Method and apparatus for IAB node integration

Abstract

[0003] According to some embodiments of the present disclosure, a first centralized unit (CU) may establish a radio resource control (RRC) connection with a network node and transmit, to a second CU, information associated with the network node to facilitate an F1 connection setup between the network node and the second CU.

Description

[Technical Field]

[0001] FIELD Embodiments of the present disclosure relate generally to communications technologies, and more particularly to integrated access and backhaul (IAB) node integration. [Background technology]

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasting, and so on. Wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of wireless communication systems may include fourth-generation (4G) systems, such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth-generation (5G) systems, sometimes referred to as New Radio (NR) systems.

[0003] To expand the coverage and availability of wireless communication systems (e.g., 5G systems), the Third Generation Partnership Project (3GPP) envisions an integrated access and backhaul (IAB) architecture to support multi-hop relay. In an IAB network, an IAB node may hop through one or more IAB nodes before reaching a base station (also called an "IAB donor" or "donor node"). A single hop may be considered a special instance of multiple hops. Multi-hop backhauling is beneficial because it provides a relatively large coverage extension compared to single-hop backhauling. In relatively high-frequency wireless communication systems (e.g., radio signals transmitted in frequency bands above 6 GHz), relatively narrow or small signal coverage can benefit from multi-hop backhauling techniques. Summary of the Invention [Problem to be solved by the invention]

[0004] The industry wants technology to facilitate communication across the IAB network. [Means for solving the problem]

[0005] Some embodiments of the present disclosure provide a first centralized unit (CU), which may include a processor configured to establish a radio resource control (RRC) connection with a network node and a transceiver coupled to the processor and configured to transmit, to a second CU, information associated with the network node to facilitate an F1 connection setup between the network node and the second CU.

[0006] In some embodiments of the present disclosure, information associated with the network node may be transmitted to the second CU via an Xn interface between the first CU and the second CU. In some embodiments of the present disclosure, information associated with the network node may be transmitted to the second CU via a core network entity.

[0007] In some embodiments of the present disclosure, the transceiver may be further configured to receive an indication from the second CU indicating that the second CU is a mobile CU specific to the mobile network node, or to receive an identifier of the second CU from a core network entity, where the second CU is a mobile CU specific to the mobile network node.

[0008] In some embodiments of the present disclosure, the instruction may be included in one of the following messages from the second CU to the first CU: an Xn Setup Response message, an Xn Setup Request message, a Next Generation Radio Access Network (NG-RAN) Node Configuration Update Acknowledgement message, and an NG-RAN Node Configuration Update message.

[0009] In some embodiments of the present disclosure, the second CU may be a donor CU or a mobile CU.

[0010] Some embodiments of the present disclosure provide a network node. The network node may include a transceiver and a processor coupled to the transceiver. The processor may be configured to establish a radio resource control (RRC) connection with a first centralized unit (CU) and to set up an F1 connection with a second CU during initial access of the network node to the network or during transition of the network node from the first CU to the second CU.

[0011] Some embodiments of the present disclosure provide a second centralized unit (CU). The second CU may include a transceiver configured to receive information associated with a network node from the first CU, the network node having a radio resource control (RRC) connection with the first CU, and a processor coupled to the transceiver and configured to set up an FI connection with the network node based at least on the information associated with the network node.

[0012] In some embodiments of the present disclosure, the information associated with the network node may include at least one of Internet Protocol (IP) header information of a downlink (DL) message associated with the F1 connection setup to the network node, a backhaul adaptation protocol (BAP) address of the network node, a distributed unit (DU) ID of the network node, or a global ID of the first CU. In some embodiments of the present disclosure, the IP header information of the DL message associated with the F1 connection setup to the network node may include at least one of a differentiated services code point (DSCP) of the DL message, an IPv6 flow label of the DL message, or an IP address or transport network layer (TNL) address of the network node.

[0013] In some embodiments of the present disclosure, the information associated with the network node may be received from the first CU via an Xn interface between the first CU and the second CU. In some embodiments of the present disclosure, the information associated with the network node may be received from the first CU via a core network entity.

[0014] In some embodiments of the present disclosure, the transceiver may be further configured to send an indication to the first CU or a core network entity indicating that the second CU is a mobile CU specific to the mobile network node. In some embodiments of the present disclosure, the indication may be included in one of the following messages: an Xn Setup Response message from the second CU to the first CU, an Xn Setup Request message from the second CU to the first CU, a Next Generation Radio Access Network (NG-RAN) Node Configuration Update Acknowledgement message from the second CU to the first CU, an NG-RAN Node Configuration Update message from the second CU to the first CU, and an NG Setup Request message from the second CU to the core network entity.

[0015] In some embodiments of the present disclosure, the transceiver may be further configured to receive an F1 setup request message from the network node, where the F1 setup request message may include a global ID of the network node. In some embodiments of the present disclosure, the global ID of the network node may include at least one of a global ID of the first CU and a Backhaul Adaptation Protocol (BAP) address of the network node, a global ID of the first CU and a Distributed Unit (DU) ID of the network node, or an Internet Protocol (IP) address of the network node.

[0016] In some embodiments of the present disclosure, the second CU may be a donor CU or a mobile CU.

[0017] Some embodiments of the present disclosure provide a method implemented by a first CU, which may include establishing a radio resource control (RRC) connection with a network node and transmitting, to a second CU, information associated with the network node for facilitating an F1 connection setup between the network node and the second CU.

[0018] Some embodiments of the present disclosure provide a method implemented by a network node, which may include establishing a radio resource control (RRC) connection with a first centralized unit (CU) and setting up an F1 connection with a second CU during initial access of the network node to the network or during transition of the network node from the first CU to the second CU.

[0019] Some embodiments of the present disclosure provide a method implemented by a second CU, which may include receiving, from a first CU, information associated with a network node, where the network node has a radio resource control (RRC) connection with the first CU, and setting up an F1 connection with the network node based at least on the information associated with the network node.

[0020] Some embodiments of the present disclosure provide an apparatus. According to some embodiments of the present disclosure, the apparatus may include at least one non-transitory computer-readable medium storing computer-executable instructions, at least one receiving circuit, at least one transmitting circuit, and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuit, and the at least one transmitting circuit, wherein the at least one non-transitory computer-readable medium and the computer-executable instructions, using the at least one processor, may be configured to cause the apparatus to perform a method according to some embodiments of the present disclosure.

[0021] Embodiments of the present disclosure provide technical solutions to facilitate and improve the implementation of various communication technologies, such as 5G NR.

[0022] To explain the manner in which the advantages and features of the present disclosure can be obtained, the disclosure will be described by reference to specific embodiments thereof that are illustrated in the accompanying drawings. These drawings illustrate only exemplary embodiments of the disclosure and therefore should not be considered limiting of its scope. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic diagram of a wireless communication system according to some embodiments of the present disclosure. [Figure 2] FIG. 2 is an example block diagram of a protocol stack for an IAB network, according to some embodiments of the present disclosure. [Figure 3] FIG. 2 is an example block diagram of a protocol stack for an IAB network, according to some embodiments of the present disclosure. [Figure 4] 1 is a schematic diagram of a wireless communication system according to some embodiments of the present disclosure. [Figure 5] 1 is a schematic diagram of a wireless communication system according to some embodiments of the present disclosure. [Figure 6] 1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 7] 1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 8] 1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 9] 1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 10] 1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 11]1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 12] 1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 13] 1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 14] 1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 15] 1 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 16] FIG. 1 is a block diagram of an exemplary apparatus according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0024] The detailed description of the accompanying drawings is intended as an illustration of preferred embodiments of the present disclosure and is not intended to represent the only form in which the present disclosure may be practiced. It is to be understood that the same or equivalent function may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present disclosure.

[0025] Reference will now be made in detail to several embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. For ease of understanding, the embodiments are provided under specific network architectures and new service scenarios, such as Third Generation Partnership Project (3GPP) 5G (NR), 3GPP Long Term Evolution (LTE) Release 8, etc. With the development of network architectures and new service scenarios, it is contemplated that all embodiments in the present disclosure are also applicable to similar technical challenges, and further, the terms listed in the present disclosure may change, which should not affect the principles of the present disclosure.

[0026] Compared with 4G communication systems, 5G communication systems impose stricter requirements on various network performance indicators, such as a 1000-fold increase in capacity, wider coverage requirements, ultra-high reliability, and ultra-low latency. Given the abundant frequency resources of high-frequency carriers, the use of high-frequency small-scale station deployments is becoming increasingly common in hotspot areas to meet the ultra-high capacity needs of 5G. However, high-frequency carriers have poor propagation characteristics, severe attenuation due to obstacles, and limited coverage. Therefore, dense deployment of small-scale stations is required. In addition, deploying optical fiber can be difficult and expensive for these small-scale stations. Therefore, an economical and convenient backhaul method is needed. Integrated access and backhaul (IAB) technology, in which both access links and backhaul links can use wireless transmission solutions to avoid fiber deployment, offers an idea for solving the above challenges.

[0027] In an IAB network, a wireless network node, such as a relay node (RN) or IAB node or wireless backhaul node / device, can provide wireless access service for a UE. For example, a UE can connect to an IAB donor relayed by one or more IAB nodes. An IAB donor may also be referred to as a donor node or donor base station (e.g., DgNB, Donor gNode B). In addition, a wireless link between an IAB donor and an IAB node or a wireless link between different IAB nodes may be referred to as a "backhaul link." Wireless network nodes in an IAB network may be stationary or mobile.

[0028] An IAB node may include an IAB mobile terminal (MT) portion and an IAB distribution unit (DU) portion. When an IAB node connects to its parent node (which may be another IAB node or an IAB donor), the IAB node may be considered in the role of a UE, i.e., an MT. When an IAB node provides services to its child node (which may be another IAB node or a UE), the IAB node may be considered in the role of a network device, i.e., a DU.

[0029] An IAB donor may be an access network element with complete base station functionality, or an access network element with a separate centralized unit (CU) and distributed unit (DU). The IAB donor may be connected to a core network (e.g., connected to a 5G core (5GC) network) and provide wireless backhaul functionality for IAB nodes. The CU of the IAB donor may be referred to as an "IAB donor CU" (or directly as a "CU"), and the DU of the IAB donor may be referred to as an "IAB donor DU." The IAB donor CU may be divided into a control plane (CP) and a user plane (UP). For example, a CU may include one CU-CP and one or more CU-UPs.

[0030] Considering the limited coverage of high frequency bands and to guarantee the coverage performance of the network, multi-hop networking can be adopted in the IAB network. Taking into account the requirements of service transmission reliability, IAB nodes can support dual connectivity (DC) or multi-connectivity to improve transmission reliability and deal with abnormal situations that may occur on the backhaul (BH) link, such as radio link failure (RLF) or jamming, load fluctuation, etc.

[0031] If an IAB network supports multi-hop and dual connectivity networking, there may be multiple transmission paths between a UE and an IAB donor. A transmission path may include multiple nodes, such as a UE, one or more IAB nodes, and an IAB donor (if the IAB donor is in the form of separate CU and DU, the IAB donor may also include an IAB donor DU and an IAB donor CU). Each IAB node may treat a neighboring node that provides backhaul services for the IAB node as a parent node (or parent IAB node), and each IAB node may be considered a child node (or child IAB node) of its parent node.

[0032] FIG. 1 illustrates a schematic diagram of a wireless communication system 100 in accordance with some embodiments of the present disclosure.

[0033] 1, wireless communications system 100 may include several base stations (e.g., IAB donor 110A and IAB donor 110B), several IAB nodes (e.g., IAB node 120A, IAB node 120B, and IAB node 120C), and several UEs (e.g., UE 130A and UE 130B). Although a particular number of UEs, IAB nodes, and IAB donors are illustrated in FIG. 1, it is contemplated that any number of UEs, IAB nodes, and IAB donors may be included in wireless communications system 100.

[0034] Each of IAB donor 110A, IAB donor 110B, IAB node 120A, IAB node 120B, and IAB node 120C may be directly connected to one or more IAB nodes according to some other embodiments of the present disclosure. Each of IAB donor 110A, IAB donor 110B, IAB node 120A, IAB node 120B, and IAB node 120C may be directly connected to one or more UEs according to some other embodiments of the present disclosure.

[0035] The UEs 130A and 130B may be any type of device configured to operate and / or communicate in a wireless environment. For example, the UEs 130A and 130B may include computing devices such as desktop computers, laptop computers, personal digital assistants (PDAs), tablet computers, smart televisions (e.g., televisions connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), in-vehicle computers, network devices (e.g., routers, switches, and modems). According to some embodiments of the present disclosure, the UEs 130A and 130B may include portable wireless communication devices, smartphones, cellular telephones, flip phones, devices with subscriber identity modules, personal computers, selective call receivers, or any other devices capable of transmitting and receiving communication signals over a wireless network. In some embodiments of the present disclosure, the UEs 130A and 130B may include wearable devices such as smart watches, fitness bands, optical head-mounted displays, Internet of Things (IoT) devices, etc. Further, UE 130A and UE 130B may be referred to as subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, wireless terminals, fixed terminals, subscriber stations, user terminals, or devices, or may be described using other terms used in the art.

[0036] The IAB donors 110A and 110B may be in communication with a core network (not shown in FIG. 1). The core network (CN) may include multiple core network components, such as a mobility management entity (MME) (not shown in FIG. 1) or an access and mobility management function (AMF) (not shown in FIG. 1). The CN may act as a gateway for UEs to access the public switched telephone network (PSTN) and / or other networks (not shown in FIG. 1).

[0037] The wireless communication system 100 may be compatible with any type of network capable of transmitting and receiving wireless communication signals. For example, the wireless communication system 100 may be compatible with a wireless communication network, a cellular telephone network, a time division multiple access (TDMA)-based network, a code division multiple access (CDMA)-based network, an orthogonal frequency division multiple access (OFDMA)-based network, an LTE network, a 3GPP-based network, a 3GPP 5G network, a satellite communication network, a high altitude platform network, and / or other communication networks.

[0038] In some embodiments of the present disclosure, the wireless communication system 100 is compatible with the 3GPP protocol 5G NR. For example, the IAB donors 110A and 110B may transmit data using an orthogonal frequency division multiplexing (OFDM) modulation scheme on the DL. The UEs 130A and 130B may transmit data using a discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) or cyclic prefix OFDM (CP-OFDM) scheme on the UL. However, more generally, the wireless communication system 100 may implement some other open or proprietary communication protocol, such as WiMAX, among other protocols.

[0039] Those skilled in the art should understand that as technology develops and advances, the terms described in the present disclosure may change, but this should not affect or limit the principles and spirit of the present disclosure.

[0040] Referring to FIG. 1, IAB node 120A may be directly connected to IAB donors 110A and 110B, and IAB node 120B may be directly connected to IAB donor 110A. IAB donors 110A and 110B are parent nodes of IAB node 120A, and IAB donor 110A is the parent node of IAB node 120B. In other words, IAB nodes 120A and 120B are child IAB nodes of IAB donor 110A, and IAB node 120A is also a child IAB node of IAB donor 110B. IAB node 120C can reach IAB donor 110A by hopping through IAB node 120B. IAB node 120B is the parent IAB node of IAB node 120C. In other words, IAB node 120C is a child IAB node of IAB node 120B.

[0041] In some other embodiments of the present disclosure, an IAB node may be connected to IAB node 120C so that the IAB node can reach IAB donor 110A by hopping through IAB node 120C and IAB node 120B. This IAB node and IAB node 120C may be referred to as descendant IAB nodes of IAB node 120B.

[0042] UEs 130A and 130B may be connected to IAB nodes 120A and 120C, respectively. Accordingly, IAB nodes 120A and 120C may be referred to as access IAB nodes. Uplink (UL) packets (e.g., data or signaling) from UE 130A or UE 130B may be transmitted to an IAB donor (e.g., IAB donor 110A or 110B) via one or more IAB nodes and then transmitted by the IAB donor to a mobile gateway device (such as a user plane function (UPF) in 5GC). Downlink (DL) packets (e.g., data or signaling) may be transmitted from the IAB donor (e.g., IAB donor 110A or 110B) after being received by the gateway device and then transmitted to UE 130A or 130B through one or more IAB nodes.

[0043] 1, UE 130A may transmit UL data to or receive DL data from IAB donor 110A or 110B via IAB node 120A. UE 130B may transmit UL data to or receive DL data from IAB donor 110A via IAB node 120C and IAB node 120B.

[0044] In an IAB deployment such as wireless communication system 100, a wireless link between an IAB donor (e.g., IAB donor 110A or 110B in FIG. 1) and an IAB node or between two IAB nodes may be referred to as a backhaul link (BL). A wireless link between an IAB donor (e.g., IAB donor 110A or 110B in FIG. 1) and a UE or between an IAB node and a UE may be referred to as an access link (AL). For example, in FIG. 1, wireless links 140A to 140D are BLs, and wireless links 150A and 150B are ALs.

[0045] A backhaul adaptation protocol (BAP) layer, which is a protocol layer above the radio link control (RLC) layer, is introduced into the IAB system and can be used to realize packet routing, bearer mapping, and flow control on the wireless backhaul link.

[0046] An F1 interface may be established between an IAB node (e.g., a DU portion of the IAB node) and an IAB donor (e.g., an IAB donor CU). The F1 interface may support both user plane protocols (e.g., F1-U) and control plane protocols (e.g., F1-C). The user plane protocols of the F1 interface may include one or more of General Packet Radio Service (GPRS) Tunneling Protocol User Plane (GTP-U), User Datagram Protocol (UDP), Internet Protocol (IP), and other protocols. The control plane protocols of the F1 interface may include one or more of F1 Application Protocol (F1AP), Stream Control Transport Protocol (SCTP), IP, and other protocols.

[0047] Through the control plane of the F1 interface, the IAB node and the IAB donor can perform, for example, interface management, IAB-DU management, and UE context-related configuration. Through the user plane of the F1 interface, the IAB node and the IAB donor can perform, for example, user plane data transmission and downlink transmission status feedback functions.

[0048] Figure 2 shows an example block diagram of a user plane (UP) protocol stack 200 for an IAB network, in accordance with some embodiments of the present disclosure. Figure 3 shows an example block diagram of a control plane (CP) protocol stack 300 for an IAB network, in accordance with some embodiments of the present disclosure. In Figures 2 and 3, a UE may be connected to an IAB donor via IAB node 2 and IAB node 1. In some other embodiments of the present disclosure, a UE may be connected to an IAB donor via more or fewer IAB nodes.

[0049] 2, the UP protocol stack of the UE may include a Service Data Adaptation Protocol (SDAP) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer. The UP protocol stack of the DU of IAB node 2 may include a GTP-U layer, a UDP layer, an IP layer, an RLC layer, a MAC layer, and a PHY layer. The UP protocol stack of the MT of IAB node 2 or the DU or MT of IAB node 1 may include a BAP layer, an RLC layer, a MAC layer, and a PHY layer. The UP protocol stack of the DU of the IAB donor may include an IP layer, a BAP layer, an RLC layer, a MAC layer, and a PHY layer, with the PHY layer belonging to Layer 1 (L1) and the BAP layer, RLC layer, and MAC layer belonging to Layer 2 (L2). The protocol stack of IAB Donor CU-UP may include a GTP-U layer, a UDP layer, an IP layer, an SDAP layer, a PDCP layer, an L2 layer, and an L1 layer.

[0050] Referring to Figure 3, the CP protocol stack of the UE may include a radio resource control (RRC) layer, a PDCP layer, an RLC layer, a MAC layer, and a physical (PHY) layer. The CP protocol stack of the DU of IAB node 2 may include an F1AP layer, an SCTP layer, an IP layer, an RLC layer, a MAC layer, and a PHY layer. The CP protocol stack of the MT of IAB node 2 or the DU or MT of IAB node 1 may include a BAP layer, an RLC layer, a MAC layer, and a PHY layer. The CP protocol stack of the DU of the IAB donor may include an IP layer, a BAP layer, an RLC layer, a MAC layer, and a PHY layer, with the PHY layer belonging to L1 and the BAP layer, RLC layer, and MAC layer belonging to L2. The protocol stack of the CU-CP of the IAB donor may include an RRC layer, a PDCP layer, an F1AP layer, an SCTP layer, an IP layer, an L2 layer, and an L1 layer.

[0051] The protocol stacks shown in Figures 2 and 3 are for illustrative purposes only. For example, the sequence of some of the protocol layers in the protocol stacks of Figures 2 and 3 may be rearranged for illustrative purposes. For example, the SDAP and PDCP layers belong to L2, but these layers are shown above the GTP-U, UDP, and IP layers in the protocol stack of IAB Donor CU-UP in Figure 2.

[0052] Signals between each node in the IAB network may include, for example, the following, which may be applicable to the present disclosure: - IAB Donor CU and IAB Donor DU: F1AP message, - IAB donor CU and IAB node: F1AP messages between CU and IAB-DU or RRC messages between CU and IAB-MT; - IAB Donor CU and UE: RRC messages, - Access IAB nodes and UEs: L2 control PDUs, such as MAC Control Elements (CEs) or RLC control PDUs, and - An IAB node and another child or parent IAB node: L2 control PDUs such as MAC CE, RLC control PDUs, or BAP control PDUs.

[0053] Regarding BAP routing in an IAB network, each UL or DL ​​packet in the BH link may be mapped to a specific BAP routing identification (ID) and added to the BAP header. The BAP routing ID may be configured by the IAB donor CU. The BAP routing ID may include a BAP address indicating the BAP address of the destination node in the BH link. The destination nodes of the BH link for DL ​​and UL are the access IAB node and the IAB donor DU, respectively. In addition, the BAP routing ID may further include a path ID indicating the routing path terminated at the destination node.

[0054] As demand for improved cellular coverage and connectivity continues to grow, communications in outdoor and mobility scenarios may face additional challenges. In some embodiments of the present disclosure, a mobile wireless network node acting as a relay between a UE and a 3GPP communication network (e.g., 5G) may be employed to facilitate communications in such scenarios. The mobile wireless network node may, for example, provide an access link to the UE, wirelessly connected (e.g., using NR) to a core network through a BS (e.g., a donor Next Generation Radio Access Network (NG-RAN)). In some examples, such a mobile wireless network node may also be referred to as a mobile base station relay or mobile relay. The above description of the wireless network node and IAB node may apply to the mobile base station relay. That is, the mobile base station relay may be a mobile IAB node.

[0055] In some examples, a mobile base station relay may be mounted on a vehicle. The mobile base station relay may serve UEs that are inside or outside the vehicle or that enter or leave the vehicle. In the context of this disclosure, inside or outside the mobile base station relay may mean inside or outside the vehicle or other device on which the mobile wireless network node is mounted.

[0056] In some examples, the radio links used between the mobile base station relay and the served UE and between the mobile base station relay and the BS may be Uu links (e.g., NR-Uu) different from the UE relay (e.g., providing indirect connectivity to remote UEs using a PC5-based link). In some examples, there may be at least one hop between the UE and the mobile base station relay. In some examples, there may be at least one hop between the mobile base station relay and the BS.

[0057] The adoption of such mobile wireless network nodes is advantageous in various aspects and can be applied to various scenarios. For example, in some outdoor environments, the availability of vehicles equipped with mobile base station relays following certain known / predictable itineraries (e.g., buses, trams, etc.) or located at convenient locations (e.g., outdoor stadiums, hotspot areas, or emergency sites) can significantly increase cellular coverage and capacity on an ad-hoc basis when or where needed. These relays may, for example, use 5G wireless backhaul toward the macro network, thus providing better coverage and connectivity to nearby UEs. Mobile relays are also well suited to improving connectivity for users or devices inside vehicles equipped with mobile relays in different environments, for example, for passengers in buses, cars / taxis, or trains, or for special / specialized personnel or equipment. Such mobile wireless network nodes may also be used to reach users or devices that would otherwise have no or very poor macro coverage, for example, in the case of first responders who have moved into indoor buildings / areas, using relays located nearby or in outdoor vehicles to obtain the necessary coverage and connectivity.

[0058] The technical benefits of using such mobile wireless network nodes further include, among other things, the ability to leverage better radio frequency, antenna, and power capabilities to obtain better macro coverage than nearby UEs. Additionally, besides the value to network operators and end users, valuable incentives may also be found for other parties, for example, vehicle manufacturers, and vehicle and fleet owners or providers, to install and operate relays in their vehicles.

[0059] Due to the mobility of wireless network nodes (e.g., mobile base station relays or mobile IAB nodes), the wireless network nodes may need to transition (or handover) from one IAB donor to another. For example, referring back to FIG. 1, IAB node 120C or IAB node 120B may transition from IAB donor 110A to IAB donor 110B. Mobility of mobile IAB nodes over a wide area may face challenges when the mobile IAB node changes IAB donors. For example, because the PDCP and RRC connections of a UE served by the mobile IAB node may be affected, the UE may experience a non-trivial amount of signaling due to mobility in, for example, idle mode (due to the need to adapt TA values ​​to new BS-assigned values ​​and change PDCP terminations and security for the user plane) and connected mode, even if the UE is stationary inside a vehicle in which the IAB node is installed.

[0060] This root cause of mobility-related signaling can be mitigated if a mobile IAB node (e.g., a DU of the mobile IAB node) can be served by a CU covering a much larger area (e.g., a city). In some embodiments of the present disclosure, a mobile CU (m-CU) is introduced to mitigate the impact of IAB donor changes. The m-CU can serve as a CU for the mobile IAB node or a mobile base station relay. In short, it can be advantageous to provide homing of the mobile IAB node to a dedicated mobile control unit (e.g., m-CU) that controls the UEs connected to the mobile IAB node. This allows the mobile IAB node to move across a much larger RAN coverage area without changing m-CU. Thus, the mobility of the mobile IAB node between IAB donors can be hidden from the UEs connected to the mobile IAB node as long as the controller remains in the same m-CU.

[0061] 4 illustrates a schematic diagram of a wireless communication system 400 in accordance with some embodiments of the present disclosure. The wireless communication system 400 may support an m-CU.

[0062] 4, a wireless communication system 400 may include Donor 1 and Donor 2, each including a CU and a DU, and a wireless network node 420, including an IAB-MT and an IAB-DU. The wireless network node 420 is a mobile wireless network node and may be mounted in a vehicle and serve a UE inside the vehicle. Due to the mobility of the wireless network node 420, its IAB-MT may switch from Donor 1 to Donor 2, but the m-CU can always serve as the CU for the wireless network node 420.

[0063] In some embodiments of the present disclosure, in the structure of a wireless network node (e.g., a mobile IAB node or a mobile base station relay) with an m-CU, when the wireless network node performs integration (i.e., initial access), it is preferable that the MT of the wireless network node establishes an RRC connection with the IAB donor, and it is preferable that the DU of the wireless network node establishes an F1 connection with the m-CU.

[0064] 5 shows a schematic diagram of a wireless communication system 500 according to some embodiments of the present disclosure. The wireless communication system 500 may support an m-CU (e.g., a CU 540).

[0065] 5, a wireless communication system 500 may include an IAB donor 510 including an IAB donor CU and an IAB donor DU, and wireless network nodes 520A and 520B, each including an MT and a DU. Wireless network node 520B may be directly connected to the IAB donor 510. Wireless network node 520A may be a mobile node, such as a mobile IAB node.

[0066] 5, when the wireless network node 520A performs integration (i.e., initial access), the MT of the wireless network node 520A can establish an RRC connection with the IAB donor 510, and the DU of the wireless network node 520A can set up an F1 connection with the CU 540. Embodiments of the present disclosure provide a solution for performing such integration of wireless network nodes. Further details regarding embodiments of the present disclosure are described in the following text in combination with the accompanying drawings.

[0067] Although the embodiments of the present disclosure are discussed based on some specific components (e.g., IAB donors or mobile IAB nodes) under a specific network architecture (e.g., IAB architecture), it should be noted that the embodiments of the present disclosure are also applicable to other similar network architectures and new service scenarios.

[0068] In some embodiments of the present disclosure, an F1 connection setup between a DU of a wireless network node (for simplicity, hereinafter referred to as a “mobile DU”) and an m-CU may occur after establishment of an RRC connection between an MT of the wireless network node (for simplicity, hereinafter referred to as a “mobile MT”) and a CU of an IAB donor (for simplicity, hereinafter referred to as an “IAB donor CU”).

[0069] Signaling associated with the F1 connection setup between the mobile DU and the m-CU should be transported over the backhaul link under the control of the IAB donor CU (e.g., referring to FIG. 5, IAB donor DU <-> wireless network node 520B <-> MT of wireless network node 520A). This means that UL / DL traffic for the F1 setup with the m-CU may need to be configured by the IAB donor CU in the backhaul configuration. Therefore, a preparation procedure between the IAB donor CU (e.g., IAB donor CU shown in FIG. 5) and the m-CU (e.g., CU 540 shown in FIG. 5) is required to ensure UL / DL F1 setup-related signaling transmission over the backhaul link.

[0070] In the context of the present disclosure, F1 setup related messages or signaling may include at least one of an F1 setup request from a DU of a network node (e.g., an IAB-DU or a mobile DU) to a CU, an F1 setup response from a CU to a DU of a network node, and SCTP association establishment or TNL association establishment signaling between a CU and a DU of a network node.

[0071] 6 illustrates a flowchart of an example procedure 600 for wireless communication in accordance with some embodiments of the present disclosure. The procedure 600 can ensure UL / DL F1 setup-related signaling transmission over a backhaul link under an IAB donor CU. As described in detail below, the procedure 600 can be used to exchange essential information between the IAB donor CU and an m-CU.

[0072] The details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in Figure 6. For example, the BS 610 may function as an IAB donor as described above and may include a CU and a DU. The network node 620 may function as an IAB node as described above and may include an MT and a DU. The CU 640 may function as an m-CU as described above. In some examples, the CN entity 650 may be an AMF.

[0073] 6, in operation 611, a network node 620 (e.g., an MT of the network node 620) may establish an RRC connection with a BS 610 (e.g., a CU of the BS 610). In some examples, the network node 620 may be directly connected to the BS 610 (e.g., without any other network nodes connected between the network node 620). In some examples, the network node 620 may be indirectly connected to the BS 610 (e.g., one or more other network nodes may be connected between the network node 620 and the BS 610).

[0074] In some embodiments of the present disclosure, in response to the network node 620 setting up an RRC connection to the CU of the BS 610, the BS 610 may trigger a preparation procedure (e.g., procedure 621 or procedure 631) to facilitate an F1 connection setup between the network node 620 and the CU 640. In some other embodiments of the present disclosure, the preparation procedure may be triggered by an indication from the network node 620 indicating that the network node 620 intends to set up an F1 connection to the CU 640. Details of such an indication are described later in this disclosure.

[0075] In some examples, the preparation procedure may be an Xn procedure between the BS 610 and the CU 640, such as procedure 621.

[0076] In some embodiments of the present disclosure, the Xn procedure may be a class 2 elementary procedure that does not have a response message. For example, procedure 621 may include only operation 623.

[0077] For example, the CU of the BS 610 may initiate the procedure by sending information associated with the network node 620 to facilitate an F1 connection setup between the network node 620 and the CU 640 in operation 623. In some examples, this procedure may be referred to as an "IAB-DU Setup Indication" procedure. The information associated with the network node 620 may be sent in an IAB-DU Setup Indication message.

[0078] In some embodiments, the information associated with the network node 620 (or the IAB-DU Setup Indication message) may include at least one of the following: IP header information of a DL message associated with the F1 connection setup to the network node 620, a BAP address of the network node 620, a DU ID (e.g., gNB DU ID) of the network node 620, or a global ID of a CU of the BS 610 (e.g., global gNB ID). In some embodiments, the IP header information of the DL message associated with the F1 connection setup to the network node 620 may include at least one of a Differentiated Services Code Point (DSCP) of the DL message, an IPv6 flow label of the DL message, or an IP address or a Transport Network Layer (TNL) address of the network node 620. The above information associated with the network node 620 may be used in later procedures for the F1 connection setup (e.g., in the F1 Setup Request).

[0079] For example, the information associated with the network node 620 may include IP header information. For example, the information associated with the network node 620 may include a BAP address of the network node 620. For example, the information associated with the network node 620 may include a DU ID of the network node 620. For example, the information associated with the network node 620 may include a global ID of a CU of the BS 610 and a BAP address of the network node 620, the combination of which may also be referred to as a global ID of the network node 620. For example, the information associated with the network node 620 may include a global ID of a CU of the BS 610 and a gNB DU ID of the network node 620, the combination of which may also be referred to as a global ID of the network node 620.

[0080] For DL ​​messages associated with an F1 connection setup, the CU of the BS 610 may configure the DU of the BS 610 with IP header information and associated BAP configuration (e.g., routing and bearer mapping). Because the configuration is generated by the CU of the BS 610 by employing the above procedure, the CU 640 can be aware of the configuration and generate the appropriate IP header for DL ​​messages associated with an F1 connection setup.

[0081] In some embodiments of the present disclosure, the Xn procedure may be a class 1 elementary procedure with a response message. For example, procedure 621 may include operations 623 and 625.

[0082] For example, the CU of the BS 610 may initiate the procedure by sending information relating to the network node 620 to facilitate an F1 connection setup between the network node 620 and the CU 640 in operation 623. The above description regarding the information relating to the network node 620 may also apply here. For example, the information associated with the network node 620 may include at least one of: IP header information of a DL message associated with the F1 connection setup to the network node 620, a BAP address of the network node 620, a DU ID (e.g., gNB DU ID) of the network node 620, or a global ID (e.g., global gNB ID) of a CU of the BS 610. For example, the IP header information of the DL message associated with the F1 connection setup to the network node 620 may include at least one of a DSCP of the DL message, an IPv6 flow label of the DL message, or an IP address or TNL address of the network node 620.

[0083] In some examples, the procedure may be referred to as an "IAB-DU Setup Preparation" procedure. Information related to the network node 620 may be sent in an IAB-DU Setup Request message.

[0084] In response to receiving the information-related network node 620 (or the IAB-DU setup request message), the CU 640 may respond to the CU of the BS 610 with an IAB-DU setup response message in operation 625. Alternatively, in the event of a failure, the CU 640 may respond to the CU of the BS 610 with an IAB-DU setup reject / reject message in operation 625. In some embodiments, in the response message, the CU 640 may indicate its IP address to the CU of the BS 610. In some embodiments, the response message may include only an acknowledgment of the information from the CU of the BS 610.

[0085] In some instances, the preparation procedure may involve communication over the NG interface. For example, if there is no direct Xn connection between the CU of the BS 610 and the CU 640, the preparation procedure needs to be extended to the NG interface.

[0086] For example, the CU of BS 610 may initiate the NG interface procedure by sending a message (denoted as message #1, which may be an IAB-DU setup request message or another message) to the core network (e.g., CN entity 650) in operation 633. In response to message #1, CN entity 650 may initiate the NG interface procedure in operation 635 by sending a message (denoted as message #2, which may be an IAB-DU setup request message or another message) to CU 640 based on a request from the CU of BS 610.

[0087] Both message #1 and message #2 may include information relating to network node 620 to facilitate F1 connection setup between network node 620 and CU 640.

[0088] In some embodiments, the information associated with the network node 620 may include at least one of IP header information of a DL message associated with the F1 connection setup to the network node 620, a BAP address of the network node 620, a DU ID of the network node 620 (e.g., a gNB DU ID), or a global ID of a CU of the BS 610 (e.g., a global gNB ID).

[0089] For example, the information associated with the network node 620 may include IP header information. For example, the information associated with the network node 620 may include a global ID of a CU of the BS 610 and a BAP address of the network node 620, the combination of which may also be referred to as a global ID of the network node 620. For example, the information associated with the network node 620 may include a global ID of a CU of the BS 610 and a gNB DU ID of the network node 620, the combination of which may also be referred to as a global ID of the network node 620.

[0090] The above description regarding the IP header information of the DL message may also apply here. For example, the IP header information of the DL message associated with the F1 connection setup to the network node 620 may include at least one of the DSCP of the DL message, the IPv6 flow label of the DL message, or the IP address or TNL address of the network node 620. The above information associated with the network node 620 may be used in later procedures for the F1 connection setup (e.g., in the F1 setup request).

[0091] In some embodiments, message #1 and message #2 may have corresponding reply messages.

[0092] For example, in operation 637 (optionally indicated by a dotted arrow), CU 640 may send a response message to CN entity 650 in response to message #2 (e.g., an IAB-DU setup request message or another message). In some embodiments, the response message may include an IP address of CU 640. In some embodiments, the response message may include only an acknowledgment of information from CN entity 650.

[0093] For example, in operation 639 (optionally indicated by a dotted arrow), the CN entity 650 may send a response message to the CU of the BS 610 in response to message #1 (e.g., an IAB-DU setup request message or another message). In some embodiments, the response message may include the IP address of the CU 640. In some embodiments, the response message may include only an acknowledgment of the information from the CU of the BS 610.

[0094] In some embodiments, message #1, message #2, or both may not have a corresponding reply message, i.e., operation 637, operation 639, or both may be omitted.

[0095] The procedure 600 may also be applied to a scenario of DU migration of a network node without the involvement of an m-CU. For example, the CU of the BS 610 in Figure 6 may be implemented as a CU (e.g., a donor CU) having an RRC connection with the network node 620, and the CU 640 in Figure 6 may be implemented as another CU (e.g., another donor CU) to which the DU of the network node 620 sets up an F1 connection. Further clarification in this regard is provided in the following text.

[0096] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 600 may be changed and that some of the operations in the exemplary procedure 600 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0097] In some embodiments of the present disclosure, during integration, the wireless network node may set up an F1 connection with the IAB donor or the m-CU. Embodiments of the present disclosure provide a procedure for the wireless network node to set up an F1 connection with the IAB donor or the m-CU. In addition, embodiments of the present disclosure also provide a discovery procedure for the IAB donor to find the m-CU before the F1 connection setup. When the wireless network node is to set up an F1 connection with the m-CU, the IAB donor may find the m-CU in advance through the discovery procedure for communication between the IAB donor and the m-CU in preparation for setting up a DU for the wireless network node.

[0098] In some embodiments of the present disclosure, for each IAB donor's CU, a corresponding m-CU may be pre-configured via Operations, Administration and Maintenance (OAM).

[0099] In some embodiments of the present disclosure, the CU of the IAB donor may be aware of the existence of the m-CU prior to integration of the wireless network node (eg, a mobile IAB node).

[0100] In some embodiments of the present disclosure, the IAB donor's CU may initiate a discovery procedure for the m-CU. For example, the IAB donor's CU may find the m-CU via an Xn setup procedure between the IAB donor's CU and the m-CU.

[0101] 7 shows a flowchart of an example procedure 700 for wireless communication according to some embodiments of the present disclosure. Details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in FIG. 7. For example, the BS 710 may function as an IAB donor as described above and may include a CU and a DU. The CU 740 may function as an m-CU as described above.

[0102] 7, the BS 710 (e.g., a CU of the BS 710) may initiate a discovery procedure by sending an Xn Setup Request message (or another message) to the CU 740 in operation 711. In operation 713, the CU 740 may respond to the BS 710 (e.g., a CU of the BS 710) with an Xn Setup Response message (or another message). In some embodiments of the present disclosure, the Xn Setup Response message may include an indication that the CU 740 is a mobile CU specific to the mobile network node.

[0103] In some other embodiments, the above indication may be carried in an NG-RAN node configuration update acknowledgement message in an NG-RAN node configuration update procedure. For example, the BS 710 (e.g., a CU of the BS 710) may trigger an NG-RAN node configuration update procedure (e.g., as a discovery procedure) and send an NG-RAN node configuration update message in operation 711.

[0104] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 700 may be changed and some of the operations in the exemplary procedure 700 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0105] In some embodiments of the present disclosure, the m-CU may initiate the discovery procedure. For example, the IAB donor's CU may find the m-CU via an Xn setup procedure between the IAB donor's CU and the m-CU.

[0106] 8 shows a flowchart of an example procedure 800 for wireless communication according to some embodiments of the present disclosure. Details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in FIG. 8. For example, the BS 810 may function as an IAB donor as described above and may include a CU and a DU. The CU 840 may function as an m-CU as described above.

[0107] 8, the CU 840 may initiate the discovery procedure by sending an Xn Setup Request message (or another message) to the BS 810 (e.g., a CU of the BS 810) in operation 811. The BS 810 (e.g., a CU of the BS 810) may respond with an Xn Setup Response message (or another message) to the CU 840 in operation 813. In some embodiments of the present disclosure, the Xn Setup Request message may include an indication that the CU 840 is a mobile CU specific to the mobile network node.

[0108] In some other embodiments, the above indication may be carried in an NG-RAN node configuration update message in an NG-RAN node configuration update procedure. For example, the CU 840 may trigger an NG-RAN node configuration update procedure (e.g., as a discovery procedure) and send an NG-RAN node configuration update message in operation 811.

[0109] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 800 may be changed and some of the operations in the exemplary procedure 800 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0110] In some embodiments of the present disclosure, the CU of the IAB donor can discover the m-CU via the NG interface.

[0111] 9 shows a flowchart of an example procedure 900 for wireless communication according to some embodiments of the present disclosure. Details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in FIG. 9. For example, the BS 910 may function as an IAB donor as described above and may include a CU and a DU. The CU 940 may function as an m-CU as described above. The CN entity 950 may function as a CN entity as described above.

[0112] 9, the CU 940 may first initiate an NG setup procedure toward the core network. For example, in operation 921, the CU 940 may send an NG setup request message to the CN entity 950. In some embodiments, the NG setup request message may indicate that the CU 940 is a mobile CU specific to the mobile network node.

[0113] At operation 923, the CN entity 950 may respond to the CU 940 with an NG Setup Response message.

[0114] At operation 925, in response to the NG setup request message, the CN entity 950 may send an identifier of the CU 940 to the BS 910 (e.g., a CU of the BS 910) via an NG message. The identifier may be a global RAN node ID or any other global identifier of the CU 940. The NG message may be an NG setup response message, a RAN configuration update acknowledgement message, or an AMF configuration update.

[0115] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 900 may be changed and some of the operations in the exemplary procedure 900 may be deleted or modified without departing from the spirit and scope of the present disclosure. For example, in some other embodiments of the present disclosure, operation 925 may precede operation 923 or occur simultaneously with operation 923.

[0116] As mentioned above, the F1 terminating CU of a wireless network node (e.g., a mobile IAB node) may be a CU or an m-CU of a BS (e.g., an IAB donor). Various embodiments may be applied to determining or selecting the F1 terminating CU of a wireless network node.

[0117] In some embodiments of the present disclosure, the F1 termination CU of a wireless network node (eg, a mobile IAB node) may be determined by the CU of the BS (eg, an IAB donor).

[0118] For example, in response to a wireless network node (e.g., a mobile IAB node MT) initiating an RRC connection setup with a CU of a BS, the CU of the BS may indicate to the wireless network node to set up an F1 connection to the CU of the BS or to an m-CU. The indication may be sent via an RRC message.

[0119] For example, in some embodiments, the indication may indicate that either the CU or the m-CU of the BS is an F1-terminated CU of the wireless network node. For example, in some embodiments, the CU of the BS may send the indication only when the F1-terminated CU of the wireless network node is an m-CU. That is, in the absence of an indication, the wireless network node should set up an F1 connection to the CU of the BS.

[0120] In some embodiments of the present disclosure, the F1 termination CU of a wireless network node (e.g., a mobile IAB node) may be determined by the wireless network node.

[0121] For example, if a wireless network node desires to set up an F1 connection for an m-CU, the wireless network node may send an indication to the CU of the BS indicating that the wireless network node will set up an F1 connection for the m-CU, so that the CU of the BS can perform the preparation procedure in advance. The indication may be included in an RRC message, e.g., message 5 during the initial access procedure. The preparation procedure described above with respect to FIG. 6 may apply here. For example, referring back to FIG. 6, in response to receiving an indication from the network node 620 indicating a decision to set up an F1 connection for a CU different from the CU of the BS 610 (e.g., the m-CU), the BS 610 may perform procedure 621 or procedure 631 to facilitate the F1 connection setup.

[0122] In some embodiments of the present disclosure, when the MT and DU of a wireless network node terminate in different CUs (e.g., the CU and m-CU of an IAB donor, respectively, or different CUs of different IAB donors), a procedure for associating the MT and DU of the wireless network node may be required. For example, an F1 setup request message from the DU of the wireless network node to the m-CU may need to be associated with information sent from the CU of the IAB donor to the m-CU. Embodiments of the present disclosure provide solutions for solving the above problems.

[0123] 10 shows a flowchart of an example procedure 1000 for wireless communication according to some embodiments of the present disclosure. Details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in FIG. 10. For example, the network node 1020 may function as an IAB node as described above and may include an MT and a DU. The CU 1040 may function as an m-CU as described above.

[0124] 10 , the network node 1020 (e.g., an MT of the network node 1020) may have an RRC connection with a CU of a BS not shown in FIG. 10 (e.g., an IAB donor CU). In operation 1011, the network node 1020 (e.g., a DU of the network node 1020) may establish a first transport network layer association (TNLA) TNLA (or SCTP association) with the CU 1040. In some embodiments, the TNL or IP address of the CU 1040 may be pre-configured by OAM. In some embodiments, the TNL or IP address of the CU 1040 may be obtained from the CU 1040 via an Xn message or from the core network via an NG message, for example, as described with respect to operation 625 or operation 639 of FIG. 6 .

[0125] The network node 1020 (e.g., a DU of the network node 1020) may initiate an F1 setup procedure and may send an F1 setup request message to the CU 1040 in operation 1013. In some embodiments, the F1 setup request message may include information to assist the CU 1040 in associating the DU of the network node 1020 and information indicated from a CU of the BS specific to the network node 1020 (e.g., an IAB donor CU). For example, some information elements (IEs) of the F1 setup request message may be the same as the information associated with a network node for facilitating F1 connection setup as described with respect to FIG. 6.

[0126] For example, the F1 setup request message may include a global ID of the network node 1020. In some embodiments, the global ID of the network node 1020 may include at least one of a global ID of a CU of the BS (e.g., an IAB donor CU) and a BAP address of the network node 1020, a global ID of a CU of the BS and a DU ID of the network node 1020 (e.g., a gNB-DU ID), or an IP address of the network node 1020. The global ID of the CU of the BS may be a global gNB ID.

[0127] At operation 1015, the CU 1040 may send an F1 setup response message to the network node 1020 (e.g., a DU of the network node 1020) in response to the F1 setup request message.

[0128] Note that all messages between the network node 1020 (e.g., a DU of the network node 1020) and the CU 1040 may be transmitted over the BH link in a topology of a CU (e.g., an IAB donor CU) of a BS. For example, referring back to FIG. 5, DL traffic may be transmitted from the CU 540 to an IAB donor DU of the IAB donor CU, which may deliver the DL traffic to the wireless network node 520A over the BH link. UL traffic may be transmitted over the same path in the reverse direction.

[0129] The procedure 1000 may also be applied to a scenario of DU migration of a network node without the involvement of an m-CU. For example, the CU of the BS may be implemented as a CU (e.g., a donor CU) having an RRC connection with the network node 1020, and the CU 1040 of FIG. 10 may be implemented as another CU (e.g., another donor CU) to which the DU of the network node 1020 sets up an F1 connection. Further clarification in this regard is provided in the following text.

[0130] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 1000 may be changed and that some of the operations in the exemplary procedure 1000 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0131] 11 shows a flowchart of an example procedure 1100 for wireless communication according to some embodiments of the present disclosure. Details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in FIG. 11. For example, the BS 1110 may function as an IAB donor as described above and may include a CU and a DU. The CU 1140 may function as an m-CU as described above. The network node 1120 may function as an IAB node as described above.

[0132] The procedure 1100 may be adopted for the integration of a wireless network node (e.g., a mobile IAB node) with the m-CU architecture. In the procedure 1100, the MT of the network node 1120 may first establish an RRC connection to the CU of the BS 1110, and then the DU of the network node 1120 may set up an F1 connection to the CU 1140 via a BH link under the CU of the BS 1110.

[0133] Referring to FIG. 11, in operation 1111, an MT of a network node 1120 may establish an RRC connection to a CU of a BS 1110.

[0134] In this operation, the MT of the network node 1120 may connect to the network in the same manner as a UE, for example, by performing an RRC connection setup procedure with the CU of the BS 1110, authentication by the core network, IAB node-related context management, access traffic-related radio bearer configuration of the IAB node on the RAN side (e.g., signaling radio bearers (SRBs) and optionally data radio bearers (DRBs)), and optionally, OAM connectivity establishment by using an IAB-MT PDU session.

[0135] In operation 1113, the CU of the BS 1110 or the network node 1120 may determine the F1 terminating CU of the network node 1120.

[0136] For example, in some embodiments, the CU of the BS 1110 may indicate to the network node 1120 that it wishes to set up an F1 connection to a CU or CU 1140 of the BS 1110, as described in the previous embodiment. Such an indication may be sent via RRC signaling. In some embodiments, the network node 1120 may send an indication to a CU of the BS 1110 that it wishes to set up an F1 connection to a CU (e.g., an m-CU such as CU 1140) different from the CU of the BS 1110, as described in the previous embodiment. If the above indication indicates an F1 connection to CU 1140, the procedure proceeds to operation 1115.

[0137] At operation 1115, negotiation may be performed between the CU of BS 1110 and CU 1140.

[0138] For example, the CU of the BS 1110 may discover the CU 1140 via a procedure such as that described above with respect to Figures 7-9. Note that such a discovery procedure may be performed before operation 1113 or operation 1111. For example, the CU of the BS 1110 and the CU 1140 may perform a procedure such as that described above with respect to Figure 6 (e.g., procedure 621 or 631 of Figure 6).

[0139] In operation 1117, the CU of the BS 1110 may configure a BH configuration for the BH link between the DU of the BS 1110 and the network node 1120 to ensure DL / UL transmission of F1 setup related messages.

[0140] For example, in the DL case, the CU of BS1110 may initiate an F1AP procedure to configure the DU of BS1110 with a mapping from IP header fields to the BAP routing ID associated with network node 1120. The routing tables and BH RLC CH may be updated with routing entries for the new BAP routing ID associated with network node 1120 on all ancestor network nodes (e.g., IAB nodes), if any, and on the DU of BS1110.

[0141] For the UL, a default configuration including a default BH RLC channel and a default BAP routing ID may be configured for the network node 1120 for UL F1 setup related messages. In some examples, the UL BH configuration for the BH link between the network node 1120 and the DU of the BS 1110 may also be updated.

[0142] In operation 1119, the network node 1120 (e.g., a DU of the network node 1120) may set up an F1 connection with the CU 1140. For example, the procedure as described above with respect to FIG. 10 may be applied here.

[0143] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 1100 may be changed and that some of the operations in the exemplary procedure 1100 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0144] 12 shows a flowchart of an example procedure 1200 for wireless communication according to some embodiments of the present disclosure. Details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in FIG. 12. For example, the BS 1210 may function as an IAB donor as described above and may include a CU and a DU. The network node 1220 may function as an IAB node as described above. The CU 1240 may function as an m-CU, a CU of the BS, or a CU of the IAB donor as described above.

[0145] In some embodiments, procedure 1200 may be employed for integration of a wireless network node (e.g., a mobile IAB node) with the architecture of an m-CU. In such embodiments, CU 1240 may function as the m-CU. In some embodiments, procedure 1200 may be employed for migration of a DU of a wireless network node (e.g., a mobile IAB node) without involvement of an m-CU. In such embodiments, CU 1240 may function as a CU of a BS or a CU of an IAB donor.

[0146] In procedure 1200, an MT of network node 1220 may first establish an RRC connection to a CU of BS1210, then a DU (DU1) of network node 1220 may set up an F1 connection to a CU of BS1210, and finally another DU (DU2) of network node 1220 may set up an F1 connection to CU1240.

[0147] 12, in operation 1211, the network node 1220 may perform integration with the CU of the BS 1210. For example, operation 1211 may include an IAB-MT setup procedure, a BH RLC channel establishment procedure, a routing update procedure, and an IAB-DU partial setup procedure.

[0148] For example, during an IAB-MT setup procedure, an MT at network node 1220 may connect to the network in the same manner as a UE. Network node 1220 may select a parent node for access based on an over-the-air indication from a potential parent node IAB-DU, which may be transmitted in System Information Block 1 (SIB1). In some examples, to indicate its IAB capabilities, the MT at network node 1220 may include an IAB node indication in an RRC Setup Complete message to assist BS 1210 in selecting an AMF that supports IAB.

[0149] For example, in the BH RLC channel establishment procedure, one default BH RLC channel for non-UP traffic may be established during the bootstrapping procedure, e.g., to carry F1-C traffic / non-F1 traffic with network node 1220 during the integration phase. This may require the setup of a new BH RLC channel or modification of an existing BH RLC channel between network node 1220's parent node (if any) and BS 1210's DU. The CU of BS 1210 may establish an additional (non-default) BH RLC channel. This procedure may also include configuring network node 1220's BAP address and default BAP routing ID for the upstream direction.

[0150] For example, in a routing update procedure, the BAP layer may be updated to support routing between network node 1220 and the DU of BS 1210. For the downstream direction, the CU of BS 1210 may initiate an F1AP procedure to configure the DU of BS 1210 with a mapping from IP header fields to a BAP routing ID associated with network node 1220. Routing tables may be updated with routing entries for the new BAP routing ID on all ancestor network nodes of network node 1220 and on the DU of BS 1210. This procedure may also include an IP address allocation procedure for network node 1220. Network node 1220 may request one or more IP addresses from the CU of BS 1210 via RRC. The CU of BS 1210 may send the IP addresses to network node 1220 via RRC. The CU of BS 1210 may obtain an IP address from the DU of BS 1210 via F1AP or by other means (e.g., OAM, Dynamic Host Configuration Protocol (DHCP), etc.). The IP address allocation procedure may occur any time after the RRC connection is established.

[0151] For example, in an IAB-DU partial setup procedure, a DU (e.g., DU1) of network node 1220 may be configured via OAM. The DU (e.g., DU1) of network node 1220 may initiate TNL establishment and F1 connection setup with a CU of BS 1210 using the allocated IP address. The CU of BS 1210 may discover the co-location of the MT of network node 1220 and the DU (e.g., DU1) of network node 1220 from the BAP address included in the F1 setup request message. After the F1 connection is set up, network node 1220 can start serving the UE.

[0152] In an architecture with an m-CU (e.g., CU 1240 is an m-CU), the CU of BS 1210 or network node 1220 may determine an F1-terminated CU of network node 1220 in operation 1213 (optionally indicated by a dotted arrow). For example, the CU of BS 1210 may indicate to network node 1220 that it will set up an F1 connection to CU or CU 1240 of BS 1210, as described in the previous embodiment. Such an indication may be sent via RRC signaling. In some embodiments, network node 1220 may send an indication to the CU of BS 1210 that it wishes to set up an F1 connection to m-CU, as described in the previous embodiment. If the indication indicates an F1 connection to CU 1240, the procedure proceeds to operation 1215.

[0153] In the case of a DU transition without the involvement of an m-CU (e.g., CU 1240 is a CU of another BS), the CU of BS 1210 may trigger an F1 transition for network node 1220 and may indicate to network node 1220 to set up an F1 connection to the target CU (e.g., CU 1240).

[0154] At operation 1215, negotiation may be performed between a CU of BS 1210 and CU 1240 (which may be an m-CU of a CU of another BS).

[0155] For example, in an architecture with an m-CU (e.g., CU 1240 is an m-CU), the CU of the BS 1210 may discover the CU 1240 via a procedure such as that described above with respect to Figures 7-9. Note that such a discovery procedure may be performed before operation 1213 or operation 1211. For example, the CU and CU 1240 of the BS 1210 may perform a negotiation procedure such as that described above with respect to Figure 6 (e.g., procedure 621 or 631 of Figure 6).

[0156] For example, in the case of a DU transition without the involvement of an m-CU (eg, CU 1240 is a CU of another BS), the CU of BS 1210 can find CU 1240 based on the measurement report.

[0157] In operation 1217, the CU of the BS 1210 may configure a BH configuration for the BH link between the DU of the BS 1210 and the network node 1220 to ensure DL / UL transmission of F1 setup related messages.

[0158] For example, in the DL case, the CU of BS1210 may initiate an F1AP procedure to configure the DU of BS1210 with a mapping from IP header fields to a BAP routing ID associated with network node 1220. The routing tables and BH RLC CH may be updated with routing entries for the new BAP routing ID associated with network node 1220 on all ancestor network nodes (e.g., IAB nodes), if any, and on the DU of BS1210.

[0159] For the UL, the UL F1 setup related message may reuse the UL BH configuration along with the mapping between non-UP traffic types and egress BH RLC CHs for the BAP routing ID. The DU of the BS 1210 may deliver the UL F1 setup related message to the CU 1240 (e.g., the m-CU or a CU of another BS) based on the target IP address.

[0160] In operation 1219, the network node 1220 (e.g., another DU (e.g., DU2) of the network node 1220) may set up an F1 connection with the CU 1240 (e.g., an m-CU or a CU of another BS). For example, the procedure as described above with respect to FIG. 10 may be applied here.

[0161] Unlike the procedure 1100 of FIG. 11, the network node 1220 has two logical DUs (eg, DU1 and DU2), and DU2 sets up an F1 connection to a CU 1240 (eg, an m-CU or a CU of another BS).

[0162] In some embodiments, the CU of BS1210 may hand over all served UEs of network node 1220 to DU2 connected to CU1240 (e.g., m-CU or a CU of another BS) and then delete the F1 connection between DU1 and the CU of BS1210.

[0163] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 1200 may be changed and that some of the operations in the exemplary procedure 1200 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0164] Figure 13 shows a flowchart of an example procedure 1300 for wireless communication according to some embodiments of the present disclosure. The details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in Figure 13. The example procedure 1300 may be performed by a BS (e.g., an IAB donor), or more specifically, a CU of the BS (e.g., an IAB donor CU).

[0165] 13, in operation 1311, a CU (denoted as a "first CU" for clarity) may establish an RRC connection with a network node. The network node may be an IAB node.

[0166] In operation 1313, the first CU may transmit to another CU (denoted as a “second CU” for clarity) information associated with the network node for facilitating an F1 connection setup between the network node and the second CU. In some embodiments of the present disclosure, the second CU may be a donor CU or a mobile CU.

[0167] In some embodiments of the present disclosure, the information associated with the network node may include at least one of: IP header information of a DL message associated with the F1 connection setup to the network node, a BAP address of the network node, a DU ID of the network node, or a global ID of the first CU. In some embodiments of the present disclosure, the IP header information of the DL message associated with the F1 connection setup to the network node may include at least one of: a DSCP of the DL message, an IPv6 flow label of the DL message, or an IP address or TNL address of the network node.

[0168] In some embodiments of the present disclosure, information associated with the network node may be transmitted to the second CU via an Xn interface between the first CU and the second CU. In some embodiments of the present disclosure, information associated with the network node may be transmitted to the second CU via a core network entity.

[0169] In some embodiments of the present disclosure, transmitting the information associated with the network node may include transmitting the information associated with the network node in response to an RRC connection establishment between the first CU and the network node, or in response to an indication from the network node indicating a decision to set up an F1 connection to a CU different from the first CU.

[0170] In some embodiments of the present disclosure, the first CU may send an indication to the network node indicating to the network node to set up an F1 connection to a CU different from the first CU. In some embodiments of the present disclosure, the first CU may receive an indication from the network node indicating that the network node has decided to set up an F1 connection to a CU different from the first CU.

[0171] In some embodiments of the present disclosure, the first CU may receive an indication from the second CU indicating that the second CU is a mobile CU specific to the mobile network node. In some embodiments of the present disclosure, the first CU may receive an identifier of the second CU from a core network entity, the second CU being a mobile CU specific to the mobile network node. In some embodiments of the present disclosure, the indication may be included in one of the following messages from the second CU to the first CU: an Xn Setup Response message, an Xn Setup Request message, an NG-RAN Node Configuration Update Acknowledgement message, and an NG-RAN Node Configuration Update message.

[0172] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 1300 may be changed and that some of the operations in the exemplary procedure 1300 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0173] Figure 14 shows a flowchart of an example procedure 1400 for wireless communication in accordance with some embodiments of the present disclosure. The details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in Figure 14. The example procedure 1400 may be performed by a network node (e.g., an IAB node).

[0174] 14, in operation 1411, a network node may establish an RRC connection with a CU (denoted as a "first CU" for clarity). In operation 1413, the network node may set up an F1 connection with another CU (denoted as a "second CU" for clarity) during the network node's initial access to the network or during the network node's transition from the first CU to the second CU.

[0175] In some embodiments of the present disclosure, a network node may receive an indication from a first CU indicating to the network node to set up an F1 connection to a CU different from the first CU. In some embodiments of the present disclosure, the network node may send an indication to the first CU indicating that the network node has decided to set up an F1 connection to a CU different from the first CU.

[0176] In some embodiments of the present disclosure, the network node may send an F1 setup request message to the second CU, and the F1 setup request message may include a global ID of the network node. In some embodiments of the present disclosure, the global ID of the network node may include at least one of a global ID of the first CU and a BAP address of the network node, a global ID of the first CU and a DU ID of the network node, or an IP address of the network node.

[0177] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 1400 may be changed and that some of the operations in the exemplary procedure 1400 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0178] 15 shows a flowchart of an example procedure 1500 for wireless communication according to some embodiments of the present disclosure. The details described in all of the above embodiments of the present disclosure are applicable to the embodiment shown in FIG. 15. The example procedure 1500 may be performed by an m-CU or a BS (or more specifically, a CU of a BS (e.g., an IAB donor CU)).

[0179] 15, at operation 1511, a CU (denoted as a "second CU" for clarity) may receive information associated with a network node from another CU (denoted as a "first CU" for clarity), the network node having an RRC connection with the first CU. In some embodiments of the present disclosure, the second CU may be a donor CU or a mobile CU. The network node may be an IAB node. The first CU may be an IAB donor CU.

[0180] In operation 1513, the second CU may set up an F1 connection with the network node based at least on the information associated with the network node.

[0181] In some embodiments of the present disclosure, the information associated with the network node may include at least one of: IP header information of a DL message associated with the F1 connection setup to the network node, a BAP address of the network node, a DU ID of the network node, or a global ID of the first CU. In some embodiments of the present disclosure, the IP header information of the DL message associated with the F1 connection setup to the network node may include at least one of: a DSCP of the DL message, an IPv6 flow label of the DL message, or an IP address or TNL address of the network node.

[0182] In some embodiments of the present disclosure, the information associated with the network node may be received from the first CU via an Xn interface between the first CU and the second CU. In some embodiments of the present disclosure, the information associated with the network node may be received from the first CU via a core network entity.

[0183] In some embodiments of the present disclosure, the second CU may send an indication to the first CU or a core network entity indicating that the second CU is a mobile CU specific to the mobile network node. In some embodiments of the present disclosure, the indication may be included in one of the following messages: an Xn Setup Response message from the second CU to the first CU, an Xn Setup Request message from the second CU to the first CU, an NG-RAN Node Configuration Update Acknowledgement message from the second CU to the first CU, an NG-RAN Node Configuration Update message from the second CU to the first CU, and an NG Setup Request message from the second CU to the core network entity.

[0184] In some embodiments of the present disclosure, the second CU may receive an F1 setup request message from the network node, and the F1 setup request message may include a global ID of the network node. In some embodiments of the present disclosure, the global ID of the network node may include at least one of the global ID of the first CU and a BAP address of the network node, the global ID of the first CU and a DU ID of the network node, or an IP address of the network node.

[0185] It will be appreciated by those skilled in the art that the sequence of operations in the exemplary procedure 1500 may be changed and that some of the operations in the exemplary procedure 1500 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0186] FIG. 16 illustrates a block diagram of an example apparatus 1600 according to some embodiments of the present disclosure.

[0187] As shown in FIG. 16 , the apparatus 1600 may include at least one processor 1606 and at least one transceiver 1602 coupled to the processor 1606. The apparatus 1600 may be a network node (e.g., an IAB node), a BS (e.g., an IAB donor, an IAB donor CU, or an IAB donor DU), a DU of the BS, a CU of the BS, or an m-CU. If the apparatus 1600 is a BS, the apparatus 1600 may further include a CU and a DU coupled to the CU. The CU and DU may be co-located or separately located. The CU and DU may be coupled to the processor 1606. If the apparatus 1600 is a network node, the apparatus 1600 may further include a MT and a DU coupled to the MT. The MT and DU may be coupled to the processor 1606.

[0188] In this figure, elements such as at least one transceiver 1602 and processor 1606 are described in the singular, but the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present application, the transceiver 1602 may be divided into two devices, such as a receiving circuit and a transmitting circuit. In some embodiments of the present application, the apparatus 1600 may further include an input device, a memory, and / or other components.

[0189] In some embodiments of the present application, the apparatus 1600 may be a BS. The processor 1606 may interact with other elements of the apparatus 1600 (e.g., the transceiver 1602, the DU, or the CU) to perform operations related to the BS, IAB donor, IAB donor CU, or IAB donor DU described in FIGS. 1-15 . In some embodiments of the present application, the apparatus 1600 may be a network node. The transceiver 1602 and the processor 1606 may interact with each other to perform operations related to the network node or IAB node (mobile or stationary) described in FIGS. 1-15 . In some embodiments of the present application, the apparatus 1600 may be a CU (e.g., an m-CU or a CU of a BS). The transceiver 1602 and the processor 1606 may interact with each other to perform operations related to the CU (e.g., an m-CU or a CU of a BS) described in FIGS. 1-15 .

[0190] In some embodiments of the present application, the apparatus 1600 may further include at least one non-transitory computer-readable medium.

[0191] In some embodiments of the present disclosure, a non-transitory computer-readable medium may store computer-executable instructions that cause the processor 1606 to implement a method related to a BS, an IAB donor, an IAB donor CU, or an IAB donor DU, as described above. For example, the computer-executable instructions, when executed, cause the processor 1606, interacting with, for example, the transceiver 1602, to perform operations related to a BS, an IAB donor, an IAB donor CU, or an IAB donor DU, as described in FIGS. 1-15.

[0192] For example, in some embodiments of the present disclosure, a non-transitory computer-readable medium may store computer-executable instructions that cause the processor 1606 to implement methods related to a network node or IAB node (mobile or stationary) as described above. For example, the computer-executable instructions, when executed, cause the processor 1606 interacting with the transceiver 1602 to perform operations related to a network node or IAB node (mobile or stationary) described in FIGS. 1-15.

[0193] For example, in some embodiments of the present disclosure, a non-transitory computer-readable medium may store computer-executable instructions that cause the processor 1606 to implement a method for a CU (e.g., an m-CU or a CU of a BS) as described above. For example, the computer-executable instructions, when executed, cause the processor 1606, interacting with the transceiver 1602, to perform operations for a CU (e.g., an m-CU or a CU of a BS) described in FIGS. 1-15.

[0194] Those skilled in the art will understand that the operations or steps of a method described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Additionally, in some aspects, the operations or steps of a method may reside as one or any combination or set of codes and / or instructions on a non-transitory computer-readable medium, which may be incorporated into a computer program product.

[0195] While the present disclosure has been described using specific embodiments thereof, it is apparent that many alternatives, modifications, and variations may be apparent to those skilled in the art. For example, various components of the embodiments may be exchanged, added, or substituted in other embodiments. Also, not all elements in the figures are necessary for the operation of the disclosed embodiments. For example, one skilled in the art of the disclosed embodiments would be able to make and use the teachings of the present disclosure by simply employing the elements of the independent claims. Accordingly, the embodiments of the present disclosure described herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0196] In this document, the terms "handover," "path switch," and "migration" may be used interchangeably. The terms "includes," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements, but may include other elements not specifically listed or inherent in such process, method, article, or apparatus. An element preceded by "a," "an," etc., does not, without further constraints, preclude the presence of additional identical elements in a process, method, article, or apparatus that includes that element. Also, the term "another" is defined as at least a second or more. Terms such as "having," as used herein, are defined as "including." Phrases such as "A and / or B" or "at least one of A and B" may include any and all combinations of the words listed with that phrase. For example, the phrase "A and / or B" or "at least one of A and B" may include A, B, or both A and B. Phrases such as "first," "second," etc. are used only to clarify embodiments of the present application, but are not used to limit the content of the present application. [Explanation of symbols]

[0197] 100 Wireless Communication System 110A, 110B IAB donor 120A, 120B, 120C IAB nodes 130A, 130B UE 140A, 140B, 140C, 140D Wireless Link 150A, 150B wireless link 200 User Plane (UP) Protocol Stack 300 Control Plane (CP) Protocol Stack 400 Wireless Communication System 420 Wireless Network Node 500 Wireless Communication System 510 IAB donors 520A, 520B Wireless Network Node 540 CU 600 steps 610 BS 620 network nodes 621 Procedure 631 Procedure 640 CU 650 CN entities 700 steps 710 BS 740 CU 800 Procedures 810 BS 840 CU 900 steps 910 BS 940 CU 950 CN entities 1000 steps 1020 network nodes 1040 CU 1100 steps 1110 BS 1120 Network Node 1140 CU 1200 steps 1210 BS 1220 Network Nodes 1240 CU 1300 steps 1400 steps 1500 steps 1600 equipment 1602 transceiver 1606 processor

Claims

1. a first centralized unit (CU), Establishing a Radio Resource Control (RRC) connection with a network node a processor configured to: coupled to the processor, transmitting, to a second CU, information associated with the network node for facilitating an F1 connection setup between the network node and the second CU; and a transceiver configured as A first CU comprising:

2. the information associated with the network node: Internet Protocol (IP) header information of a downlink (DL) message associated with the F1 connection setup to the network node; a Backhaul Adaptation Protocol (BAP) address of the network node; a Distributed Unit (DU) ID of said network node; or The global ID of the first CU The first CU of claim 1 , comprising at least one of:

3. the IP header information of the DL message associated with the F1 connection setup to the network node, The differentiated services code point (DSCP) of the DL message; the IPv6 flow label of said DL message, or The IP address or Transport Network Layer (TNL) address of the network node The first CU of claim 2 , comprising at least one of:

4. 2. The first CU of claim 1, wherein transmitting the information associated with the network node comprises transmitting the information associated with the network node in response to the RRC connection establishment between the first CU and the network node or in response to an indication from the network node indicating a decision to set up an F1 connection to a CU different from the first CU.

5. The transceiver sending an indication to the network node indicating to the network node to set up an F1 connection to a CU different from the first CU, or receiving an indication from the network node indicating that the network node has decided to set up an F1 connection to a CU different from the first CU; The first CU of claim 1 , further configured:

6. The transceiver receiving an indication from the second CU indicating that the second CU is a mobile CU specific to a mobile network node; or receiving, from a core network entity, an identifier of the second CU, the second CU being a mobile CU specific to a mobile network node; The first CU of claim 1 , further configured to:

7. a network node, A transceiver; coupled to the transceiver, Establishing a radio resource control (RRC) connection with a first centralized unit (CU); Setting up an F1 connection with the second CU during an initial access of the network node to a network or during a transition of the network node from the first CU to a second CU. and a processor configured as A network node comprising:

8. The transceiver receiving an indication from the first CU indicating to the network node to set up an F1 connection to a CU different from the first CU; or sending an indication to the first CU that the network node has decided to set up an F1 connection to a CU different from the first CU; 8. The network node of claim 7, configured to:

9. The network node of claim 7 , wherein the transceiver is configured to send an F1 setup request message to the second CU, the F1 setup request message including a global ID of the network node.

10. The global ID of the network node is: a global ID of the first CU and a backhaul adaptation protocol (BAP) address of the network node; a global ID of the first CU and a distributed unit (DU) ID of the network node; or The Internet Protocol (IP) address of said network node 10. The network node of claim 9, comprising at least one of:

11. a second centralized unit (CU), receiving, from the first CU, information associated with the network node; wherein the network node has a radio resource control (RRC) connection with the first CU; coupled to the transceiver, setting up an F1 connection with the network node based at least on the information associated with the network node. and a processor configured as A second CU comprising:

12. the information associated with the network node: Internet Protocol (IP) header information of a downlink (DL) message associated with the F1 connection setup to the network node; a Backhaul Adaptation Protocol (BAP) address of the network node; a Distributed Unit (DU) ID of said network node; or The global ID of the first CU The second CU of claim 11 , comprising at least one of:

13. the IP header information of the DL message associated with the F1 connection setup to the network node, The differentiated services code point (DSCP) of the DL message; the IPv6 flow label of said DL message, or The IP address or Transport Network Layer (TNL) address of the network node The second CU of claim 12, comprising at least one of:

14. The second CU of claim 11 , wherein the transceiver is further configured to send an indication to the first CU or a core network entity indicating that the second CU is a mobile CU specific to a mobile network node.

15. The second CU of claim 11, wherein the transceiver is configured to receive an F1 setup request message from the network node, the F1 setup request message including a global ID of the network node.

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