIGRATION MODIFICATION REQUEST message, which is sent by a non-F1 terminating IAB-donor-CU of a border IAB node to an F1 terminating IAB-donor-CU to modify or release the border IAB node's migration traffic related settings (e.g., for traffic revocation).

[0092] For example, the enhanced part may be a new IE or field added to the message, for example, adding a new field to the Traffic To Be Released Information IE to indicate that the source, i.e., the non-F1 terminating donor of the IAB node, is made the source donor of the IAB node, and the IAB node is handed over to the target donor, and the node identifier of the target donor node or the cell identifier of the target cell is notified.

[0093] Table 1 shows an example of a traffic release information element in an embodiment of the present invention, which is an enhanced Traffic To Be Released Information IE.

[0094] [Table 1] As shown in Table 1, a field (e.g., called Target Cell Global ID) may be added to the Full Release group, which is used to indicate the target cell global identifier (CGI) of the IAB node. Alternatively, it may be used to indicate the global NG-RAN node identifier of the target donor node. The field may be called, for example, Target Global NG-RAN Node ID.

[0095] Since the cell global identifier includes a global NR-RAN node indicator, the F1 terminating donor of the IAB node can identify the target IAB donor of the IAB node through the received message. When the F1 terminating donor node of the IAB node receives the target cell indicator or the node indicator of the target IAB donor, it can perform an IAB transmission transition management process with the target donor node to transition the F1 traffic of the IAB node 3 to the topology of the target donor node.

[0096] One more field (e.g., called Cause) may be added to the Full Release group, which indicates the cause of releasing all traffic, e.g., the value may be HO (handover), which indicates that the transition IAB node is performing an inter-donor handover. A new value, e.g., Handover, may be defined for the Cause IE of XnAP.

[0097] In some other implementations, the first instruction information is sent by the second donor-CU using a transition notification message in an XnAP message. Optionally, the first donor-CU sends a transition notification confirmation message to the second donor-CU.

[0098] The transition notification message includes a target cell global identifier of the mobile node or a global node identifier of the target donor node, and a transition cause, which may include that the mobile node is performing an inter-donor handover or that the mobile node is performing an inter-donor Radio Link Failure (RLF) recovery.

[0099] The topology adaptation process in the embodiment of the present invention will be further exemplarily described below through signaling interactions.

[0100] FIG. 10 is another signaling flowchart of topology adaptation in an embodiment of the present invention.

[0101] As shown in Figure 10, the transition IAB node (IAB node 3 mentioned above) changes non-F1 terminating donors and maintains F1 terminating donors. In Figure 10, the transition node assumes that both the source path and the target path have a parent node and intermediate nodes between the parent node and IAB-donor. These nodes may not exist, in which case the parent node of the transition node is IAB-donor.

[0102] The flow shown in FIG. 10 is almost the same as that shown in FIG. 9, and its specific contents are omitted here. The difference is that 916 and 917 in FIG. 9 are changed to one new basic Xn process (as shown in 1016 and 1017). It may be a class 1 basic process or a class 2 basic process. The new Xn process has the same purpose as 916 and 917 in FIG. 9, and is used by the source IAB donor node to notify the m-CU that "IAB-MT of IAB node 3 has been handed over to the target IAB donor." This process may also be called an IAB Migration notification process (procedure).

[0103] As shown in Figure 10, the non-F1 terminating IAB-donor-CU of the border IAB node sends a notification message to the F1 terminating IAB-donor-CU, which is called, for example, an IAB MIGRATION NOTIFICATION message, and the message may further include a target cell global identifier, a notification cause, etc. in addition to a message type, an F1 terminating IAB donor UE XnAP ID, and a non-F1 terminating IAB donor UE XnAP ID.

[0104] Table 2 shows an example of information elements in a notification message in an embodiment of the present invention.

[0105] [Table 2] As shown in Table 2, the specific contents of the IE are the same as the corresponding fields in Table 1.

[0106] If the process is Type 2 basic, the m-CU does not need to send a message back. If the process is Type 1 basic, the m-CU must further send an IAB MIGRATION NOTIFICATION ACKNOWLEDGE message back to the sender, indicating successful receipt of the IAB MIGRATION NOTIFICATION message, which may instruct the source IAB donor node to release the XnAP UE ID of the migration node stored in the source IAB donor node.

[0107] In some implementations, the first indication information is sent by the mobile node using an F1AP message.

[0108] For example, the F1AP message is a gNB-DU Configuration Update message, and the gNB Configuration Update message includes address information for the mobile node to be anchored to the donor-DU of the third donor-CU and the first indication information. For example, the F1AP message includes a target cell global identifier of the mobile IAB node or a global node identifier of the target donor node.

[0109] The F1AP message also includes a transition cause, which may include the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor Radio Link Failure (RLF) recovery.

[0110] The topology adaptation process in the embodiment of the present invention will be further exemplarily described below through signaling interactions.

[0111] FIG. 11 is another signaling flowchart of topology adaptation in an embodiment of the present invention.

[0112] As shown in Figure 11, the transition IAB node (IAB node 3 mentioned above) changes non-F1 terminating donors and maintains F1 terminating donors. In Figure 11, the transition node assumes that both the source path and the target path have parent nodes and intermediate nodes between the parent node and IAB-donor. These nodes may not exist, in which case the parent node of the transition node is IAB-donor.

[0113] The flow shown in Figure 11 is almost the same as that shown in Figure 9, and the specific details are omitted here. The difference is that at 1115 in Figure 11, the DU of the border IAB node can notify the m-CU that the MT of the border IAB node has already been handed over to the cell of the target IAB donor node. This can be achieved by F1AP signaling from the border IAB-DU to the m-CU. For example, the gNB-DU CONFIGURATION UPDATE message of the F1AP can be enhanced to report the target cell global identifier of the transition IAB-MT to the m-CU.

[0114] Specifically, at 1115, the F1-C connection between the transition IAB node and the m-CU is handed over to the target path using the transition IAB node's new TNL address information. The transition IAB node can report the new TNL address it wants to use for F1-U traffic to the m-CU via a gNB-DU CONFIGURATION UPDATE message. In the gNB-DU CONFIGURATION UPDATE message, the transition IAB-DU can further report the target cell global identifier of the transition IAB-MT.

[0115] Table 3 shows an example of a modified gNB-DU CONFIGURATION UPDATE message.

[0116] [Table 3] As shown in Table 3, IAB-MT target cell indication information is added to the message, for example, it is called IAB Migration Target Cell CGI IE, and the target cell CGI to which this IAB node will migrate consists of the PLMN-Identity (Public Land Mobile Network-Identity) and cellIdentity (cell ID) that the migration IAB-MT obtains from the SIB1 message of the target cell.

[0117] Similar to the previous implementation, this IE may be replaced with an indicator of the target donor node, e.g., a global NG-RAN node indicator, and this IE may be called, for example, IAB Migration Target Global NG-RAN Node ID. This global node identifier may also consist of the PLMN-Identity and cellIdentity (cell ID) that the migration IAB-MT obtains from the SIB1 message of the target cell. The message may also include an IAB Migration Cause IE. Similar to the previous implementation, a new value, e.g., Handover, may be defined for the Cause IE of the F1AP.

[0118] As shown in FIG. 11, 916 and 917 in FIG. 9 or 1016 and 1017 in FIG. 10 can be removed.

[0119] The topology adaptation process in the embodiment of the present invention has been described above using handover as an example, and revocation will now be described as an example.

[0120] An IAB node may migrate due to traffic offloading or node movement within the m-CU. Any traffic offloading or movement performed for the topology adaptation process within the m-CU of the migrating IAB node can be undone.

[0121] For example, the non-F1 terminating IAB-donor-CU can initiate the cancellation of all traffic to the m-CU by performing the XnAP handover preparation process. When the transitioning IAB-MT is handed over to the m-CU, the traffic of the IAB-DU of the transitioning IAB node is routed according to the topology of the m-CU. At this time, both the F1 terminating donor and the RRC terminating node of the transitioning IAB node are m-CUs, i.e., the partial transition state has ended.

[0122] Also, for example, the non-F1 terminating IAB-donor-CU can initiate the cancellation of all traffic to the previous source IAB-donor-CU by performing the XnAP handover preparation process. This process corresponds to performing another topology adaptation in the m-CU, and the process is similar to the previous embodiment. Traffic of the IAB-DU of the transition IAB node is again routed by the previous source path.

[0123] In some embodiments, the first donor-CU requests the third donor-CU to release all or part of the offloaded traffic via a transmission transition management request message.

[0124] For example, the m-CU can initiate the cancellation of all traffic by requesting that the non-F1 terminating IAB-donor-CU release all offloaded traffic by sending an IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message to the non-F1 terminating IAB-donor-CU. The message can trigger the XnAP handover preparation process in which the migration IAB-MT is handed over to the m-CU.

[0125] Also, for example, the m-CU may request the non-F1 terminating IAB-donor-CU to release some of the offloaded traffic by an IAB TRANSPORT MIGRATION MANAGEMENT REQUEST message.

[0126] The RLF recovery will now be further illustrated by way of example.

[0127] The backhaul radio link failure (RLF) recovery process in the m-CU of an IAB node allows the IAB node to recover to a parent node under another IAB-donor-CU when it detects a backhaul RLF, while maintaining the m-CU as an F1-terminating IAB-donor-CU. At this time, the recovered IAB node becomes a boundary node. The RLF recovery process of an IAB-MT is similar to the inter-donor backhaul RLF recovery process in the prior art, as shown in steps 1201-1213 in Figure 12. In the RLF recovery process, the second donor-CU of the IAB node is also referred to as the initial donor-CU, and the third donor-CU is also referred to as the new donor-CU.

[0128] The F1 transmission transition process of the boundary IAB node adopts the same steps as the topology adaptation method in the m-CU, which is similar to the above-mentioned embodiment, and Figures 9 to 11 can all be adaptively changed to the RLF recovery process in the m-CU of the corresponding IAB node.

[0129] Figure 12 is a diagram illustrating signaling of an RLF recovery process in an embodiment of the present invention. As shown in Figure 12, the corresponding steps in 1218 are the same as the corresponding steps in Figures 9 to 11 (e.g., 914 to 922, or 1014 to 1022, or 1114 to 1120), and detailed descriptions thereof will be omitted here. The Cause value in each corresponding embodiment represents the cause of the release of all traffic or the cause of transition. For example, the cause value of the RLF recovery process may be RLF recovery, which indicates that the IAB node is performing inter-donor RLF recovery.

[0130] The new IAB-donor-CU can request a change to the Layer 2 transmission of traffic offloaded in the new IAB-donor-CU's topology using a TRANSPORT MIGRATION MODIFICATION REQUEST message. The m-CU reconfigures the uplink backhaul mapping based on the request and confirms the change using an IAB TRANSPORT MIGRATION MODIFICATION RESPONSE message. The new IAB-donor-CU can also reconfigure the TNL address for the recovered IAB node via RRC. The revocation process for traffic of an IAB node with a recovered RLF is similar to the revocation process for a migration node described above.

[0131] The above-mentioned embodiment solves problems such as IAB node migration between non-F1 donor nodes, RLF recovery, and traffic cancellation, thereby supporting IAB node movement within the control area of ​​the m-CU and ensuring the service quality of the moving IAB node for the UE.

[0132] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications may be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0133] As can be seen from the above embodiment, the first donor-CU receives first indication information, which includes indicator information related to the third donor-CU, and the first donor-CU sends second indication information to the third donor-CU based on the indicator information to indicate traffic context, thereby supporting the mobile node to move within the control domain without service interruption, and thus ensuring the service quality of the mobile node for the user equipment.

[0134] <Example of the second aspect> In an embodiment of the present invention, a communication method for a network node is provided, which is described from the perspective of a second donor-CU, and the same content as in the embodiment of the first aspect will not be described here. The first donor-CU is an F1 terminating donor-CU of a mobile node, the second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and the third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery.

[0135] FIG. 13 illustrates a communication method for a network node in an embodiment of the present invention. As shown in FIG. 13, the method includes the following steps: 1301: A second donor-CU sends first instruction information to a first donor-CU, where the first instruction information includes indicator information regarding the third donor-CU.

[0136] Note that, although the above-mentioned FIG. 13 is used to exemplify an embodiment of the present invention, the present invention is not limited thereto. For example, the execution order of each operation may be appropriately adjusted, or some operations may be appropriately increased or decreased. Those skilled in the art may make appropriate modifications based on the above content without being limited to the description of the above-mentioned FIG. 13.

[0137] In some embodiments, the first instruction information is sent by the second donor-CU using a transmission transition change request message, and as shown in FIG. 13 , the method may further include the following steps: 1302: A second donor-CU receives a transmission transition change response message sent by the first donor-CU.

[0138] In some embodiments, the transmission transition change request message includes a target cell global identifier of the mobile node or a global node identifier of a target donor node.

[0139] In some embodiments, the target cell global identifier of the mobile node or the global node identifier of the target donor node is included in a traffic release information element carried by the transmission transition change request message.

[0140] In some embodiments, the transmission transition change request message includes a traffic release cause.

[0141] In some embodiments, the traffic release cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor Radio Link Failure (RLF) recovery.

[0142] In some embodiments, the first instruction information is sent by the second donor-CU using a transition notification message in an XnAP message.

[0143] In some embodiments, the second donor-CU receives a transition notification confirmation message sent by the first donor-CU.

[0144] In some embodiments, the transition notification message includes a target cell global identifier of the mobile node or a global node identifier of the target donor node.

[0145] In some embodiments, the transition notification message includes a transition cause.

[0146] In some embodiments, the transition cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor Radio Link Failure (RLF) recovery.

[0147] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications may be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0148] As can be seen from the above embodiment, the second donor-CU sends first instruction information to the first donor-CU, and the first instruction information includes indicator information about the third donor-CU, where the indicator information is used by the first donor-CU to send second instruction information to the third donor-CU to indicate traffic context, thereby supporting the mobile node to move within a control domain without service interruption, and thus ensuring the service quality of the mobile node for the user equipment.

[0149] <Example of the third aspect> In an embodiment of the present invention, a communication method for a network node is provided, which will be described from the perspective of a third donor-CU, and the same content as in the first and second aspects will not be described here. The first donor-CU is an F1 terminating donor-CU of a mobile node, the second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and the third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery.

[0150] FIG. 14 illustrates a communication method for a network node in an embodiment of the present invention. As shown in FIG. 14, the method includes the following steps: 1401: A third donor-CU receives second instruction information for indicating the context of traffic sent by a first donor-CU based on identification information, where the identification information is related to the third donor-CU and is included in the first instruction information received by the first donor-CU.

[0151] Note that, although the above-mentioned FIG. 14 is used to exemplify an embodiment of the present invention, the present invention is not limited thereto. For example, the execution order of each operation may be appropriately adjusted, or some operations may be appropriately increased or decreased. Those skilled in the art may make appropriate modifications based on the above content without being limited to the description of the above-mentioned FIG. 14.

[0152] In some embodiments, the second instruction information is sent by a transmission transition management request message. As shown in Figure 14, the method may further include the following steps: 1402: The third donor-CU sets or changes downlink mapping based on the downlink address information included in the second indication information.

[0153] In some embodiments, the third donor-CU sends a transmission transition management response message to the first donor-CU, and the transmission transition management response message includes mapping information for offloaded traffic and / or Layer 2 information on the topology of the third donor-CU.

[0154] In some embodiments, the third donor-CU initiates cancellation of traffic for which the mobile node's mobile terminal (MT) is handed over to the first donor-CU.

[0155] In some embodiments, when the mobile terminal of the mobile node is handed over to the first donor-CU, traffic of the distributed unit (DU) of the mobile node is routed according to the topology of the first donor-CU.

[0156] In some embodiments, the third donor-CU initiates traffic revocation for the mobile node's mobile terminal to be handed over to the second donor-CU.

[0157] In some embodiments, when the mobile terminal of the mobile node is handed over to the second donor-CU, traffic of the distributed units of the mobile node is routed according to the topology of the second donor-CU.

[0158] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications may be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0159] As can be seen from the above embodiment, the third donor-CU receives second indication information for indicating traffic context sent by the first donor-CU according to the indicator information, where the indicator information is related to the third donor-CU and is included in the first indication information received by the first donor-CU, thereby supporting the mobile node to move within the control domain without service interruption, and thus ensuring the service quality of the mobile node for the user equipment.

[0160] <Example of the fourth aspect> In an embodiment of the present invention, a mobile node communication method is provided, which will be described from the mobile node side, and the same content as in the first to third aspects will not be described here. A first donor-CU is an F1 terminating donor-CU of a mobile node, a second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and a third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery.

[0161] FIG. 15 is a diagram illustrating a communication method of a mobile node in an embodiment of the present invention. As shown in FIG. 15, the method includes the following steps: 1501: An F1-C connection between a mobile node and a first donor-CU is handed over to a target route using address information that anchors the mobile node to a donor-DU of the third donor-CU.

[0162] Note that, although the above-mentioned FIG. 15 is used to exemplify an embodiment of the present invention, the present invention is not limited thereto. For example, the execution order of each operation may be appropriately adjusted, or some operations may be appropriately increased or decreased. Those skilled in the art may make appropriate modifications based on the above content without being limited to the description of the above-mentioned FIG. 15.

[0163] In some embodiments, as shown in FIG. 15, the method may further include the following steps: 1502: The mobile node sends to the first donor-CU address information by which the mobile node is anchored to a donor-DU of the third donor-CU.

[0164] In some embodiments, the mobile node sends first instruction information to the first donor-CU, the first instruction information including indicator information regarding the third donor-CU, in which the indicator information is used by the first donor-CU to send second instruction information to the third donor-CU to indicate a traffic context.

[0165] In some embodiments, the F1-U connection from the mobile node to the first donor-CU is handed over using an address where the mobile node is anchored to a donor-DU of the third donor-CU.

[0166] In some embodiments, the mobile node receives uplink backhaul information for traffic transmitted by the first donor-CU.

[0167] In some embodiments, the first indication information is sent by the mobile node using an F1AP message.

[0168] In some embodiments, the F1AP message is a gNB-DU configuration update message, and the gNB configuration update message includes address information for anchoring the mobile node to the donor-DU of the third donor-CU and the first indication information.

[0169] In some embodiments, the F1AP message includes a target cell global identifier of the mobile IAB node or a global node identifier of the target donor node.

[0170] In some embodiments, the F1AP message includes a transition cause, the transition cause including the mobile node performing an inter-donor handover or the mobile node performing an inter-donor Radio Link Failure (RLF) recovery.

[0171] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications may be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0172] As can be seen from the above embodiment, the F1-C connection between the mobile node and the first donor-CU is handed over to the target route using address information that anchors the mobile node to the donor-DU of the third donor-CU, which can support the mobile node to move within the control domain without service interruption, thereby ensuring the service quality of the mobile node for the user equipment.

[0173] <Example of the fifth aspect> In the embodiments of the present invention, a donor device is provided, and description of the same content as in the embodiments of the first to fourth aspects will be omitted here. The device may be, for example, an IAB donor-CU in an IAB system (e.g., the first donor-CU in the embodiments of the first to fourth aspects), or may be one or more components, assemblies, or modules disposed in the IAB donor-CU.

[0174] The donor device is the F1 terminating donor-CU of the mobile node, the second donor-CU is a non-F1 terminating donor-CU before the mobile node's migration or radio link failure (RLF) recovery, and the third donor-CU is a non-F1 terminating donor-CU after the mobile node's migration or RLF recovery.

[0175] 16 is a diagram illustrating a donor device in accordance with an embodiment of the present invention. As shown in FIG. 16, the donor device 1600 includes: A receiving unit 1601 receives first instruction information, the first instruction information including indicator information related to the third donor-CU; and A transmitting unit 1602: transmits second instruction information for instructing the third donor-CU about the traffic context.

[0176] In some embodiments, the donor device is an F1 terminating donor-CU for multiple mobile nodes within a designated area, and F1 connections of the multiple mobile nodes are always terminated at the donor device.

[0177] In some embodiments, the receiving unit 1601 further receives address information sent by the mobile node, which anchors the mobile node to a donor-DU of the third donor-CU.

[0178] In some embodiments, the second instruction information is sent by a transmission transition management request message, and the second instruction information includes downlink address information to allow the third donor-CU to configure or change downlink mapping.

[0179] The receiving unit 1601 further receives a transmission transition management response message sent by the third donor-CU, where the transmission transition management response message includes mapping information of the traffic to be offloaded and / or Layer 2 information on the topology of the third donor-CU.

[0180] In some embodiments, the transmitter 1602 further transmits uplink backhaul information of traffic to the mobile node.

[0181] In some embodiments, the first instruction information is sent by the second donor-CU using a transmission transition change request message.

[0182] The sending unit 1602 further sends a transmission transition change response message to the second donor-CU.

[0183] In some embodiments, the transmission transition change request message includes a target cell global identifier of the mobile node or a global node identifier of a target donor node.

[0184] The target cell global identifier of the mobile node or the global node identifier of the target donor node is included in a traffic release information element carried by the transmission transition change request message.

[0185] In some embodiments, the transmission transition change request message includes a traffic release cause.

[0186] The traffic release cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor Radio Link Failure (RLF) recovery.

[0187] In some embodiments, the first instruction information is sent by the second donor-CU using a transition notification message in an XnAP message.

[0188] The sending unit 1602 further sends a transition notification confirmation message to the second donor-CU.

[0189] In some embodiments, the transition notification message includes a target cell global identifier of the mobile node or a global node identifier of the target donor node.

[0190] In some embodiments, the transition notification message includes a traffic release cause.

[0191] The traffic release cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor Radio Link Failure (RLF) recovery.

[0192] In some embodiments, the first indication information is sent by the mobile node using an F1AP message.

[0193] The F1AP message is a gNB-DU configuration update message, and the gNB configuration update message includes address information for anchoring the mobile node to the donor-DU of the third donor-CU and the first indication information.

[0194] In some embodiments, the F1AP message includes a transition cause.

[0195] The transition cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor Radio Link Failure (RLF) recovery.

[0196] In some embodiments, the transmitter 1602 further requests the third donor-CU to release all or part of the offloaded traffic via a transmission transition management request message.

[0197] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications may be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0198] Although the components and modules related to the present invention have been described above, the present invention is not limited thereto. The donor device 1600 according to the embodiment of the present invention may further include other components or modules. For details of these components or modules, please refer to the related art.

[0199] 16 shows only the connection relationships or signal directions between each component or module for convenience, but as will be understood by those skilled in the art, various related technologies such as bus connection may be adopted. Each of the above-mentioned components or modules may be realized by hardware such as a processor, memory, transmitter (device), or receiver (device), but the implementation of the present invention is not limited to these.

[0200] As can be seen from the above embodiment, the first donor-CU receives first indication information, which includes indicator information related to the third donor-CU, and the first donor-CU sends second indication information to the third donor-CU based on the indicator information to indicate traffic context, thereby supporting the mobile node to move within the control domain without service interruption, and thus ensuring the service quality of the mobile node for the user equipment.

[0201] <Example of the sixth aspect> In the embodiments of the present invention, a donor device is provided, and description of the same content as in the embodiments of the first to fourth aspects will be omitted here. The device may be, for example, an IAB donor-CU in an IAB system (e.g., a second donor-CU in the embodiments of the first to fourth aspects), or may be one or more components, assemblies, or modules disposed in the IAB donor-CU.

[0202] The first donor-CU is the F1 terminating donor-CU of the mobile node, the donor device is a non-F1 terminating donor-CU before the mobile node's migration or radio link failure (RLF) recovery, and the third donor-CU is a non-F1 terminating donor-CU after the mobile node's migration or RLF recovery.

[0203] 17 is a diagram illustrating a donor device in accordance with an embodiment of the present invention. As shown in FIG. 17, the donor device 1700 includes: A sending unit 1701: sends first instruction information to the first donor-CU, where the first instruction information includes indicator information related to the third donor-CU.

[0204] In some embodiments, the first instruction information is sent by the second donor-CU using a transmission transition change request message. As shown in Figure 17, the donor device 1700 may further include: A receiving unit 1702 receives a transmission transition change response message sent by the first donor-CU.

[0205] In some embodiments, the first instruction information is sent by the second donor-CU using a transition notification message in an XnAP message. The receiving unit 1702 further receives a transition notification confirmation message sent by the first donor-CU.

[0206] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications may be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0207] Although the components and modules related to the present invention have been described above, the present invention is not limited thereto. The donor device 1700 according to the embodiment of the present invention may further include other components or modules. For details of these components or modules, please refer to the related art.

[0208] 17 shows only the connection relationships or signal directions between each component or module, but as will be understood by those skilled in the art, various related technologies such as bus connection may be adopted. Each of the above-described components or modules may be realized by hardware such as a processor, memory, transmitter, or receiver, but the implementation of the present invention is not limited to these.

[0209] As can be seen from the above embodiment, the second donor-CU sends first instruction information to the first donor-CU, and the first instruction information includes indicator information about the third donor-CU, where the indicator information is used by the first donor-CU to send second instruction information to the third donor-CU to indicate traffic context, thereby supporting the mobile node to move within a control domain without service interruption, and thus ensuring the service quality of the mobile node for the user equipment.

[0210] <Example of the seventh aspect> In an embodiment of the present invention, a donor device is provided, and description of the same content as in the embodiments of the first to fourth aspects will be omitted here. The device may be, for example, an IAB donor-CU in an IAB system (e.g., the third donor-CU in the embodiments of the first to fourth aspects), or may be one or more components, assemblies, or modules disposed in the IAB donor-CU.

[0211] The first donor-CU is the F1 terminating donor-CU of the mobile node, the second donor-CU is a non-F1 terminating donor-CU before the mobile node's migration or radio link failure (RLF) recovery, and the donor device is a non-F1 terminating donor-CU after the mobile node's migration or RLF recovery.

[0212] 18 is a diagram illustrating a donor device in accordance with an embodiment of the present invention. As shown in FIG. 18, the donor device 1800 includes: A receiving unit 1801: receives second indication information for indicating a traffic context, which is transmitted by the first donor-CU based on the identification information.

[0213] Wherein, the indicator information relates to the third donor-CU and is included in the first instruction information received by the first donor-CU.

[0214] In some embodiments, the second instruction information is sent by a transmission transition management request message. As shown in FIG. 18, the donor device 1800 may further include: Processing unit 1802: Sets or changes downlink mapping based on downlink address information included in the second instruction information.

[0215] In some embodiments, as shown in FIG. 18, the donor device 1800 may further include: A sending unit 1803: sends a transmission transition management response message to the first donor-CU, where the transmission transition management response message includes mapping information of offloaded traffic and / or Layer 2 information on the topology of the third donor-CU.

[0216] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications may be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0217] Although the components and modules related to the present invention have been described above, the present invention is not limited thereto. The donor device 1800 according to the embodiment of the present invention may further include other components or modules. For details of these components or modules, please refer to the related art.

[0218] 18 shows only the connection relationships or signal directions between each component or module, but as will be understood by those skilled in the art, various related technologies such as bus connection may be adopted. Each of the above-described components or modules may be realized by hardware such as a processor, memory, transmitter, or receiver, but the implementation of the present invention is not limited thereto.

[0219] As can be seen from the above embodiment, the third donor-CU receives second indication information for indicating traffic context sent by the first donor-CU according to the indicator information, where the indicator information is related to the third donor-CU and is included in the first indication information received by the first donor-CU, thereby supporting the mobile node to move within the control domain without service interruption, and thus ensuring the service quality of the mobile node for the user equipment.

[0220] <Example of the eighth aspect> In the embodiments of the present invention, a mobile node is provided, and description of the same content as in the embodiments of the first to fourth aspects will be omitted here. The mobile node may be, for example, an IAB node in an IAB system (e.g., a mobile IAB node in the embodiments of the first to fourth aspects), or may be one or more components, assemblies, or modules disposed in the IAB node.

[0221] Figure 19 is a diagram illustrating a mobile node in an embodiment of the present invention. As shown in Figure 19, a mobile node 1900 includes a mobile terminal (MT) 1901 and a distributed unit (DU) 1902. The mobile terminal (MT) 1901 of the mobile node is handed over or RLF recovered from the second donor-CU to the third donor-CU.

[0222] The F1-C connection between the mobile node's distributed unit (DU) 1902 and the first donor-CU is handed over to a target route using address information that anchors the mobile node to the donor-DU of the third donor-CU.

[0223] In some embodiments, the mobile node's distributed unit (DU) 1902 sends to the first donor-CU address information where the mobile node is anchored to a donor-DU of the third donor-CU.

[0224] In some embodiments, the mobile node's distributed unit (DU) 1902 sends first indication information to the first donor-CU, where the first indication information includes indicator information regarding the third donor-CU.

[0225] In some embodiments, the F1-U connection from the mobile node's distributed unit (DU) 1902 to the first donor-CU is handed over using an address at which the mobile node is anchored to the donor-DU of the third donor-CU.

[0226] In some embodiments, the mobile node's distributed unit (DU) 1902 receives uplink backhaul information for traffic transmitted by the first donor-CU.

[0227] In some embodiments, the first indication information is sent by the mobile node using an F1AP message.

[0228] In some embodiments, the F1AP message is a gNB-DU configuration update message, and the gNB configuration update message includes address information for anchoring the mobile node to the donor-DU of the third donor-CU and the first indication information.

[0229] In some embodiments, the F1AP message includes a target cell global identifier of the mobile IAB node or a global node identifier of the target donor node.

[0230] In some embodiments, the F1AP message includes a transition cause.

[0231] In some embodiments, the transition cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor Radio Link Failure (RLF) recovery.

[0232] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications may be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0233] Although the components and modules related to the present invention have been described above, the present invention is not limited to these. The mobile node 1900 in the embodiment of the present invention may further include other components or modules, and the specific contents of these components or modules can be found in the related art.

[0234] 19 only shows the connection relationships or signal directions between each component or module, but as will be understood by those skilled in the art, various related technologies such as bus connection may be adopted. Each of the above-described components or modules may be realized by hardware such as a processor, memory, transmitter, or receiver, but the implementation of the present invention is not limited to these.

[0235] As can be seen from the above embodiment, the F1-C connection between the mobile node and the first donor-CU is handed over to a target route using address information that anchors the mobile node to a donor-DU of the third donor-CU, which can support the mobile node to move within a control domain without service interruption, thereby ensuring the service quality of the mobile node for user equipment.

[0236] <Example of the ninth aspect> In an embodiment of the present invention, a communication system is provided, which includes a donor device and a mobile node (e.g., an IAB node). The network configuration and specific contents of the donor device and the IAB node can be further referred to in the related art, and detailed description thereof will be omitted here.

[0237] In some embodiments, the communication system includes a first donor-CU, a second donor-CU, a third donor-CU, a donor-DU of each donor-CU, and a mobile node. Each donor-DU can perform operations corresponding to each donor-CU and mobile node. For details, please refer to the related art, and detailed descriptions thereof will be omitted here.

[0238] The first donor-CU is the F1 terminating donor-CU of the mobile node, the second donor-CU is a non-F1 terminating donor-CU before the mobile node's migration or radio link failure (RLF) recovery, and the third donor-CU is a non-F1 terminating donor-CU after the mobile node's migration or RLF recovery.

[0239] The first donor-CU receives first instruction information, the first instruction information including identification information regarding the third donor-CU, and the first donor-CU sends second instruction information to the third donor-CU to indicate the context of the traffic.

[0240] The second donor-CU sends first instruction information to the first donor-CU, and the first instruction information includes identification information regarding the third donor-CU.

[0241] The third donor-CU receives second instruction information sent by the first donor-CU based on identification information to indicate a traffic context, wherein the identification information relates to the third donor-CU and is included in the first instruction information received by the first donor-CU.

[0242] The F1-C connection between the mobile node and the first donor-CU is handed over to a target route using address information that anchors the mobile node to a donor-DU of the third donor-CU.

[0243] An embodiment of the present invention further provides an IAB device, which may be an IAB donor device or an IAB node (transition node or child node).

[0244] 20 is a diagram illustrating an IAB device according to an embodiment of the present invention. As shown in FIG. 20, the IAB device 2000 includes a processor (e.g., a central processing unit (CPU)) 2001 and a memory 2002, which is connected to the processor 2001. The memory 2002 can store various data and can further store a program 2005 for information processing, and can execute the program 2005 under the control of the central processing unit 2001.

[0245] For example, the processor 2001 may be configured to execute a program to implement the network node communication method according to the first aspect of the present invention. For example, the processor 2001 may be configured to perform the following control: receive first instruction information, the first instruction information including indicator information related to a third donor-CU; and send second instruction information to the third donor-CU to indicate a traffic context.

[0246] Also, for example, the processor 2001 may be configured to execute a program to implement the network node communication method according to the second aspect of the present invention. For example, the processor 2001 may be configured to perform the following control: send first instruction information to a first donor-CU, where the first instruction information includes identification information about a third donor-CU.

[0247] For example, the processor 2001 may be configured to execute a program to implement the network node communication method according to the third aspect. For example, the processor 2001 may be configured to perform the following control: receive second instruction information for indicating a traffic context sent by a first donor-CU based on identification information, where the identification information relates to a third donor-CU and is included in the first instruction information received by the first donor-CU.

[0248] Also, for example, the processor 2001 may be configured to execute a program to implement the mobile node communication method according to the fourth aspect. For example, the processor 2001 may be configured to perform the following control: the F1-C connection between the first donor-CU is handed over to a target route using address information that anchors the mobile node to a donor-DU of a third donor-CU.

[0249] 20, the IAB device 2000 may further include the following: a transceiver 2003, an antenna 2004, etc., among which the functions of the above-mentioned components are the same as those of the prior art, and detailed description thereof will be omitted here. Note that the IAB device 2000 does not need to include all of the components shown in FIG. 20. The IAB device 2000 may also include components not shown in FIG. 20, but reference can be made to the prior art for this.

[0250] An embodiment of the present invention further provides a computer-readable program, which, when executed in an IAB device, causes a computer to perform the network node communication method in the embodiments of the first to third aspects or the mobile node communication method in the embodiment of the fourth aspect in the IAB device.

[0251] An embodiment of the present invention further provides a storage medium storing a computer-readable program, wherein the computer-readable program causes a computer to execute the network node communication method in the embodiment of the first to third aspects or the mobile node communication method in the embodiment of the fourth aspect in an IAB device.

[0252] The above-described devices and methods may be realized by software or hardware, or by a combination of hardware and software. The present invention further relates to a computer-readable program as described below, which, when executed by a logic component, causes the logic component to realize the above-described devices or components, or to perform each of the above-described methods or steps. The logic component may be, for example, an FPGA (Field Programmable Gate Array), a microprocessor, or a processing unit used in a computer. The present invention also relates to a storage medium, such as a hard disk, magnetic disk, optical hard disk, DVD, or flash memory, that stores the above-described program.

[0253] Furthermore, one or more combinations of the functional blocks illustrated in the figures and / or one or more combinations of the functional blocks may be implemented as a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic component, a discrete gate or transistor logic component, a discrete hardware assembly, or any other suitable combination for performing the functions described herein. Also, one or more combinations of the functional blocks illustrated in the figures and / or one or more combinations of the functional blocks may be further implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors communicatively coupled with a DSP, or any other configuration.

[0254] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and any modifications to the present invention that do not depart from the spirit of the present invention fall within the technical scope of the present invention.

[0255] Furthermore, the following additional notes are disclosed regarding the above-described embodiments.

[0256] (Appendix 1) A method for communication between network nodes, comprising: a first donor-CU is an F1 terminating donor-CU of a mobile node, a second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and a third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery; The method comprises: The first donor-CU receives first instruction information, the first instruction information including identification information regarding the third donor-CU; and The first donor-CU sending second instruction information to the third donor-CU to indicate a traffic context.

[0257] (Appendix 2) 2. The method of claim 1, comprising: The first donor-CU is an F1 terminating donor-CU for multiple mobile nodes within a designated area, and the F1 connections of the multiple mobile nodes are always terminated at the first donor-CU.

[0258] (Appendix 3) 10. The method according to claim 1 or 2, The method further comprises: The first donor-CU receiving address information sent by the mobile node, the address information being anchored to a donor-DU of the third donor-CU.

[0259] (Appendix 4) 4. The method of any one of claims 1 to 3, comprising: The second instruction information is sent by a transmission transition management request message, and the second instruction information includes downlink address information for allowing the third donor-CU to configure or change downlink mapping.

[0260] (Appendix 5) 5. The method of claim 4, The method further comprises: the first donor-CU receiving a transmission transition management response message sent by the third donor-CU; The transmission transition management response message includes mapping information of offloaded traffic and / or Layer 2 information on the topology of the third donor-CU.

[0261] (Appendix 6) 6. The method of any one of claims 1 to 5, comprising: The method further comprises: The first donor-CU sending uplink backhaul information of traffic to the mobile node.

[0262] (Appendix 7) 7. The method of any one of claims 1 to 6, comprising: The first instruction information is sent by the second donor-CU using a transmission transition change request message, and the method further comprises: The first donor-CU sending a transmission transition change response message to the second donor-CU.

[0263] (Appendix 8) 8. The method of claim 7, The transmission transition change request message includes a target cell global identifier of the mobile node or a global node identifier of a target donor node.

[0264] (Appendix 9) 9. The method of claim 8, The target cell global identifier of the mobile node or the global node identifier of the target donor node is included in a traffic release information element carried by the transmission transition change request message.

[0265] (Appendix 10) 10. The method of any one of claims 7 to 9, comprising: The transmission transition change request message includes a traffic release cause.

[0266] (Appendix 11) 11. The method of claim 10, The traffic release cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor radio link failure (RLF) recovery.

[0267] (Appendix 12) 7. The method of any one of claims 1 to 6, comprising: The first instruction information is sent by the second donor-CU using a transition notification message in an XnAP message.

[0268] (Appendix 13) 13. The method of claim 12, The method further comprises: The first donor-CU sending a transition notification confirmation message to the second donor-CU.

[0269] (Appendix 14) 14. The method according to claim 12 or 13, The transition notification message includes a target cell global identifier of the mobile node or a global node identifier of a target donor node.

[0270] (Appendix 15) 15. The method of any one of claims 12 to 14, comprising: The migration notification message includes a migration cause.

[0271] (Appendix 16) 16. The method of claim 15, The transition cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor radio link failure (RLF) recovery.

[0272] (Appendix 17) 7. The method of any one of claims 1 to 6, comprising: The first instruction information is transmitted by the mobile node using an F1AP message.

[0273] (Appendix 18) 18. The method of claim 17, The F1AP message is a gNB-DU configuration update message, and the gNB configuration update message includes address information for anchoring the mobile node to the donor-DU of the third donor-CU and the first instruction information.

[0274] (Appendix 19) 19. The method according to claim 17 or 18, The F1AP message includes a target cell global identifier of the moving IAB node or a global node identifier of the target donor node.

[0275] (Appendix 20) 20. The method of any one of claims 17 to 19, comprising: The F1AP message includes a transition cause.

[0276] (Appendix 21) 21. The method of claim 20, The transition cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor radio link failure (RLF) recovery.

[0277] (Appendix 22) 22. The method of any one of claims 1 to 21, comprising: The method further comprises: The first donor-CU may request, via a transmission transition management request message, that the third donor-CU release all or part of the offloaded traffic.

[0278] (Appendix 23) A method for communication between network nodes, comprising: a first donor-CU is an F1 terminating donor-CU of a mobile node, a second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and a third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery; The method comprises: receiving, by the third donor-CU, second indication information for indicating a traffic context, the second indication information being transmitted by the first donor-CU based on the indicator information; The indicator information relates to the third donor-CU and is included in first instruction information received by the first donor-CU.

[0279] (Appendix 24) 24. The method of claim 23, The second indication information is sent by a transmission transition management request message, and the method further comprises: The third donor-CU setting or changing downlink mapping based on downlink address information included in the second instruction information.

[0280] (Appendix 25) 25. The method of claim 24, The method further comprises: the third donor-CU sending a transmission transition management response message to the first donor-CU; The transmission transition management response message includes mapping information of offloaded traffic and / or Layer 2 information on the topology of the third donor-CU.

[0281] (Appendix 26) 26. The method of any one of claims 23 to 25, comprising: The method further comprises: The third donor-CU initiates cancellation of traffic for which the mobile terminal (MT) of the mobile node is handed over to the first donor-CU.

[0282] (Appendix 27) 27. The method of claim 26, When the mobile terminal of the mobile node is handed over to the first donor-CU, traffic of the distributed unit (DU) of the mobile node is routed according to the topology of the first donor-CU.

[0283] (Appendix 28) 26. The method of any one of claims 23 to 25, comprising: The method further comprises: The third donor-CU initiates cancellation of traffic for which the mobile terminal of the mobile node is handed over to the second donor-CU.

[0284] (Appendix 29) 29. The method of claim 28, When the mobile terminal of the mobile node is handed over to the second donor-CU, traffic of the distributed unit of the mobile node is routed according to the topology of the second donor-CU.

[0285] (Appendix 30) A method for communication between network nodes, comprising: a first donor-CU is an F1 terminating donor-CU of a mobile node, a second donor-CU is a non-F1 terminating donor-CU of the mobile node before migration or radio link failure (RLF) recovery, and a third donor-CU is a non-F1 terminating donor-CU of the mobile node after migration or RLF recovery; The method comprises: the second donor-CU sending first instruction information to the first donor-CU; the first instruction information includes label information regarding the third donor-CU, The indicator information is used by the first donor-CU to send second indication information to the third donor-CU to indicate a traffic context.

[0286] (Appendix 31) 31. The method of claim 30, The first instruction information is sent by the second donor-CU using a transmission transition change request message, and the method further comprises: The second donor-CU receiving a transmission transition change response message sent by the first donor-CU.

[0287] (Appendix 32) 32. The method of claim 31, The transmission transition change request message includes a target cell global identifier of the mobile node or a global node identifier of a target donor node.

[0288] (Appendix 33) 33. The method of claim 32, The target cell global identifier of the mobile node or the global node identifier of the target donor node is included in a traffic release information element carried by the transmission transition change request message.

[0289] (Appendix 34) 34. The method of any one of claims 31 to 33, comprising: The transmission transition change request message includes a traffic release cause.

[0290] (Appendix 35) 35. The method of claim 34, The traffic release cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor radio link failure (RLF) recovery.

[0291] (Appendix 36) 31. The method of claim 30, The first instruction information is sent by the second donor-CU using a transition notification message in an XnAP message.

[0292] (Appendix 37) 37. The method of claim 36, The method further comprises: The method includes the second donor-CU receiving a transition notification confirmation message sent by the first donor-CU.

[0293] (Appendix 38) 38. The method of claim 36 or 37, The transition notification message includes a target cell global identifier of the mobile node or a global node identifier of a target donor node.

[0294] (Appendix 39) 39. The method of any one of claims 36 to 38, comprising: The migration notification message includes a migration cause.

[0295] (Appendix 40) 39. The method of claim 39, The transition cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor radio link failure (RLF) recovery.

[0296] (Appendix 41) A method for communicating with a mobile node, comprising: a first donor-CU is an F1 terminating donor-CU of the mobile node, a second donor-CU is a non-F1 terminating donor-CU before the mobile node transition or radio link failure (RLF) recovery, and a third donor-CU is a non-F1 terminating donor-CU after the mobile node transition or RLF recovery; The method comprises: The F1-C connection between the mobile node and the first donor-CU is handed over to a target route using address information that anchors the mobile node to a donor-DU of the third donor-CU.

[0297] (Appendix 42) 42. The method of claim 41, The method further comprises: The mobile node transmitting to the first donor-CU address information by which the mobile node is anchored to a donor-DU of the third donor-CU.

[0298] (Appendix 43) 43. The method of claim 41 or 42, The method further comprises: the mobile node sending first instruction information to the first donor-CU; the first instruction information includes label information regarding the third donor-CU, The indicator information is used by the first donor-CU to send second indication information to the third donor-CU to indicate a traffic context.

[0299] (Appendix 44) 44. The method of any one of claims 41 to 43, comprising: The method further comprises: The F1-U connection from the mobile node to the first donor-CU includes the mobile node being handed over using an address anchored to a donor-DU of the third donor-CU.

[0300] (Appendix 45) 45. The method of any one of claims 41 to 44, comprising: The method further comprises: The mobile node receiving uplink backhaul information of traffic transmitted by the first donor-CU.

[0301] (Appendix 46) 44. The method of claim 43, The first instruction information is transmitted by the mobile node using an F1AP message.

[0302] (Appendix 47) 47. The method of claim 46, The F1AP message is a gNB-DU configuration update message, and the gNB configuration update message includes address information for anchoring the mobile node to the donor-DU of the third donor-CU and the first instruction information.

[0303] (Appendix 48) 48. The method of claim 46 or 47, The F1AP message includes a target cell global identifier of the moving IAB node or a global node identifier of the target donor node.

[0304] (Appendix 49) 49. The method of any one of claims 46 to 48, comprising: The F1AP message includes a transition cause.

[0305] (Appendix 50) 49. The method of claim 49, The transition cause includes the mobile node undergoing an inter-donor handover or the mobile node undergoing an inter-donor radio link failure (RLF) recovery.

[0306] (Appendix 51) A mobile node, a memory and a processor; The storage device stores a computer program, The processor is configured to execute the computer program to implement the mobile node communication method described in any one of Supplementary Notes 41 to 50.

[0307] (Appendix 52) A donor device, comprising: a memory and a processor; The storage device stores a computer program, The processor is configured to execute the computer program to implement the network node communication method according to any one of Supplementary Notes 1 to 40.

[0308] (Appendix 53) 1. A communication system comprising: The mobile node includes a first donor-CU, a second donor-CU, a third donor-CU, and a mobile node, wherein the first donor-CU is an F1 terminating donor-CU of the mobile node, the second donor-CU is a non-F1 terminating donor-CU before migration or radio link failure (RLF) recovery of the mobile node, and the third donor-CU is a non-F1 terminating donor-CU after migration or RLF recovery of the mobile node; the first donor-CU receives first instruction information, the first instruction information including indicator information regarding the third donor-CU, and the first donor-CU sends second instruction information to the third donor-CU to indicate a traffic context; the second donor-CU sends first instruction information to the first donor-CU, the first instruction information including identification information about the third donor-CU; the third donor-CU receives second indication information for indicating a traffic context, the second indication information being sent by the first donor-CU based on the indicator information; the indicator information relates to the third donor-CU and is included in first instruction information received by the first donor-CU; The F1-C connection between the mobile node and the first donor-CU is handed over to a target route using address information that anchors the mobile node to a donor-DU of the third donor-CU.

Claims

1. A donor device applied to an F1 termination donor-CU of a mobile IAB node, a receiver for receiving first indication information, the first indication information including indicator information regarding a third donor-CU, the third donor-CU being an RRC terminating donor-CU after a transition or radio link failure recovery of the mobile IAB node; and The donor device includes a transmitter that transmits second instruction information to the third donor-CU to instruct a traffic context.

2. A donor device according to claim 1, the receiver receives the first indication information when the mobile IAB node is transitioned from a second donor-CU to the third donor-CU; The second donor-CU is an RRC terminating donor-CU before the mobile IAB node transition or radio link failure recovery, donor equipment.

3. A donor device according to claim 1, The receiver further receives address information transmitted by the mobile IAB node, by which the mobile IAB node is anchored to the third donor-CU.

4. A donor device according to claim 1, The second instruction information is sent by an IAB transmission transition management request message, and the second instruction information includes downlink address information for allowing the third donor-CU to set or change downlink mapping; The receiver further receives an IAB transmission transition management response message sent by the third donor-CU, the IAB transmission transition management response message including mapping information of offloaded traffic and / or Layer 2 information on the topology of the third donor-CU, donor equipment.

5. A donor device according to claim 1, The donor equipment further includes a transmitter that transmits updated uplink backhaul information of the traffic to the mobile IAB node based on uplink backhaul information received from the third donor-CU.

6. A donor device according to claim 2, The second donor-CU sends an Xn HANOVER REQUEST message to the third donor-CU, and the Xn HANOVER REQUEST message includes TNL address information of the mobile IAB node in an RRC container.

7. The donor device of claim 1, the first instruction information is transmitted by the mobile IAB node using an F1AP message; The F1AP message is a gNB-DU configuration update message, donor equipment.

8. The donor device of claim 7, The F1AP message includes address information for anchoring the mobile IAB node to the third donor-CU, donor device.

9. The donor device of claim 7, The donor device, wherein the first instruction information is the global gNB ID of the target IAB donor.

10. The donor device of claim 1, The transmitter further sends an IAB transmission transition management request message to the third donor-CU, requesting the third donor-CU to release all offloaded traffic or to release a portion of the offloaded traffic.

11. A mobile IAB node, comprising: a transmitter for transmitting first instruction information to the first donor-CU; A mobile IAB node, wherein the first donor-CU is an F1 terminating donor-CU of the mobile IAB node, the first indication information includes indicator information regarding a third donor-CU, and the third donor-CU is an RRC terminating donor-CU after migration or radio link failure recovery of the mobile IAB node.

12. A mobile IAB node as claimed in claim 11, A mobile IAB node, wherein the first instruction information is used by the first donor-CU to send second instruction information for instructing the third donor-CU about a traffic context.

13. A mobile IAB node as claimed in claim 11, The transmitter further transmits address information anchored to the third donor-CU to the first donor-CU, a mobile IAB node.

14. A mobile IAB node as claimed in claim 11, The mobile IAB node hands over the F1-C connection between the mobile IAB node and the first donor-CU to a target route using the new TNL address information of the mobile IAB node.

15. A mobile IAB node as claimed in claim 14, comprising: The mobile IAB node further reports to the first donor-CU the new TNL address it wishes to use for F1-U traffic by a gNB-DU CONFIGURATION UPDATE message.

16. A mobile IAB node as claimed in claim 15, The mobile IAB node uses the new TNL address to hand over the F1-U connection between the mobile IAB node and the first donor-CU.

17. A donor device applied to an RRC terminating donor-CU after a mobile IAB node transition or radio link failure recovery, comprising: a receiver for receiving second indication information for indicating a traffic context, the second indication information being transmitted by the first donor-CU based on the indicator information; A donor device, wherein the first donor-CU is an F1 terminating donor-CU of the mobile IAB node, and the identification information relates to the donor device and is included in first instruction information received by the first donor-CU.

18. The donor device of claim 17, the second instruction information is sent by an IAB transmission transition management request message; The donor device further comprises: The donor device includes a processor that sets or changes downlink mapping based on downlink address information included in the second instruction information.

19. The donor device of claim 18, The donor device further comprises: a transmitter for transmitting an IAB transmission transition management response message to the first donor-CU; The IAB transport transition management response message includes mapping information for offloaded traffic and / or Layer 2 information on the donor device's topology.

20. The donor device of claim 18, The donor device further re-establishes a BH RLC channel and a BAP sub-layer routing entry on a target path from the mobile IAB node to the donor device.

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