WO2024251303A1

WO2024251303A1 - Method and apparatus for xn connection setup in a wireless access backhaul network

Info

Publication number: WO2024251303A1
Application number: PCT/CN2024/106452
Authority: WO
Inventors: Yibin ZHUO; Mingzeng Dai; Lianhai WU
Original assignee: Lenovo Beijing Ltd
Current assignee: Lenovo Beijing Ltd
Priority date: 2024-07-19
Filing date: 2024-07-19
Publication date: 2024-12-12
Anticipated expiration: 2027-01-19

Abstract

Embodiments of the present disclosure relate to a method and apparatus for Xn connection setup in a wireless access backhaul network. According to some embodiments of the disclosure, a first wireless network node may: support a BS part and an MT part; determine a node type of a candidate RAN node, wherein the candidate RAN node is a BS part of a second wireless network node, a BH RAN node serving the first wireless network node, or a RAN node not serving the first wireless network node; and perform an Xn connection setup procedure with the candidate RAN node based on the node type of candidate RAN node.

Description

METHOD AND APPARATUS FOR XN CONNECTION SETUP IN A WIRELESS ACCESS BACKHAUL NETWORK

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to wireless communication technology, and more particularly to wireless communication in a wireless access backhaul (WAB) network.

BACKGROUND

A wireless communication system may include one or multiple network communication devices, such as base stations (BSs) , which may support wireless communication for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communication system may support wireless communication with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers, or the like) . Additionally, the wireless communication system may support wireless communication across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) (which is also known as new radio (NR) or next generation (NG) ) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

SUMMARY

An article "a" before an element is unrestricted and understood to refer to "at least one" of those elements or "one or more" of those elements. The terms "a, " "at least one, " "one or more, " and "at least one of one or more" may be interchangeable. As used herein, including in the claims, "or" as used in a list of items (e.g., a list of items prefaced by a phrase such as "at least one of" or "one or more of" or "one or both of" ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase "based on" shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as "based on condition A" may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" shall be construed in the same manner as the phrase "based at least in part on. " Further, as used herein, including in the claims, a "set" may include one or more elements.

Some embodiments of the present disclosure provide a first wireless network node. The first wireless network node may support a BS part and a mobile terminal (MT) part and include: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the first wireless network node to: determine a node type of a candidate radio access network (RAN) node, wherein the candidate RAN node is a BS part of a second wireless network node, a backhaul (BH) RAN node serving the first wireless network node, or a RAN node not serving the first wireless network node; and perform an Xn connection setup procedure with the candidate RAN node based on the node type of candidate RAN node

Some embodiments of the present disclosure provide a first RAN node. The first RAN node may include: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the first RAN node to: establish a transport network layer (TNL) association with a first wireless network node, wherein the first wireless network node supports a BS part and an MT part; and perform an Xn connection setup procedure with the first wireless network node, including: receiving, from the first wireless network node, a first Xn setup request message indicating a node type of the first wireless network node, or transmitting, to the first wireless network node, a second Xn setup request message indicating a node type of the first RAN node.

Some embodiments of the present disclosure provide a method for wireless communication, including: determining, by a first wireless network node, a node type of a candidate RAN node, wherein the first wireless network node supports a BS part and an MT part and the candidate RAN node is a BS part of a second wireless network node, a BH RAN node serving the first wireless network node, or a RAN node not serving the first wireless network node; and performing, by the first wireless network node, an Xn connection setup procedure with the candidate RAN node based on the node type of candidate RAN node.

Some embodiments of the present disclosure provide a method for wireless communication, including: establishing a TNL association between a first wireless network node and a first RAN node; and performing an Xn connection setup between the first wireless network node and the first RAN node, including: receiving, from the first wireless network node to the first RAN node, a first Xn setup request message indicating a node type of the first wireless network node, or transmitting, from the first RAN node to the first wireless network node, a second Xn setup request message indicating a node type of the first RAN node.

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 having stored thereon computer-executable instructions; at least one receiving circuitry; at least one transmitting circuitry; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuitry and the at least one transmitting circuitry, wherein the at least one non-transitory computer-readable medium and the computer executable instructions may be configured to, with the at least one processor, cause the apparatus to perform a method according to some embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the advantages and features of the disclosure can be obtained, a description of the disclosure is rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. These drawings depict only exemplary embodiments of the disclosure and are not therefore to be considered limiting of its scope.

FIG. 1 illustrates a schematic diagram of a wireless communication system in accordance with some embodiments of the present disclosure;

FIG. 2 illustrates an example of a WAB architecture in accordance with some embodiments of the present disclosure;

FIG. 3 illustrates an exemplary procedure for automatic neighbor relation (ANR) in accordance with some embodiments of the present disclosure;

FIG. 4 illustrates an exemplary Xn-C TNL address discovery procedure in accordance with some embodiments of the present disclosure;

FIGs. 5-7 illustrate exemplary Xn connection setup procedures in accordance with some embodiments of the present disclosure;

FIG. 8 illustrates an exemplary WAB node integration procedure in accordance with some embodiments of the present disclosure;

FIGs. 9 and 10 illustrate flowcharts of methods for wireless communication in accordance with some embodiments of the present disclosure;

FIG. 11 illustrates an example of network equipment (NE) in accordance with some embodiments of the present disclosure; and

FIG. 12 illustrates an example of a processor in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of the preferred embodiments of the present disclosure and is not intended to represent the only form in which the present disclosure may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present disclosure.

Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under a specific network architecture (s) and new service scenarios, such as the 3rd generation partnership project (3GPP) 5G NR or 6G, 3GPP LTE, and so on. It is contemplated that along with the developments of network architectures and new service scenarios, all embodiments in the present disclosure are also applicable to similar technical problems; and moreover, the terminologies recited in the present disclosure may change, which should not affect the principles of the present disclosure.

In a WAB network, a wireless network node such as a relay node (RN) or a WAB node, a wireless BH node, or a wireless backhaul device can provide wireless access services for UEs. For example, a UE can connect to a BS (i.e., a BH RAN node) relayed by one or more WAB nodes. The BH RAN node may also be called a donor node or a donor base station (e.g., DgNB, Donor gNodeB) or a WAB donor. In addition, the wireless link between a BH RAN node and a WAB node, or the wireless link between different WAB nodes can be referred to as a "backhaul link. " It should be noted that although, for convenience, some embodiments of the present disclosure use WAB node and BH RAN node to describe the WAB network, the scope of the embodiments is not limited in this respect. For example, the entities in a WAB network may have different terminologies but the embodiments may still apply.

A WAB node may include (or support) an MT part (i.e., WAB-MT) and a BS part (i.e., WAB-BS) . In some examples, the WAB-MT may be a mobile terminal. When a WAB node connects to its parent node (which may be another WAB node or a BH RAN node) , it can be regarded as a UE, i.e., the role of an MT. In some examples, the WAB-MT can be called WAB-UE. That is, the MT part may be referred to as a UE part or UE component. When a WAB node provides service to its child node (which may be another WAB node or a UE) , it can be regarded as a network device, i.e., the role of a BS (e.g., a gNB) . In some examples, the WAB-BS can be called WAB-gNB.

In some embodiments, a WAB node may be referred to as a “mobile WAB node (MWAB) , " which is a mobile base station acting as a relay between a UE and the network (e.g., a mobile WAB node with wireless access backhauling) . For example, the WAB node may provide a NR access link to UEs and connected wirelessly (using NR) through a donor NG-RAN to the 5G Core. In some examples, such mobile base station relay may be mounted on a vehicle and may serve UEs that can be located inside (onboard) or outside (surrounding) the vehicle, or UEs that enter or leave the vehicle.

A BH RAN node or the WAB-BS can be an access network element with a complete base station function, or an access network element with a separate form of a centralized unit (CU) and a DU. The BH RAN node or the WAB-BS may be connected to the core network (for example, connected to the 5G core (5GC) network) , and provide the wireless backhaul function for the WAB nodes. For example, the CU of a BH RAN node may be separated 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.

Considering the limited coverage of a high frequency band, and in order to ensure coverage performance of the network, multi-hop networking may be adopted in a WAB network. Taking into account the requirements of service transmission reliability, WAB nodes can support dual connectivity (DC) or multi-connectivity to improve transmission reliability, so as to deal with abnormal situations that may occur on the backhaul link, such as radio link failure (RLF) or blockage, load fluctuations, etc.

In the case where a WAB network supports multi-hop and dual-connection networking, there may be multiple transmission paths between the UE and the BH RAN node. A transmission path may include multiple nodes, such as a UE, one or more WAB nodes, and a BH RAN node (if the BH RAN node is in the form of a separate CU and DU, it may also contain a DU and a CU of the BH RAN node) . Each WAB node may treat the neighboring node that provides backhaul services for it as a parent node (or parent WAB node) , and each WAB node can be regarded as a child node (or child WAB node) of its parent node.

Technologies for facilitating communications in a WAB network are desired. For example, embodiments of the present disclosure provide various solutions to facilitate the establishment of Xn connection in a WAB network. For example, methods for avoiding establishing an Xn connection between two WAB nodes are provided. For example, methods for establishing an Xn connection between a WAB node (e.g., a WAB-BS) and BH RAN node are provided. For example, methods for establishing an Xn connection between a WAB node (e.g., a WAB-BS) and a surrounding RAN node are provided.

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

As shown in FIG. 1, wireless communication system 100 may include some base stations (e.g., BH RAN node 110A and BH RAN node 110B) , some WAB nodes (e.g., WAB node 120A, WAB node 120B, and WAB node 120C) , and some UEs (e.g., UE 130A and UE 130B) . Although a specific number of UEs, WAB nodes, and BH RAN nodes is depicted in FIG. 1, it is contemplated that any number of UEs, WAB nodes, and BH RAN nodes may be included in wireless communication system 100. Each of BH RAN node 110A, BH RAN node 110B, WAB node 120A, WAB node 120B, and WAB node 120C may be directly connected to one or more WAB nodes in accordance with some other embodiments of the present disclosure. Each of BH RAN node 110A, BH RAN node 110B, WAB node 120A, WAB node 120B, and WAB node 120C may be directly connected to one or more UEs in accordance with some other embodiments of the present disclosure.

Wireless communication system 100 may be compatible with any type of network that is capable of transmitting and receiving wireless communication signals. Wireless communication system 100 may support various radio access technologies. In some implementations, wireless communication system 100 may be a 4G network, such as an LTE network or an LTE-Advanced (LTE-A) network. In some other implementations, wireless communication system 100 may be a NR network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultra-wideband (5G-UWB) network. In other implementations, wireless communication system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , and IEEE 802.20. Wireless communication system 100 may support radio access technologies beyond 5G, for example, 6G. Additionally, wireless communication system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

In the context of the present disclosure, a WAB node (e.g., WAB node 120A, WAB node 120B, or WAB node 120C in FIG. 1) or a BH RAN node (e.g., BH RAN node 110A and BH RAN node 110B in FIG. 1) may also be referred to an NE. An NE may be dispersed throughout a geographic region to form wireless communication system 100. An NE may provide a geographic coverage area for which the NE may support services for one or more UEs within the geographic coverage area. For example, an NE and a UE may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, an NE may be moveable, for example, a satellite associated with a non-terrestrial network (NTN) or a relay mounted on a moving vehicle. In some implementations, different geographic coverage areas associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with a different NE.

UE 130A and UE 130B may be dispersed throughout a geographic region of wireless communication system 100. UE 130A and UE 130B may be any type of device configured to operate and/or communicate in a wireless environment. For example, UE 130A or UE 130B may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, UE 130A or UE 130B may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, UE 130A or UE 130B may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples.

UE 130A and UE 130B may be able to support wireless communication directly with each other or other UEs over a communication link. For example, UE 130A may support wireless communication directly with UE 130B over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link between two UEs may be referred to as a sidelink. For example, UE 130A may support wireless communication directly with UE 130B over a PC5 interface. Similarly, an MT part of a WAB node and an MT part of another WAB node may communication directly with each other over a sidelink.

A BH RAN node may support communication with a core network (CN) , or with another RAN node, or both. For example, BH RAN node 110A may interface with BH RAN node 110B or the CN (not shown in FIG. 1) through one or more backhaul links (e.g., S1, X2, NG, Xn, or other network interface) . In some implementations, BH RAN nodes may communicate with each other directly. In some other implementations, BH RAN nodes may communicate with each other indirectly (e.g., via the CN) .

The CN may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for UEs served by a WAB node or a BH RAN node associated with the CN.

The CN may communicate with a packet data network over one or more backhaul links (e.g., via an N6 or another network interface) . The packet data network may include an application server. In some implementations, one or more UEs may communicate with the application server. A UE may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the CN via, for example, a BH RAN node. The CN may route traffic (e.g., control information, data, and the like) between the UE and the application server using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE and the CN (e.g., one or more network functions of the CN) .

In wireless communication system 100, NEs (e.g., WAB nodes and RAN nodes such as BH RAN nodes) and UEs may use resources of wireless communication system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communication) .

In wireless communication system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, wireless communication system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, NEs and UEs may perform wireless communication over one or more of the operating frequency bands. In some implementations, FR1 may be used by NEs and UEs, among other equipment or devices for cellular communication traffic (e.g., control information, data) . In some implementations, FR2 may be used by NEs and UEs, among other equipment or devices for short-range, high data rate capabilities.

A UE 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) , vehicle on-board computers, network devices (e.g., routers, switches, and modems) , vehicles or the like. According to some embodiments of the present disclosure, a UE may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiver, or any other device that is capable of sending and receiving communication signals on a wireless network. In some embodiments of the present disclosure, a UE includes wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, a UE may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art. A UE may communicate with an NE (e.g., a BH RAN node or a WAB node) via uplink (UL) communication signals. An NE may communicate with a UE via downlink (DL) communication signals.

In some embodiments of the present disclosure, an NE (e.g., a wireless network node, a BS, a RAN node, a BH RAN node or a WAB node) and a UE may communicate over licensed spectrums, whereas in some other embodiments, an NE and a UE may communicate over unlicensed spectrums. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

Persons skilled in the art should understand that as technology develops and advances, the terminologies described in the present disclosure may change, but should not affect or limit the principles and spirit of the present disclosure.

Referring to FIG. 1, WAB node 120A can be directly connected to BH RAN nodes 110A and 110B, and WAB node 120B can be directly connected to BH RAN node 110A. BH RAN nodes 110A and 110B are parent nodes of WAB node 120A, and BH RAN node 110A is a parent node of WAB node 120B. In other words, WAB nodes 120A and 120B are child WAB nodes of BH RAN node 110A, and WAB node 120A is also a child WAB node of BH RAN node 110B. WAB node 120C can reach BH RAN node 110A by hopping through WAB node 120B. WAB node 120B is a parent WAB node of WAB node 120C. In other words, WAB node 120C is a child WAB node of WAB node 120B.

In some other embodiments of the present disclosure, a WAB node may be connected to WAB node 120C so it can reach BH RAN node 110A by hopping through WAB node 120C and WAB node 120B. This WAB node and WAB node 120C may be referred to as the descendant WAB nodes of WAB node 120B.

UEs 130A and 130B can be connected to WAB nodes 120A and 120C, respectively. WAB nodes 120A and 120C may therefore be referred to as access WAB nodes. UL packets (e.g., data or signaling) from UE 130A or UE 130B can be transmitted to a BH RAN node (e.g., BH RAN node 110A or 110B) via one or more WAB nodes, and then transmitted by the BH RAN node to a mobile gateway device (such as the UPF in the 5GC) . DL packets (e.g., data or signaling) can be transmitted from the BH RAN node (e.g., BH RAN node 110A or 110B) after being received by the gateway device, and then transmitted to UE 130A or 130B through one or more WAB nodes.

For example, referring to FIG. 1, UE 130A may transmit UL data to BH RAN node 110A or 110B or receive DL data therefrom via WAB node 120A. UE 130B may transmit UL data to BH RAN node 110A or receive DL data therefrom via WAB node 120C and WAB node 120B.

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

It should be noted that the WAB network shown in FIG. 1 is for illustrative purposes only. There are various WAB networks that support single-hop, single-connection, multi-hop, multi-connection, or any combination thereof. It should be noted that, although embodiments of the present disclosure may be discussed under a specific network architecture (e.g., WAB architecture) and based on certain specific components (e.g., a BH RAN node or a WAB node) , embodiments of the present disclosure are also applicable to other similar network architectures and new service scenarios.

FIG. 2 illustrates an example of a WAB architecture in accordance with some embodiments of the present disclosure. In FIG. 2, the traffic of the BS part of a WAB node is transported via PDU session backhaul.

Referring to FIG. 2, a WAB-node includes a BS part (i.e., WAB-BS in FIG. 2) and an MT part (e.g., WAB-MT in FIG. 2) . The WAB-node serves a UE and is served by a BH RAN-node. The WAB-MT connects to a BH-CN (e.g., 5GC or next-generation core (NGC) ) via the BH RAN-node. A BH PDU session (s) is established between the WAB-MT and the BH-CN (e.g., a UPF) . The WAB-BS sets up an NG interface to another CN (e.g., UE-CN in FIG. 2, which can be 5GC or NGC) over the BH PDU session of the WAB-MT. The UE establishes a PDU session with the UE-CN (e.g., a UPF) . The traffic of the WAB-BS is transported via PDU session backhaul. For example, the NG traffic of the WAB-BS is transported over the BH PDU session (s) . The WAB node (e.g., the WAB-BS) may establish an Xn connection with a neighbor RAN node, which can be any type of RAN node including, for example, the BH RAN-node, another BH RAN-node or an NG-RAN node. The Xn traffic of the WAB-BS is transported over the BH PDU session (s) . The network operations and maintenance (OAM) traffic of the WAB-BS can also be transferred over the BH PDU session (s) .

Although FIG. 2 shows that the UE and the WAB-MT are connected to different CNs (e.g., different UPFs or different AMFs) , it should be appreciated by persons skilled in the art that WAB network 200 can support the same CN entity (e.g., UPF or AMF) for both the UE and the WAB-MT.

As described above, a WAB node (e.g., the BS part of the WAB node) may establish an Xn connection towards a RAN node such as a BH RAN node or a neighbor or surrounding RAN node. In some embodiments, Xn connections between two WAB nodes (e.g., the BS parts of the two WAB nodes) may not be supported. Embodiments of the present disclosure provide methods for avoiding Xn connection setup between two WAB nodes. More details on the embodiments of the present disclosure will be illustrated in the following text in combination with the appended drawings.

In some embodiments of the present disclosure, a node type for a RAN node is introduced to avoid an Xn connection setup between two WAB nodes.

For example, in some embodiments, an Xn setup triggering WAB node (e.g., the BS part of the WAB node) may obtain the type of a potential peer node (e.g., a candidate RAN node) and avoid setting up an Xn connection with another WAB node (e.g., the BS part of the another WAB node) .

In some examples, a WAB node (denoted as WAB node #A) may obtain the node type of a candidate RAN node from a measurement report of a UE served by WAB node #A.

For example, in FIG. 3, WAB node 320A may include (or support) a BS part and an MT part. WAB node 320A (or its BS part or the cells of its BS part) may support an ANR function. The definition regarding the ANR function can be found in 3GPP specifications (e.g., TR 38.300) . WAB node 320A may serve one or more UEs (e.g., UE 330) . In RRC_CONNECTED, WAB node 320A may instruct a UE (e.g., UE 330) to perform measurements on neighbor cells. WAB node 320A may use different policies for instructing a UE (s) to perform measurements and for determining when to report these measurements to WAB node 320A according to RRC measurement and reporting procedures.

For example, referring to FIG. 3, at 311, UE 330 may transmit a measurement report regarding a cell (denoted as cell B) of RAN node 320B. The measurement report may include a physical cell identifier (PCI) of cell B. In response to receiving the measurement report, WAB node 320A may, at 313, instruct UE 330, using the newly discovered PCI of cell B as parameter, to obtain more information of cell B or RAN node 320B such as global cell identity (Global-CID) of cell B. For example, WAB node 320A may instruct UE 330 to read all the broadcast NR cell global identifiers (NCGIs) or E-UTRAN cell global identifiers (ECGIs) , tracking area codes (TACs) , routing area network access identifier codes (RANACs) , public land mobile network (PLMN) IDs and, for neighbor NR cells, the NR frequency band (s) and the gNB ID length (s) . For example, WAB node 320A may schedule appropriate idle periods to allow UE 330 to read the NCGI/ECGI from the broadcast channel of the detected neighbor cell. UE 330 may receive a broadcast control channel (BCCH) from cell B or RAN node 320B. For example, at 315, UE 330 may receive system information (e.g., system information block 1 (SIB1) ) from RAN node 320B and may identify the Global-CID of cell B. For example, UE 330 may obtain NCGIs or ECGIs of cell B.

At 317, UE 330 may report the obtained information to WAB node 320A. For example, UE 330 may report the Global-CID of cell B such as NCGIs or ECGIs of cell B to WAB node 320A. UE 330 may also report all the TACs, RANACs and PLMN IDs and, for neighbor NR cells, the NR frequency band (s) , and the gNB ID length (s) that have been read by UE 330. In some examples, the above information may be transmitted in a measurement report. In some embodiments, the measurement report may indicate a node type of RAN node 320B, which may be obtained from the system information (e.g., SIB1) of cell B or RAN node 320B. In some embodiments, RAN node 320B may be a WAB node or a BS part of the WAB node. The node type of RAN node 320B can be indicated in the WAB specific indication in the SIB1 of the cell (s) of the BS part of the WAB node.

In some examples, WAB node #A may obtain the node type of a candidate RAN node from a measurement report of the MT part of WAB node #A.

For example, WAB node #A may include (or support) a BS part and an MT part. WAB node #A (or its BS part or the cells of its BS part) may support an ANR function. In RRC_CONNECTED, the MT part of WAB node #A may perform measurements on neighbor cells (e.g., cell C) based on the request and configuration from a parent node (e.g., a BH RAN node) . For example, the MT part of WAB node #A may perform a procedure similar to the one performed by UE 330 in FIG. 3. The MT part of WAB node #A may obtain a node type of a RAN node serving cell C during such procedure. The MT part of WAB node #A may transmit a measure report indicating the node type of the RAN node serving cell C to the BS part of WAB node #A.

In some examples, WAB node #A may obtain the node type of a candidate RAN node from neighbor information of the BH RAN node serving WAB node #A. In some embodiments, the neighbor information of a RAN node may include cell configuration information of a neighbor cell (s) of the RAN node, for example, PCI, cell global identifier (CGI) and so on. Details of the neighbor information can be referred to in 3GPP specifications (e.g., TS 38.423) .

For example, because WAB node #Ais a child node of the BH RAN node, the neighbor information of the BH RAN node can be, to some extent, regarded as the neighbor information of WAB node #A (or its BS part) . WAB node #A (or its BS part or the cells of its BS part) may support an ANR function. The BH RAN node may send its neighbor information to WAB node #A (or the BS part of WAB node #A) . In some embodiments, the neighbor information may indicate the node type of the RAN node for each cell in the neighbor information.

In some embodiments, the neighbor information may only include cells not served by the BS part of a WAB node (or by a WAB node) . In other words, WAB node #A may determine that a candidate RAN node is not the BS part of a WAB node if a cell served by the candidate RAN node is indicated in the neighbor information from the BH RAN node. This can be regarded as a method for implicitly indicating the node type and can also avoid the Xn connection setup between two WAB nodes.

In some embodiments, the node type of a RAN node may include: a WAB-BS or a non-WAB-BS. In some embodiments, the node type of a RAN node may include: a WAB or a non-WAB. In some embodiments, the node type of non-WAB-BS or non-WAB may include one or more of: a BH RAN node, an NG-RAN node and an enhanced gNodeB (en-gNB) . In some embodiments, the node type of a RAN node may only be applied to a WAB node or the BS part of a WAB node. For example, only when the node type of a certain RAN node is a WAB-BS (or a WAB) , the measurement report or the neighbor information as described above may include an (explicit) indication for the node type. That is, the absence of the node type indication implicitly indicates that the node type is a non-WAB-BS (or a non-WAB) . WAB node #A may assume that a RAN node is not a WAB node or the BS part of a WAB node if WAB node #Adoes not receive the node type of the RAN node.

For example, referring again to FIG. 3, if RAN node 320B is a WAB node or the BS part of a WAB node, the measurement report at 317 in FIG. 3 may indicate the node type of RAN node 320B being WAB or WAB-BS. Otherwise, if RAN node 320B is not a WAB node or the BS part of a WAB node, the measurement report at 317 in FIG. 3 may not indicate the node type of RAN node 320B. WAB node 320A may assume that RAN node 320B is not a WAB node or the BS part of a WAB node if WAB node 320A does not receive the node type of RAN node 320B. Or the measurement report at 317 in FIG. 3 may explicitly indicate that RAN node 320B is not a WAB node or the BS part of a WAB node.

In some embodiments, based on the measurement report of the UE, the measurement report of the MT part of WAB node #A, or the neighbor information of the BH RAN node of WAB node #A, WAB node #Acan update the neighbor cell relation list in the ANR function and setup a new Xn interface to a candidate RAN node (except a WAB node or the BS part of a WAB node) .

In some embodiments, before setting up an Xn connection with the candidate RAN node (denoted as RAN node #B) , WAB node #A may need to obtain the TNL or internet protocol (IP) address of RAN node #B via an Xn-C (Xn control plane) TNL address discovery procedure. FIG. 4 illustrates exemplary Xn-C TNL address discovery procedure 400 in accordance with some embodiments of the present disclosure.

Referring to FIG. 4, if RAN node 420A is aware of the RAN node ID of RAN node 420B (i.e., the candidate RAN node) via, for example, the ANR function, but not aware of a TNL address or IP address suitable for stream control transport protocol (SCTP) connectivity, then RAN node 420A can utilize the CN (e.g., an AMF RAN node 420A is connected to) to obtain the TNL address or IP address of RAN node 420B.

For example, at 411, RAN node 420A may transmit an UPLINK RAN CONFIGURATION TRANSFER message to CN node 440 (e.g., an AMF) to request the TNL address or IP address of RAN node 420B and include relevant information such as the source and target RAN node IDs. The source RAN node ID may be the RAN node ID of RAN node 420A and the target RAN node ID may be the RAN node ID of RAN node 420B.

At 413, CN node 440 may transmit (e.g., relay) the request by transmitting a DOWNLINK RAN CONFIGURATION TRANSFER message to RAN node 420B identified by the target RAN node ID. At 415, RAN node 420B may respond by transmitting an UPLINK RAN CONFIGURATION TRANSFER message containing one or more TNL addresses or IP addresses to be used for SCTP connectivity with the initiating RAN node (e.g., RAN node 420A) and include other relevant information such as the source and target RAN node IDs. The source RAN node ID may be the RAN node ID of RAN node 420B and the target RAN node ID may be the RAN node ID of RAN node 420A. At 417, CN node 440 may transmit (e.g., relay) the response by transmitting a DOWNLINK RAN CONFIGURATION TRANSFER message to RAN node 420A (i.e., the initiating RAN node) identified by the target RAN node ID.

In some embodiments, the node type of a RAN node may be indicated by an Xn setup related message.

For example, in some embodiments, a RAN node (denoted as RAN node #C) can discover a candidate RAN node (denoted as RAN node #D) for establishing an Xn connection according to various methods. RAN node #C or RAN node #D may or may not be a WAB node or the BS part of a WAB node. Actually, RAN node #C or RAN node #D can be any type of RAN node, including, but not limited to, a WAB node, the BS part of a WAB node, a BH RAN node, a RAN node that does not serve any WAB nodes, an NG-RAN node or an en-gNB. In some examples, RAN node #C can obtain neighbor cell information in a measurement report of the UE (s) served by RAN node #C. For example, the procedure described with respect to FIG. 3 may apply here. In the case that RAN node #C is a WAB node or the BS part of a WAB node, RAN node #C can obtain neighbor cell information in a measurement report of the MT part of RAN node #C or from its BH RAN node in the neighbor information of the BH RAN node. RAN node #C can also obtain the TNL address or IP of address RAN node #D via an Xn-C TNL address discovery procedure. For example, the procedure described with respect to FIG. 4 may apply here. In some embodiments, node type information may not be (implicitly or explicitly) indicated in these measurement reports or neighbor information. RAN node #C (i.e., the Xn setup triggering node) may indicate the node type of RAN node #C in an Xn setup request message to RAN node #D, which can determine whether to accept the Xn connection setup with RAN node #C.

FIG. 5 illustrates exemplary Xn connection setup procedure 500 in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 5. It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary procedure 500 may be changed and that some of the operations in exemplary procedure 500 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

Referring to FIG. 5, at 511, RAN node 520A and RAN node 520B may establish a TNL association (TNLA) . After the TNLA is established, RAN node 520A and RAN node 520B may perform an Xn connection setup procedure. For example, RAN node 520A may initiate the Xn connection setup towards RAN node 520B. At 513, RAN node 520A may transmit an Xn setup request message to RAN node 520B. In some embodiments, the Xn setup request message may indicate the node type of RAN node 520A. RAN node 520B may determine whether to accept the Xn setup request based on the node type information in the Xn setup request message.

In some examples, RAN node 520A is a WAB node or the BS part of a WAB node. Accordingly, the node type information in the Xn setup request message may indicate that RAN node 520A is a WAB node or the BS part of a WAB node. RAN node 520B may accept the Xn setup request if RAN node 520B is not a WAB node or the BS part of a WAB node. For example, at 515, RAN node 520B may transmit an Xn setup response message to RAN node 520A. RAN node 520B may refuse the Xn setup request if RAN node 520B is a WAB node or the BS part of a WAB node. For example, at 515, RAN node 520B may transmit an Xn setup failure message to RAN node 520A. In some embodiments, the Xn setup failure message may indicate that the failure is due to the peer node (e.g., RAN node 520B) is the BS part of a WAB node (or a WAB node) .

In some examples, RAN node 520A is not a WAB node or the BS part of a WAB node. Accordingly, the node type information in the Xn setup request message may indicate that RAN node 520A is not a WAB node or the BS part of a WAB node. Alternatively, the Xn setup request message may not include the node type information, which implicitly indicates that RAN node 520A is not a WAB node or the BS part of a WAB node. RAN node 520B may accept the Xn setup request by transmitting an Xn setup response message to RAN node 520A at 515.

As described above, a WAB node (e.g., the BS part of the WAB node) may establish an Xn connection towards a neighbor (or surrounding) RAN node. Embodiments of the present disclosure provide methods for establishing such an Xn connection. More details on the embodiments of the present disclosure will be illustrated in the following text in combination with the appended drawings.

In some embodiments, the Xn connection setup between a WAB node (e.g., the BS part of the WAB node) and a neighbor RAN node may be initiated by the neighbor RAN node.

In some embodiments, the neighbor RAN node may discover a WAB node (e.g., the BS part of the WAB node) based on the measurement report from a connected UE of the neighbor RAN node. The neighbor RAN node may obtain the TNL address or IP address of the WAB node (e.g., the BS part of the WAB node) via an Xn-C TNL address discovery procedure. For example, the procedure described with respect to FIG. 4 may apply here. After a TNLA is established with the WAB node, the neighbor RAN node may initiate an Xn connection setup procedure with the WAB node.

In some embodiments, the neighbor RAN node may discover a WAB node (e.g., the BS part of the WAB node) with the help of the BH RAN node of the WAB node (e.g., the BS part of the WAB node) .

FIG. 6 illustrates exemplary Xn connection setup procedure 600 in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 6. It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary procedure 600 may be changed and that some of the operations in exemplary procedure 600 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

Referring to FIG. 6, WAB node 620A (or its BS part) is served by BH RAN node 610. At 611, WAB node 620A (or its BS part) may transmit assistance information to BH RAN node 610 to facilitate the Xn connection setup. For example, BH RAN node 610 may obtain one or more of the following information from WAB node 620A (or its BS part) : served cell information of the BS part of WAB node 620A, at least one TNL address of the BS part of WAB node 620A, and at least one IP address of the BS part of WAB node 620A (or at least one TNL address of WAB node 620A and at least one IP address of WAB node 620A) . In some embodiments, the served cell information of a RAN node may include cell configuration information of the cell (s) of the RAN node, for example, PCI, CGI and so on. Details of the served cell information can be referred to in 3GPP specifications (e.g., TS 38.423) . For example, the served cell information of the BS part of WAB node 620A may indicate the PCI and CGI of each cell of the BS part of WAB node 620A.

In some examples, the MT part of WAB node 620A has a radio resource control (RRC) connection to BH RAN node 610, and the above assistance information for the Xn connection setup may be transmitted to BH RAN node 610 via RRC signaling. In some examples, the BS part of WAB node 620A may already establish an Xn connection to BH RAN node 610 and the above assistance information may be transmitted to BH RAN node 610 via an Xn application protocol (XnAP) message. For example, in an Xn setup and NG-RAN node configuration update procedure between the BS part of WAB node 620A and BH RAN node 610, BH RAN node 610 can obtain served cell information of the BS part of WAB node 620A. In some embodiments, at least one TNL address, at least one IP address or both of the BS part of WAB node 620A may also be transmitted along with the served cell information.

There may be an Xn connection between BH RAN node 610 and neighbor RAN node 620B. At 613, neighbor RAN node 620B may receive the assistance information for the Xn connection setup (e.g., the served cell information and TNL or IP address (es) of the BS part of WAB node 620A) from BH RAN node 610 via an XnAP message. The XnAP message can be at least one of an Xn setup request message, an Xn setup response message, an NG node configuration update message or an NG node configuration update acknowledge message from BH RAN node 610 to neighbor RAN node 620B.

In some embodiments, the assistance information for the Xn connection setup may be transmitted with the served cell information and neighbor information of BH RAN node 610. For example, at 613, BH RAN node 610 may transmit an XnAP message including both the served cell information and neighbor information of BH RAN node 610 and the assistance information for the Xn connection setup. In some embodiments, the assistance information for the Xn connection setup may be included in the XnAP message independently from the neighbor information of BH RAN node 610 (e.g., using separate information elements (IEs) ) . In some embodiments, the assistance information for the Xn connection setup may be included in the neighbor information of BH RAN node 610 in the XnAP message. The neighbor information may further include an indicator to distinguish between cells of WAB node 620A (e.g., cells of the BS part of WAB node 620A) and cells of a RAN node which is not a WAB node or the BS part of a WAB node. For example, neighbor information of BH RAN node 610 may indicate cell configuration information of a neighbor cell (e.g., cell M) of BH RAN node 610 and cell M belongs to RAN node #M. If RAN node #M is a WAB node or the BS part of a WAB node, the neighbor information may indicate that cell M belongs to the BS part of a WAB node.

At 615, neighbor RAN node 620B may initiate an Xn connection setup procedure with a WAB node (e.g., WAB node 620A or its BS part) . In some embodiments, neighbor RAN node 620B may update a neighbor cell relation table (NCRT) based on the received assistance information. In some embodiments, in the case that the TNL address or IP address of the BS part of WAB node 620A is indicated to neighbor RAN node 620B, neighbor RAN node 620B can trigger a TNLA establishment and an Xn connection setup to the BS part of WAB node 620A. Otherwise, if neighbor RAN node 620B is not aware of the TNL address or IP address of the BS part of WAB node 620A, neighbor RAN node 620B may first obtain the TNL address or IP address from the CN (e.g., an AMF) via an Xn-C TNL address discovery procedure.

In some embodiments, the Xn connection setup between a WAB node (e.g., the BS part of the WAB node) and a neighbor RAN node may be initiated by the WAB node (e.g., the BS part of the WAB node) .

FIG. 7 illustrates exemplary Xn connection setup procedure 700 in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 7. It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary procedure 700 may be changed and that some of the operations in exemplary procedure 700 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

Referring to FIG. 7, WAB node 720A (or its BS part) is served by BH RAN node 710. WAB node 720A (e.g., the BS part of WAB node 720A) can initiate an ANR procedure based on the measurement report from a UE served by WAB node 720A (e.g., by the BS part of WAB node 720A) , or based on the measurement report of the MT part of WAB node 720A. At 711, WAB node 720A (e.g., the BS part of WAB node 720A) can receive neighbor information from BH RAN node 710. WAB node 720A (e.g., the BS part of WAB node 720A) can initiate an ANR procedure based on the neighbor information. The neighbor information of BH RAN node 710 may include information related to the neighbor RAN node (s) of BH RAN node 710 such as PCIs and CGIs of cells of the neighbor RAN node (s) . In some embodiments, at least one TNL address, at least one IP address or both of the neighbor RAN node (s) of BH RAN node 710 may be transmitted with the neighbor information. For example, at least one TNL address or at least one IP address of neighbor RAN node 720B may be transmitted to WAB node 720A (or its BS part) .

At 713, WAB node 720A (e.g., the BS part of WAB node 720A) may initiate an Xn connection setup procedure with a neighbor RAN node (e.g., neighbor RAN node 720B) based on the information received at 711.

In some embodiments, in the case that the TNL address or IP address of neighbor RAN node 720B is indicated to WAB node 720A (or its BS part) , WAB node 720A (or its BS part) can trigger a TNLA establishment and an Xn connection setup to neighbor RAN node 720B. Otherwise, if WAB node 720A (or its BS part) is not aware of the TNL address or IP address of neighbor RAN node 720B, it may first obtain the TNL address or IP address from the CN (e.g., an AMF) via an Xn-C TNL address discovery procedure.

FIG. 8 illustrates exemplary WAB node integration procedure 800 in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 8. It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary procedure 800 may be changed and that some of the operations in exemplary procedure 800 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

Referring to FIG. 8, WAB node 820 may include a BS part (i.e., WAB-BS in FIG. 8) and an MT part (i.e., WAB-MT in FIG. 8) . A WAB-MT setup may be performed at 811. For example, the WAB-MT of WAB node 820 may connect to the network in the same way as a UE by performing an RRC connection setup procedure with BH RAN node 810. The WAB-MT may then perform authorization and authentication with BH CN 840A. After the WAB-MT is authorized, the WAB-MT may establish one or more PDU sessions with BH CN 840A for backhauling.

A WAB-BS setup may be performed at 813-817. At 813, a WAB-BS initialization may be performed. For example, the WAB-BS of WAB node 820 may be configured by an OAM (not shown in FIG. 8) with, for example, the information of AMF(s) to serve UEs, and may be service-authorized by the security gateway or by the OAM. At 815, an NG connection setup may be performed. For example, the WAB-BS of WAB node 820 may establish NG connection (s) toward UE CN 840B (e.g., the AMF (s) ) . After the NG connection (s) is set up, the WAB-BS of WAB node 820 can start serving UEs. At 817, an Xn connection setup may be performed. For example, if needed, the WAB-BS of WAB node 820 may establish an Xn connection (s) towards BH RAN node 810 and/or other RAN node (s) (not shown in FIG. 8) .

As described above, a WAB node (e.g., the BS part of the WAB node) may establish an Xn connection with its BH RAN node. Embodiments of the present disclosure provide methods for facilitating such an Xn connection.

In some embodiments, the Xn connection setup between a WAB node (e.g., the BS part of the WAB node) and its BH RAN node may be initiated by the WAB node (e.g., the BS part of the WAB node) . For example, referring to FIG. 8, at 811, the WAB-MT of WAB node 820 can be aware of the RAN node ID of BH RAN node 810 via reading the broadcast information. In some embodiments, BH RAN node 810 can transmit at least one of its TNL addresses, at least one of its IP addresses or both to WAB node 820 (e.g., to the WAB-MT) . The TNL or IP address information can be transmitted via an RRC message, for example, in an RRC reconfiguration message. In response to receiving the TNL or IP address information of BH RAN node 810, the WAB node (e.g., the BS part of the WAB node) can trigger a TNLA establishment and an Xn connection setup to BH RAN node 810.

In some embodiments, the Xn connection setup between a WAB node (e.g., the BS part of the WAB node) and its BH RAN node may be initiated by the BH RAN node. Compared to the embodiments where such an Xn connection setup is initiated by the WAB node, this method may have larger impacts on the BH RAN node so it can become aware of the completion of the setup of the BS part of the WAB node.

FIG. 9 illustrates a flow chart of exemplary method 900 for wireless communications in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 9. In some examples, method 900 may be performed by a NE such as a network node, a wireless network node or a WAB node. In some embodiments, the NE may execute a set of instructions to control the functional elements of the network node to perform the described functions or operations. For the sake of simplicity, the operations in method 900 are described as follows with respect to a wireless network node.

At 911, a first wireless network node may determine a node type of a candidate RAN node, wherein the candidate RAN node is a BS part of a second wireless network node, a BH RAN node serving the first wireless network node, or a RAN node not serving the first wireless network node. The first wireless network node may support or include a BS part and an MT part. At 913, the first wireless network node may perform an Xn connection setup procedure with the candidate RAN node based on the node type of candidate RAN node.

In some embodiments, the first wireless network node may determine whether to set up an Xn connection with the candidate RAN node based on the node type of candidate RAN node. In some embodiments, the first wireless network node may perform the Xn connection setup procedure in response to determining the node type of the candidate RAN node indicating that the candidate RAN node is not the BS part of the second wireless network node. In some embodiments, the first wireless network node may prohibit setting up the Xn connection with the candidate RAN node in response to determining the node type of the candidate RAN node indicating that the candidate RAN node is the BS part of the second wireless network node.

In some embodiments, the first wireless network node may receive the node type of the candidate RAN node from a first measurement report of a UE served by the first wireless network node, a second measurement report of the MT part of the first wireless network node, or a neighbor information of the BH RAN node. In some embodiments, the first wireless network node may determine that the candidate RAN node is not the BS part of the second wireless network node in response to not receiving the node type of the candidate RAN node.

In some embodiments, the first wireless network node may transmit, to the BH RAN node, served cell information of the BS part of the first wireless network node and one of at least one TNL address of the first wireless network node and at least one IP address of the first wireless network node.

In some embodiments, the served cell information and one of the at least one TNL address and the at least one IP address of the first wireless network node is transmitted via RRC signaling or an XnAP message.

In some embodiments, the first wireless network node may receive, from the BH RAN node, at least one TNL address of a neighbor RAN node of the BH RAN node or at least one IP address of the neighbor RAN node of the BH RAN node.

In some embodiments, the first wireless network node may receive, from the BH RAN node, at least one TNL address of the BH RAN node or at least one IP address of the BH RAN node.

In some embodiments, the at least one TNL address or the at least one IP address of the BH RAN node is received by the MT part of the first wireless network node from the BH RAN node via RRC signaling.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary method 900 may be changed and that some of the operations in exemplary method 900 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 10 illustrates a flow chart of exemplary method 1000 for wireless communications in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 10. In some examples, method 1000 may be performed by a RAN node such as a BH RAN node or any other RAN node (e.g., a neighbor or surrounding RAN node as mentioned above) . In some embodiments, the RAN node may execute a set of instructions to control the functional elements of the RAN node to perform the described functions or operations.

At 1011, a first RAN node may establish a TNL association with a first wireless network node. The first wireless network node may support or include a BS part and an MT part. At 1013, the first RAN node may perform an Xn connection setup procedure with the first wireless network node, including: receiving, from the first wireless network node, a first Xn setup request message indicating a node type of the first wireless network node, or transmitting, to the first wireless network node, a second Xn setup request message indicating a node type of the first RAN node.

In some embodiments, performing the Xn connection setup procedure further includes one of: transmitting an Xn setup response message to the first wireless network node in response to receiving the first Xn setup request message and the first RAN node not being a BS part of a second wireless network node; receiving an Xn setup response message from the first wireless network node in response to transmitting the second Xn setup request message and the first RAN node not being the BS part of the second wireless network node; transmitting a first Xn setup failure message to the first wireless network node in response to receiving the first Xn setup request message and the first RAN node being the BS part of the second wireless network node, wherein the first Xn setup failure message indicates that the Xn setup has failed due to the first RAN node being the BS part of the second wireless network node; and receiving a second Xn setup failure message from the first wireless network node in response to transmitting the second Xn setup request message and the first RAN node being the BS part of the second wireless network node, wherein the second Xn setup failure message indicates that the Xn setup has failed due to the first wireless network node including the BS part.

In some embodiments, the first RAN node is in an RRC connection with the MT part of the first wireless network node. In some embodiments, the first wireless network node may transmit, to the first wireless network node, at least one TNL address of a neighbor RAN node of the first RAN node or at least one IP address of the neighbor RAN node of the first RAN node.

In some embodiments, the first RAN node is in an RRC connection with the MT part of the first wireless network node. In some embodiments, the first wireless network node may receive, from the first wireless network node, served cell information of the BS part of the first wireless network node and one of at least one TNL address of the first wireless network node and at least one IP address of the first wireless network node.

In some embodiments, the first wireless network node may transmit an XnAP message to a second RAN node, and wherein the XnAP message includes the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node.

In some embodiments, the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node are included in neighbor information of the first RAN node in the XnAP message. The neighbor information of the first RAN node further includes an indicator to distinguish between cells of the first wireless network node and cells of a RAN node which is not a wireless network node.

In some embodiments, the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node are included in the XnAP message independently from the neighbor information of the first RAN node.

In some embodiments, the first wireless network node may receive an XnAP message from a second RAN node, which is in an RRC connection with the MT part of the first wireless network node. The XnAP message includes served cell information of the BS part of the first wireless network node and one of at least one TNL address of the first wireless network node and at least one IP address of the first wireless network node.

In some embodiments, the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node are included in neighbor information of the second RAN node in the XnAP message. The neighbor information of the second RAN node further includes an indicator to distinguish between cells of the first wireless network node and cells of a RAN node which is not a wireless network node

In some embodiments, the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node are included in the XnAP message independently from the neighbor information of the second RAN node.

In some embodiments, the first wireless network node may establish an RRC connection with the MT part of the first wireless network node; and transmit, to the MT part of the first wireless network node, at least one TNL address of the first RAN node or at least one IP address of the first RAN node.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary method 1000 may be changed and that some of the operations in exemplary method 1000 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 11 illustrates an example of an NE 1100 in accordance with aspects of the present disclosure. NE 1100 may be a network node, a wireless network node, a WAB node, a BS, or any types of RAN node such as a BH RAN node or a RAN node not serving any WAB nodes. The NE 1100 may include a processor 1102, a memory 1104, a controller 1106, and a transceiver 1108. The processor 1102, the memory 1104, the controller 1106, or the transceiver 1108, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 1102, the memory 1104, the controller 1106, or the transceiver 1108, or various combinations or components thereof may be implemented in hardware (e.g., circuitry) . The hardware may include a processor, a DSP, an ASIC, or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 1102 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 1102 may be configured to operate the memory 1104. In some other implementations, the memory 1104 may be integrated into the processor 1102. The processor 1102 may be configured to execute computer-readable instructions stored in the memory 1104 to cause the NE 1100 to perform various functions of the present disclosure.

The memory 1104 may include volatile or non-volatile memory. The memory 1104 may store computer-readable, computer-executable code including instructions when executed by the processor 1102 cause the NE 1100 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 1104 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 1102 and the memory 1104 coupled with the processor 1102 may be configured to cause the NE 1100 to perform one or more of the functions described herein (e.g., executing, by the processor 1102, instructions stored in the memory 1104) . For example, the processor 1102 may support wireless communication at the NE 1100 in accordance with examples as disclosed herein.

For example, the NE 1100 may be configured to support means for performing the operations as described with respect to FIGs. 1-9. For example, the NE 1100 may support a BS part and an MT part and may be configured to support: a means for determining a node type of a candidate RAN node, wherein the candidate RAN node is a BS part of a second wireless network node, a BH RAN node serving the NE 1100, or a RAN node not serving the NE 1100; and a means for performing an Xn connection setup procedure with the candidate RAN node based on the node type of candidate RAN node.

For example, the NE 1100 may be configured to support means for performing the operations as described with respect to FIGs. 1-8 and 10. For example, the NE 1100 may be configured to support: a means for establishing a TNL association with a first wireless network node, wherein the first wireless network node supports a BS part and an MT part; and a means for performing an Xn connection setup procedure with the first wireless network node, including: receiving, from the first wireless network node, a first Xn setup request message indicating a node type of the first wireless network node, or transmitting, to the first wireless network node, a second Xn setup request message indicating a node type of the NE 1100.

The controller 1106 may manage input and output signals for the NE 1100. The controller 1106 may also manage peripherals not integrated into the NE 1100. In some implementations, the controller 1106 may utilize an operating system such as or other operating systems. In some implementations, the controller 1106 may be implemented as part of the processor 1102.

In some implementations, the NE 1100 may include at least one transceiver 1108. In some other implementations, the NE 1100 may have more than one transceiver 1108. The transceiver 1108 may represent a wireless transceiver. The transceiver 1108 may include one or more receiver chains 1110, one or more transmitter chains 1112, or a combination thereof.

A receiver chain 1110 may be configured to receive signals (e.g., control information, data, or packets) over a wireless medium. For example, the receiver chain 1110 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 1110 may include at least one amplifier (e.g., an LNA) configured to amplify the received signal. The receiver chain 1110 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 1110 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 1112 may be configured to generate and transmit signals (e.g., control information, data, or packets) . The transmitter chain 1112 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as AM, FM, or digital modulation schemes like PSK or QAM. The transmitter chain 1112 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 1112 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

It should be appreciated by persons skilled in the art that the components in exemplary NE 1100 may be changed, for example, some of the components in exemplary NE 1100 may be omitted or modified or a new component (s) may be added to exemplary NE 1100, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the NE 1100 may not include the controller 1106.

FIG. 12 illustrates an example of a processor 1200 in accordance with aspects of the present disclosure. The processor 1200 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 1200 may include a controller 1202 configured to perform various operations in accordance with examples as described herein. The processor 1200 may optionally include at least one memory 1204, which may be, for example, an L1/L2/L3 cache. Additionally, or alternatively, the processor 1200 may optionally include one or more arithmetic-logic units (ALUs) 1206. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 1200 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 1200) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 1202 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 1200 to cause the processor 1200 to support various operations in accordance with examples as described herein. For example, the controller 1202 may operate as a control unit of the processor 1200, generating control signals that manage the operation of various components of the processor 1200. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 1202 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 1204 and determine a subsequent instruction (s) to be executed to cause the processor 1200 to support various operations in accordance with examples as described herein. The controller 1202 may be configured to track memory address of instructions associated with the memory 1204. The controller 1202 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 1202 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 1200 to cause the processor 1200 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 1202 may be configured to manage flow of data within the processor 1200. The controller 1202 may be configured to control transfer of data between registers, ALUs, and other functional units of the processor 1200.

The memory 1204 may include one or more caches (e.g., memory local to or included in the processor 1200 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 1204 may reside within or on a processor chipset (e.g., local to the processor 1200) . In some other implementations, the memory 1204 may reside external to the processor chipset (e.g., remote to the processor 1200) .

The memory 1204 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1200, cause the processor 1200 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 1202 and/or the processor 1200 may be configured to execute computer-readable instructions stored in the memory 1204 to cause the processor 1200 to perform various functions. For example, the processor 1200 and/or the controller 1202 may be coupled with or to the memory 1204, the processor 1200, the controller 1202, and the memory 1204 may be configured to perform various functions described herein. In some examples, the processor 1200 may include multiple processors and the memory 1204 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 1206 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 1206 may reside within or on a processor chipset (e.g., the processor 1200) . In some other implementations, the one or more ALUs 1206 may reside external to the processor chipset (e.g., the processor 1200) . One or more ALUs 1206 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 1206 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 1206 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 1206 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 1206 to handle conditional operations, comparisons, and bitwise operations.

The processor 1200 may support wireless communication in accordance with examples as disclosed herein.

For example, the processor 1200 may be configured to support means for performing the operations as described with respect to FIGs. 1-9. For example, the processor 1200 may be configured to or operable to support a BS part and an MT part of a first wireless network node and support: a means for determining a node type of a candidate RAN node, wherein the candidate RAN node is a BS part of a second wireless network node, a BH RAN node serving the first wireless network node, or a RAN node not serving the first wireless network node; and a means for performing an Xn connection setup procedure with the candidate RAN node based on the node type of candidate RAN node.

For example, the processor 1200 may be configured to support means for performing the operations as described with respect to FIGs. 1-8 and 10. For example, the processor 1200 may be configured to support: a means for establishing a TNL association with a first wireless network node, wherein the first wireless network node supports a BS part and an MT part; and a means for performing an Xn connection setup procedure with the first wireless network node, including: receiving, from the first wireless network node, a first Xn setup request message indicating a node type of the first wireless network node, or transmitting, to the first wireless network node, a second Xn setup request message indicating a node type of the processor 1200.

It should be appreciated by persons skilled in the art that the components in exemplary processor 1200 may be changed, for example, some of the components in exemplary processor 1200 may be omitted or modified or a new component (s) may be added to exemplary processor 1200, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the processor 1200 may not include the ALUs 1206.

Those having ordinary skill in the art would understand that the operations or steps of the methods 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 the methods 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.

While this disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations may be apparent to those skilled in the art. The disclosure is not limited to the examples and designs described herein but is to be accorded with the broadest scope consistent with the principles and novel features disclosed herein. For example, various components of the embodiments may be interchanged, added, or substituted in other embodiments. Also, all of the elements of each figure are not necessary for the operation of the disclosed embodiments. For example, one of ordinary skill in the art of the disclosed embodiments would be enabled to make and use the teachings of the disclosure by simply employing the elements of the independent claims. Accordingly, embodiments of the disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure.

In this document, this document, the terms "comprises, " "comprising, " "includes, " "including, " or any other variation thereof, are intended to cover a 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 expressly listed or inherent to such process, method, article, or apparatus. The term "transport" may mean "receive" or "transmit" depending on the context. An element proceeded by "a, " "an, " or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term "another" is defined as at least a second or more. The term "having" or the like, as used herein, is defined as "including. " Expressions such as "A and/or B" or "at least one of A and B" may include any and all combinations of words enumerated along with the expression. For instance, the expression "A and/or B" or "at least one of A and B" may include A, B, or both A and B. The wording "the first, " "the second" or the like is only used to clearly illustrate the embodiments of the present disclosure, but is not used to limit the substance of the present disclosure.

Claims

A first wireless network node, the first wireless network node supporting a base station (BS) part and a mobile terminal (MT) part and comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the first wireless network node to:

determine a node type of a candidate radio access network (RAN) node, wherein the candidate RAN node is a BS part of a second wireless network node, a backhaul (BH) RAN node serving the first wireless network node, or a RAN node not serving the first wireless network node; and

perform an Xn connection setup procedure with the candidate RAN node based on the node type of candidate RAN node.
The first wireless network node of Claim 1, wherein the Xn connection setup procedure is performed in response to determining the node type of the candidate RAN node indicating that the candidate RAN node is not the BS part of the second wireless network node; and

wherein the at least one processor is configured to cause the first wireless network node to prohibit setting up an Xn connection with the candidate RAN node in response to determining the node type of the candidate RAN node indicating that the candidate RAN node is the BS part of the second wireless network node.
The first wireless network node of Claim 1, wherein the at least one processor is configured to cause the first wireless network node to:

receive the node type of the candidate RAN node from a first measurement report of a user equipment (UE) served by the first wireless network node, a second measurement report of the MT part of the first wireless network node, or a neighbor information of the BH RAN node; or

determine that the candidate RAN node is not the BS part of the second wireless network node in response to not receiving the node type of the candidate RAN node.
The first wireless network node of Claim 1, wherein the at least one processor is configured to cause the first wireless network node to transmit, to the BH RAN node, served cell information of the BS part of the first wireless network node and one of at least one transport network layer (TNL) address of the first wireless network node and at least one internet protocol (IP) address of the first wireless network node.
The first wireless network node of Claim 4, wherein the served cell information and one of the at least one TNL address and the at least one IP address of the first wireless network node is transmitted via radio resource control (RRC) signaling or an Xn application protocol (XnAP) message.
The first wireless network node of Claim 1, wherein the at least one processor is configured to cause the first wireless network node to receive, from the BH RAN node, at least one transport network layer (TNL) address of a neighbor RAN node of the BH RAN node or at least one internet protocol (IP) address of the neighbor RAN node of the BH RAN node.
The first wireless network node of Claim 1, wherein the at least one processor is configured to cause the first wireless network node to receive, from the BH RAN node, at least one transport network layer (TNL) address of the BH RAN node or at least one internet protocol (IP) address of the BH RAN node.
The first wireless network node of Claim 7, wherein the at least one TNL address or the at least one IP address of the BH RAN node is received by the MT part of the first wireless network node from the BH RAN node via radio resource control (RRC) signaling.
A first radio access network (RAN) node, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the first RAN node to:

establish a transport network layer (TNL) association with a first wireless network node, wherein the first wireless network node supports a base station (BS) part and a mobile terminal (MT) part; and

perform an Xn connection setup procedure with the first wireless network node, comprising: receiving, from the first wireless network node, a first Xn setup request message indicating a node type of the first wireless network node, or transmitting, to the first wireless network node, a second Xn setup request message indicating a node type of the first RAN node.
The first RAN node of Claim 9, wherein performing the Xn connection setup procedure further comprises one of:

transmitting an Xn setup response message to the first wireless network node in response to receiving the first Xn setup request message and the first RAN node not being a BS part of a second wireless network node;

receiving an Xn setup response message from the first wireless network node in response to transmitting the second Xn setup request message and the first RAN node not being the BS part of the second wireless network node;

transmitting a first Xn setup failure message to the first wireless network node in response to receiving the first Xn setup request message and the first RAN node being the BS part of the second wireless network node, wherein the first Xn setup failure message indicates that the Xn setup has failed due to the first RAN node being the BS part of the second wireless network node; and

receiving a second Xn setup failure message from the first wireless network node in response to transmitting the second Xn setup request message and the first RAN node being the BS part of the second wireless network node, wherein the second Xn setup failure message indicates that the Xn setup has failed due to the first wireless network node including the BS part.
The first RAN node of Claim 9, wherein the first RAN node is in a radio resource control (RRC) connection with the MT part of the first wireless network node and the at least one processor is configured to cause the first RAN node to:

transmit, to the first wireless network node, at least one TNL address of a neighbor RAN node of the first RAN node or at least one internet protocol (IP) address of the neighbor RAN node of the first RAN node.
The first RAN node of Claim 9, wherein the first RAN node is in a radio resource control (RRC) connection with the MT part of the first wireless network node and the at least one processor is configured to cause the first RAN node to:

receive, from the first wireless network node, served cell information of the BS part of the first wireless network node and one of at least one TNL address of the first wireless network node and at least one internet protocol (IP) address of the first wireless network node.
The first RAN node of Claim 12, wherein the at least one processor is configured to cause the first RAN node to transmit an Xn application protocol (XnAP) message to a second RAN node, and wherein the XnAP message includes the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node.
The first RAN node of Claim 13, wherein the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node are included in neighbor information of the first RAN node in the XnAP message, and wherein the neighbor information of the first RAN node further includes an indicator to distinguish between cells of the first wireless network node and cells of a RAN node which is not a wireless network node; or

wherein the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node are included in the XnAP message independently from the neighbor information of the first RAN node.
The first RAN node of Claim 9, wherein the at least one processor is configured to cause the first RAN node to receive an Xn application protocol (XnAP) message from a second RAN node, which is in a radio resource control (RRC) connection with the MT part of the first wireless network node; and

wherein the XnAP message includes served cell information of the BS part of the first wireless network node and one of at least one TNL address of the first wireless network node and at least one internet protocol (IP) address of the first wireless network node.
The first RAN node of Claim 15, wherein the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node are included in neighbor information of the second RAN node in the XnAP message, and wherein the neighbor information of the second RAN node further includes an indicator to distinguish between cells of the first wireless network node and cells of a RAN node which is not a wireless network node; or

wherein the served cell information of the BS part of the first wireless network node and the one of the at least one TNL address and the at least one IP address of the first wireless network node are included in the XnAP message independently from the neighbor information of the second RAN node.
The first RAN node of Claim 9, wherein the at least one processor is configured to cause the first RAN node to:

establish a radio resource control (RRC) connection with the MT part of the first wireless network node; and

transmit, to the MT part of the first wireless network node, at least one TNL address of the first RAN node or at least one internet protocol (IP) address of the first RAN node.
A method for wireless communication, comprising:

determining, by a first wireless network node, a node type of a candidate radio access network (RAN) node, wherein the first wireless network node supports a base station (BS) part and a mobile terminal (MT) part and the candidate RAN node is a BS part of a second wireless network node, a backhaul (BH) RAN node serving the first wireless network node, or a RAN node not serving the first wireless network node; and

performing, by the first wireless network node, an Xn connection setup procedure with the candidate RAN node based on the node type of candidate RAN node.
The method of Claim 18, wherein the Xn connection setup procedure is performed in response to determining the node type of the candidate RAN node indicating that the candidate RAN node is not the BS part of the second wireless network node and the method further comprises:

prohibiting setting up an Xn connection with the candidate RAN node in response to determining the node type of the candidate RAN node indicating that the candidate RAN node is the BS part of the second wireless network node.
A method for wireless communication, comprising:

establishing a transport network layer (TNL) association between a first wireless network node and a first radio access network (RAN) node; and

performing an Xn connection setup between the first wireless network node and the first RAN node, comprising:

receiving, from the first wireless network node to the first RAN node, a first Xn setup request message indicating a node type of the first wireless network node, or

transmitting, from the first RAN node to the first wireless network node, a second Xn setup request message indicating a node type of the first RAN node.