WO2024217085A1

WO2024217085A1 - Method and apparatus for wireless communication in wireless access backhaul network

Info

Publication number: WO2024217085A1
Application number: PCT/CN2024/072051
Authority: WO
Inventors: Yibin ZHUO; Mingzeng Dai; Lianhai WU; Haiyan Luo
Original assignee: Lenovo Beijing Ltd
Current assignee: Lenovo Beijing Ltd
Priority date: 2024-01-12
Filing date: 2024-01-12
Publication date: 2024-10-24
Anticipated expiration: 2026-07-12

Abstract

Embodiments of the present disclosure relate to a method and apparatus for wireless communication in a WAB network. According to some embodiments of the disclosure, a first wireless network node may: support a BS part and an MT part; trigger an Xn connection setup procedure to a second node, wherein the second node is a second wireless network node or a BS; and perform one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the second node over a wireless air interface; and receiving a second XnAP message from the second node over the wireless air interface.

Description

METHOD AND APPARATUS FOR WIRELESS COMMUNICATION IN 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) ) .

To extend the coverage and availability of wireless communication systems, the 3rd generation partnership project (3GPP) is envisioning WAB architecture to provide wireless access services to UEs. The industry desires technologies for facilitating communications in a WAB network.

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 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: support a BS part and a mobile terminal (MT) part; trigger an Xn connection setup procedure to a second node, wherein the second node is a second wireless network node or a BS; and perform one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first Xn application protocol (XnAP) message to the second node over a wireless air interface; and receiving a second XnAP message from the second node over the wireless air interface.

In some embodiments of the present disclosure, the at least one processor is configured to cause the first wireless network node to receive, from the second node, at least one internet protocol (IP) address of the second node or at least one transport network layer (TNL) address of the second node.

In some embodiments of the present disclosure, the at least one processor is configured to cause the first wireless network node to transmit a request message to the second node to request the at least one IP address or the at least one TNL address.

In some embodiments of the present disclosure, the request message includes an IP address of the first wireless network node or a TNL address of the first wireless network node.

In some embodiments of the present disclosure, the at least one IP address or the at least one TNL address is received via a radio resource control (RRC) message between the first wireless network node and the second node, or is received via a PC5-RRC message or a PC5-S message between the first wireless network node and the second wireless network node, or is received from an intermediate wireless network node between the first wireless network node and the second node.

In some embodiments of the present disclosure, the wireless air interface includes: a Uu interface between the MT part of the first wireless network node and the BS; a Uu interface between the MT part of the first wireless network node and a BS part of the second wireless network node; a Uu interface between the BS part of the first wireless network node and an MT part of the second wireless network node; or a PC5 interface between the MT part of the first wireless network node and the MT part of the second wireless network node.

In some embodiments of the present disclosure, the wireless air interface is a Uu interface and wherein the first XnAP message and the second XnAP message are transported by a radio resource control (RRC) message, encapsulated in a user plane (UP) packet, or carried by a signaling radio bearer (SRB) for transporting an XnAP message.

In some embodiments of the present disclosure, the first XnAP message or the second XnAP message includes a downlink (DL) message indicating that a target of the DL message is a BS part of a wireless network node or indicating that the DL message is related to an Xn interface.

In some embodiments of the present disclosure, the wireless air interface is a sidelink (SL) interface and wherein the first XnAP message and the second XnAP message are transported by an SL PC5 radio resource control (RRC) message or an SL PC5-S message, encapsulated in an SL user plane (UP) packet, or carried by an SL signaling radio bearer (SRB) for transporting an XnAP message.

In some embodiments of the present disclosure, the first XnAP message or the second XnAP message includes a first SL message indicating that the target of the first SL message is a BS part of a wireless network node or indicating that the first SL message is related to an Xn interface.

In some embodiments of the present disclosure, the at least one processor is further configured to cause the first wireless network node to perform stream control transport protocol (SCTP) association or transport network layer association (TNLA) establishment between the first wireless network node and the second node.

In some embodiments of the present disclosure, the wireless air interface is a Uu interface and wherein to perform the SCTP association or TNLA establishment, the at least one processor is configured to cause the first wireless network node to transport a message related to the SCTP association or TNLA establishment, which is transported by a radio resource control (RRC) message, or encapsulated in a user plane (UP) packet, or carried by a signaling radio bearer (SRB) for transporting the message related to the SCTP association or TNLA establishment, to the second node.

In some embodiments of the present disclosure, the message related to the SCTP association or TNLA establishment includes a downlink (DL) message indicating that a target of the DL message is a BS part of a wireless network node.

In some embodiments of the present disclosure, the wireless air interface is a sidelink (SL) interface and wherein to perform the SCTP association or TNLA establishment, the at least one processor is configured to cause the first wireless network node to transport a message related to the SCTP association or TNLA establishment, which is transported by an SL PC5 radio resource control (RRC) message or an SL PC5-S message, or encapsulated in an SL user plane (UP) packet, or carried by an SL signaling radio bearer (SRB) for transporting the message related to the SCTP association or TNLA establishment, to the second wireless network node.

In some embodiments of the present disclosure, the message related to the SCTP association or TNLA establishment includes an SL message indicating that its target is a BS part of a wireless network node.

In some embodiments of the present disclosure, the triggering of the Xn connection setup procedure is based on one of the following: an operation administration and maintenance (OAM) configuration, an access between the first wireless network node and the second node, an inter discovery between the first wireless network node and the second node, or a reception of node information of the second node.

In some embodiments of the present disclosure, the at least one processor is further configured to cause the first wireless network node to receive node information of the second node from an intermediate wireless network node between the first wireless network node and the second node.

In some embodiments of the present disclosure, the node information of the second node includes: (a) an identifier of the BS or a BS part of the second wireless network node; or both (b) an internet protocol (IP) address of the second node or a transport network layer (TNL) address of the second node and (a) .

In some embodiments of the present disclosure, the node information of the second node is received via a radio resource control (RRC) message between the intermediate wireless network node and the first wireless network node.

In some embodiments of the present disclosure, the first XnAP message and the second XnAP message are relayed by an intermediate wireless network node between the first wireless network node and the second node, and indicate one of a source BS ID for multi-hop routing and a source internet protocol (IP) address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.

In some embodiments of the present disclosure, to perform the SCTP association or TNLA establishment, the at least one processor is configured to cause the first wireless network node to transport a message related to the SCTP association or TNLA establishment, which is relayed by an intermediate wireless network node between the first wireless network node and the second node and indicates one of a source BS ID for multi-hop routing and a source internet protocol (IP) address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.

Some embodiments of the present disclosure provide a BS. The BS may include: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the BS to: trigger an Xn connection setup procedure to a first wireless network node, wherein the first wireless network node supports a BS part and an MT part; and perform one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the first wireless network node over a wireless air interface; and receiving a second XnAP message from the first wireless network node over the wireless air interface.

In some embodiments of the present disclosure, the at least one processor is configured to cause the BS to receive, from the first wireless network node, at least one IP address of the first wireless network node or at least one TNL address of the first wireless network node.

In some embodiments of the present disclosure, the at least one processor is configured to cause the BS to transmit a request message to the first wireless network node to request the at least one IP address or the at least one TNL address.

In some embodiments of the present disclosure, the request message includes an IP address of the BS or a TNL address of the BS.

In some embodiments of the present disclosure, the at least one IP address or the at least one TNL address is received via an RRC message between the first wireless network node and the BS, or is received from an intermediate wireless network node between the first wireless network node and the BS.

In some embodiments of the present disclosure, the wireless air interface includes a Uu interface between the MT part of the first wireless network node and the BS.

In some embodiments of the present disclosure, the first XnAP message and the second XnAP message are transported by an RRC message, encapsulated in a UP packet, or carried by an SRB for transporting an XnAP message.

In some embodiments of the present disclosure, the first XnAP message indicates that a target of the first XnAP message is a BS part of a wireless network node or indicates that the first XnAP message is related to an Xn interface.

In some embodiments of the present disclosure, the at least one processor is further configured to cause the BS to perform SCTP association or TNLA establishment between the first wireless network node and the BS.

In some embodiments of the present disclosure, to perform the SCTP association or TNLA establishment, the at least one processor is configured to cause the BS to transport a message related to the SCTP association or TNLA establishment, which is transported by an RRC message, or encapsulated in a UP packet, or carried by an SRB for transporting the message related to the SCTP association or TNLA establishment, to the first wireless network node.

In some embodiments of the present disclosure, the message related to the SCTP association or TNLA establishment includes a DL message indicating that a target of the DL message is a BS part of a wireless network node.

In some embodiments of the present disclosure, the triggering of the Xn connection setup procedure is based on one of the following: an OAM configuration, an access between the first wireless network node and the BS, an inter discovery between the first wireless network node and the BS, or a reception of node information of the first wireless network node.

In some embodiments of the present disclosure, the at least one processor is further configured to cause the BS to receive node information of the first wireless network node from an intermediate wireless network node between the first wireless network node and the BS.

In some embodiments of the present disclosure, the node information of the first wireless network node includes: (a) an identifier of the BS part of the first wireless network node; or both (b) an IP address of the first wireless network node or a TNL address of the first wireless network node and (a) .

In some embodiments of the present disclosure, the node information of the first wireless network node is received via an RRC message between the intermediate wireless network node and the BS.

In some embodiments of the present disclosure, the first XnAP message and the second XnAP message are relayed by an intermediate wireless network node between the first wireless network node and the BS, and indicate one of a source BS ID for multi-hop routing and a source IP address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.

In some embodiments of the present disclosure, to perform the SCTP association or TNLA establishment, the at least one processor is configured to cause the BS to transport a message related to the SCTP association or TNLA establishment, which is relayed by an intermediate wireless network node between the first wireless network node and the BS and indicates one of a source BS ID for multi-hop routing and a source IP address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.

Some embodiments of the present disclosure provide a method for wireless communication, including: triggering, by a first wireless network node, an Xn connection setup procedure to a second node, wherein the first wireless network node supports a BS part and an MT part and the second node is a second wireless network node or a BS; and performing, by the first wireless network node, one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the second node over a wireless air interface; and receiving a second XnAP message from the second node over the wireless air interface.

Some embodiments of the present disclosure provide a method for wireless communication, including: triggering an Xn connection setup procedure to a first wireless network node, wherein the first wireless network node supports a BS part and an MT part; and performing one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the first wireless network node over a wireless air interface; and receiving a second XnAP message from the first wireless network node over the wireless air interface.

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 exemplary procedure for managing TNLAs for Xn-C in accordance with some embodiments of the present disclosure;

FIGs. 3-5 illustrate flow charts of exemplary procedures for establishing an Xn interface in accordance with some embodiments of the present disclosure;

FIGs. 6A and 6B illustrate exemplary block diagrams of communication networks supporting multi-hop in accordance with some embodiments of the present disclosure;

FIGs. 7 and 8 illustrate flowcharts of methods for wireless communication in accordance with some embodiments of the present disclosure;

FIG. 9 illustrates an example of network equipment (NE) in accordance with some embodiments of the present disclosure; and

FIG. 10 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 backhaul 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 WAB donor) relayed by one or more WAB nodes. The WAB donor may also be called a donor node or a donor base station (e.g., DgNB, Donor gNodeB) . In addition, the wireless link between a WAB donor 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 WAB donor 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 a mobile terminal (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 WAB donor) , it can be regarded as a UE, i.e., the role of an MT. 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 embodiments, a WAB node may be referred to as a “mobile base station relay, " which is a mobile base station acting as a relay between a UE and the network. For example, the WAB node may provide a NR access link to UEs and connected wirelessly (using NR) through a donor NG-radio access network (RAN) (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 WAB donor 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 WAB donor 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 WAB donor may be referred to as a "WAB donor-CU" (or directly referred to as a "CU" ) , and the DU of the WAB donor may be referred to as a "WAB donor-DU. " The WAB donor-CU or the CU of the WAB-BS 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 (BH) 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 WAB donor. A transmission path may include multiple nodes, such as a UE, one or more WAB nodes, and a WAB donor (if the WAB donor is in the form of a separate CU and DU, it may also contain a WAB donor-DU and a WAB donor-CU) . 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, due to the mobility of a WAB node (i.e., wireless network node) , a wired Xn interface between a WAB node and a WAB donor or between WAB nodes cannot be deployed via optical fiber. Embodiments of the present disclosure provide solutions for establishing an Xn interface between, for example, a WAB node and a WAB donor or between WAB nodes.

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., WAB donor 110A and WAB donor 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 WAB donors is depicted in FIG. 1, it is contemplated that any number of UEs, WAB nodes, and WAB donors may be included in wireless communication system 100. Each of WAB donor 110A, WAB donor 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 WAB donor 110A, WAB donor 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 WAB donor (e.g., WAB donor 110A and WAB donor 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 of a WAB node and an MT of another WAB node may communication directly with each other over a sidelink.

A WAB donor may support communication with a core network (CN) , or with another WAB donor, or both. For example, WAB donor 110A may interface with WAB donor 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, WAB donors may communicate with each other directly. In some other implementations, WAB donors 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 WAB donor 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 WAB donor. 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 donors and WAB 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 WAB donor 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 WAB donor 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 WAB donors 110A and 110B, and WAB node 120B can be directly connected to WAB donor 110A. WAB donors 110A and 110B are parent nodes of WAB node 120A, and WAB donor 110A is a parent node of WAB node 120B. In other words, WAB nodes 120A and 120B are child WAB nodes of WAB donor 110A, and WAB node 120A is also a child WAB node of WAB donor 110B. WAB node 120C can reach WAB donor 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 WAB donor 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 WAB donor (e.g., WAB donor 110A or 110B) via one or more WAB nodes, and then transmitted by the WAB donor to a mobile gateway device (such as the UPF in the 5GC) . DL packets (e.g., data or signaling) can be transmitted from the WAB donor (e.g., WAB donor 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 WAB donor 110A or 110B or receive DL data therefrom via WAB node 120A. UE 130B may transmit UL data to WAB donor 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 WAB donor (e.g., WAB donor 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 WAB donor (e.g., WAB donor 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 only for illustrative purposes. 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., the WAB architecture) and based on certain specific components (e.g., a WAB donor or a WAB node) , embodiments of the present disclosure are also applicable to other similar network architectures and new service scenarios.

As described above, for WAB topology, a WAB node may connect to a donor node directly, or connect to a donor node relayed by another WAB node (s) . In some embodiments, UEs served by a WAB node or a donor node may need to perform a handover (s) between a WAB node and a donor node or between WAB nodes. Embodiments of the present disclosure provide enhancements to signaling between these nodes. In some embodiments, due to, for example, the mobility of a WAB node (i.e., wireless network node) , a wired Xn interface between a WAB node and a donor node or between WAB nodes cannot be deployed via optical fiber. Embodiments of the present disclosure provide solutions for establishing an Xn interface between, for example, a WAB node and a donor WAB or between WAB nodes. For example, solutions for triggering an Xn setup procedure are provided. For example, solutions for obtaining the TNL or IP address of a peer node for an Xn connection are provided. For example, solutions for transporting an Xn related messages are provided. For example, solutions for transporting messages related to an SCTP association or a TNLA establishment are provided. More details on the embodiments of the present disclosure will be illustrated in the following text in combination with the appended drawings.

FIG. 2 illustrates exemplary procedure 200 for managing TNLAs for Xn-C 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. 2.

Referring to FIG. 2, at 211, BS 210A may establish a TNLA (denoted as TNLA #1) with BS 210B using a configured TNL address. In some examples, BS 210A and BS 210B may be an NG-RAN node. In some examples, BS 210A may use a different source and/or destination IP end point (s) if the TNL establishment towards one IP end point fails.

In response to TNLA #1 being established, BS 210A may initiate an Xn Setup procedure to exchange application level configuration data. For example, at 213, BS 210A may transmit an Xn setup request message to BS 210B. In response, BS 210B may transmit an Xn setup response message to BS 210A at 215.

In some embodiments, BS 210B may add an additional TNL endpoint (s) to be used for Xn-C signaling between the BS 210A and BS 210B pair using a BS configuration update procedure (e.g., "NG-RAN node Configuration Update procedure" as specified in 3GPP specifications) . This procedure may allow BS 210B to request BS 210A to modify or release the TNLA (s) . For example, at 217, BS 210B may transmit an NG-RAN node configuration update message to BS 210A. At 219, BS 210A may establish another TNLA (denoted as TNLA #2) with BS 210B. At 221, BS 210A may transmit an NG-RAN node configuration update acknowledgement message to BS 210B.

In some embodiments, BS 210A may add an additional TNL end point (s) to be used for Xn-C signaling between the BS 210A and BS 210B pair using a BS configuration update procedure (e.g., "NG-RAN node Configuration Update procedure" as specified in 3GPP specifications) . This procedure may allow BS 210A to request BS 210B to modify or release the TNLA (s) . For example, at 223, BS 210A may transmit an NG-RAN node configuration update message to BS 210B. At 225, BS 210B may establish yet another TNLA (denoted as TNLA #3) with BS 210A. At 227, BS 210B may transmit an NG-RAN node configuration update acknowledgement message to BS 210A.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary method 200 may be changed and that some of the operations in exemplary method 200 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 3 illustrates a flow chart of exemplary procedure 300 for establishing an Xn interface 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. 3.

Node 310A and node 310B may be two adjacent nodes along a routing path. That is, node 310A may be a parent node of node 310B or vice versa. In some embodiments, one of node 310A and node 310B may be a parent WAB donor, which may be stationary, and the other may be a child WAB node. The parent WAB donor may communicate with the MT of the child WAB node over a Uu interface. An Xn interface between the parent WAB donor and the BS part of the child WAB node is to be established. In some embodiments, one of node 310A and node 310B may be a parent WAB node and the other may be a child WAB node. The BS part of the parent WAB node may communicate with the MT of the child WAB node over a Uu interface. An Xn interface between the BS part of the parent WAB node and the BS part of the child WAB node is to be established.

Referring to FIG. 3, node 310A may trigger an Xn connection setup procedure to node 310B. As mentioned above, node 310A may be either the parent node or the child node along a routing path. In some embodiments, the triggering of the Xn connection setup procedure may be based on an OAM configuration or indication for node 310A (e.g., the parent node or child node) . In some embodiments, node 310A (e.g., the parent node or child node) may trigger the Xn connection setup procedure in response to (e.g., after) node 310B (e.g., the child node or parent node) being connected to node 310A (e.g., the parent node or child node) . As will be described later, in response to triggering the Xn connection setup procedure, node 310A and node 310B may transport XnAP messages between each other.

Node 310A (i.e., the triggering node) may obtain at least one TNL address or IP address of node 310B. For example, node 310A may receive, from node 310B, at least one IP address of node 310B or at least one TNL address of node 310B. In some embodiments, at 311 (denoted by a dotted arrow as an option) , node 310A may transmit, to node 310B, a request message to request the at least one IP address or the at least one TNL address of node 310B. In some embodiments, the request message may include the TNL address or IP address of node 310A (i.e., the triggering node) . At 315 (denoted by a dotted arrow as an option) , node 310B may transmit the at least one IP address or the at least one TNL address of node 310B to node 310A.

In some embodiments, the request message may be an RRC message. In some embodiments, the at least one IP address or the at least one TNL address of node 310B may be transported via an RRC message. In some embodiments, in the case that node 310A is a child node of node 310B, the request message may be a UL RRC message (e.g., an IABOtherinformation or a WABOtherinformation message) and the least one IP address or the at least one TNL address of node 310B may be transported via a DL RRC message (e.g., an RRCReconfiguration message) . In some embodiments, in the case that node 310A is a parent node of node 310B, the request message may be a DL RRC message (e.g., an RRCReconfiguration message) and the least one IP address or the at least one TNL address of node 310B may be transported via a UL RRC message (e.g., an RRCReconfigurationComplete message) .

In the context of the present disclosure, the TNL address or IP address of a node (e.g., the triggering node such as node 310A or the peer node such as node 310B) can be used for addressing the node, for example, used for the destination IP end point of the TNLA or SCTP association or data transmission.

At 317, node 310A and node 310B may perform an SCTP association or TNLA establishment with each other. For example, node 310A and node 310B may transport one or more messages related to the SCTP association or TNLA establishment therebetween. The one or more messages may include handshaking messages for the SCTP association or TNLA establishment. In some embodiments, the one or more messages may be transported by an RRC message (e.g., as a container of a DL or UL RRC message) , encapsulated in a UP packet, or carried by an SRB for transporting a message related to an SCTP association or TNLA establishment. In some embodiments, the SRB may be an SRB dedicated to transporting SCTP association or TNLA establishment related messages.

In some embodiments, the messages related to the SCTP association or TNLA establishment may include a DL message indicating that a target of the DL message is a BS part of a wireless network node (e.g., a WAB node) . For example, node 310A is a child WAB node of node 310B, and node 310B may transmit, to node 310A, a DL message related to the SCTP association or TNLA establishment, which may include an indication indicating that the target entity is the BS part of node 310A, rather than the MT part of node 310A. For example, node 310B is a child WAB node of node 310A, and node 310A may transmit, to node 310B, a DL message related to the SCTP association or TNLA establishment, which may include an indication indicating that the target entity is the BS part of node 310B, rather than the MT part of node 310B.

In some embodiments, in response to triggering the Xn connection setup procedure, node 310A and node 310B may transport XnAP messages between each other at 319. For example, node 310A may transmit an Xn setup request message to node 310B over the wireless air interface between node 310A and node 310B. Node 310B may respond with an Xn setup response message to node 310A over the wireless air interface between node 310A and node 310B. For example, node 310A and node 310B may transport subsequent Xn related messages (e.g., messages associated with an NG-RAN node configuration update procedure and handover preparation procedure) between each other over the wireless air interface.

In some embodiments, the wireless air interface between node 310A and node 310B may be a Uu interface. In some examples, the wireless air interface between node 310A and node 310B may be a Uu interface between the MT part of node 310A and node 310B (that is, node 310A is a child WAB node and node 310B is the parent WAB donor) . In some examples, the wireless air interface between node 310A and node 310B may be a Uu interface between node 310A and the MT part of node 310B (that is, node 310A is the parent WAB donor and node 310B is the child WAB node) . In some examples, the wireless air interface between node 310A and node 310B may be a Uu interface between the MT part of node 310A and the BS part of node 310B (that is, node 310A is a child WAB node and node 310B is the parent WAB node) . In some examples, the wireless air interface between node 310A and node 310B may be a Uu interface between the BS part of node 310A and the MT part of node 310B (that is, node 310A is a parent WAB node and node 310B is the child WAB node) .

In some embodiments, the XnAP messages (e.g., the Xn setup request message, the Xn setup response message and the Xn related messages) may be transported by an RRC message (e.g., as a container of a DL or UL RRC message) , encapsulated in a UP packet, or carried by an SRB for transporting an XnAP message. In some embodiments, the SRB may be an SRB dedicated to transporting XnAP messages.

In some embodiments, the XnAP messages may include a DL message indicating that a target of the DL message is a BS part of a wireless network node or indicating that the DL message is an XnAP message (i.e., indicating that the message is related to the Xn interface) . For example, node 310A is a child WAB node of node 310B, and node 310B may transmit, to node 310A, a DL message, which may include an indication indicating that the target entity is the BS part of node 310A, rather than the MT part of node 310A (or indicating that the message is related to the Xn interface) . For example, node 310B is a child WAB node of node 310A, and node 310A may transmit, to node 310B, a DL message, which may include an indication indicating that the target entity is the BS part of node 310B, rather than the MT part of node 310B (or indicating that the message is related to the Xn interface) .

The Xn interface XnAP procedures can be divided into the following two modules.

1. XnAP Basic Mobility Procedures: include procedures used to handle UE mobility within a RAN (e.g., NG-RAN) . For example, messages for this module may include a handover request and a handover request acknowledge.

2. XnAP Global Procedures: include procedures that are not related to a specific UE. The procedures in this module are in contrast to the above module involving two peer NG-RAN nodes. For example, messages for this module may include an Xn setup request and an Xn setup response.

In some embodiments, XnAP messages in the context of the present disclosure can include messages for the above XnAP procedures.

In some embodiments, in the case of a UE handover between node 310A and node 310B, the UE handover may trigger an Xn setup between the two nodes. The handover request and Xn setup request can be included in the same XnAP message to reduce handover latency.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary procedure 300 may be changed and that some of the operations in exemplary procedure 300 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 4 illustrates a flow chart of exemplary procedure 400 for establishing an Xn interface 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. 4.

Node 410A and node 410B may be two neighbor nodes. In some embodiments, one of node 410A and node 410B may be a WAB node, and the other may be a neighbor WAB donor, which may be stationary. In some embodiments, node 410A and node 410B may be two neighbor WAB nodes.

Before setting up an Xn connection between node 410A and node 410B, a Uu connection may be set up between node 410A and node 410B. For example, in the case that one of node 410A and node 410B is a WAB node and the other is a neighbor WAB donor, the MT of the WAB node may set up a Uu interface with the neighbor WAB donor. For example, in the case that node 410A and node 410B are two neighbor WAB nodes, the MT of one WAB node may set up a Uu interface with the BS part of the neighbor WAB node. In some embodiments, one of node 410A and node 410B discovers the other node before setting up the Xn connection. In some embodiments, node 410A and node 410B discover each other before setting up the Xn connection.

For example, at 411, an inter-node discovery may be performed between node 410A and node 410B. The discovery can reuse legacy procedures such as integrated access and backhaul (IAB) inter-node discovery, which may be based on IAB-specific synchronization signal block (SSB) /channel state information reference signal (CSI-RS) based measurements, or based on the measurement of one WAB-MT which detects the cell ID of the other BS or the BS part of the other WAB node.

After the discovery procedure, node 410A and node 410B can communicate over a Uu interface therebetween. For example, the MT of one of node 410A and node 410B may access the other one of node 410A and node 410B (that is, the other one may be a WAB node or a WAB donor as described above) . Similar to node 310A and node 310B, one of node 410A and node 410B may be a child node and the other may be a parent node.

The descriptions with respect to procedure 300 (e.g., operations 311-319) may apply to operations 413 to 419 for establishing an Xn interface between node 410A and node 410B.

For example, node 410A may trigger an Xn connection setup procedure to node 410B. Node 410A may be either the parent node or the child node. In some embodiments, the triggering of the Xn connection setup procedure may be based on an OAM configuration or indication for node 410A. In some embodiments, node 410A may trigger the Xn connection setup procedure in response to the setup of the Uu connection between node 410A and node 410B. In some embodiments, the Xn connection setup procedure may be triggered in response to a UE handover.

Node 410A (i.e., the triggering node) may obtain at least one TNL address or IP address of node 410B. For example, node 410A may receive, from node 410B, at least one IP address of node 410B or at least one TNL address of node 410B. In some embodiments, at 413 (denoted by a dotted arrow as an option) , node 410A may transmit, to node 410B, a request message to request the at least one IP address or the at least one TNL address of node 410B. In some embodiments, the request message may include the TNL address or IP address of node 410A (i.e., the triggering node) . At 415 (denoted by a dotted arrow as an option) , node 410B may transmit the at least one IP address or the at least one TNL address of node 410B to node 410A.

In some embodiments, the request message may be an RRC message. In some embodiments, the at least one IP address or the at least one TNL address of node 410B may be transported via an RRC message. In some embodiments, in the case that node 410A is a child node of node 410B, the request message may be a UL RRC message (e.g., an IABOtherinformation or a WABOtherinformation message) and the least one IP address or the at least one TNL address of node 410B may be transported via a DL RRC message (e.g., an RRCReconfiguration message) . In some embodiments, in the case that node 410A is a parent node of node 410B, the request message may be a DL RRC message (e.g., an RRCReconfiguration message) and the least one IP address or the at least one TNL address of node 410B may be transported via a UL RRC message (e.g., an RRCReconfigurationComplete message) .

At 417, node 410A and node 410B may perform an SCTP association or TNLA establishment with each other. For example, node 410A and node 410B may transport one or more messages related to the SCTP association or TNLA establishment between the two nodes. Such messages may include handshaking messages for the SCTP association or TNLA establishment. In some embodiments, the one or more messages may be transported by an RRC message (e.g., as a container of a DL or UL RRC message) , encapsulated in a UP packet, or carried by an SRB for transporting a message related to SCTP association or TNLA establishment. In some embodiments, the SRB may be an SRB dedicated to transporting SCTP association or TNLA establishment related messages.

In some embodiments, the messages related to the SCTP association or TNLA establishment may include a DL message indicating that a target of the DL message is a BS part of a wireless network node (e.g., a WAB node) .

In some embodiments, in response to triggering the Xn connection setup procedure, node 410A and node 410B may transport XnAP messages between each other at 419. For example, node 410A may transmit an Xn setup request message to node 410B over the wireless air interface between node 410A and node 410B. Node 410B may respond with an Xn setup response message to node 410A over the wireless air interface between node 410A and node 410B. For example, node 410A and node 410B may transport subsequent Xn related messages (e.g., messages associated with an NG-RAN node configuration update procedure and a handover preparation procedure) between each other over the wireless air interface.

In some embodiments, the wireless air interface between node 410A and node 410B may be the Uu interface. In some examples, the wireless air interface between node 410A and node 410B may be a Uu interface between the MT part of node 410A and node 410B (that is, node 410A is a child WAB node and node 410B is the parent WAB donor) . In some examples, the wireless air interface between node 410A and node 410B may be a Uu interface between node 410A and the MT part of node 410B (that is, node 410A is the parent WAB donor and node 410B is the child WAB node) . In some examples, the wireless air interface between node 410A and node 410B may be a Uu interface between the MT part of node 410A and the BS part of node 410B (that is, node 410A is a child WAB node and node 410B is the parent WAB node) . In some examples, the wireless air interface between node 410A and node 410B may be a Uu interface between the BS part of node 410A and the MT part of node 410B (that is, node 410A is a parent WAB node and node 410B is the child WAB node) .

In some embodiments, the XnAP messages may include a DL message indicating that a target of the DL message is a BS part of a wireless network node or indicating that the DL message is an XnAP message (i.e., indicating that the message is related to the Xn interface) .

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary procedure 400 may be changed and that some of the operations in exemplary procedure 400 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 5 illustrates a flow chart of exemplary procedure 500 for establishing an Xn interface 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.

Node 510A and node 510B may be two neighbor WAB nodes. Before setting up an Xn connection between node 510A and node 510B, an SL connection may be set up between node 510A and node 510B. For example, the MT of node 510A may set up an SL connection with the MT of node 510B. An Xn connection between the BS parts of node 510A and node 510B may be established based on the SL connection.

For example, at 511, an inter-node discovery may be performed between node 510A and node 510B. The discovery may be based on an SL discovery between the MT parts of node 510A and node 510B. After the discovery procedure, UE-to-UE direct communication is set up using the sidelink between the MT parts of node 510A and node 510B and a PC5 interface is established between the MT parts of node 510A and node 510B. As will be described later, an Xn interface may be established based on the sidelink between node 510A and node 510B.

For example, node 510A may trigger an Xn connection setup procedure to node 510B. In some embodiments, the triggering of the Xn connection setup procedure may be based on an OAM configuration or indication for node 510A. In some embodiments, node 510A may trigger the Xn connection setup procedure in response to (e.g., after) the setup of the SL between node 510A and node 510B. In some embodiments, the Xn connection setup procedure may be triggered in response to a UE handover. As will be described later, in response to triggering the Xn connection setup procedure, node 510A and node 510B may transport XnAP messages between each other.

Node 510A (i.e., the triggering node) may obtain at least one TNL address or IP address of node 510B. For example, node 510A may receive, from node 510B, at least one IP address of node 510B or at least one TNL address of node 510B. In some embodiments, at 513 (denoted by a dotted arrow as an option) , node 510A may transmit, to node 510B, a request message to request the at least one IP address or the at least one TNL address of node 510B. In some embodiments, the request message may include the TNL address or IP address of node 510A (i.e., the triggering node) . At 515 (denoted by a dotted arrow as an option) , node 510B may transmit the at least one IP address or the at least one TNL address of node 510B to node 510A.

In some embodiments, the request message may be an SL message (e.g., a PC5-RRC message or a PC5-S message) . In some embodiments, the at least one IP address or the at least one TNL address of node 510B may be transported via an SL message (e.g., a PC5-RRC message or a PC5-S message) .

At 517, node 510A and node 510B may perform an SCTP association or TNLA establishment with each other. For example, node 510A and node 510B may transport one or more messages related to the SCTP association or TNLA establishment therebetween. The one or more messages may include handshaking messages for the SCTP association or TNLA establishment. In some embodiments, the one or more messages may be transported by an SL message (e.g., a PC5 RRC message or a PC5-S message) , encapsulated in an SL UP packet, or carried by an SL SRB for transporting a message related to an SCTP association or TNLA establishment. In some embodiments, the SRB may be an SRB dedicated to transporting SCTP association or TNLA establishment related messages.

In some embodiments, the messages related to the SCTP association or TNLA establishment may include an SL message indicating that a target of the SL message is a BS part of a wireless network node (e.g., a WAB node) . For example, node 510B may transmit, to node 510A, an SL message related to the SCTP association or TNLA establishment, which may include an indication indicating that the target entity is the BS part of node 510A, rather than the MT part of node 510A.

In some embodiments, in response to triggering the Xn connection setup procedure, node 510A and node 510B may transport XnAP messages between each other at 519. For example, node 510A may transmit an Xn setup request message to node 510B over the wireless air interface between node 510A and node 510B. Node 510B may respond with an Xn setup response message to node 510A over the wireless air interface between node 510A and node 510B. For example, node 510A and node 510B may transport subsequent Xn related messages (e.g., messages associated with an NG-RAN node configuration update procedure and a handover preparation procedure) between each other over the wireless air interface.

As mentioned above, in this case, the wireless air interface between node 510A and node 510B is the PC5 interface between the MT parts of node 510A and node 510B. In some embodiments, the XnAP messages (e.g., the Xn setup request message, the Xn setup response message and the Xn related messages) may be transported by an SL message (e.g., a PC5 RRC message or a PC5-S message) , encapsulated in an SL UP packet, or carried by an SL SRB for transporting an XnAP message. . In some embodiments, the SRB may be an SRB dedicated to transporting XnAP messages.

In some embodiments, the XnAP messages may include an SL message indicating that a target of the SL message is a BS part of a wireless network node (e.g., a WAB node) or indicating that the SL message is an XnAP message (i.e., indicating that the message is related to the Xn interface) . For example, node 510A may transmit, to node 510B, an SL message, which may include an indication indicating that the target entity is the BS part of node 510B, rather than the MT part of node 510B (or indicating that the message is related to the Xn interface) .

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.

FIGs. 6A and 6B illustrate exemplary block diagrams of communication networks supporting multi-hop in accordance with some embodiments of the present disclosure.

FIG. 6A shows a routing path where WAB node 610B directly connects to BS 610A (WAB donor) and WAB node 610C directly connects to WAB node 610B. That is, the MT part of WAB node 610B connects to BS 610A via a Uu interface and the MT part of WAB node 610C connects to the BS part of WAB node 610B via a Uu interface. WAB node 610C can reach BS 610A by hopping through WAB node 610B. In some other embodiments of the present disclosure, there may be one or more WAB nodes between WAB node 610C and WAB node 610B. In some other embodiments of the present disclosure, WAB node 610C may connect to WAB node 610B via a sidelink. That is, the MT part of WAB node 610C connects to the MT part of WAB node 610B via a PC5 interface. As will be described later, an Xn interface between two non-adjacent nodes along a routing path, for example, BS 610A and WAB node 610C in FIG. 6A, can be established.

FIG. 6B shows a routing path where WAB node 620B directly connects to WAB node 620A and WAB node 620C directly connects to WAB node 620B. That is, the MT part of WAB node 620B connects to the BS part of WAB node 620A via a Uu interface and the MT part of WAB node 620C connects to the BS part of WAB node 620B via a Uu interface. WAB node 620C can reach WAB node 620A by hopping through WAB node 620B. In some other embodiments of the present disclosure, there may be one or more WAB nodes between WAB node 620C and WAB node 620B. In some other embodiments of the present disclosure, WAB node 620C may connect to WAB node 620B via a sidelink. That is, the MT part of WAB node 620C connects to the MT part of WAB node 620B via a PC5 interface. In some other embodiments of the present disclosure, WAB node 620B may connect to WAB node 620A via a sidelink. That is, the MT part of WAB node 620B connects to the MT part of WAB node 620A via a PC5 interface. As will be described later, an Xn interface between two non-adjacent nodes along a routing path, for example, WAB node 620A and WAB node 620C in FIG. 6B, can be established.

The following text describes an exemplary method for establishing an Xn interface between two non-adjacent nodes (denoted as node #1 and node #2 for clarity) along a routing path. For example, node #1 may be one of BS 610A and WAB node 610C in FIG. 6A and node #2 may be the other one of BS 610A and WAB node 610C in FIG. 6A. For example, node #1 may be one of WAB node 620A and WAB node 620C in FIG. 6B and node #2 may be the other one of WAB node 620A and WAB node 620C in FIG. 6B. Details described in all of the foregoing embodiments of the present disclosure are applicable for this exemplary method. It should be appreciated by persons skilled in the art that the sequence of the operations in the exemplary method may be changed and that some of the operations may be eliminated or modified, without departing from the spirit and scope of the disclosure.

In some embodiments, adjacent nodes belonging to the same routing path may share information of upstream or downstream nodes between each other. For example, node #1 or node #2 may receive node information of its upstream or downstream nodes from a node (denoted as node #3 for clarity) between node #1 and node #2. For example, node #3 may be a wireless network node such as WAB node 610B in FIG. 6A or WAB node 620B in FIG. 6B.

For example, node #1 may receive node information of node #2 from node #3 and node #2 may receive node information of node #1 from node #3. Node #1 and node #2 may also receive node information of node #3 from node #3. In some embodiments, node information of a specific node may include (a1) an identifier of this node (e.g., BS ID or BS-CU ID) and (b1) an IP address or a TNL address of this node. In some embodiments, node information of a specific node may include information (a1) . Information (b1) may be obtained in response to triggering an Xn setup procedure. For example, operations similar to operations 311 and 315 in FIG. 3 or operations 513 and 515 in FIG. 5 may be applied to obtain information (b1) , except that relevant messages may be relayed by node #3 since node #1 and node #2 are not directly connected to each other. For example, node #1 may obtain at least one IP address or TNL address of node #2 from node #3.

For example, referring to FIG. 6A, BS 610A may receive node information of downstream nodes (e.g., WAB node 610B and WAB node 610C) from WAB node 610B. WAB node 610B may receive node information of a downstream node (s) (e.g., WAB node 610C) from WAB node 610C and may receive node information of an upstream node (s) (e.g., BS 610A) from BS 610A. WAB node 610C may receive node information of upstream nodes (e.g., BS 610A and WAB node 610B) from WAB node 610B.

For example, referring to FIG. 6B, WAB node 620A may receive node information of downstream nodes (e.g., WAB node 620B and WAB node 620C) from WAB node 620B. WAB node 620B may receive node information of a downstream node (s) (e.g., WAB node 620C) from WAB node 620C and may receive node information of an upstream node (s) (e.g., WAB node 620A) from WAB node 620A. WAB node 620C may receive node information of upstream nodes (e.g., WAB node 620A and WAB node 620B) from WAB node 620B.

In some embodiments, the above node information may be received via an RRC message. For example, node #1 may receive node information of node #2 from node #3 via an RRC message between node #1 and node #3. In some embodiments, node information may be transported in an SL message. For example, assuming that node #1 connects to node #3 via an SL link, node #1 may receive corresponding node information via an SL message from node #3.

Node #1 may trigger an Xn connection setup procedure to node #2. In some embodiments, the triggering of the Xn connection setup procedure may be based on an OAM configuration or indication for node #1. In some embodiments, node #1 may trigger the Xn connection setup procedure in response to (e.g., after) receiving the node information. For example, in response to receiving node information of node #2 which has not established an Xn connection with node #1, node #1 may trigger the Xn connection setup procedure with node #2. In some embodiments, the Xn connection setup procedure may be triggered in response to a UE handover. As will be described later, in response to triggering the Xn connection setup procedure, node #1 and node #2 may transport XnAP messages between each other.

As mentioned above, in some embodiments, node #1 may obtain at least one TNL address or IP address of node #2 in response to triggering the Xn connection setup procedure.

For example, similar to operation 317 in FIG. 3 or operation 517 in FIG. 5, node #1 and node #2 may perform an SCTP association or TNLA establishment with each other, except that relevant messages may be relayed by node #3 since node #1 and node #2 are not directly connected to each other. For example, the SCTP association or TNLA establishment related message may be transported by an RRC message and relayed by node #3. In some embodiments, a message related to the SCTP association or TNLA establishment may indicate one of a source BS ID for multi-hop routing and a source IP address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.

Similar to operation 319 in FIG. 3 or operation 519 in FIG. 5, node #1 and node #2 may transport XnAP messages between each other except that relevant messages may be relayed by node #3 since node #1 and node #2 are not directly connected to each other. For example, an XnAP message may be transported by an RRC message and relayed by node #3. In some embodiments, an XnAP message may indicate one of a source BS ID for multi-hop routing and a source IP address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.

FIG. 7 illustrates a flow chart of exemplary method 700 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. 7. In some examples, method 700 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 700 are described as follows with respect to a wireless network node.

At 711, a wireless network node (denoted as "first wireless network node" for clarity) may trigger an Xn connection setup procedure to a second node. The first wireless network node may support a BS part and an MT part. For example, the first wireless network node may be a WAB node. The second node may be another wireless network node (denoted as "second wireless network node" for clarity) or a BS. For example, the second wireless network node may be a WAB node or a WAB donor.

At 713, the first wireless network node may perform one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the second node over a wireless air interface; and receiving a second XnAP message from the second node over the wireless air interface. The first XnAP message may include an Xn setup request or an Xn related message. The second XnAP message may include an Xn setup response or an Xn related message.

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

In some embodiments of the present disclosure, the first wireless network node may transmit a request message to the second node to request the at least one IP address or the at least one TNL address. In some embodiments of the present disclosure, the request message may include an IP address of the first wireless network node or a TNL address of the first wireless network node.

In some embodiments of the present disclosure, the at least one IP address or the at least one TNL address is received via an RRC message between the first wireless network node and the second node. In some embodiments of the present disclosure, the at least one IP address or the at least one TNL address is received via a PC5-RRC message or a PC5-S message between the first wireless network node and the second wireless network node. In some embodiments of the present disclosure, the at least one IP address or the at least one TNL address is received from an intermediate wireless network node between the first wireless network node and the second node.

In some embodiments of the present disclosure, the wireless air interface may include (e.g., the wireless air interface is) : a Uu interface between the MT part of the first wireless network node and the BS; a Uu interface between the MT part of the first wireless network node and a BS part of the second wireless network node; a Uu interface between the BS part of the first wireless network node and an MT part of the second wireless network node; or a PC5 interface between the MT part of the first wireless network node and the MT part of the second wireless network node.

In some embodiments of the present disclosure, the wireless air interface is a Uu interface. The first XnAP message and the second XnAP message may be transported by an RRC message, encapsulated in a UP packet, or carried by an SRB for transporting an XnAP message. In some embodiments of the present disclosure, the first XnAP message or the second XnAP message may include a DL message indicating that a target of the DL message is a BS part of a wireless network node or indicating that the DL message is related to an Xn interface.

In some embodiments of the present disclosure, the wireless air interface is an SL interface. The first XnAP message and the second XnAP message may be transported by an SL PC5 RRC message or an SL PC5-S message, encapsulated in an SL UP packet, or carried by an SL SRB for transporting an XnAP message. In some embodiments of the present disclosure, the first XnAP message or the second XnAP message may include a first SL message indicating that the target of the first SL message is a BS part of a wireless network node or indicating that the first SL message is related to an Xn interface.

In some embodiments of the present disclosure, the first wireless network node may perform an SCTP association or TNLA establishment between the first wireless network node and the second node.

In some embodiments of the present disclosure, the wireless air interface is a Uu interface. Performing the SCTP association or TNLA establishment may include transporting a message related to the SCTP association or TNLA establishment, which is transported by an RRC message, or encapsulated in a UP packet, or carried by an SRB for transporting the message related to the SCTP association or TNLA establishment, to the second node. In some embodiments of the present disclosure, the message related to the SCTP association or TNLA establishment may include a DL message indicating that a target of the DL message is a BS part of a wireless network node.

In some embodiments of the present disclosure, the wireless air interface is an SL interface. Performing the SCTP association or TNLA establishment may include transporting a message related to the SCTP association or TNLA establishment, which is transported by an SL PC5 RRC message or an SL PC5-S message, or encapsulated in an SL UP packet, or carried by an SL SRB for transporting the message related to the SCTP association or TNLA establishment, to the second wireless network node. In some embodiments of the present disclosure, the message related to the SCTP association or TNLA establishment includes an SL message indicating that its target is a BS part of a wireless network node.

In some embodiments of the present disclosure, the triggering of the Xn connection setup procedure may be based on one of the following: an OAM configuration, an access between the first wireless network node and the second node, an inter discovery between the first wireless network node and the second node, or a reception of node information of the second node.

In some embodiments of the present disclosure, the first wireless network node may receive node information of the second node from an intermediate wireless network node between the first wireless network node and the second node.

In some embodiments of the present disclosure, the node information of the second node includes: (a) an identifier of the BS or a BS part of the second wireless network node; or both (b) an IP address of the second node or a TNL address of the second node and (a) .

In some embodiments of the present disclosure, the node information of the second node may be received via an RRC message between the intermediate wireless network node and the first wireless network node.

In some embodiments of the present disclosure, the first XnAP message and the second XnAP message may be relayed by an intermediate wireless network node between the first wireless network node and the second node, and indicate one of a source BS ID for multi-hop routing and a source IP address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.

In some embodiments of the present disclosure, performing the SCTP association or TNLA establishment may include transporting a message related to the SCTP association or TNLA establishment, which is relayed by an intermediate wireless network node between the first wireless network node and the second node and indicates one of a source BS ID for multi-hop routing and a source IP address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing, to the second node.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary method 700 may be changed and that some of the operations in exemplary method 700 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 8 illustrates a flow chart of exemplary method 800 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. 8. In some examples, method 800 may be performed by a NE such as a BS or a WAB donor. 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 800 are described as follows with respect to a BS.

At 811, a BS may trigger an Xn connection setup procedure to a wireless network node (denoted as "first wireless network node" for clarity) . The first wireless network node may support a BS part and an MT part. For example, the first wireless network node may be a WAB node, and the BS may be a WAB donor.

At 813, the BS may perform one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the first wireless network node over a wireless air interface; and receiving a second XnAP message from the first wireless network node over the wireless air interface. The first XnAP message may include an Xn setup request or an Xn related message. The second XnAP message may include an Xn setup response or an Xn related message.

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

In some embodiments of the present disclosure, the BS may transmit a request message to the first wireless network node to request the at least one IP address or the at least one TNL address. In some embodiments of the present disclosure, the request message may include an IP address of the BS or a TNL address of the BS.

In some embodiments of the present disclosure, the at least one IP address or the at least one TNL address may be received via an RRC message between the first wireless network node and the BS. In some embodiments of the present disclosure, the at least one IP address or the at least one TNL address may be received from an intermediate wireless network node between the first wireless network node and the BS.

In some embodiments of the present disclosure, the wireless air interface may include (e.g., the wireless air interface is) a Uu interface between the MT part of the first wireless network node and the BS.

In some embodiments of the present disclosure, the first XnAP message and the second XnAP message may be transported by an RRC message, encapsulated in a UP packet, or carried by an SRB for transporting an XnAP message. In some embodiments of the present disclosure, the first XnAP message may indicate that a target of the first XnAP message is a BS part of a wireless network node or indicates that the first XnAP message is related to an Xn interface.

In some embodiments of the present disclosure, the BS may perform an SCTP association or TNLA establishment between the first wireless network node and the BS.

In some embodiments of the present disclosure, performing the SCTP association or TNLA establishment may include transporting a message related to the SCTP association or TNLA establishment, which is transported by an RRC message, or encapsulated in a UP packet, or carried by an SRB for transporting the message related to the SCTP association or TNLA establishment, to the first wireless network node. In some embodiments of the present disclosure, the message related to the SCTP association or TNLA establishment may include a DL message indicating that a target of the DL message is a BS part of a wireless network node.

In some embodiments of the present disclosure, the triggering of the Xn connection setup procedure may be based on one of the following: an OAM configuration, an access between the first wireless network node and the BS, an inter discovery between the first wireless network node and the BS, or a reception of node information of the first wireless network node.

In some embodiments of the present disclosure, the BS may receive node information of the first wireless network node from an intermediate wireless network node between the first wireless network node and the BS.

In some embodiments of the present disclosure, the first XnAP message and the second XnAP message may be relayed by an intermediate wireless network node between the first wireless network node and the BS, and indicate one of a source BS ID for multi-hop routing and a source IP address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.

In some embodiments of the present disclosure, performing the SCTP association or TNLA establishment may include transporting a message related to the SCTP association or TNLA establishment, which is relayed by an intermediate wireless network node between the first wireless network node and the BS and indicates one of a source BS ID for multi-hop routing and a source IP address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary method 800 may be changed and that some of the operations in exemplary method 800 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 9 illustrates an example of an NE 900 in accordance with aspects of the present disclosure. NE 900 may be a network node, a wireless network node, a WAB node, a BS or a WAB donor. The NE 900 may include a processor 902, a memory 904, a controller 906, and a transceiver 908. The processor 902, the memory 904, the controller 906, or the transceiver 908, 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 902, the memory 904, the controller 906, or the transceiver 908, 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 902 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 902 may be configured to operate the memory 904. In some other implementations, the memory 904 may be integrated into the processor 902. The processor 902 may be configured to execute computer-readable instructions stored in the memory 904 to cause the NE 900 to perform various functions of the present disclosure.

The memory 904 may include volatile or non-volatile memory. The memory 904 may store computer-readable, computer-executable code including instructions when executed by the processor 902 cause the NE 900 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 904 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 902 and the memory 904 coupled with the processor 902 may be configured to cause the NE 900 to perform one or more of the functions described herein (e.g., executing, by the processor 902, instructions stored in the memory 904) . For example, the processor 902 may support wireless communication at the NE 900 in accordance with examples as disclosed herein.

For example, the NE 900 may be configured to support means for performing the operations as described with respect to FIG. 7. For example, the NE 900 may support a BS part and an MT part and may be configured to support: a means for triggering an Xn connection setup procedure to a second node, wherein the second node is a second wireless network node or a BS; and a means for performing one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the second node over a wireless air interface; and receiving a second XnAP message from the second node over the wireless air interface.

For example, the NE 900 may be configured to support means for performing the operations as described with respect to FIG. 8. For example, the NE 900 may be configured to support: a means for triggering an Xn connection setup procedure to a first wireless network node, wherein the first wireless network node supports a BS part and an MT part; and a means for performing one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the first wireless network node over a wireless air interface; and receiving a second XnAP message from the first wireless network node over the wireless air interface.

The controller 906 may manage input and output signals for the NE 900. The controller 906 may also manage peripherals not integrated into the NE 900. In some implementations, the controller 906 may utilize an operating system such as or other operating systems. In some implementations, the controller 906 may be implemented as part of the processor 902.

In some implementations, the NE 900 may include at least one transceiver 908. In some other implementations, the NE 900 may have more than one transceiver 908. The transceiver 908 may represent a wireless transceiver. The transceiver 908 may include one or more receiver chains 910, one or more transmitter chains 912, or a combination thereof.

A receiver chain 910 may be configured to receive signals (e.g., control information, data, or packets) over a wireless medium. For example, the receiver chain 910 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 910 may include at least one amplifier (e.g., an LNA) configured to amplify the received signal. The receiver chain 910 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 910 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 912 may be configured to generate and transmit signals (e.g., control information, data, or packets) . The transmitter chain 912 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 912 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 912 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 900 may be changed, for example, some of the components in exemplary NE 900 may be omitted or modified or a new component (s) may be added to exemplary NE 900, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the NE 900 may not include the controller 906.

FIG. 10 illustrates an example of a processor 1000 in accordance with aspects of the present disclosure. The processor 1000 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 1000 may include a controller 1002 configured to perform various operations in accordance with examples as described herein. The processor 1000 may optionally include at least one memory 1004, which may be, for example, an L1/L2/L3 cache. Additionally, or alternatively, the processor 1000 may optionally include one or more arithmetic-logic units (ALUs) 1006. 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 1000 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 1000) 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 1002 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 1000 to cause the processor 1000 to support various operations in accordance with examples as described herein. For example, the controller 1002 may operate as a control unit of the processor 1000, generating control signals that manage the operation of various components of the processor 1000. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 1002 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 1004 and determine a subsequent instruction (s) to be executed to cause the processor 1000 to support various operations in accordance with examples as described herein. The controller 1002 may be configured to track memory address of instructions associated with the memory 1004. The controller 1002 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 1002 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 1000 to cause the processor 1000 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 1002 may be configured to manage flow of data within the processor 1000. The controller 1002 may be configured to control transfer of data between registers, ALUs, and other functional units of the processor 1000.

The memory 1004 may include one or more caches (e.g., memory local to or included in the processor 1000 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 1004 may reside within or on a processor chipset (e.g., local to the processor 1000) . In some other implementations, the memory 1004 may reside external to the processor chipset (e.g., remote to the processor 1000) .

The memory 1004 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1000, cause the processor 1000 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 1002 and/or the processor 1000 may be configured to execute computer-readable instructions stored in the memory 1004 to cause the processor 1000 to perform various functions. For example, the processor 1000 and/or the controller 1002 may be coupled with or to the memory 1004, the processor 1000, the controller 1002, and the memory 1004 may be configured to perform various functions described herein. In some examples, the processor 1000 may include multiple processors and the memory 1004 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 1006 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 1006 may reside within or on a processor chipset (e.g., the processor 1000) . In some other implementations, the one or more ALUs 1006 may reside external to the processor chipset (e.g., the processor 1000) . One or more ALUs 1006 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 1006 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 1006 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 1006 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 1006 to handle conditional operations, comparisons, and bitwise operations.

The processor 1000 may support wireless communication in accordance with examples as disclosed herein.

For example, the processor 1000 may be configured to support means for performing the operations as described with respect to FIG. 7. For example, the processor 1000 may be configured to or operable to support: a means for triggering an Xn connection setup procedure to a second node, wherein the second node is a second wireless network node or a BS; and a means for performing one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the second node over a wireless air interface; and receiving a second XnAP message from the second node over the wireless air interface

For example, the processor 1000 may be configured to support means for performing the operations as described with respect to FIG. 8. For example, the processor 1000 may be configured to or operable to support: a means for triggering an Xn connection setup procedure to a first wireless network node, wherein the first wireless network node supports a BS part and an MT part; and a means for performing one or more of the following in response to triggering the Xn connection setup procedure: transmitting a first XnAP message to the first wireless network node over a wireless air interface; and receiving a second XnAP message from the first wireless network node over the wireless air interface.

It should be appreciated by persons skilled in the art that the components in exemplary processor 1000 may be changed, for example, some of the components in exemplary processor 1000 may be omitted or modified or a new component (s) may be added to exemplary processor 1000, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the processor 1000 may not include the ALUs 1006.

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 "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, 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:

support a base station (BS) part and a mobile terminal (MT) part;

trigger an Xn connection setup procedure to a second node, wherein the second node is a second wireless network node or a BS; and

perform one or more of the following in response to triggering the Xn connection setup procedure:

transmitting a first Xn application protocol (XnAP) message to the second node over a wireless air interface; and

receiving a second XnAP message from the second node over the wireless air interface.
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 second node, at least one internet protocol (IP) address of the second node or at least one transport network layer (TNL) address of the second node.
The first wireless network node of Claim 2, wherein the at least one IP address or the at least one TNL address is received via a radio resource control (RRC) message between the first wireless network node and the second node, or is received via a PC5-RRC message or a PC5-S message between the first wireless network node and the second wireless network node, or is received from an intermediate wireless network node between the first wireless network node and the second node.
The first wireless network node of Claim 1, wherein the wireless air interface comprises:

a Uu interface between the MT part of the first wireless network node and the BS;

a Uu interface between the MT part of the first wireless network node and a BS part of the second wireless network node;

a Uu interface between the BS part of the first wireless network node and an MT part of the second wireless network node; or

a PC5 interface between the MT part of the first wireless network node and the MT part of the second wireless network node.
The first wireless network node of Claim 1, wherein the wireless air interface is a Uu interface and wherein the first XnAP message and the second XnAP message are transported by a radio resource control (RRC) message, encapsulated in a user plane (UP) packet, or carried by a signaling radio bearer (SRB) for transporting an XnAP message.
The first wireless network node of Claim 1, wherein the wireless air interface is a sidelink (SL) interface and wherein the first XnAP message and the second XnAP message are transported by an SL PC5 radio resource control (RRC) message or an SL PC5-S message, encapsulated in an SL user plane (UP) packet, or carried by an SL signaling radio bearer (SRB) for transporting an XnAP message.
The first wireless network node of Claim 1, wherein the at least one processor is further configured to cause the first wireless network node to perform stream control transport protocol (SCTP) association or transport network layer association (TNLA) establishment between the first wireless network node and the second node.
The first wireless network node of Claim 7, wherein the wireless air interface is a Uu interface and wherein to perform the SCTP association or TNLA establishment, the at least one processor is configured to cause the first wireless network node to transport a message related to the SCTP association or TNLA establishment, which is transported by a radio resource control (RRC) message, or encapsulated in a user plane (UP) packet, or carried by a signaling radio bearer (SRB) for transporting the message related to the SCTP association or TNLA establishment, to the second node.
The first wireless network node of Claim 1, wherein the triggering of the Xn connection setup procedure is based on one of the following: an operation administration and maintenance (OAM) configuration, an access between the first wireless network node and the second node, an inter discovery between the first wireless network node and the second node, or a reception of node information of the second node.
The first wireless network node of Claim 1 or 9, wherein the at least one processor is further configured to cause the first wireless network node to receive node information of the second node from an intermediate wireless network node between the first wireless network node and the second node.
The first wireless network node of Claim 10, wherein the node information of the second node comprises:

(a) an identifier of the BS or a BS part of the second wireless network node; or

both (b) an internet protocol (IP) address of the second node or a transport network layer (TNL) address of the second node and (a) .
A base station (BS) , comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the BS to:

trigger an Xn connection setup procedure to a first wireless network node, wherein the first wireless network node supports a BS part and a mobile terminal (MT) part; and

perform one or more of the following in response to triggering the Xn connection setup procedure:

transmitting a first Xn application protocol (XnAP) message to the first wireless network node over a wireless air interface; and

receiving a second XnAP message from the first wireless network node over the wireless air interface.
The BS of Claim 12, wherein the at least one processor is configured to cause the BS to receive, from the first wireless network node, at least one internet protocol (IP) address of the first wireless network node or at least one transport network layer (TNL) address of the first wireless network node.
The BS of Claim 13, wherein the at least one IP address or the at least one TNL address is received via a radio resource control (RRC) message between the first wireless network node and the BS, or is received from an intermediate wireless network node between the first wireless network node and the BS.
The BS of Claim 12, wherein the wireless air interface comprises a Uu interface between the MT part of the first wireless network node and the BS.
The BS of Claim 12, wherein the first XnAP message and the second XnAP message are transported by a radio resource control (RRC) message, encapsulated in a user plane (UP) packet, or carried by a signaling radio bearer (SRB) for transporting an XnAP message.
The BS of Claim 12, wherein the at least one processor is further configured to cause the BS to perform stream control transport protocol (SCTP) association or transport network layer association (TNLA) establishment between the first wireless network node and the BS.
The BS of Claim 12, wherein the first XnAP message and the second XnAP message are relayed by an intermediate wireless network node between the first wireless network node and the BS, and indicate one of a source BS ID for multi-hop routing and a source internet protocol (IP) address for multi-hop routing and one of a target BS ID for multi-hop routing and a target IP address for multi-hop routing.
A method for wireless communication, comprising:

triggering, by a first wireless network node, an Xn connection setup procedure to a second node, wherein the first wireless network node supports a base station (BS) part and a mobile terminal (MT) part and the second node is a second wireless network node or a BS; and

performing, by the first wireless network node, one or more of the following in response to triggering the Xn connection setup procedure:

transmitting a first Xn application protocol (XnAP) message to the second node over a wireless air interface; and

receiving a second XnAP message from the second node over the wireless air interface.
A method for wireless communication, comprising:

triggering an Xn connection setup procedure to a first wireless network node, wherein the first wireless network node supports a base station (BS) part and a mobile terminal (MT) part; and

performing one or more of the following in response to triggering the Xn connection setup procedure:

transmitting a first Xn application protocol (XnAP) message to the first wireless network node over a wireless air interface; and

receiving a second XnAP message from the first wireless network node over the wireless air interface.