Supporting relaying in integrated access and backhaul networks

Abstract

Techniques are described for supporting relay communications in an integrated access and backhaul (IAB) network. An example wireless communication method includes receiving, by a relay node in a wireless access and backhaul network, internet protocol (IP) address information from a parent node of the relay node, the IP address information comprising a default IP address or an identification of a donor node, transmitting, to the donor node, a first control message using the default IP address or the identification of the donor node, the first control message comprising a request for the IP address information, and receiving, from the donor node in response to transmitting the request, a second control message comprising allocated IP address information.

Description

Technical Field

[0001] This disclosure generally relates to digital wireless communications. Background Technology

[0002] Mobile telecommunications technologies are driving the world toward an increasingly interconnected and networked society. Compared to existing wireless networks, next-generation systems and wireless communication technologies will need to support a wider range of use case characteristics and provide more complex and granular access requirements and flexibility.

[0003] Long Term Evolution (LTE) is a wireless communication standard developed by the 3rd Generation Partnership Project (3GPP) for mobile devices and data terminals. LTE Advanced (LTE-A) is a wireless communication standard that enhances the LTE standard. The fifth-generation wireless system (known as 5G) advances the LTE and LTE-A wireless standards and aims to support higher data rates, massive connectivity, ultra-low latency, high reliability, and other emerging service requirements. Summary of the Invention

[0004] This document describes methods, systems, and apparatuses for supporting relay communication in Integrated Access and Backhaul (IAB) networks. In 5G systems, IAB networks allow for multi-hop backhaul using the same frequency as the user equipment (UE) access frequency or different dedicated frequencies, and provide an alternative to fiber optic site backhaul by leveraging the spectral efficiency of New Radio (NR) and the greater capacity offered by higher frequency bands in 5G. Embodiments of the disclosed technology provide mechanisms for Internet Protocol (IP) address allocation for wireless relay nodes in IAB networks.

[0005] In one example aspect, a wireless communication method includes: transmitting a first control message from a relay node in a wireless access and backhaul network to the parent node of the relay node, the first control message including a request for Internet Protocol (IP) address information; and receiving the IP address information from the parent node.

[0006] In another example aspect, a wireless communication method includes: receiving Internet Protocol (IP) address information, including a default IP address or an identifier of a host node, from a relay node in a wireless access and backhaul network; transmitting a first control message to the host node using the default IP address or the identifier of the host node, the first control message including a request for the IP address information; and receiving a second control message from the host node, the second control message including the assigned IP address information, in response to transmitting the request.

[0007] In yet another example, a wireless communication method includes transmitting host-related information from a host node to a relay node in a wireless access and backhaul network.

[0008] In yet another example, a wireless communication method includes transmitting host-related information associated with a host node from a first relay node to a second relay node in a wireless access and backhaul network.

[0009] In yet another example, the above-described method is embodied in processor-executable code and stored in a non-transitory computer-readable storage medium. When executed by a processor, the code contained in the computer-readable storage medium causes the processor to implement the method described in this patent document.

[0010] In yet another example, an apparatus configured or operable to perform the methods described above is disclosed.

[0011] The above and other aspects and their embodiments are described in more detail in the accompanying drawings, description and claims. Attached Figure Description

[0012] Figure 1 An example of an Integrated Access and Backhaul (IAB) architecture is shown.

[0013] Figure 2A and Figure 2B An example of an IAB network is shown.

[0014] Figure 3 This example illustrates the parent-child relationship of an IAB node.

[0015] Figures 4A to 4D A flowchart of an example wireless communication method is shown.

[0016] Figure 5 A block diagram of an example hardware platform that may be part of a network device or a communication device is shown.

[0017] Figure 6 Examples of wireless communication systems are shown, including base stations (BS) and user equipment (UE) and based on some implementations of the disclosed technologies. Detailed Implementation

[0018] Integrated Access and Backhaul (IAB) architecture (also known as Radio Access and Backhaul or WAB architecture) supports radio access and backhaul via NR, enabling flexible and very dense deployment of NR cells while reducing the need for wired transmission infrastructure. In these systems, relay nodes (e.g., IAB nodes or WAB nodes) support access and backhaul via NR. The terminating node for NR backhaul on the network side is called the host node, which represents a gNB with additional functionality to support radio access and backhaul.

[0019] Backhaul can occur via single hop or multiple hops. An example of an Integrated Access and Backhaul (IAB) architecture is shown in... Figure 1As shown in the figure, relay node 2 (120) is the parent node of relay node 1 (110), that is, relay node 1 (110) is the child node of relay node 2 (120). Similarly, relay node 3 (130) is the parent node of relay node 2 (120), that is, relay node 2 (120) is the child node of relay node 3 (130). In addition, the IAB host node (150) is the parent node of relay node 3 (130), and relay node 1 (110) is the parent node of UE (105).

[0020] In the IAB network, the relay node supports the gNodeB (gNB) function to terminate to the UE's NR access interface and to the Xn / NG protocol of the host node / access and mobility management function (AMF).

[0021] Figure 2A and Figure 2B Examples of IAB architectures are shown, one with the IAB node and NGC using SA mode, and the other with the IAB node using EN-DC. The IAB node supports gNB-DU functionality (as defined in 3GPP TS 38.401) to terminate to the NR access interface of the UE and the next-hop IAB node, and to terminate to the F1 protocol of gNB-CU functionality (as defined in 3GPP TS 38.401) on the IAB host. The gNB-DU functionality on the IAB node is also called... IAB-DU .

[0022] In addition to gNB functionality, the relay node also supports a subset of UE functionality, referred to as... MT It includes, for example, physical layer, layer 2, radio resource control (RRC), and non-access layer (NAS) functions to connect to another relay node or host node and the core network.

[0023] IAB nodes can access the network using SA mode or EN-DC. In EN-DC, IAB nodes also connect to the MeNB via E-UTRA, and the IAB host terminates the X2-C as the SgNB (see 3GPP TS 37.340).

[0024] All IAB nodes connected to the IAB host via one or more hops form a directed acyclic graph (DAG) topology rooted at the IAB host, such as... Figure 3 As shown. In this DAG topology, the adjacent nodes on the IAB-DU interface are called... son Nodes and adjacent nodes on the IAB-MT interface are called father Node. The direction toward the child nodes is further called... Downstream The direction towards the parent node is called... Upstream The IAB host performs centralized resource, topology, and routing management for the IAB topology.

[0025] The example headings in the following sections are for ease of understanding of the disclosed subject matter and do not limit the scope of the claimed subject matter in any way. Therefore, one or more features of one example section may be combined with one or more features of another example section. Furthermore, for clarity, the term "5G" is used, but the technologies disclosed in this document are not limited to 5G technology alone and can be used in wireless systems implementing other protocols.

[0026] Example #1 In existing implementations, relay nodes (e.g., the gNB portion of a relay node) need to obtain IP addresses to establish Xn / NG connections with the host node and AMF, and to deliver Xn-U / NG-U services. To be able to deliver control plane signaling and user plane data via the IAB host, the IP address used by the relay node in CP / UP packets needs to be anchored at the host node. Otherwise, packets may be dropped at the host node, for example, if source IP filtering is used. Some disclosed embodiments provide mechanisms for determining how a relay node can obtain an IP address anchored at the host node.

[0027] In some embodiments, the following technical solutions are used to implement how a relay node can obtain an IP address anchored at a host node.

[0028] Step 1: The relay node sends a first IP address request message to its parent node via RRC, for example, during the RRC setup phase, or after the relay node has established an RRC connection with its parent node. The first IP address request message includes at least one of the following: the number of IP addresses requested, and the purpose of the requested IP addresses. The purpose of the IP addresses includes at least one of the following: all services, F1-C services, F1-U services, non-F1 services, OAM services, Xn-C services, Xn-U services, NG-C services, NG-U services, non-Xn services, non-NG services, and non-Xn / NG services. The requested IP addresses include at least one of the following: an IPv4 IP address or an IPv6 IP address or an IPv6 prefix.

[0029] Step 2: The parent node sends a second IP address request message to its parent node or host node via an RRC or Xn message. The second IP address request message includes at least one of the following: the relay node's identifier, the parent node's identifier, and the first IP address request message. For example, the relay node / parent node's identifier includes one of the following: BAP address, an identifier assigned by the host node, gNB ID, or IP address.

[0030] Step 3: The parent node receives IP address information from its parent or host node via RRC or Xn. The IP address information includes at least one of the following: the relay node's identifier, the parent node's identifier, the host node's identifier, the host node's BAP address, the assigned IP address information, and the purpose of the IP address. The assigned IP address information includes one of the following: an IPv4 IP address or an IPv6 IP address or an IPv6 prefix.

[0031] Note that if the parent node is the host node, steps 2 and 3 can be skipped.

[0032] Step 4: The parent node / host node sends the IP address information to the relay node via RRC.

[0033] Example #2 In some embodiments, the following technical solutions are used to implement how a relay node can obtain an IP address anchored at a host node.

[0034] Step 1: Optionally, the relay node sends a first IP address request to the parent node.

[0035] Step 2: The parent node sends the first IP address information to the relay node via an RRC message. The first IP address information includes the host node's BAP address or default IP address, for example, for NG-C, Xn-C, or OAM services. The default IP address can be an IPv4 IP address, an IPv6 IP address, or an IPv6 prefix.

[0036] Step 3: The relay node establishes an Xn connection with the host node using the IP address received in the first IP address information. The relay node sends a second IP address request message to the host node via the Xn message. The second IP address request message includes at least one of the following: the relay node's identifier, the parent node's identifier, the number of requested IP addresses, and the purpose of the requested IP addresses.

[0037] Step 4: The host node sends the second IP address information to the relay node via the Xn message. The second IP address information includes at least one of the following: the relay node's identifier, the parent node's identifier, the host node's identifier, the host node's BAP address, the assigned IP address information, and the purpose of the IP address. The assigned IP address information includes one of the following: an IPv4 IP address or an IPv6 IP address or an IPv6 prefix.

[0038] Example #3 In some embodiments, the following technical solutions are used to implement how a relay node can identify or determine which node is the host node, or how a relay node can obtain information about the host node.

[0039] Option 1: The host node broadcasts hop count information. For example, a hop count set to a specified value (e.g., 0) indicates that the node is the host node. Optionally, the relay node broadcasts hop count information. In the example, the hop count indicates the number of backhaul links between the relay node and the host node, or the number of hops between the relay node and the host node.

[0040] Option 2: The host node broadcasts a host instruction.

[0041] Option 3: The host node sends host-related information to the relay node via Xn or RRC. Host-related information includes at least one of the following: hop count information indicating the number of backhaul links or hop counts between the relay node and the host node, host indication, capability information, the host node's identifier, the host node's IP address, or the Backhaul Adaptation Protocol (BAP) address. In the example, host-related information is transmitted from the host node to the relay node via broadcast information, Radio Resource Control (RRC) signaling, or Xn messages. Capability information indicates whether the node supports host functionality or whether the node is a host node.

[0042] Option 4: The relay node sends host-related information to another relay node via RRC or Xn. In the example, the host-related information is transmitted from the first relay node to the second relay node via broadcast information, Radio Resource Control (RRC) signaling, or Xn messages. The host-related information includes at least one of the following: host indication, host capabilities, host node identifier (e.g., gNB ID), host node Internet Protocol (IP) address, host node Backhaul Adaptation Protocol (BAP) address, or hop count between the relay node and the host node.

[0043] Example #4 In existing implementations, relay nodes (e.g., mobile IAB nodes) may (or may not) be authorized to perform relay or (mobile) IAB operations. If unauthorized, the relay node is treated as a regular UE, and its authorization status can change or be updated over time or based on its location. However, in existing systems, the host node serving the MT portion (also known as the RRC termination host) of the relay node cannot determine the status of the connection and / or service between the F1 termination host (i.e., the host node with an F1 connection to the DU portion of the relay node) and the relay node. This prevents the RRC termination host from determining whether to release backhaul resources or send an updated authorization status to the F1 termination host when the authorization status changes. In some embodiments, the following technical solutions address this problem.

[0044] Step 1: The RRC termination host transmits an IAB transport migration modification request message to the F1 termination host, which includes the authorization status of the relay node. As an example, if the authorization status is "unauthorized", the F1 termination host performs an ordered F1 release procedure, such as initiating a handover for the UE served by the relay node and releasing the F1 connection between the relay node and the F1 termination host.

[0045] Step 2: The F1 termination host sends an Xn message (e.g., an IAB transport migration management request or an IAB transport migration modification response) to the RRC termination host. This Xn message includes one of the following: a service release list, all service release indications, or an F1 release indication. As an example, this Xn message is sent after all UEs have been switched or released from the relay node, or after the F1 connection between the relay node and the F1 termination host has been released.

[0046] Step 3: The RRC terminates the host and releases all backhaul resources of the relay node (e.g., BAP address, IP address, BAP configuration).

[0047] Example methods and implementations of the disclosed technology Figure 4A A flowchart of an example wireless communication method 410 is shown. Method 410 includes, at operation 412, a relay node in a wireless access and backhaul network transmitting a first control message to the parent node of the relay node, the first control message including a request for Internet Protocol (IP) address information.

[0048] Method 410 includes receiving the IP address information from the parent node at operation 414.

[0049] Figure 4B A flowchart of an example wireless communication method 420 is shown. Method 420 includes, at operation 422, a relay node in a wireless access and backhaul network receiving Internet Protocol (IP) address information from its parent node, the IP address information including a default IP address or an identifier of the host node.

[0050] Method 420 includes, at operation 424, transmitting a first control message to the host node using the default IP address or the identifier of the host node, the first control message including a request for the IP address information.

[0051] Method 420 includes, at operation 426, receiving a second control message from the host node in response to transmitting the request, the second control message including allocated IP address information.

[0052] Figure 4CA flowchart of an example wireless communication method 430 is shown. Method 430 includes, at operation 432, transmitting host-related information from a host node to a relay node in a wireless access and backhaul network.

[0053] Figure 4D A flowchart of an example wireless communication method 440 is shown. Method 440 includes, at operation 442, transmitting host-related information associated with a host node to a second relay node in a wireless access and backhaul network from a first relay node.

[0054] The described features can be implemented to further provide one or more of the following technical solutions: 1. A wireless communication method, comprising: transmitting a first control message from a relay node in a wireless access and backhaul network to a parent node of the relay node, the first control message including a request for Internet Protocol (IP) address information; and receiving the IP address information from the parent node. In some examples, the first control message is the first IP address request information in embodiment #1.

[0055] 2. The method as described in Scheme 1, wherein the parent node is configured to: transmit a second control message to an upstream node upon receiving the first control message, the second control message including a request for the IP address information and / or the identifier of the relay node, wherein the upstream node is the parent node's parent node or host node; and after transmitting the second control message, receive a third control message from the upstream node, the third control message including the IP address information.

[0056] 3. The method as described in Scheme 2, wherein the first control message is a Radio Resource Control (RRC) message, and the second control message or the third control message is an RRC message or an Xn message.

[0057] 4. The method as described in Scheme 1, wherein the first control message includes the number of IP addresses and / or the purpose of the IP address information.

[0058] 5. The method described in Scheme 4, wherein the purpose of the IP address information includes at least one of the following indications: all services, F1-C services, F1-U services, non-F1 services, OAM services, Xn-C services, Xn-U services, NG-C services, NG-U services, non-Xn services, non-NG services, or non-Xn / NG services.

[0059] 6. A wireless communication method comprising: receiving Internet Protocol (IP) address information from a parent node of a relay node in a wireless access and backhaul network, the IP address information including a default IP address or an identifier of a host node; transmitting a first control message to the host node using the default IP address or the identifier of the host node, the first control message including a request for the IP address information; and receiving a second control message from the host node in response to transmitting the request, the second control message including allocated IP address information. In some examples, the IP address information is the first IP address information in embodiment #2.

[0060] 7. The method of Scheme 6, wherein the second control message is received via the Xn connection, and wherein the method further includes: establishing an Xn connection with the host node using the default IP address or the identifier of the host node.

[0061] 8. The method as described in Scheme 6 or 7, wherein the identifier of the host node includes a Backwards Adaptation Protocol (BAP) address, a network node identifier, or the IP address of the network node, and wherein the IP address of the network node is an IPv4 IP address, an IPv6 IP address, or an IPv6 prefix.

[0062] 9. The method of any one of claims 6 to 8, wherein the first control message is a Radio Resource Control (RRC) message or an Xn message, and wherein the second control message is an RRC message or an Xn message.

[0063] 10. The method of any one of Schemes 6 to 8, wherein the first control message includes at least one of the following: the identifier of the relay node, the identifier of the parent node, the number of IP addresses, or the purpose of the IP address information.

[0064] 11. A wireless communication method comprising: transmitting host-related information from a host node to a relay node in a wireless access and backhaul network. In some examples, the host-related information is as described in embodiment #3.

[0065] 12. The method of Scheme 11, wherein the host-related information includes at least one of the following: hop count information indicating the number of backhaul links or hop count between the relay node and the host node, host indication, capability information, the identifier of the host node, the IP address of the host node, or the Backhaul Adaptation Protocol (BAP) address of the host node.

[0066] 13. The method of Scheme 11, wherein the host-related information is transmitted from the host node to the relay node via broadcast information, Radio Resource Control (RRC) signaling, or Xn message.

[0067] 14. A wireless communication method comprising: transmitting host-related information associated with a host node from a first relay node to a second relay node in a wireless access and backhaul network. In some examples, the host-related information is as described in embodiment #3.

[0068] 15. The method of Scheme 14, wherein the host-related information is transmitted from the first relay node to the second relay node via broadcast information, Radio Resource Control (RRC) signaling, or Xn message.

[0069] 16. The method of Scheme 14, wherein the host-related information includes at least one of the following: host indication, host capability, identifier of the host node, Internet Protocol (IP) address of the host node, Backhaul Adaptation Protocol (BAP) address of the host node, or hop count between the relay node and the host node.

[0070] 17. An apparatus for wireless communication, comprising a processor configured to implement one or more of the methods described in embodiments 1 to 16.

[0071] 18. A non-transitory computer-readable program storage medium having code stored thereon, which, when executed by a processor, causes the processor to perform one or more of the methods described in schemes 1 to 16.

[0072] Figure 5 An exemplary block diagram is shown of a hardware platform 500 that may be part of a network device (e.g., a base station) or a communication device (e.g., a user equipment (UE)). The hardware platform 500 includes at least one processor 510 and a memory 505 storing instructions thereon. When executed by the processor 510, the instructions configure the hardware platform 500 to perform the various embodiments described in this patent document. Figure 1 The operation is as described in Figure 4. Transmitter 515 transmits or sends information or data to another device. For example, a network device transmitter can send a message to a user equipment. Receiver 520 receives information or data transmitted or sent by another device. For example, a user equipment can receive a message from a network device.

[0073] The implementation methods discussed above will be applied to wireless communication. Figure 6An example of a wireless communication system (e.g., a 5G or NR cellular network) including a base station 620 and one or more user equipments (UEs) 611, 612, and 613 is shown. In some embodiments, the UE accesses the BS (e.g., the network) using a communication link to the network (sometimes referred to as the uplink direction, as shown by dashed arrows 631, 632, and 633), which then enables subsequent communication from the BS to the UE (e.g., the direction from the network to the UE, sometimes referred to as the downlink direction, as shown by arrows 641, 642, and 643). In some embodiments, the BS sends information to the UE (sometimes referred to as the downlink direction, as shown by arrows 641, 642, and 643), which then enables subsequent communication from the UE to the BS (e.g., the direction from the UE to the BS, sometimes referred to as the uplink direction, as shown by dashed arrows 631, 632, and 633). The UE may be, for example, a smartphone, tablet, mobile computer, machine-to-machine (M2M) device, Internet of Things (IoT) device, etc.

[0074] Some embodiments described herein are described in the general context of methods or processes that may be implemented in one embodiment by a computer program product embodied in a computer-readable medium, including computer-executable instructions, such as program code, that are executed by a computer in a networked environment. Computer-readable media may include removable and non-removable storage devices, including but not limited to read-only memory (ROM), random access memory (RAM), optical disc (CD), digital versatile optical disc (DVD), etc. Therefore, computer-readable media may include non-transitory storage media. Typically, program modules may include routines, programs, objects, components, data structures, etc., that perform a particular task or implement a particular abstract data type. Computer-executable or processor-executable instructions, associated data structures, and program modules represent examples of program code for performing steps of the methods disclosed herein. A particular sequence of such executable instructions or associated data structures represents examples of corresponding actions for implementing the functionality described in such steps or processes.

[0075] Some disclosed embodiments may be implemented as devices or modules using hardware circuitry, software, or a combination thereof. For example, hardware circuitry implementations may include discrete analog and / or digital components integrated, for example, as part of a printed circuit board. Alternatively or additionally, the disclosed components or modules may be implemented as application-specific integrated circuits (ASICs) and / or field-programmable gate arrays (FPGAs). Some implementations may additionally or alternatively include digital signal processors (DSPs) as dedicated microprocessors, whose architecture is optimized for the operational requirements of digital signal processing associated with the disclosed functions of this application. Similarly, the various components or sub-components within each module may be implemented using software, hardware, or firmware. Interconnections between modules and / or between components within a module may be provided using any connection methods and media known in the art, including but not limited to communication via the Internet, wired, or wireless networks using appropriate protocols.

[0076] While this document contains numerous details, these details should not be construed as limiting the scope of the claimed invention or any possible claims, but rather as descriptions of features specific to particular embodiments. Certain features described herein in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, while features may be described above as functioning in a particular combination and even initially claimed in this way, in some cases one or more features of the claimed combination may be removed from the combination, and the claimed combination may involve sub-combinations or variations thereof. Similarly, while operations are depicted in a specific order in the figures, this should not be construed as requiring such operations to be performed in the specific or sequential order shown, or that all shown operations must be performed to achieve the desired result.

[0077] Only a few implementations and examples have been described, and other implementations, enhancements and modifications can be made based on the content described and illustrated in this disclosure.

Claims

1. A wireless communication method, comprising: A relay node in the wireless access and backhaul network transmits a first control message to its parent node, the first control message including a request for Internet Protocol (IP) address information; and Receive the IP address information from the parent node.

2. The method as described in claim 1, wherein, The parent node is configured as follows: Upon receiving the first control message, a second control message is transmitted to the upstream node, the second control message including a request for the IP address information and / or the identifier of the relay node, wherein the upstream node is the parent node of the parent node or the host node; as well as After transmitting the second control message, a third control message is received from the upstream node, the third control message including the IP address information.

3. The method as described in claim 2, wherein, The first control message is a Radio Resource Control (RRC) message, wherein the second control message or the third control message is an RRC message or an Xn message.

4. The method of claim 1, wherein, The first control message includes the number of IP addresses and / or the purpose of the IP address information.

5. The method of claim 4, wherein, The purpose of the IP address information includes at least one of the following indications: all services, F1-C services, F1-U services, non-F1 services, OAM services, Xn-C services, Xn-U services, NG-C services, NG-U services, non-Xn services, non-NG services, or non-Xn / NG services.

6. A wireless communication method, comprising: The relay node in the wireless access and backhaul network receives Internet Protocol (IP) address information from its parent node, the IP address information including a default IP address or the identifier of the host node; A first control message is transmitted to the host node using the default IP address or the identifier of the host node, the first control message including a request for the IP address information; as well as In response to transmitting the request, a second control message is received from the host node, the second control message including the allocated IP address information.

7. The method of claim 6, wherein, The second control message is received via the Xn connection, and the method further includes: Establish an Xn connection with the host node using the default IP address or the identifier of the host node.

8. The method of claim 6 or 7, wherein, The identifier of the host node includes a Backhaul Adaptor Protocol (BAP) address, a network node identifier, or the IP address of the network node, wherein the IP address of the network node is an IPv4 IP address, an IPv6 IP address, or an IPv6 prefix.

9. The method according to any one of claims 6 to 8, wherein, The first control message is a Radio Resource Control (RRC) message or an Xn message, and the second control message is an RRC message or an Xn message.

10. The method according to any one of claims 6 to 8, wherein, The first control message includes at least one of the following: the identifier of the relay node, the identifier of the parent node, the number of IP addresses, or the purpose of the IP address information.

11. A wireless communication method, comprising: The host node transmits host-related information to relay nodes in the wireless access and backhaul network.

12. The method of claim 11, wherein, The host-related information includes at least one of the following: hop count information indicating the number of backhaul links or hop counts between the relay node and the host node, host indication, capability information, the identifier of the host node, the IP address of the host node, or the Backhaul Adaptor Protocol (BAP) address of the host node.

13. The method of claim 11, wherein, The host-related information is transmitted from the host node to the relay node via broadcast information, Radio Resource Control (RRC) signaling, or Xn messages.

14. A wireless communication method, comprising: The first relay node transmits host-related information associated with the host node to the second relay node in the wireless access and backhaul network.

15. The method of claim 14, wherein, The host-related information is transmitted from the first relay node to the second relay node via broadcast information, Radio Resource Control (RRC) signaling, or Xn messages.

16. The method of claim 14, wherein, The host-related information includes at least one of the following: host indication, host capability, identifier of the host node, Internet Protocol (IP) address of the host node, Backhaul Adaptor (BAP) address of the host node, or hop count between the relay node and the host node.

17. An apparatus for wireless communication, comprising a processor configured to implement the method as claimed in one or more of claims 1 to 16.

18. A non-transitory computer-readable program storage medium having code stored thereon, the code, when executed by a processor, causing the processor to perform the method as described in one or more of claims 1 to 16.

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