CN115707149A

CN115707149A - Communication method and communication device

Info

Publication number: CN115707149A
Application number: CN202110892477.5A
Authority: CN
Inventors: 孙飞; 朱元萍; 史玉龙
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-08-04
Filing date: 2021-08-04
Publication date: 2023-02-17
Also published as: WO2023011245A1

Abstract

The application provides a communication method and a communication device, which can determine a dual-connection mode of an F1 interface and improve the stability of service communication. The method comprises the following steps: the first network device receives capability information of at least one second network device from the wireless backhaul node, the at least one second network device or the network management device, where the capability information indicates whether the IAB host capability is provided and/or whether the F1AP message is supported to be transmitted over an air interface, and the first network device is a master base station of the wireless backhaul node. And the first network equipment determines the target second network equipment as a secondary base station of the wireless backhaul node according to the capability information of the at least one second network equipment. And the first network equipment configures a dual-connection mode of an F1 interface of the wireless backhaul node according to the capability information of the first network equipment and the target network equipment.

Description

Communication method and communication device

Technical Field

The present application relates to the field of communications, and in particular, to a communication method and a communication apparatus.

Background

In consideration of abundant high-frequency carrier frequency resources, in hot spot areas, in order to meet the ultra-high capacity requirement of future communication, networking by using high-frequency small stations is more popular. However, the high-frequency carrier is seriously shielded and attenuated, and the coverage area is not wide, so a large number of densely deployed high-frequency small stations are needed, and the cost of Backhaul (BH) provided for the large number of densely deployed high-frequency small stations through optical fibers is high, the construction difficulty is high, and therefore a more economic and convenient backhaul scheme is needed. In addition, when network coverage is provided in some remote areas, the deployment difficulty of the optical fiber is high, and the cost is high, so that a flexible and convenient backhaul scheme also needs to be designed. The wireless backhaul device provides a solution to the above-mentioned problems. Both an Access Link (AL) and a Backhaul Link (BL) of the wireless backhaul device adopt a wireless transmission scheme, so that optical fiber deployment can be reduced. The wireless backhaul device may be a Relay Node (RN), such as an Integrated Access Backhaul (IAB) node.

The wireless backhaul device may transmit the data packet of the terminal back to the host node through the wireless backhaul link, or may transmit the data packet from the host node to the terminal through the wireless access link. The communication network formed by one or more wireless backhaul devices may be referred to as a wireless backhaul network or a relay network. Usually, one relay node is connected to only one host node, however, as the relay network evolves, a communication scenario occurs in which one relay node is connected to a plurality of host nodes.

The relay node is connected to the core network via a host node, and for example, under a fifth generation mobile communication technology (5G) architecture of a stand-alone network (SA), the relay node is connected to a 5G core network (5G core,5 gc) via the host node. In a 5G architecture (e.g., non-independent Networking (NSA) or NR-DC scenario) with Dual Connectivity (DC) or multi-connectivity (MC), the relay node may be connected to an Evolved Packet Core (EPC) through an evolved NodeB (eNB) or connected to the 5G core through a host node on a main path.

The topologies relied on by the dual-connection architecture of the F1 interface in the current IAB network may include a redundant topology (topology) and a non-redundant topology. At present, how to determine which type of dual connection mode of an F1 interface is used by a terminating node of a control plane message (F1-C), such as a host node, is a problem to be solved urgently.

Disclosure of Invention

The embodiment of the application provides a communication method and a communication device, which can determine which dual-connection mode of an F1 interface is adopted, so as to improve the stability of service communication between an IAB node and a terminal.

In a first aspect, a communication method is provided, including: the method includes that a first network device acquires capability information of at least one second network device, the capability information indicates whether the first network device has an IAB host capability and/or supports transmission of an F1 interface application protocol (F1 AP) message through an air interface, and the first network device is a Master Node (MN) of a wireless backhaul node. The first network device selects a target second network device from the at least one second network device as a Secondary Node (SN) of the wireless backhaul node according to the capability information of the at least one second network device. The first network device configures a dual connectivity for the F1 interface of the wireless backhaul node.

In this embodiment of the present application, the first network device may determine, according to the acquired capability information of the network device, to configure a dual connection mode of the F1 interface of the wireless backhaul node, which is beneficial to improving stability of service communication between the IAB node and the terminal, and improving service experience of the terminal.

With reference to the first aspect, in some implementation manners of the first aspect, the dual connection manner of the F1 interface includes that the F1AP message is transmitted over an air interface, and the F1 interface data of the user plane is transmitted over a backhaul link.

In the embodiment of the application, for a CP-UP split dual connection mode based on a non-redundant topology, the F1AP message and the F1 interface data of the user plane may be transmitted through different paths, which is beneficial to improving the data transmission rate.

With reference to the first aspect, in some implementation manners of the first aspect, the transmitting the F1AP message over an air interface includes: the F1AP message is transmitted to the target second network device through an air interface between the wireless backhaul node and the first network device. Or, the F1AP message is transmitted to the first network device through an air interface between the wireless backhaul node and the target second network device.

In this embodiment of the present application, for CP-UP separation in which the host node serves as an SN role and the terminating node of the F1AP message is a non-redundant topology of an SN, the F1AP message may be transmitted to the SN through an air interface between the wireless backhaul node and the MN. For the CP-UP separation of the non-redundant topology in which the host node is MN and the terminating node is MN, the F1AP message may be transmitted to MN through an air interface between the wireless backhaul node and the SN.

With reference to the first aspect, in certain implementations of the first aspect, the backhaul link is a communication link between the wireless backhaul node and the first network device or the target second network device.

With reference to the first aspect, in certain implementations of the first aspect, the F1AP message and the F1 interface data of the user plane are transmitted over a backhaul link, which is a communication link between the wireless backhaul node and the first network device and the target second network device. It can be understood that, under the F1 interface dual-connection architecture, the wireless backhaul node may transmit the F1AP message and/or the F1 interface data of the user plane through the backhaul link with the first network device; the wireless backhaul node may also transmit F1AP messages, and/or F1 interface data of the user plane, via a backhaul link with the second network device. The information (F1 AP message or F1 interface data of the user plane) of which F1 interface the wireless backhaul node specifically transmits through which backhaul link may be determined by the wireless backhaul node itself, or may be configured or updated by the network device.

In this embodiment, the first network device and the target second network device are host nodes of the wireless backhaul node, and the F1 interface of the wireless backhaul node may adopt a dual connection mode of a redundant topology, in which the F1AP message and the F1 interface data of the user plane may be transmitted through a backhaul link between the wireless backhaul node and the first network device and the target second network device. The double connection mode is beneficial to improving the stability of data transmission.

With reference to the first aspect, in some implementations of the first aspect, the obtaining, by the first network device, the capability information of at least one second network device includes: the first network device receives capability information of at least one second network device from the at least one second network device.

With reference to the first aspect, in certain implementations of the first aspect, the first network device determines whether an Xn interface between the first network device and at least one second network device supports transmission of F1AP messages over Xn interface application protocol XnAP messages. The first network device selects a target second network device from the at least one second network device as a secondary node SN of the wireless backhaul node according to the capability information of the at least one second network device, and the method includes: and the first network equipment selects a target second network equipment from the at least one second network equipment as the SN of the wireless backhaul node according to the capability information of the at least one second network equipment and whether the Xn interface supports the transmission of the F1AP message through the XnAP message.

In this embodiment of the present application, if the first network device interacts capability information with the at least one second network device, it is further required that the interaction Xn interface supports transmission of the F1AP message through the XnAP message, which is beneficial to stability of transmission of the F1AP message.

With reference to the first aspect, in some implementations of the first aspect, the obtaining, by the first network device, the capability information of at least one second network device includes: the first network device receiving capability information of at least one second network device from the wireless backhaul node; or, the first network device receives the capability information of at least one second network device from the network management device.

With reference to the first aspect, in certain implementations of the first aspect, the first network device receives a measurement report of at least one second network device, the measurement report including a signal quality between the wireless backhaul node and the at least one second network device. The first network device selects a target second network device from the at least one second network device as a secondary node SN of the wireless backhaul node according to the capability information of the at least one second network device, and the method includes: the first network device selects the target second network device from the at least one second network device as the SN of the wireless backhaul node according to the capability information of the at least one second network device and the measurement report.

With reference to the first aspect, in certain implementations of the first aspect, the configuring, by the first network device, a dual connectivity mode of an F1 interface of the wireless backhaul node includes: the first network device sends first indication information to the wireless backhaul node, where the first indication information indicates a dual connectivity mode of the F1 interface.

With reference to the first aspect, in certain implementations of the first aspect, the first indication information is default backhaul radio link control (default BH RLC) channel configuration information. The default BH RLC channel is the BH RLC channel used by the wireless backhaul node to send F1AP messages for the first time.

In this embodiment, the first network device may indicate, for the wireless backhaul node, a form adopted by the transmission F1AP, that is, transmission through the backhaul link or transmission through an air interface.

With reference to the first aspect, in certain implementations of the first aspect, the first network device sends the first indication information to the wireless backhaul node through the target second network device.

With reference to the first aspect, in certain implementations of the first aspect, the first network device broadcasts the capability information of the first network device. The first network device receives access request information from the wireless backhaul node.

In this embodiment of the present application, the first network device broadcasts the capability information of the first network device to the outside, so that the wireless backhaul node can sense the support condition of the first network device on the IAB hosting capability, which is beneficial for the wireless backhaul node to access a suitable network device as an MN.

In a second aspect, a communication method is provided, including: and the target second network equipment sends the capability information of the target second network equipment, wherein the capability information indicates whether the IAB host capability is provided and/or whether the F1AP message is supported to be transmitted through an air interface. The target second network device receives the access request information from the wireless backhaul node, and the target second network device is an auxiliary node SN of the wireless backhaul node.

In this embodiment of the application, the target second network device is an SN that is added to the wireless backhaul node by the MN and matches with the dual connectivity mode, which is beneficial to improving the stability of service communication between the IAB node and the terminal and improving the service experience of the terminal.

With reference to the second aspect, in some implementation manners of the second aspect, the dual connection manner of the F1 interface includes that the F1AP message is transmitted over an air interface, and the F1 interface data of the user plane is transmitted over a backhaul link.

With reference to the second aspect, in some implementation manners of the second aspect, the transmitting the F1AP message over an air interface includes: the F1AP message is transmitted to the target second network device over an air interface between the wireless backhaul node and the first network device. Or, the F1AP message is transmitted to the first network device through an air interface between the wireless backhaul node and the target second network device.

With reference to the second aspect, in certain implementations of the second aspect, the backhaul link is a backhaul link between the wireless backhaul node and the first network device or the target second network device.

With reference to the second aspect, in certain implementations of the second aspect, the F1AP message and the F1 interface data of the user plane are transmitted over a backhaul link, which is a communication link between the wireless backhaul node and the first network device and the target second network device.

With reference to the second aspect, in some implementations of the second aspect, the sending, by the target second network device, the capability information of the target second network device includes: the target second network device sends the capability information of the target second network device to the first network device. The method further comprises the following steps: the target second network device sends whether an Xn interface between the target second network device and the first network device supports transmission of F1AP messages over XnAP messages.

With reference to the second aspect, in some implementations of the second aspect, the sending, by the target second network device, the capability information of the target second network device includes: the target second network device broadcasts capability information of the target second network device.

With reference to the second aspect, in certain implementations of the second aspect, the target second network device sends second indication information to the wireless backhaul node, where the second indication information indicates a dual connectivity mode of the F1 interface.

With reference to the second aspect, in some implementations of the second aspect, the second indication information includes default BH RLC channel configuration information. The default BH RLC channel is the BH RLC channel used by the wireless backhaul node to send F1AP messages for the first time.

With reference to the second aspect, in certain implementations of the second aspect, the target second network device sends the second indication information to the wireless backhaul node through the first network device.

In a third aspect, a communication method is provided, including: the wireless backhaul node obtains capability information of at least one network device, where the capability information is used to indicate whether the IAB host capability is available and/or whether the F1AP message is supported to be transmitted over an air interface. The wireless backhaul node accesses a first network device based on capability information of at least one network device, the first network device being a master node MN of the wireless backhaul node. The wireless backhaul node receives first configuration information, where the first configuration information is used to configure a target second network device as a secondary node SN of the wireless backhaul node. The wireless backhaul node receives second configuration information, where the second configuration information is used to configure a dual connectivity mode of the F1 interface of the wireless backhaul node.

In this embodiment of the present application, the wireless backhaul node may determine the MN and the SN according to the acquired capability information of the network device, where the MN and/or the SN have an IAB host capability, and configure a dual connection mode matching with the capability information of the host node for the F1 interface according to the second configuration information, which is beneficial to improving stability of service communication between the IAB node and the terminal, and improving service experience of the terminal.

With reference to the third aspect, in some implementation manners of the third aspect, the dual connectivity mode includes that the F1AP message is transmitted over an air interface, and the F1 interface data of the user plane is transmitted over a backhaul link.

With reference to the third aspect, in certain implementations of the third aspect, the F1AP message and the F1 interface data of the user plane are transmitted over a backhaul link between the wireless backhaul node and the first network device and the target second network device.

With reference to the third aspect, in some implementations of the third aspect, the second configuration information includes default BH RLC channel configuration information. The default BH RLC channel is the BH RLC channel used by the wireless backhaul node to send F1AP messages for the first time.

With reference to the third aspect, in certain implementations of the third aspect, the wireless backhaul node sends the F1AP message over a backhaul link between the wireless backhaul node and the first network device or the target second network device.

In a fourth aspect, a communication method is provided, including: a Centralized Unit (CU) of a first network device determines a target path between a CU of the first network device and a Distributed Unit (DU) of a second network device from a plurality of candidate paths. The CU of the first network device transmits data to the DU of the second network device via the target path.

In the embodiment of the present application, for the path selection between the CU of the first network device and the DU of the second network device under the redundant topology, the CU of the first network device may determine a target path that is simple to implement from multiple candidate paths, which is beneficial to reducing the loss of data packets and improving the reliability of data transmission. In the embodiment of the present application, the CU of the first network device determines the target path as an example, and in addition, the DU of the second network device may determine the target path for data transmission, which is not limited in the present application.

With reference to the fourth aspect, in some implementations of the fourth aspect, the plurality of candidate paths includes at least one of path 1: the CU of the first network device connects to the DU of the second network device through an Internet Protocol (IP) network. Alternatively, path 2: the CU of the first network device passes through the CU of the second network device to the DU of the second network device. Alternatively, path 3: the CU of the first network device passes through the DU of the first network device to the DU of the second network device.

With reference to the fourth aspect, in some implementations of the fourth aspect, the IP paths of path 1 and path 2 are normal and the IP path of path 3 is abnormal. The CU of the first network device determining a target path between the CU of the first network device and the DU of the second network device from a plurality of candidate paths, comprising: if the source IP address of the data packet to be transmitted is in the white list of the filter unit of the IP router between the CU of the first network device and the DU of the second network device, or the IP router between the CU of the first network device and the DU of the second network device does not start the filter unit, the CU of the first network device determines that path 1 is the target path.

In the embodiment of the present application, taking uplink transmission as an example, since the path 2 needs to add the outer IP once at the DU of the second network device and add the outer IP once at the CU of the second network device, the implementation is complicated, and the path 1 only needs to add the outer IP once at the DU of the second network device, which is convenient to implement, so that the path 1 is selected as the target path to transmit data.

With reference to the fourth aspect, in some implementations of the fourth aspect, the IP paths of path 1 and path 3 are normal and the IP path of path 2 is abnormal. The CU of the first network device determining a target path between the CU of the first network device and the DU of the second network device from a plurality of candidate paths, comprising: if there is a tunnel between the DU of the first network device and the DU of the second network device, the CU of the first network device determines that path 3 is the target path.

In the embodiment of the present application, since tunneling is more stable than IP network transmission, when there is a tunnel between the DU of the first network device and the DU of the second network device, the path 3 is selected as the target path to transmit data.

With reference to the fourth aspect, in some implementations of the fourth aspect, the IP paths of path 1 and path 3 are normal and the IP path of path 2 is abnormal. The CU of the first network device determining a target path between the CU of the first network device and the DU of the second network device from a plurality of candidate paths, comprising: if an IP network is used between the DU of the first network device and the DU of the second network device, the CU of the first network device determines that path 1 or path 3 is the target path. In the embodiment of the present application, the selection of path 1 and path 3 is implemented based on the base station.

With reference to the fourth aspect, in some implementations of the fourth aspect, the IP paths of path 2 and path 3 are normal, and the IP path of path 1 is abnormal; the CU of the first network device determining a target path between the CU of the first network device and the DU of the second network device from a plurality of candidate paths, comprising: the CU of the first network device determines path 3 to be the target path.

In the embodiment of the present application, the path 2 is implemented in a complex manner, and the data transmission between the DU1 of the first network device and the CU1 of the first network device in the path 3 is consistent with the original data packet processing method, which is simple to implement, so the path 3 is selected as the target path to transmit data.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the IP paths of path 1, path 2, and path 3 are normal. The CU of the first network device determining a target path between the CU of the first network device and the DU of the second network device from a plurality of candidate paths, comprising: the CU of the first network device determines path 1 or path 3 as the target path.

In the embodiment of the present application, if the IP paths of the three candidate paths are normal, path 1 and path 3 are preferentially selected, and since the two paths are simple to implement, the target path can be determined in path 1 and path 3.

With reference to the fourth aspect, in certain implementations of the fourth aspect, the method further includes: the CU of the first network device determines whether the IP paths of the candidate paths are normal or abnormal through testing ping values or based on an Internet Control Message Protocol (ICMP).

In the embodiment of the present application, before determining the target path, the first network device first needs to test the IP path condition of each candidate path, so that the candidate path with an abnormal IP path can be eliminated, which is favorable for the reliability of data transmission.

In a fifth aspect, a communication apparatus is provided, including: for performing the method of any one of the possible implementations of any one of the above aspects. In particular, the apparatus comprises means for performing the method of any one of the above-described aspects in any possible implementation.

In one design, the apparatus may include a module corresponding to one or more of the methods/operations/steps/actions described in the foregoing aspects, and the module may be a hardware circuit, a software circuit, or a combination of a hardware circuit and a software circuit.

In another design, the device is a communication chip that may include an input circuit or interface for sending information or data and an output circuit or interface for receiving information or data.

In another design, the apparatus is a communication device that may include a transmitter to transmit information or data and a receiver to receive information or data.

In another design, the apparatus is configured to perform the method in the foregoing aspects or any possible implementation manner of the aspects, and the apparatus may be configured in the foregoing first network device, the target second network device, or the wireless backhaul node, or the apparatus itself is the foregoing first network device, the target second network device, or the wireless backhaul node.

In a sixth aspect, there is provided another communication apparatus comprising a processor, a memory for storing a computer program, and the processor being configured to retrieve and execute the computer program from the memory, so that the apparatus performs the method of any one of the possible implementations of any one of the above aspects.

Optionally, the number of the processors is one or more, and the number of the memories is one or more.

Alternatively, the memory may be integral to the processor or provided separately from the processor.

Optionally, the apparatus is a communication device, and the communication device further includes a transmitter (transmitter) and a receiver (receiver), and the transmitter and the receiver may be separately provided or integrated together, and are referred to as a transceiver (transceiver).

In a seventh aspect, a processor is provided, including: input circuit, output circuit and processing circuit. The processing circuit is configured to receive a signal via the input circuit and transmit a signal via the output circuit, such that the processor performs the method of any one of the possible implementations of any one of the above aspects.

In a specific implementation process, the processor may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a flip-flop, various logic circuits, and the like. The input signal received by the input circuit may be received and input by, for example and without limitation, a receiver, the signal output by the output circuit may be output to and transmitted by a transmitter, for example and without limitation, and the input circuit and the output circuit may be the same circuit that functions as the input circuit and the output circuit, respectively, at different times. The embodiment of the present application does not limit the specific implementation manner of the processor and various circuits.

In an eighth aspect, there is provided a communication system comprising: means for implementing the method of the first aspect or any one of the possible implementations of the first aspect, means for implementing the method of the second aspect or any one of the possible implementations of the second aspect, and means for implementing the method of the third aspect or any one of the possible implementations of the third aspect.

In one possible design, the communication system may further include other devices interacting with the first network device, the target second network device, and/or the wireless backhaul node in the solution provided in the embodiment of the present application.

In a ninth aspect, there is provided a computer program product, the computer program product comprising: computer program (also called code, or instructions), which when executed, causes a computer to perform the method of any of the possible implementations of any of the above aspects.

In a tenth aspect, a computer-readable medium is provided, which stores a computer program (which may also be referred to as code, or instructions) that, when executed on a computer, causes the computer to perform the method of any of the possible implementations of any of the above aspects.

Drawings

FIG. 1 is a schematic diagram of an IAB network communication system;

fig. 2 is a schematic diagram of a control plane protocol stack in an IAB network;

fig. 3 is a schematic diagram of a user plane protocol stack in an IAB network;

FIG. 4 is a schematic diagram of a communication scenario;

fig. 5 is a schematic diagram of a dual connectivity communication scenario;

FIG. 6 is a schematic diagram of a communication architecture;

FIG. 7 is a schematic diagram of a communication scenario A;

FIG. 8 is a schematic diagram of a communication scenario B;

FIG. 9 is a schematic diagram of a communication scenario C;

FIG. 10 is a schematic diagram of a communication scenario D;

FIG. 11 is a schematic diagram of another communication architecture;

fig. 12 is a schematic diagram of an IAB network architecture provided in an embodiment of the present application;

fig. 13 is a schematic flow chart of a communication method provided by an embodiment of the present application;

FIG. 14 is a schematic diagram of a topology provided by an embodiment of the present application;

FIG. 15 is a schematic diagram of another topology provided by an embodiment of the present application;

FIG. 16 is a schematic diagram of yet another topology provided by an embodiment of the present application;

fig. 17 is a schematic flow chart of another communication method provided by an embodiment of the present application;

fig. 18 is a schematic flow chart of still another communication method provided by an embodiment of the present application;

FIG. 19 is a schematic diagram of a candidate path according to an embodiment of the present disclosure;

FIG. 20 is a schematic diagram of yet another topology provided by an embodiment of the present application;

fig. 21 is a schematic block diagram of a communication device provided in an embodiment of the present application;

fig. 22 is a schematic block diagram of another communication device provided in an embodiment of the present application;

fig. 23 is a schematic block diagram of still another communication device provided in an embodiment of the present application;

fig. 24 is a schematic block diagram of another communication device provided in an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

Before describing the communication method and the communication apparatus provided in the embodiments of the present application, the following description is made.

First, in the embodiments shown below, terms and english abbreviations such as F1 interface, capability information, IAB host capability, F1AP message, etc. are exemplary examples given for convenience of description, and should not limit the present application in any way. This application is not intended to exclude the possibility that other terms may be defined in existing or future protocols to carry out the same or similar functions.

Second, the first, second and various numerical numbers in the embodiments shown below are merely for convenience of description and are not intended to limit the scope of the embodiments of the present application. For example, to distinguish between different network devices, to distinguish between different indication information, etc.

Third, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, and c, may represent: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c, wherein a, b and c can be single or multiple.

It should be noted that, the communication system to which the embodiment of the present application is applied includes, but is not limited to: a narrowband internet of things (NB-IoT) system, a Wireless Local Access Network (WLAN) system, a Long Term Evolution (LTE) system, a next generation 5G mobile communication system, or a communication system of a subsequent evolution, such as a New Radio (NR) communication system.

The donor base station (donor base station) may be a donor node of the IAB node. In the present application, the donor base station may include, but is not limited to: a next generation base station (generation Node B, gbb), an evolved Node B (eNB), a Radio Network Controller (RNC), a Node B (NB), a Base Station Controller (BSC), a Base Transceiver Station (BTS), a home base station (home evolved Node B or home Node B), a transmission point (transmission and reception point or transmission point), a roadside Unit (RSU) having a base station function, a baseband Unit (BBU), a Radio Remote Unit (Remote Radio Unit, RRU), an active antenna Unit (active antenna Unit, AAU), one or a group of antenna panels, or a Node having a base station function in a subsequent system, and the like.

The host base station may be an entity and may further comprise a centralized unit CU entity plus at least one distributed unit DU entity. The interface between CU and DU may be referred to as F1 interface. The two ends of the F1 interface are respectively a CU and a DU, the opposite end of the F1 interface of the CU is the DU, and the opposite end of the F1 interface of the DU is the CU. The F1 interface may further include a control plane F1 interface (F1-C) and a user plane F1 interface (F1-U). In this application, a CU of a Donor base station may be referred to as a Donor CU for short, and a DU of the Donor base station may be referred to as a Donor DU for short. Among them, the Donor CU may be in a form of separating a Control Plane (CP) and a User Plane (UP), for example: a CU may consist of one CU-CP and one (or more) CU-UPs.

In this application, a terminal is also sometimes referred to as a User Equipment (UE), a mobile station, a terminal device, etc. The terminal can be widely applied to various scenes, such as device-to-device (D2D), vehicle-to-electrical (V2X) communication, machine-type communication (MTC), internet of things (IOT), virtual reality, augmented reality, industrial control, automatic driving, telemedicine, smart grid, smart furniture, smart office, smart wearing, smart transportation, smart city, and the like. The terminal can be cell-phone, panel computer, take the computer of wireless transceiving function, wearable equipment, vehicle, unmanned aerial vehicle, helicopter, aircraft, steamer, robot, arm, intelligent house equipment etc.. Terminals may include, but are not limited to: user equipment UE, a mobile station, a mobile device, a terminal device, a user agent, a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, a computing device, other processing devices connected to a wireless modem, a vehicle-mounted device, a wearable device (such as a smart watch, a smart glasses, etc.), a smart furniture or a home appliance, a vehicle to device in a vehicle networking (V2X), a terminal device with relay function, a Customer Premises Equipment (CPE), an IAB node (specifically, an MT of the IAB node or an IAB node as a terminal), and the like.

In this application, the IAB node may include at least one Mobile Terminal (MT) and at least one distributed unit DU (DU). The IAB node may be an entity, e.g. the IAB node comprises at least one MT function and at least one DU function. The IAB node may also comprise a plurality of entities, e.g. the IAB node comprises at least one MT entity and at least one DU entity. Wherein the MT entity and the DU entity can communicate with each other, e.g. via a network cable. When the IAB node faces its parent node (the parent node may be a donor base station or other IAB node), it may serve as a terminal, for example, for various scenarios applied by the terminal, i.e., the terminal role of the IAB node. In this case, it is the MT function or MT entity that provides the terminal role for the IAB node. When the IAB node faces its child nodes (the child nodes may be other IAB nodes or terminals), it may act as a network device, i.e., a network device of the IAB node. In this case it is the DU functionality or DU entity that provides the role of network device for the IAB node. In this application, the MT of the IAB node may be referred to as IAB-MT for short, and the DU of the IAB node may be referred to as IAB-DU for short. The IAB node may access the donor base station or may be connected to the donor base station through other IAB nodes.

The IAB network supports multi-hop networking and multi-connection networking to ensure the reliability of service transmission. The IAB node treats the IAB node providing backhaul service for it as a parent node, and accordingly, the IAB node may be considered a child node of its parent node. The terminal may also regard the IAB node accessed by itself as a parent node, and correspondingly, the IAB node may also regard the terminal accessed by itself as a child node. The IAB node may regard the home base station accessed by itself as a parent node, and correspondingly, the home base station may also regard the IAB node accessed by itself as a child node.

Fig. 1 is a schematic diagram of an IAB network communication system. The communication system comprises a terminal, an IAB node and a host base station. In this application, "IAB network" is only an example, and may be replaced by "wireless backhaul network" or "relay network". The "IAB node" is also an example, and may be replaced by a "wireless backhaul device", a "wireless backhaul node", or a "relay node".

As shown in fig. 1, the parent node of IAB node 1 includes the donor base station. IAB node 1 is again a parent node of IAB node 2 or IAB node 3. The parent node of terminal 1 comprises IAB node 4. The sub-nodes of IAB node 4 include either terminal 1 or terminal 2. An IAB node to which a terminal directly accesses may be referred to as an access IAB node. IAB node 4 in fig. 1 is an access IAB node for terminal 1 and terminal 2.IAB node 5 is the access IAB node for terminal 2.

A node on an uplink transmission path from the IAB node to the host base station may be referred to as an upstream node (upstream node) of the IAB node. The upstream node may include a parent node, a parent node of the parent node (or referred to as a grandparent node), and the like. For example, IAB node 1 and IAB node 2 in fig. 1 may be referred to as upstream nodes of IAB node 5.

A node on a downlink transmission path from an IAB node to a terminal may be referred to as a downstream node (downstream node) or a descendant node (despendant node) of the IAB node. The downstream node or descendant node may include a child node, a child node (or called grandchild node) of the child node, or a terminal, etc. For example, terminal 1, terminal 2, IAB node 3, IAB node 4, or IAB node 5 in FIG. 1 may be referred to as a downstream node or descendant of IAB node 1. Also for example, IAB node 4 and IAB node 5 in FIG. 1 may be referred to as downstream or descendant nodes of IAB node 2. The terminal 1 in fig. 1 may be referred to as a downstream or descendant node of the IAB node 4.

The uplink data packet sent by the terminal to the donor base station may be transmitted to the donor base station through one or more IAB nodes, that is, the target node of the uplink data between the terminal and the donor base station may be the donor base station. The downlink data packet sent by the host base station to the terminal may be sent to the access IAB node of the terminal through one or more IAB nodes, and then sent to the terminal by the access IAB node, that is, the target node of the downlink data between the terminal and the host base station may be the access IAB node.

For example, there are two available paths for data transmission between terminal 1 and the donor base station, path 1: terminal 1 ← → IAB node 4 ← → IAB node 3 ← → IAB node 1 ← → host base station. Route 2: terminal 1 ← → IAB node 4 ← → IAB node 2 ← → IAB node 1 ← → host base station. There are three available paths for data transmission between terminal 2 and the host base station, path 1: terminal 2 ← → IAB node 4 ← → IAB node 3 ← → IAB node 1 ← → host base station, path 2: terminal 2 ← → IAB node 4 ← → IAB node 2 ← → IAB node 1 ← → host base station, path 3: terminal 2 ← → IAB node 5 ← → IAB node 2 ← → IAB node 1 ← → host base station.

It is understood that in the IAB network, one or more IAB nodes may be included on one transmission path between the terminal and the donor base station.

Each IAB node needs to maintain a Backhaul Link (BL) towards the parent node. If the sub-node of the IAB node is a terminal, the IAB node also needs to maintain an Access Link (AL) with the terminal. As shown in fig. 1, the link between IAB node 4 and terminal 1 or terminal 2 includes an AL. A BL is included between IAB node 4 and either IAB node 2 or IAB node 3.

Fig. 2 and 3 are schematic diagrams of a control plane protocol stack and a user plane protocol stack, respectively, in an IAB network. The donor base station in fig. 2 and 3 may include a donor CU and a donor DU function (in this case, the donor base station is one entity), or may include a donor CU entity and a donor DU entity (in this case, the donor base station is divided into two entities). As shown in fig. 2 or fig. 3, the peer protocol layers between the host DU and the host CU include an IP layer, layer 2 (layer 2, L2), and layer 1 (layer 1, L1). Where L1 and L2 may refer to protocol stack layers in a wired transport (e.g., fiber optic transport) network. For example, L1 may be a physical layer and L2 may be a data link layer. Backhaul Links (BL) are established between IAB node 4 and IAB node 3, between IAB node 3 and IAB node 1, and between IAB node 1 and the home DU. The peer protocol stack at both ends of the BL may include a Backhaul Adaptation Protocol (BAP) layer, a Radio Link Control (RLC), a Medium Access Control (MAC) layer, and a Physical (PHY) layer.

As shown in fig. 2, there is an interface, sometimes referred to as an air interface, between the terminal and the donor base station. For example, may be referred to as a Uu interface. One end of the Uu interface is positioned at the terminal, and the other end is positioned at the host base station. The control plane protocol stack, which is peer to peer at both ends of the Uu interface, includes a Radio Resource Control (RRC) layer, a Packet Data Convergence (PDCP) layer, an RLC layer, an MAC layer, and a PHY layer. The Uu interface control plane protocol stack includes a protocol layer that may also be referred to AS an Access Stratum (AS) of the control plane. If the donor base station includes a donor CU entity and a donor DU entity, the control plane protocol stacks of the Uu interface at the donor base station end may be located in the donor DU and the donor CU, respectively. For example, the PHY layer, the MAC layer, and the RLC layer are located in the host DU, and the RRC layer and the PDCP layer are located in the host CU.

There is an interface, for example called F1 interface, between the DU of the IAB node to which the terminal accesses (i.e. IAB node 4 in fig. 2) and the donor base station. One end of the F1 interface is located in the IAB node 4, and the other end is located in the donor base station. An opposite end of the F1 interface of the donor base station (which may be a donor CU, for example) is an IAB node (which may be specifically a DU of the IAB node), and an opposite end of the F1 interface of the IAB node (which may be specifically a DU of the IAB node) is a donor base station (which may be specifically a donor CU). The control plane protocol stack with two peer ends of the F1 interface includes an F1 application protocol (F1 AP) layer, a Stream Control Transmission Protocol (SCTP) layer, and an IP layer. The donor base station may include a donor CU entity and a donor DU entity. The control plane protocol stack of the F1 interface at the home base station may be located in the home CU, for example, the home CU includes an F1AP layer, an SCTP layer, and an IP layer. The control plane protocol stack of the F1 interface at the home base station end may also be located in the home CU and the home DU, respectively, for example, the home CU includes an F1AP layer and an SCTP layer, and the home DU includes an IP layer.

In the control plane, an RRC message of the terminal is encapsulated in an F1 interface application protocol (F1 AP) message by the access IAB node and transmitted. Specifically, in the uplink direction, the terminal encapsulates the RRC message in a PDCP Protocol Data Unit (PDU), and sends the PDU to the IAB node 4 after sequentially processing by the RLC layer, the MAC layer, and the PHY layer. And the DU of the IAB node 4 is processed by a PHY layer, an MAC layer and an RLC layer in sequence to obtain a PDCP PDU, the PDCP PDU is packaged in the F1AP message, and is processed by an SCTP layer and an IP layer in sequence to obtain an IP packet. The DU of IAB node 4 sends the IP packet to the MT of IAB node 4 over the internal interface. The MT of the IAB node 4 sends the IP packet to the DU of the IAB node 3 after passing through the processing of the BAP layer, the RLC layer, the MAC layer, and the PHY layer in sequence. The DU of the IAB node 3 is processed by a PHY layer, an MAC layer, an RLC layer and a BAP layer in sequence to obtain an IP packet. The DU of IAB node 3 sends the IP packet to the MT of IAB node 3 via the internal interface, and then the MT of IAB node 3 sends the IP packet to the DU of IAB node 1 using an operation similar to the MT of IAB node 4. The DU of IAB node 1 then sends the IP packet to the MT of IAB node 1 in a similar operation to the DU of IAB node 3. Similarly, the MT of the IAB node 1 sends the IP packet to the host DU. And after the host DU is analyzed to obtain the IP packet, the IP packet is sent to the host CU. And the host CU processes the IP packet sequentially through the SCTP layer, the F1AP layer and the PDCP layer to obtain the RRC message of the terminal. The downstream direction is similar and will not be described again.

As shown in fig. 3, the peer-to-peer user plane protocol stacks at both ends of the Uu interface between the terminal and the host base station include a Service Data Adaptation Protocol (SDAP) layer, a PDCP layer, an RLC layer, an MAC layer, and a PHY layer. The Uu interface user plane protocol stack comprises protocol layers which may also be referred to AS the Access Stratum (AS) of the user plane. If the donor base station includes a donor CU entity and a donor DU entity, the user plane protocol stacks of the Uu interface at the side of the donor base station may be located in the donor DU and the donor CU, respectively. For example, the PHY layer, the MAC layer, and the RLC layer are located in the host DU, and the SDAP layer and the PDCP layer are located in the host CU.

The user plane protocol layers that are peer to peer at both ends of the F1 interface between the DU of the IAB node 4 and the host base station include a general packet radio service (GTP-U) layer, a User Datagram Protocol (UDP) layer, and an IP layer. The donor base station may include a donor CU entity and a donor DU entity. The user plane protocol stack of the F1 interface at the donor base station may be located in the donor CU, for example, the donor CU includes a GTP-U layer, a UDP layer, and an IP layer. The user plane protocol stacks of the F1 interface at the home base station side may also be located in the home CU and the home DU, respectively, for example, the home CU includes a GTP-U layer and a UDP layer, and the home DU includes an IP layer.

On the user plane, a data packet of the terminal is encapsulated in a PDCP PDU (PDCP PDU), the PDCP PDU is sent to an access IAB node after being processed by an RLC layer, an MAC layer and a PHY layer in sequence, and the access IAB node encapsulates the received PDCP PDU in a GTP-U tunnel between the access IAB node and a host CU for transmission. The GTP-U tunnel is established on the F1-U interface. For the transmission process of the data packet of the specific terminal, reference may be made to the transmission process of the control plane RRC message, which is not described herein again.

In addition, in fig. 2 and 3, when there is a terminal accessing the home DU, the interface between the home DU and the home CU may also include an F1 interface. The control plane protocol stack of the two peer-to-peer ends of the F1 interface comprises a F1AP layer, a SCTP layer and an IP layer. The user plane protocol stack with two ends being equal to each other of the F1 interface comprises a GTP-U layer, a UDP layer and an IP layer. When a terminal accesses the IAB node 1 or the IAB node 3, the IAB node 1 or the IAB node 3 and the donor base station may also include an F1 interface, and the description of the F1 interface may refer to the description of the F1 interface between the DU of the IAB node 4 and the donor base station.

When the terminal refers to an MT function or an MT entity of an IAB node, or an IAB node serving as a terminal role, the protocol stack of the terminal shown in fig. 2 or fig. 3 is a protocol stack of the MT function or the MT entity of a certain IAB node, or a protocol stack when a certain IAB node serves as a terminal role.

The IAB node may take the role of a terminal when accessing the IAB network. In this case, the MT of the IAB node has the protocol stack of the terminal. An air interface (Uu interface) protocol stack exists between the IAB node and the host base station. The protocol stack of the terminal shown in fig. 2 and 3 includes an RRC layer or an SDAP layer, a PDCP layer, an RLC layer, an MAC layer, and a PHY layer. And the RRC message of the IAB node is encapsulated by the parent node of the IAB node on the control plane and transmitted in the F1AP message. On the user plane, a data packet of the IAB node is encapsulated in a PDCP Protocol Data Unit (PDU) and sent to a parent node of the IAB node, and the parent node of the IAB node encapsulates the received PDCP PDU in a GTP-U tunnel on an F1 interface between the parent node of the IAB node and a host CU for transmission. In addition, after the IAB node accesses the IAB network, the IAB node may still function as a normal terminal, for example, the IAB node may transmit its own data packet, such as an operation, administration and maintenance (OAM) data packet, a measurement report, and the like, with the host base station.

It should be noted that an IAB node may have one or more roles in the IAB network. For example, the IAB node may serve as a terminal, an access IAB node (e.g., a protocol stack of IAB node 4 in fig. 2 and 3), or an intermediate IAB node (e.g., a protocol stack of IAB node 1 or IAB node 3 in fig. 2 and 3). The IAB node may use the protocol stacks corresponding to the different roles for the different roles. When the IAB node has multiple roles in the IAB network, multiple sets of protocol stacks may be provided at the same time, and some same protocol layers may be shared among the sets of protocol stacks, for example, the same RLC layer, MAC layer, and PHY layer may be shared.

Fig. 4 is a schematic diagram of a communication scenario. As shown in fig. 4, a Donor base station (Donor base station) and an IAB node are included. The Donor base station may include a Donor CU (Donor CU) and at least one Donor DU (Donor DU). The communication interface between the donor base station and the IAB node may include an air interface (Uu interface) and an F1 interface. For example, an air interface (Uu interface) is provided between the MT of the IAB and the host base station, and an F1 interface is provided between the DU of the IAB and the host base station.

The IP address of the IAB node may be allocated to the IAB node by a Donor DU or by a network management device. The IP address of the Donor CU may also be assigned by the network management device. In this application, the network management device may include an operation, administration, and maintenance (OAM) element, an Element Management System (EMS), or a Network Management System (NMS).

Fig. 5 is a schematic diagram of a dual-connection communication scenario. As shown in fig. 5, a master base station (master base station), a secondary base station (secondary base station) and an IAB node are included. Wherein, the host base station of the IAB node is an auxiliary base station. The communication interface between the primary base station and the IAB node includes an air interface (Uu interface). The communication interface between the secondary base station and the IAB node includes a Uu interface and a F1 interface. In the present application, a primary base station may be referred to as a primary node of the IAB node, and a secondary base station may be referred to as a secondary node of the IAB node.

Fig. 6 is a schematic diagram of a communication architecture. As shown in fig. 6, the Donor base station 1 includes a Donor CU1 (Donor CU 1) and a Donor DU1 (Donor DU 1). The Donor base station 2 includes a Donor CU2 (Donor CU 2) and a Donor DU2 (Donor DU 2). There is a communication interface between the IAB node and the donor base station 1 or the donor base station 2. For example, the communication interface between the IAB node and the donor base station 1 or the donor base station 2 may include a Uu interface, and/or, an F1 interface. There is also a communication interface between the donor base station 1 and the donor base station 2. The Donor CU1 and the Donor CU2 may communicate with each other, for example, via an X2 or Xn interface. The Donor CU1 and the Donor DU2, and the Donor CU2 and the Donor DU1 may also communicate with each other, for example over an IP network. It will be appreciated that in the communication architecture illustrated in fig. 6, downstream or descendant nodes of the IAB node may also be included. An upstream node of the IAB node may also be included between the IAB node and the donor base station.

Fig. 7-10 are schematic diagrams of communication scenarios that may occur under the communication architecture shown in fig. 6. As shown in fig. 7-10, the IAB node includes an MT and DU part (in which case the IAB node is divided into two entities), or an MT and DU function (in which case the IAB node is one entity). The donor base station includes a donor CU entity and a donor DU entity (in this case, the donor base station is divided into two entities), or a donor CU and a donor DU function (in this case, the donor base station remains as a whole). There is also an upstream node IAB node 2 (i.e., the parent node of IAB node 3) between IAB node 3 and the donor base station. In fig. 7-10, possible paths of F1 interface communication between the IAB node and the donor base station 1 or the donor base station 2 in each scenario are illustrated by thick curves. It is to be appreciated that in fig. 7, other upstream nodes of the IAB node 3 may also be included between the IAB node 3 and the IAB node 2, or between the IAB node 3 and the IAB node 1. In FIG. 7, other downstream or descendant nodes of the IAB node 3 may also be included. In fig. 7-10, IAB node 1 may not be present, i.e. IAB node 3 may be directly connected to the donor base station 1.IAB node 2 may also be absent, i.e. IAB node 3 may be directly connected to the hosting base station 2. Described below in connection with several communication scenarios illustrated in fig. 7-10, it should be understood that the nodes represented by legend 1 in fig. 7-10 are controlled by the Donor CU1, i.e. the nodes illustrated in fig. 1 constitute the topology segments controlled by the Donor CU1.

Communication scenario a of fig. 7: when the Donor base station in the communication scenario a in fig. 7 is the Donor base station 1 (i.e., the Donor CU is the Donor CU1, and the Donor DU is the Donor DU 1), a Uu interface and an F1 interface exist between the IAB node 3 and the Donor base station 1. The F1 interface communication between the IAB node 3 and the Donor base station 1 needs to pass through the Donor DU1. The IP address 1 of the IAB node 3 in the communication scenario a may be a Donor DU1 or an IP address allocated by the network management device to the IAB node 3. Illustratively, the IP address 1 of the IAB node 3 belongs to the same network segment or has the same network prefix as the Donor DU1.

When the Donor base station in the communication scenario a in fig. 7 is the Donor base station 2 (i.e., the Donor CU is the Donor CU2, and the Donor DU is the Donor DU 2), a Uu interface and an F1 interface exist between the IAB node 3 and the Donor base station 2. The F1 interface communication between the IAB node 3 and the Donor base station 2 needs to pass through the Donor DU2. The IP address 2 of the IAB node 3 in the communication scenario B may be a Donor DU2 or an IP address allocated by the network management device to the IAB node 3. In one possible design, IP address 2 of IAB node 3 belongs to the same segment or has the same network prefix as the Donor DU2.

Communication scenario B of fig. 8: a Uu interface exists between the IAB node 3 and the Donor base station 2 (including the Donor CU2 and the Donor DU 2), and an F1 interface exists between the IAB node 3 and the Donor base station 1. The F1 interface communication between the IAB node 3 and the Donor base station 1 needs to pass through the Donor DU2. The IP address 2 of the IAB node 3 in the communication scenario B may be a Donor DU2 or an IP address allocated by the network management device to the IAB node 3. In one possible design, IP address 2 of IAB node 3 belongs to the same segment or has the same network prefix as the Donor DU2.

Communication scenario C of fig. 9: a Uu interface exists between the IAB node 3 and the Donor base station 1 (including the Donor-CU1 and the Donor-DU 1), and an F1 interface exists between the IAB node 3 and the Donor base station 2. In a communication scenario C, an F1 interface may exist between the IAB node 3 and the donor base station 1, or the F1 interface may not exist (which may also be referred to as that the F1 interface is not established between the IAB node 3 and the donor base station 1). The F1 interface communication between the IAB node and the Donor base station 2 needs to go through the Donor DU1. The IP address 1 of the IAB node 3 in the communication scenario C may be a Donor DU1 or an IP address allocated by the network management device to the IAB node 3. In one possible design, the IP address 2 of the IAB node 3 belongs to the same segment or has the same network prefix as the Donor DU1.

Communication scenario D of fig. 10 (which may also be referred to as a dual connectivity scenario): a Uu interface exists between the IAB node 3 and the Donor base station 1 (including the Donor-CU1 and the Donor-DU 1), and a Uu interface exists between the IAB node and the Donor base station 2. There is an F1 interface between the IAB node 3 and the donor base station 1. The F1 interface communication between the IAB node 3 and the Donor base station 1 may be via a Donor DU1 or via a Donor DU2, that is, the Donor base station 1 may choose to communicate with the IAB node 3 via the Donor DU1 and/or the Donor DU2 via the F1 interface.

The communication scenarios a, B, C, D of the IAB node 3 are interchangeable. For example, in the handover process of IAB node 3 across the donor base stations, a transition from communication scenario a to communication scenario B or a transition from communication scenario a to communication scenario C may be included. In this case, the donor base station 1 may be referred to as a source donor base station (S-donor), and the donor base station 2 may be referred to as a target donor base station (T-donor). The S-donor may in turn comprise S-donor CU1 and S-donor DU1. The T-donor may in turn comprise T-donor CU2 and T-donor DU2.

In this application, establishing an interface may include establishing a connection and/or bearer on the interface. For example, establishing the Uu interface may include at least one of establishing an RRC connection, establishing an SRB, and establishing a DRB. Establishing the F1 interface may include establishing an F1 connection. Disconnecting the interface may include disconnecting a connection and/or bearer on the interface. For example, disconnecting the Uu interface may include at least one of disconnecting RRC connection, disconnecting SRB, and disconnecting DRB. Disconnecting the F1 interface may include disconnecting the F1 connection.

Also for example, the IAB node 3 may also transition from communication scenario a or communication scenario B to a dual connectivity communication scenario (communication scenario D). In this case, the host base station 1 may be referred to as a master base station (M-node), and the host base station 2 may be referred to as a secondary base station (S-node). The M-donor may in turn comprise M-donor CU1 and M-donor DU1. The S-donor may in turn comprise S-donor CU2 and S-donor DU2.

The dual connection scenario under the current IAB architecture mainly includes the following two scenarios: dual connectivity based on redundant topology and dual connectivity based on CP-UP separation. The dual connection based on the redundancy topology and the dual connection based on the CP-UP separation will be described below by taking fig. 11 as an example.

Fig. 11 is a schematic diagram of another communication architecture. Similarly to fig. 6, the Donor base station 1 in fig. 11 includes a Donor CU1 (Donor CU 1) and a Donor DU1 (Donor DU 1). The Donor base station 2 includes a Donor CU2 (Donor CU 2) and a Donor DU2 (Donor DU 2). IAB node 1 includes IAB MT 1 and IAB DU1, IAB node 2 includes IAB MT 2 and IAB DU2, IAB node 3 includes IAB MT 3 and IAB DU 3, IAB node 4 includes IAB MT4 and IAB DU 4. Wherein, IAB node 2 is an access IAB node of terminal 1, and IAB node 4 is an access IAB node of terminal 2. The nodes represented in the example 1 of the figure are controlled by the Donor CU2, i.e. the node 3 is controlled by the Donor CU 2. The other nodes are controlled by the Donor CU1, i.e., IAB node 1, IAB node 2, and IAB node 4 are controlled by Donor CU1.

In the communication architecture shown in fig. 11, it is assumed that the Donor base station 1 is the master node MN, the Donor base station 2 is the slave node SN, and the MT of the IAB node 2, i.e., the IAB MT 2, is connected to the Donor DU1 and the Donor DU2 through dual connections, respectively, and the MT of the IAB node 4, i.e., the IAB MT4, is connected to the Donor DU1 and the Donor DU2 through dual connections, respectively. The F1AP message for IAB node 2 and the F1AP message for IAB node 4 are terminated on the Donor CU1, i.e. Donor CU1 is the terminating node (F1-terminating node) for the F1AP messages for IAB node 2 and IAB node 4. The topology segment formed by IAB node 3 and Donor base station 2 in fig. 11 is controlled by Donor CU2, i.e. Donor CU2 can manage IAB node 3. The topology section formed by the IAB node 4, the IAB node 2, the IAB node 1, and the Donor base station 1 is controlled by the Donor CU1, that is, the Donor CU1 can manage the IAB node 1, the IAB node 2, and the IAB node 4. In the embodiment of the present application, the F1AP message may also be referred to as an F1-C message.

As can be seen from the above description, the F1 interface can be established between the DU of the IAB node to which the terminal accesses and the donor base station. When the F1 interface is established based on the communication architecture shown in fig. 11, the dual connection mode of the F1 interface of the IAB node 2 includes that the F1AP message and the F1 interface data of the user plane are transmitted through a Backhaul Link (BL), which may be referred to as a redundant topology in this application, and the corresponding transmission paths may be path 1 and path 2 as shown in the figure.

The F1AP message and the F1 interface data of the user plane may be transmitted through a Backhaul Link (BL) in path 1, and at this time, the topology of path 2 is the redundant topology of the IAB node 2. Or, the F1AP message and the F1 interface data of the user plane may be transmitted through a Backhaul Link (BL) in the path 2, where the topology of the path 1 is the redundant topology of the IAB node 2. This dual connection mode of F1 interface can be called CP-UP non-separation based on redundancy topology, and this mode can be implemented based on the intention of IAB node itself.

In addition, the F1AP message may be transmitted through the path 1, and the F1 interface data of the user plane may be transmitted through the path 2. Or the F1AP message is transmitted through path 2, and the F1 interface data of the user plane is transmitted through path 1. This dual connection approach for the F1 interface may be referred to as CP-UP split based on a redundant topology, which may be configured by network devices in a time-varying manner.

It should be understood that the terminating nodes of the F1AP messages and/or F1 interface data of the user plane transmitted through the path 1 are the same home base station, and similarly, the terminating nodes of the F1AP messages and/or F1 interface data of the user plane transmitted through the path 2 are the same home base station. Illustratively, in the case where the terminating node is a Donor CU1, the F1AP message and/or the F1 interface data of the user plane are finally transmitted to the Donor CU1.

It should also be understood that the redundancy topology described in the embodiments of the present application includes two dual connection manners, i.e., the above CP-UP non-separation based on the redundancy topology and the CP-UP separation based on the redundancy topology.

When the F1 interface is established based on the topology structure shown in fig. 11, the dual connection mode of the F1 interface of the IAB node 4 includes that the F1AP message is transmitted through an air interface (i.e., RRC message), and the F1 interface data of the user plane is transmitted through a Backhaul Link (BL), which may be referred to as CP-UP separation of non-redundant topology in this application, and the corresponding transmission paths may be path 3 and path 4 as shown in the figure.

The F1AP message may be transmitted to the Donor DU2 through an air interface (i.e., RRC message) between the IAB MT4 and the Donor DU2, and then transmitted to the Donor CU1 through the Donor DU2 (as shown by path 4 in fig. 11). The F1 interface data of the user plane may be transmitted to the Donor DU1 through the Backhaul Link (BL) between the IAB MT4 and the Donor DU1, and then transmitted to the Donor CU1 from the Donor DU1 (as shown in fig. 11, path 3).

It should be understood that there may be three path alternatives in path 2 or path 4 transmitted from the Donor DU2 to the Donor CU1, one being Donor DU2 ← → Donor DU1 ← → Donor CU1, and the other being Donor DU2 ← → Donor CU1. The selection of the three paths will be described below.

It should also be understood that the F1 interface data of the user plane transmitted over path 3 and the terminating node of the F1AP message transmitted over path 4 are the same home base station.

The current standard specifies that the terminating node (MN or SN) of the F1AP message can determine which dual connection method the F1 interface of the IAB node adopts, i.e. redundant topology (including CP-UP splitting in redundant topology) or CP-UP splitting in non-redundant topology. However, in the process of determining the dual connectivity mode of the F1 interface of the IAB node by the terminating node, the IAB host capability of the node (i.e., whether to support the host node as the IAB node) needs to be matched with the dual connectivity mode, that is, the node capability needs to be considered when the MN adds an SN to the IAB node, or a suitable dual connectivity mode needs to be selected based on the node capability of the SN.

According to the R16 standard, a system information block 1 (SIB 1) introduces an information element, IAB-Support, which if present indicates that the base station supports IAB, which is also considered as a candidate base station for the IAB node. If the field is not present, this indicates that the base station does not support IAB and/or that the base station is prohibited from being used for IAB nodes. In the following drawings, a terminal is a UE and a base station is a gNB.

For a CP-UP separation scenario under a non-redundant topology introduced by R17, an MN without an IAB host capability (non-donor capable) may also broadcast an IAB-Support, but the MN cannot serve as a host node of an IAB node, and can only forward an F1AP message to an SN with the IAB host capability (donor capable), and F1 interface data (also referred to as F1-U data) of a user plane can only be transmitted through a backhaul link between the IAB node and the SN. It should be understood that the IAB hosting capability includes functions corresponding to the hosting base station described above, which are not described in detail here.

In view of this, for the R17 dual connectivity scenario, it needs to further distinguish whether the gNB supports the IAB hosting capability under the current IAB-Support, and the specific Support logic is as follows:

1,IAB-Support + non-donor capable, indicating that gNB supports IAB but does not have IAB host capability. Under this logic, the gNB supports transmission of F1AP messages over the air interface, but does not support transmission of F1AP messages over the backhaul link.

2,IAB-Support + donor capable, indicating that gNB supports IAB and also has IAB host capability. Under this logic, the gNB supports transmission of F1AP messages over the backhaul link, but does not necessarily support transmission of F1AP messages over the air.

It should be understood that the transmission of F1AP messages (F1 AP over NR RRC) over the air interface requires enhancement of the Uu interface, i.e. supports encapsulation of F1AP messages in RRC messages.

It should also be understood that, for a gNB with IAB hosting capability, its air interface may or may not support transmission of F1AP messages (F1 AP over NR RRC) over the air interface, or may not support transmission of F1AP messages (F1 AP over NR RRC) over the air interface.

Based on the logic, the embodiments of the present application provide a communication method and a communication apparatus, where a base station may broadcast its own IAB host capability information to the outside, and an IAB node may access a suitable base station as an MN or an SN of the IAB node according to the IAB host capability information of the base station, and determine a dual connection mode matched with the capability information of the MN and/or the SN, thereby facilitating improvement of stability of communication between the IAB node and a terminal.

The present application is applicable to IAB networks, including both independent networking (SA) and non-independent Networking (NSA) IAB networks. From the above description, it is known that an IAB node may include an MT part and a DU part, and a host node of the IAB node may be further divided into two parts, namely, a Donor DU and a Donor CU, and the Donor CU may be further divided into two parts, namely, a Donor CU-CP and a Donor CU-UP.

The architecture of the IAB node connecting to the host node over the wireless backhaul link will be described below in conjunction with fig. 12.

Fig. 12 is a schematic diagram of an IAB network architecture 900 according to an embodiment of the present application. As shown in fig. 12, the IAB network architecture 900 includes a UE, an IAB node 1, an IAB node 2, a donor node 1, a donor node 2, a gNB, and a 5G core network (5 GC).

And an F1 interface is arranged between the DU part of each IAB node and the Donor CU, and the F1 interface comprises two parts, namely a control plane (F1-C) and a user plane (F1-U), wherein the control plane is maintained between the IAB DU and the Donor CU-CP, and the user plane is maintained between the IAB DU and the Donor CU-UP. The F1 interface is not shown in fig. 12.

When the IAB node works in the SA mode, the IAB node can be singly connected to one father node or doubly connected to two father nodes, wherein the two father nodes can be controlled by the same host node or respectively controlled by different host nodes. The DU part of the IAB node may establish an F1 interface with a host node, and the host node establishing the F1 interface may be connected to the 5GC. Wherein the Donor CU-CP is connected to a control plane network element, such as an access and mobility management function (AMF), in the 5GC through an NG control plane interface (NG-C). The Donor CU-UP is connected to a user plane network element, such as a User Plane Function (UPF), in the 5GC through a NG-user plane interface (NG-U).

When the IAB node works in the NSA mode, an NR-Uu interface is arranged between the gNB and the MT part of each node, an NG interface (a control plane interface NG-C and/or a user plane interface NG-U) can be established between the gNB and the 5GC, the gNB and the host node can provide dual-connection service for the IAB node, and the gNB can serve as a main base station of the IAB node and can also serve as an auxiliary base station of the IAB node.

Wherein, IAB node 2 is the access IAB node of UE 1, and NR-Uu interface is arranged between UE 1, IAB node 1 and IAB node 2 and gNB

Illustratively, the home node 1 may serve as the MN, and the home node 2 may serve as the SN, and in this case, the dual connection mode of the F1 interface of the IAB node 2 may be the redundant topology described above. Or the roles of the host node 1 and the host node 2 are exchanged, and the dual-connection mode adopted by the IAB node 2 is similar.

Illustratively, the gNB may act as MN but not IAB home capability, and the home node 1 may act as SN, and the dual connectivity mode of the IAB node 2 may be CP-UP split based on non-redundant topology as described above.

Fig. 13 is a schematic flow chart diagram of a communication method 1300 provided in an embodiment of the present application. The method 1300 is applicable to the IAB network architecture 900 described above. The method 1300 includes the steps of:

s1301, the first network device obtains capability information of at least one second network device.

The wireless backhaul node, the at least one second network device, or the network management device sends capability information of the at least one second network device to the first network device, where the capability information indicates whether the IAB host capability is provided and/or whether the F1AP message is supported to be transmitted over an air interface, and the first network device is a master node MN of the wireless backhaul node. Accordingly, the first network device receives capability information from the wireless backhaul node, the at least one second network device or at least one second network device of the network management device.

S1302, the first network device selects a target second network device from the at least one second network device as an auxiliary node SN of the wireless backhaul node according to the capability information of the at least one second network device.

It should be understood that in the embodiment of the present application, at least one second network device is another network device in the IAB network different from the first network device, and the MN may add, in the other network device, a SN to the wireless backhaul node, where capability information of the SN matches with the dual connectivity scheme. The target second network device is a SN determined by the MN for the wireless backhaul node.

The wireless backhaul node in this step is an IAB node in the IAB network, and specifically, in the network architecture 900, the wireless backhaul node may be an IAB node 2. The wireless backhaul node may also be referred to hereinafter as an IAB node.

S1303, the first network device configures a dual connectivity mode of the F1 interface of the wireless backhaul node.

In this embodiment, the first network device (i.e., MN) may determine the secondary node of the wireless backhaul node (e.g., IAB node) according to the acquired capability information of the other network device (e.g., gNB). Based on the capability information, the first network device may determine to establish a dual-connectivity topology architecture that matches the IAB hosting capabilities. For example, for the case that MN or SN is the host node, the F1 interface of the IAB node adopts a CP-UP split dual connection mode based on a non-redundant topology. For the case that MN and SN are host nodes, the F1 interface of the IAB node adopts a dual connection mode of redundant topology. The dual-connection topology structure established in the way is beneficial to improving the stability of the service communication between the IAB node and the terminal and the service experience of the terminal.

In one possible implementation, if the home node 1 in the network architecture 900 plays a role as MN and the home node 2 plays a role as SN, the first network device is the home node 1. When the roles of the two are opposite, that is, the home node 2 acts as the MN and the home node 1 acts as the SN, the first network device is the home node 2.

In another possible implementation manner, if the gNB in the network architecture 900 plays a role of MN, and the host node 1 plays a role of SN, then the first network device is the gNB.

As an alternative embodiment, the method 1300 further comprises: the first network device receives a measurement report of at least one second network device, the measurement report comprising a signal quality between the wireless backhaul node and the at least one second network device. In this case, S1302 specifically includes: the first network device selects the target second network device from the at least one second network device as the SN of the wireless backhaul node according to the capability information of the at least one second network device and the measurement report.

In this embodiment, the MN may further obtain a measurement report including signal quality between the at least one second network device and the wireless backhaul node, and in conjunction with the measurement report, the MN may select, from the at least one second network device, a second network device with good communication quality for the wireless backhaul node as the SN of the IAB node, which is beneficial to improve communication quality.

As an alternative embodiment, the first network device receives capability information of at least one second network device from the wireless backhaul node; or, the first network device receives the capability information of at least one second network device from the network management device; still alternatively, the first network device receives capability information of at least one second network device from the at least one second network device. Correspondingly, the wireless backhaul node, the network management device or the at least one second network device sends the capability information of the at least one second network device to the first network device. Three implementations are described below:

the first network device receives capability information of at least one second network device from the wireless backhaul node.

For this implementation, the gNB broadcasts capability information, and the MT of the IAB node receives the capability information of the gNB and sends the capability information of the neighbor cell/gNB of the MN to the MN, so that the MN selects an appropriate SN to provide service to the IAB node.

2, the first network device receives the capability information of at least one second network device from the network management device.

For the implementation manner, the supporting situation of the gbb to the IAB in the network may be configured in advance by the network management device, that is, the network management device knows the capability information of each gbb in advance, and may send the capability information of the neighboring cell/gbb of each gbb to each gbb in advance, and the MN may add an SN to the IAB node based on the information sent by the network management device when the IAB node has accessed the MN.

The network management device may be an operation, administration and maintenance network element (OAM). The network management apparatus may include an Element Management System (EMS), a Network Management System (NMS). The network management device may be a functional network element located in the 5G core network, or the network management device may also be a functional network element deployed in a backbone network behind the 5G core network, or the network management device may also be deployed in other locations, and the specific deployment location of the network management device is not limited in the present application.

The first network device receives capability information of at least one second network device from the at least one second network device.

For the implementation mode, the capabilities of the gnbs can be interacted among the gnbs, and in addition, whether the Xn interface supports transmission of the F1AP message (F1 AP over XnAP) through the XnAP message can be interacted among the gnbs. In the case that the IAB node has access to the MN, the MN can add an SN to the IAB node based on the capability information sent by the neighboring gNB and whether the corresponding Xn interface supports transmission of F1AP messages over XnAP messages.

Illustratively, when the MN selects the SN according to the above three implementations, the SN may also be selected in combination with capability information of the MN itself. The determination process of the specific MN and SN will be described below.

As an optional embodiment, whether the S1301 has the IAB hosting capability and/or supports transmission of the F1AP message over the air interface may also be in the following combination:

1, the capability information indicates that the gNB does not have IAB host capability (non-donor capable). Under this indication, the gNB cannot serve as a host node for the IAB node, but the gNB supports the transmission of F1AP messages (F1 AP over NR RRC) over the air.

2, the capability information indicates that the gNB has IAB hosting capability and supports transmission of F1AP messages over the air (F1 AP over NR RRC). Under the instruction, the gNB may serve as a host node of the IAB node, and transmit the F1AP message (i.e., F1AP over BH or F1AP over BAP) through the backhaul link, or may transmit the F1AP message (F1 AP over NR RRC) through the air interface.

And 3, the capability information indicates that the gNB has IAB hosting capability and does not support F1AP message (F1 AP over NR RRC) transmission over the air interface. Under this indication, the gNB may act as a host node for the IAB node, transmitting the F1AP message over the backhaul link.

4, the capability information indicates that the gNB supports transmission of F1AP messages over the air interface (F1 AP over NR RRC). Under this indication, the gNB does not have IAB-hosting capability (non-donor capable), or the gNB has IAB-hosting capability (donor capable), but the IAB-hosting capability of the current gNB is closed or limited. Specifically, the Donor CU may control the Donor DU to open the air interface capability or the IAB hosting capability.

A procedure of how the SN is determined by knowing the capability information of the MN will be described below with reference to fig. 14 to 16. It should be understood that the MN may also determine the SN in the process of determining the SN, i.e., S1302, in combination with the capability information of the MN, and the specific determination process is as follows.

Scene 1: MN supports IAB, but does not have IAB host capability (IAB-Support + non-denor capable).

This scenario corresponds to the first indication form of the capability information, that is, the MN cannot serve as a host node of the IAB node, but supports transmission of the F1AP message over the air interface. If the IAB is to adopt double connection, only CP-UP separation based on non-redundant topology can be adopted, and SN is a terminating node of F1AP message and has IAB host capability. As shown in fig. 14, an IAB node 2 is an access IAB node of a UE, an F1-C message (i.e., an F1AP message) may be transmitted over an air interface between the IAB node 2 and an MN, and an F1-U message (i.e., user plane data) may be transmitted over a backhaul link between the IAB node 2 and a Donor CU.

Because the IAB DU2 cannot establish the F1 interface with the MN, it needs to establish a dual connection first, and the MN may select one gNB with the IAB host capability from at least one gNB as the SN access according to the three implementation manners of obtaining the capability information, and then send the F1AP message through the established Master Cell Group (MCG) link and/or Secondary Cell Group (SCG) link. The form of sending the F1AP message includes the above-mentioned transmission via a backhaul link (F1 AP over BH or F1AP over BAP), or transmission via an air interface (F1 AP over NR RRC).

Scene 2: the MN supports IAB, has IAB host capability and does not Support F1AP message transmission over the air interface (IAB-Support + denor capable + does not Support F1AP over NR RRC).

This scenario corresponds to the indication form of the third capability information, that is, the MN may serve as a host node of the IAB node, but does not support transmission of the F1AP message over the air interface. For this scenario, the selection of the SN and the selection of the dual connectivity mode can be further divided into the following scenarios:

scene 2a: the MN selects a gNB without IAB hosting capability as an SN of the IAB node, the SN supports transmission of the F1AP message through an air interface, at this time, the MN is a terminating node of the F1AP message, the dual connection mode is CP-UP separation based on a non-redundant topology, and the topology structure is as shown in fig. 15. In fig. 15, IAB node 2 is an access IAB node of the UE, the F1-C messages (i.e., F1AP messages) may be transmitted over an air interface between IAB node 2 and SN, and the F1-U messages (i.e., user plane data) may be transmitted over a backhaul link between IAB node 2 and a Donor CU.

Scene 2b: the MN selects a gNB that has an IAB hosting capability and does not support F1AP message transmission over the air interface as an SN of the IAB node, where the dual connection mode is a redundant topology, the MN or the SN is a terminating node of the IAB node, and the topology structure is shown in fig. 16. In fig. 16, IAB node 2 is an access IAB node for UE 1, IAB node 4 is an access IAB node for UE 2, the node shown in fig. 1 in the figure is controlled by Donor CU2, and the other nodes are controlled by Donor CU1. In topology a of fig. 16, IAB node 1, IAB node 2, and IAB node 4 are controlled by Donor CU1, node 3 is controlled by Donor CU2, and F1-C messages (i.e., F1AP messages) for IAB node 2 may be transmitted over the backhaul link between IAB node 2 and Donor CU1. In topology b of fig. 16, IAB node 1 is controlled by Donor CU1, IAB node 2, IAB node 3, and IAB node 4 are controlled by Donor CU2, and F1-C messages (i.e., F1AP messages) for IAB node 4 may be transmitted over the backhaul link between IAB node 4 and Donor CU1.

Scene 2c: the MN selects a gNB having an IAB hosting capability and supporting transmission of the F1AP message over the air interface as an SN of the IAB node, where the dual connection mode may be CP-UP separation based on a non-redundant topology, the MN is a terminating node of the F1AP message, and a topology structure is shown in fig. 15. The dual connection mode may also be a redundant topology, where MN or SN is a terminating node of the IAB node, and the topology structure is shown in fig. 16.

Scene 3: the MN supports IAB, has IAB host capability and supports the transmission of F1AP messages (IAB-Support + Donor capable + F1AP over NR RRC) through an air interface.

The scenario corresponds to the indication form of the second capability information, that is, the MN may serve as a host node of the IAB node, and the MN supports transmission of the F1AP message over an air interface. For this scenario, the selection of the SN and the selection of the dual connectivity mode can be further divided into the following scenarios:

scene 3a: the MN selects a gNB without IAB hosting capability as an SN of the IAB node, the SN supports transmission of the F1AP message through an air interface, at this time, the MN is a terminating node of the F1AP message, the dual connection mode is CP-UP separation based on a non-redundant topology, and the topology structure is as shown in fig. 15.

Scene 3b: the MN selects a gNB that has an IAB hosting capability and does not support F1AP message transmission over the air interface as an SN of the IAB node, at this time, the dual connection mode may be CP-UP separation based on a non-redundant topology, the MN or the SN is a terminating node of the F1AP message, and the topology structure is as shown in fig. 14. The dual connection mode may also be a redundant topology, where MN or SN is a terminating node of the F1AP message, and the topology structure is shown in fig. 16.

Scene 3c: the MN selects the gNB having the IAB hosting capability and supporting transmission of the F1AP message over the air interface as the SN of the IAB node, and at this time, the dual connection mode may be CP-UP separation based on a non-redundant topology, and the topology structure is shown in fig. 14 or 12. The dual connection mode may also be a redundant topology, where MN or SN is a terminating node of the F1AP message, and the topology structure is shown in fig. 16.

The MN may indicate a dual connection manner used by the SN for the IAB node, and taking fig. 11 as an example, the indication manner may be: MN indicates SN to adopt redundant topology for IAB node 2 and CP-UP separation based on non-redundant topology for IAB node 4. Alternatively, the MN may negotiate with the SN for IAB node 2 the quality of service (QoS) and BAP routing configuration information for the topology segment controlled by the Donor CU2, and the SN may consider the MN to indicate that a redundant topology is employed for IAB node 2. If the MN and the SN do not negotiate configuration information for the IAB node 4, the SN may consider that the MN indicates to adopt CP-UP separation based on a non-redundant topology for the IAB node 4.

For an IAB node 2 that employs a redundant topology, the sn may formulate BAP routing configuration information for the topology segment controlled by the Donor CU2 for the IAB node 2. For IAB node 4 that employs CP-UP separation based on non-redundant topology, the sn maintains RRC connection with IAB MT 4.

As mentioned above, in a scenario of establishing a dual connectivity topology of an IAB node, for example, establishing an MCG link and an SCG link, the IAB node may establish an F1 interface with a host node, and the F1AP message transmission form that may be adopted to establish the F1 interface includes transmitting an F1AP message (F1 AP over NR RRC) over an air interface and transmitting an F1AP message (F1 AP over BAP) over a backhaul.

As an alternative embodiment, the network may indicate the link used by the IAB node for F1AP message transmission as an MCG link and/or an SCG link. Specifically, the network management device may indicate the IAB node to use for the link of the F1AP message transmission. Alternatively, the MN indicates via an RRC message that the IAB MT is used for the link for F1AP message transmission. Alternatively, the SN indicates to the IAB MT through an RRC message that the IAB MT uses for the link of F1AP message transmission, or the SN sends the RRC message of the SN to the MN, and the MN encapsulates the RRC message of the SN in the RRC message of the MN (e.g., in the form of a container) and sends to the IAB MT.

If the indicated link for transmitting the F1AP message includes the default BH RLC channel, the IAB node transmits the F1AP message in a backhaul manner on the corresponding link. If the indicated link does not include the default BH RLC channel, the IAB node transmits the F1AP message on the corresponding link in a form of transmitting the F1AP message through an RRC message.

It should be understood that the default BH RLC channel is the BH RLC channel used by the wireless backhaul node for the first time to send F1AP messages. The default BH RLC channel may also be said to be used for IAB node initiated F1 interface setup requests. After the F1 interface is established, the IAB node may obtain channel configuration information used for transmitting various types of service data.

It should be understood that the default BH RLC channel configuration information may not be included on the link indicated by the network for transmitting F1AP messages described above. In this case, the network may send the first indication information to the IAB node.

In one implementation, the first indication information indicates a dual connection mode of the F1 interface. That is, the first indication information may indicate a transmission form of the F1AP message.

In another implementation, the first indication information is default BH RLC channel configuration information. In this case, the network is shown instructing the IAB node to transmit the F1AP message in a backhauled form on the indicated link.

In addition, if the network does not indicate to the IAB node the link on which to transmit the F1AP message, the IAB node selects the link including the default BH RLC channel configuration information, and transmits the F1AP message on the corresponding link in a backhaul manner.

Taking fig. 11 as an example, if the IAB node 2 receives the first indication information, where the first indication information is default BH RLC channel configuration information, and the donor base station 1 (MN) indicates the IAB node 2 to transmit the F1AP message on the MCG link, the IAB node 2 may transmit the F1AP message in a backhaul manner on the indicated MCG link.

Fig. 17 is a schematic flow chart of another communication method 1700 provided in an embodiment of the present application, where the method 1700 includes:

s1701, the target second network device sends capability information of the target second network device, where the capability information indicates whether the IAB hosting capability is available and/or whether the F1AP message is supported to be transmitted over the air interface. Accordingly, the wireless backhaul node or the first network device receives capability information of the target second network device.

S1702, the wireless backhaul node sends access request information to the target second network device. Accordingly, the target second network device receives the access request information from the wireless backhaul node, and the target second network device is a secondary node SN of the wireless backhaul node.

In the embodiment of the present application, in a case where the MN does not determine the SN, the target second network device sends capability information of the target second network device. The MN can select a SN for the wireless backhaul node in at least one second network device, and after the wireless backhaul node accesses the target second network device, the target second network device can serve as the SN for the wireless backhaul node.

As an alternative embodiment, S1701 includes: the target second network device sends the capability information of the target second network device to the first network device. The method 1700 further includes: the target second network device sends, to the first network device, information on whether an Xn interface between the target second network device and the first network device supports transmission of an F1AP message through an XnAP message.

As an alternative embodiment, S1701 includes: the target second network device broadcasts capability information of the target second network device. In addition, the target second network device may also send the capability information to the outside in a broadcast or multicast manner, or send the capability information to the first network device in a unicast manner.

As an optional embodiment, the target second network device sends second indication information to the wireless backhaul node, where the second indication information is used to indicate a dual connectivity manner of the F1 interface.

As an optional embodiment, the second indication information is default BH RLC channel configuration information, and the default BHRLC channel is a BH RLC channel used by the wireless backhaul node to send the F1AP message for the first time.

The explanation of the second indication information is similar to that of the first indication information, and is not described herein again.

As an alternative embodiment, the target second network device sends the second indication information to the wireless backhaul node via the first network device.

In this embodiment, the SN may send the second indication information to the MN, and the MN may send the second indication information to the wireless backhaul node as a container encapsulated in an RRC message of the MN.

Fig. 18 is a schematic flow chart of yet another communication method 1800 provided in an embodiment of the present application, where the method 1800 includes:

s1801, the network device sends, to the wireless backhaul node, capability information of at least one network device, where the capability information is used to indicate whether the IAB host capability is provided and/or whether the F1AP message is supported to be transmitted over an air interface. Accordingly, the wireless backhaul node receives capability information of the at least one network device.

S1802, the wireless backhaul node accesses a first network device based on the capability information of the at least one network device, where the first network device is a master node MN of the wireless backhaul node.

S1803, the network device sends first configuration information to the wireless backhaul node, where the first configuration information is used to configure the target second network device as an auxiliary node SN of the wireless backhaul node. Accordingly, the wireless backhaul node receives the first configuration information.

In this step, the network device refers to the first network device that is in the role of MN.

S1804, the network device sends second configuration information to the wireless backhaul node, where the second configuration information is used to configure a dual connectivity mode of the F1 interface of the wireless backhaul node. Accordingly, the wireless backhaul node receives also the second configuration information.

In this embodiment, the wireless backhaul node may select, at least one network device, to access a first network device as an MN of the wireless backhaul node, and access a target second network device as an SN of the wireless backhaul node according to the first configuration information, so as to configure a dual connection mode of an F1 interface of the wireless backhaul node according to the second configuration information.

It should be understood that the second configuration information may be configured for the wireless backhaul node by the first network device, or may be configured for the wireless backhaul node by the target second network device. The second configuration information may be default BH RLC channel configuration information.

Under the condition that the adopted dual connectivity and the transmission form of the F1AP message are determined, taking the topology structure shown in fig. 11 as an example, the IAB node 2 adopts the dual connectivity with redundant topology, and assuming that the terminating node of the F1AP message is the Donor CU1 (Donor CU 1), the uplink data packet of the IAB node 2 is transmitted to the Donor DU2 (Donor DU 2) of the Donor base station 2 through the path 2 shown in fig. 11, and then is transmitted to the Donor CU1 by the Donor DU2. The downlink data packet of the Donor CU1 is transmitted to the Donor DU2 (Donor DU 2) of the Donor base station 2 via the path 2 shown in fig. 11, and then transmitted to the IAB node 2 via the Donor DU2.

As an alternative embodiment, the CU of the first network device determines a target path between the CU of the first network device and the DU of the second network device from a plurality of candidate paths. The CU of the first network device transmits data to the DU of the second network device via the target path.

In the embodiment of the present application, multiple candidate paths exist between the Donor DU2 and the Donor CU1, and the CU of the first network device may select a stable and general target path for data transmission, which is beneficial to improving the stability of data transmission between the IAB node and the terminal.

Fig. 19 is a schematic diagram of a candidate path according to an embodiment of the present application. As can be seen from fig. 19, three paths as shown in fig. 19 may be included between the Donor DU2 and the Donor CU1.

Route 1: for uplink transmission, for example, the packet may add an outer Internet Protocol (IP) at the Donor DU2, where the destination IP address of the outer IP is the IP address of the Donor CU1, and the source IP address is the IP address of the Donor DU2. The Donor CU1 and the Donor DU2 may be routed through an IP network, and data packets transmitted between the two may need to pass through a plurality of IP routers.

Route 2: donor CU1 ← → Donor CU2 ← → Donor DU2, for example, for upstream transmission, a packet can add an outer layer IP at Donor DU2, the destination IP address of which is the IP address of Donor CU1, and the source IP address of which is the IP address of Donor DU2. After the data packet arrives at the Donor CU2, the Donor CU2 needs to remove the outer layer IP added to the Donor-DU 2 and add the outer layer IP again, for example, for the uplink data packet, the destination IP address is the IP address of the Donor CU1, and the source IP address is the IP address of the Donor CU2, and then the Donor CU2 may send the data packet to the Donor CU1.

Route 3: donor CU1 ← → Donor DU2, and the packet can be transferred between Donor DU1 and Donor DU2 through a static or dynamic tunnel or can be routed through IP. As above, for uplink transmission, for example, the data packet may add an outer IP at the Donor DU2, where the destination IP address of the outer IP is the IP address of the Donor DU1, and the source IP address is the IP address of the Donor DU2. After the data packet reaches the Donor DU1, the Donor DU1 removes the outer layer IP, and the Donor DU1 may directly route the data packet to the Donor CU1, without any other change between the Donor CU1 and the Donor DU1 in this path. An implementation of the specific determination of the target path is described below.

First, the Donor CU1 or the Donor DU2 can determine whether the paths of the underlying IPs of the three paths are normal or abnormal. Possible judgment methods include testing ping values, or based on ICMP judgment.

Further, the Donor CU1 or the Donor DU2 may select a target path according to IP path conditions of three paths, where the path conditions of the three paths include the following combination forms:

1, if the IP path of one path is normal, selecting the path as a target path.

2, if the IP paths of the path 1 and the path 2 are normal and the IP path of the path 3 is abnormal, the following conditions are considered:

(1) For uplink transmission, if the source IP address of the packet is in the white list of the Donor DU2 and the IP filter (IP filter) of the IP router between the Donor DU2 and the Donor CU1, path 1 is preferentially selected. This is because path 1 needs to add the outer IP once, and path 2 needs to add the outer IP twice, which is complex to implement.

(2) If the IP filters of the Donor DU2 and the IP routers between the Donor DU2 to the Donor CU1 are in an unavailable (disable) state, i.e., the filtering function is not enabled, path 1 is preferentially selected. The reason for this is the same as above and will not be described here.

(3) If neither of the two conditions is satisfied, path 2 is preferentially selected. This is because if the source IP address of the packet is in the blacklist of the IP filter of the IP router between the Donor DU2 and the Donor CU1, the transmitted IP packet may be discarded, which may cause interruption of service data and decrease stability of data transmission.

In the embodiment of the present application, the IP filter of the IP router may be referred to as a filtering unit of the IP router, which may drop IP packets that are not known or are not within the allowable range.

If the IP paths of the path 1 and the path 3 are normal and the IP path of the path 2 is abnormal, the following conditions are considered:

(1) If a tunnel exists between the Donor DU1 and the Donor DU2, path 3 is preferentially selected. This is because tunneling is advantageous to improve stability of data transmission with respect to IP routing.

(2) If the IP routing method is used between the Donor DU1 and the Donor DU2, the selection of the path 1 or the path 3 as the target path is implemented based on the base station.

And 4, if the IP paths of the path 2 and the path 3 are normal and the IP path of the path 1 is abnormal, preferentially selecting the path 3, and selecting the path 2 only under the condition that the IP filter of the IP router between the Donor DU2 and the Donor DU1 can filter out the target data packet. This is because the path 2 is indirect data forwarding, and needs to add two outer layer IPs, which is complex to implement, while the path 3 only needs to add one outer layer IP at the Donor DU2, and data transmission between the Donor DU1 and the Donor CU1 is consistent with the original data packet processing method, and can be directly routed from the Donor DU1 to the Donor CU1, which is simpler to implement in comparison with the path 2.

If the IP paths of path 1, path 2, and path 3 are normal, path 1 and path 3 that are simple to implement are preferentially selected, and the selection of path 1 and path 3 may refer to the content corresponding to the combination form 3, which is not described herein again.

For the redundant topology scene, the Donor CU1 or the Donor DU2 can select a proper data transmission path, which is beneficial to improving the stability of data transmission of the IAB node and the terminal.

Fig. 20 is a schematic diagram of another topology provided in an embodiment of the present application. As shown in fig. 20, the Donor base station 1 includes one Donor CU, i.e., donor CU1, and two Donor DUs, i.e., donor DU1 and Donor DU2. The Donor DU1 is a source host DU, the Donor DU2 is a target host DU, and the data packet of the source host DU is switched from the link transmission subordinate to the source host DU to the link transmission subordinate to the target host DU.

In fig. 20, IAB node 2 may be connected to the target parent node (IAB node 3 in fig. 20) from the source parent node (IAB node 1 in fig. 20) after performing the handover. IAB node 4, which is subordinate to IAB node 2, and UE 1 and UE 2 may also follow IAB node 2 to perform handover. In this case, the transmission of the packet is selectable by two paths, i.e., path 1 and path 3 shown in fig. 19, of Donor CU1 ← → Donor DU2 and Donor CU1 ← → Donor DU2.

The IAB node 2 performing the handover may be referred to as a boundary IAB node (boundary IAB node), and the handover procedure of the IAB node may also be referred to as a migration (migration) procedure of the IAB node, which is not limited in this embodiment of the present invention.

For the routing of the data packets between the Donor CU1 and the Donor DU2 in the two different scenarios shown in fig. 16 and fig. 20, for example, in the uplink transmission, after the data packet from the IAB node 2 is routed to the Donor DU2 through the BAP, because the Donor DU2 and the Donor CU1 are IP routed, the original BAP packet header of the corresponding data packet is removed, and the remaining IP address of the IP data packet is the IP address of the IAB node 2 or the IAB node 4, if the IP filter of the Donor DU2 cannot identify the source IP address of the data packet, the IP filter filters the corresponding data packet when the IP filtering function is turned on, so that the data packet from the UE 1 or the UE 2 cannot reach the Donor CU1, which causes the loss of the data packet, and reduces the reliability of the transmission.

Therefore, taking uplink transmission of a data packet of UE 1 as an example, in the process that the data packet from UE 1 is routed from IAB node 2 to IAB node 3, and then routed from IAB node 3 to Donor DU2, the boundary node may add indication information in the BAP header of the original data packet.

In one possible implementation, the indication information indicates that the data packet is a re-header packet (or a re-routing packet).

In another possible implementation, the indication information indicates that the Donor DU2 retains the data packet, i.e., does not perform a filtering operation on the data packet.

After receiving the data packet with the added indication information, the Donor DU2 may obtain the indication information in the BAP header, so that even if the IP filter of the Donor DU2 cannot identify the source IP address of the data packet, the data packet may be normally transmitted according to the indication information, which is beneficial to improving the reliability of data transmission.

In addition, in order to smoothly transfer the packet including the indication information to the Donor DU2, a correct destination BAP address is also required. Since the destination BAP address in the BAP header of the original data packet is the BAP address of the Donor DU1, if the original data packet is intended to be transmitted to the Donor DU2 through the IAB node 3, the boundary node IAB node 2 needs to rewrite the BAP routing identity (BAP routing ID) of the BAP header in the original data packet, and change the destination BAP address to the BAP address of the Donor DU2, so that the original data packet can be normally transmitted to the Donor DU2, and then the Donor DU2 can perform data transmission on the path 1 or the path 3 as shown in fig. 19. The specific process of determining the path and transmitting the data is described above, and is not described herein again.

It should be understood that, the sequence numbers of the above processes do not imply any order of execution, and the order of execution of the processes should be determined by their functions and inherent logic, and should not limit the implementation process of the embodiments of the present application in any way.

The communication method according to the embodiment of the present application is described in detail above with reference to fig. 1 to 20, and the communication apparatus according to the embodiment of the present application will be described in detail below with reference to fig. 21 to 24.

Fig. 21 is a schematic block diagram of a communication apparatus 2100 according to an embodiment of the present application, where the apparatus 2100 includes: an acquisition module 2110 and a processing module 2120.

Wherein, the obtaining module 2110 is configured to: and acquiring capability information of at least one second network device, wherein the capability information indicates whether the second network device has an IAB host capability and/or supports F1AP message transmission through an air interface, and the first network device is a master node MN of the wireless backhaul node. The processing module 2120 is configured to: and according to the capability information of the at least one second network device, selecting a target second network device from the at least one second network device as an auxiliary node SN of the wireless backhaul node, and configuring a dual-connection mode of an F1 interface of the wireless backhaul node.

Optionally, the dual connection mode of the F1 interface includes that the F1AP message is transmitted over an air interface, and the F1 interface data of the user plane is transmitted over a backhaul link.

Optionally, the F1AP message is transmitted over an air interface, including: the F1AP message is transmitted to the target second network device over an air interface between the wireless backhaul node and the first network device. Or, the F1AP message is transmitted to the first network device through an air interface between the wireless backhaul node and the target second network device.

Optionally, the backhaul link is a communication link between the wireless backhaul node and the apparatus or the target second network device.

Optionally, the F1AP message and the F1 interface data of the user plane are transmitted through a backhaul link, which is a communication link between the wireless backhaul node and the apparatus and the target second network device.

Optionally, the obtaining module 2110 is configured to: capability information of at least one second network device from the at least one second network device is received.

Optionally, the processing module 2120 is configured to: and selecting a target second network device from the at least one second network device as the SN of the wireless backhaul node according to the capability information of the at least one second network device and whether the Xn interface supports the transmission of the F1AP message through the XnAP message.

Optionally, the obtaining module 2110 is configured to: receiving capability information of at least one second network device from the wireless backhaul node; or, receiving the capability information of at least one second network device from the network management device.

Optionally, the obtaining module 2110 is configured to: receiving a measurement report of at least one second network device, the measurement report comprising a signal quality between the wireless backhaul node and the at least one second network device. The processing module 2120 is configured to: selecting the target second network device from the at least one second network device as the SN of the wireless backhaul node according to the capability information of the at least one second network device and the measurement report.

Optionally, the apparatus 2100 further includes a sending module 2130 configured to send, to the wireless backhaul node, first indication information indicating a dual connectivity manner of the F1 interface.

Optionally, the first indication information is default BH RLC channel configuration information, and the default BH RLC channel is a BH RLC channel used by the wireless backhaul node to send the F1AP message for the first time.

Optionally, the sending module 2130 is configured to: sending the first indication information to the wireless backhaul node through the target second network device.

Optionally, the sending module 2130 is configured to: capability information of the first network device is broadcast. The obtaining module 2110 is configured to: access request information is received from the wireless backhaul node.

In an alternative example, it may be understood by those skilled in the art that the apparatus 2100 may be embodied as the first network device in the above embodiment, or the functions of the first network device in the above embodiment may be integrated in the apparatus 2100. The above functions may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the functions described above. For example, the obtaining module 2110 may be a communication interface, such as a transceiver interface. The apparatus 2100 may be configured to perform various procedures and/or steps corresponding to the first network device in the above method embodiments.

Fig. 22 shows a schematic block diagram of another communication apparatus 2200 provided in an embodiment of the present application, where the apparatus 2200 includes: a transmitting module 2210 and a receiving module 2220.

Wherein, the sending module 2210 is configured to: and sending capability information, wherein the capability information indicates whether the IAB host capability is provided and/or whether the F1AP message is supported to be transmitted through an air interface. The receiving module 2220 is configured to: access request information is received from a wireless backhaul node.

Optionally, the F1AP message is transmitted over an air interface, including: the F1AP message is transmitted to the target second network device through an air interface between the wireless backhaul node and the first network device. Or, the F1AP message is transmitted to the first network device through an air interface between the wireless backhaul node and the target second network device.

Optionally, the sending module 2210 is configured to: and sending the capability information to the first network equipment, and sending whether the Xn interface supports F1AP message transmission through the XnAP message.

Optionally, the sending module 2210 is configured to: broadcasting the capability information.

Optionally, the sending module 2210 is configured to: and sending second indication information to the wireless backhaul node, wherein the second indication information is used for indicating the dual connectivity mode of the F1 interface.

Optionally, the second indication information includes default BH RLC channel configuration information, where the default BH RLC channel is a BH RLC channel used by the wireless backhaul node to send the F1AP message for the first time.

Optionally, the sending module 2210 is configured to: sending the second indication information to the wireless backhaul node through the first network device.

In an alternative example, it can be understood by those skilled in the art that the apparatus 2200 may be embodied as the target second network device in the above embodiment, or the functions of the target second network device in the above embodiment may be integrated in the apparatus 2200. The above functions may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the functions described above. For example, the transmitting module 2210 may be a communication interface, such as a transceiving interface. Apparatus 2200 may be configured to perform various processes and/or steps corresponding to the target second network device in the above-described method embodiments.

Fig. 23 shows a schematic block diagram of another communication device 2300 provided by the embodiment of the present application, where the device 2300 includes: an obtaining module 2310 and a processing module 2220.

The obtaining module 2310 is configured to: and acquiring capability information of at least one network device, wherein the capability information is used for indicating whether the IAB host capability is provided and/or whether F1AP information transmission through an air interface is supported. Processing module 2220 is configured to: accessing the first network device based on the capability information of the at least one network device. The obtaining module 2310 is further configured to: first configuration information and second configuration information are received.

Optionally, the dual connectivity mode includes that the F1AP message is transmitted over an air interface and the F1 interface data of the user plane is transmitted over a backhaul link.

Optionally, the F1AP message and the F1 interface data of the user plane are transmitted through a backhaul link, where the backhaul link is a backhaul link between the wireless backhaul node and the first network device and the target second network device.

Optionally, the second configuration information includes configuration information of a default BH RLC channel, where the default BH RLC channel is a BH RLC channel used by the first-time transmission of the F1AP message.

Optionally, apparatus 2300 further comprises a sending module 2330 for sending the F1AP message over a backhaul link between the apparatus and the first network device or the target second network device.

In an alternative example, those skilled in the art can understand that the apparatus 2300 may be embodied as a wireless backhaul node in the above embodiment, or the functions of the wireless backhaul node in the above embodiment may be integrated into the apparatus 2300. The above functions may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the functions described above. For example, the obtaining module 2310 may be a communication interface, such as a transceiving interface. Apparatus 2300 can be configured to perform various procedures and/or steps corresponding to the wireless backhaul node in the above-described method embodiments.

It should be understood that the apparatus 2100, 2200, and 2300 herein are embodied in the form of functional modules. The term module, as used herein, may refer to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (e.g., a shared, dedicated, or group processor), and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that support the described functionality.

In embodiments of the present application, the apparatus 2100, the apparatus 2200, and the apparatus 2300 may also be a chip or a chip system, such as: system on chip (SoC). Correspondingly, the obtaining module 2310 may be a transceiver circuit of the chip, which is not limited herein.

Fig. 24 is a schematic block diagram of still another data transmission apparatus 2400 provided in an embodiment of the present application. The apparatus 2400 includes a processor 2410, a transceiver 2420, and a memory 2430. The processor 2410, the transceiver 2420 and the memory 2430 can communicate with each other via internal communication paths, the memory 2430 can be configured to store instructions, and the processor 2410 can be configured to execute the instructions stored by the memory 2430 to control the transceiver 2420 to transmit and/or receive signals.

It should be understood that the apparatus 2400 may be embodied as the first network device, the target second network device, or the wireless backhaul node in the foregoing embodiment, or the functions of the first network device, the target second network device, or the wireless backhaul node in the foregoing embodiment may be integrated in the apparatus 2400, and the apparatus 2400 may be configured to execute the respective steps and/or processes corresponding to the first network device, the target second network device, or the wireless backhaul node in the foregoing method embodiment. The memory 2430 can alternatively comprise both read-only memory and random-access memory, and provides instructions and data to the processor. The portion of memory may also include non-volatile random access memory. For example, the memory may also store device type information. The processor 2410 can be configured to execute the instructions stored in the memory, and when the processor executes the instructions, the processor 2410 can perform the various steps and/or processes corresponding to the first network device, the target second network device, or the wireless backhaul node in the above-described method embodiments.

It should be understood that, in the embodiments of the present application, the processor may be a Central Processing Unit (CPU), and the processor may also be other general processors, digital Signal Processors (DSPs), application Specific Integrated Circuits (ASICs), field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The steps of a method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in a processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor executes instructions in the memory, in combination with hardware thereof, to perform the steps of the above-described method. To avoid repetition, it is not described in detail here.

Those of ordinary skill in the art will appreciate that the various illustrative modules and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the system, the apparatus and the module described above may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the modules is merely a logical division, and in actual implementation, there may be other divisions, for example, multiple modules or components may be combined or integrated into another system, or some features may be omitted, or not implemented. In addition, the shown or discussed coupling or direct coupling or communication connection between each other may be through some interfaces, indirect coupling or communication connection between devices or modules, and may be in an electrical, mechanical or other form.

The modules described as separate parts may or may not be physically separate, and parts displayed as modules may or may not be physical modules, may be located in one place, or may be distributed on a plurality of network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, functional modules in the embodiments of the present application may be integrated into one processing module, or each of the modules may exist alone physically, or two or more modules are integrated into one module.

The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of communication, the method comprising:

a first network device acquires capability information of at least one second network device, wherein the capability information indicates whether the first network device has access to a backhaul integrated IAB host capability and/or supports transmission of an F1 interface application protocol (F1 AP) message through an air interface, and the first network device is a master node MN of a wireless backhaul node;

the first network equipment selects a target second network equipment from the at least one second network equipment as an auxiliary node SN of the wireless backhaul node according to the capability information of the at least one second network equipment;

and the first network equipment configures a dual connection mode of an F1 interface of the wireless backhaul node.

2. The method according to claim 1, wherein the dual connectivity for the F1 interface comprises the F1AP message being transmitted over an air interface and the F1 interface data for the user plane being transmitted over a backhaul link.

3. The method of claim 2, wherein the F1AP message is transmitted over an air interface, and wherein the transmitting comprises:

the F1AP message is transmitted to the target second network equipment through an air interface between the wireless backhaul node and the first network equipment; alternatively, the first and second electrodes may be,

and the F1AP message is transmitted to the first network equipment through an air interface between the wireless backhaul node and the target second network equipment.

4. The method according to claim 2 or 3, wherein the backhaul link is a communication link between the wireless backhaul node and the first network device or the target second network device.

5. The method according to claim 1, wherein the F1AP message and the F1 interface data of the user plane are transmitted over a backhaul link, which is a communication link between the wireless backhaul node and the first network device and the target second network device.

6. The method according to any of claims 1-5, wherein the first network device obtaining capability information of at least one second network device comprises:

the first network device receives capability information of the at least one second network device from the at least one second network device.

7. The method of claim 6, further comprising:

the first network device determining whether an Xn interface between the first network device and the at least one second network device supports transmission of F1AP messages over Xn interface application protocol XnAP messages;

the first network device selecting a target second network device from the at least one second network device as an auxiliary node SN of the wireless backhaul node according to the capability information of the at least one second network device, including:

and the first network device selects the target second network device from the at least one second network device as the SN of the wireless backhaul node according to the capability information of the at least one second network device and whether the Xn interface supports transmission of the F1AP message through the XnAP message.

8. The method according to any of claims 1-5, wherein the first network device obtaining capability information of at least one second network device comprises:

the first network device receiving capability information of the at least one second network device from the wireless backhaul node; alternatively, the first and second liquid crystal display panels may be,

the first network device receives the capability information of the at least one second network device from the network management device.

9. The method according to claim 7 or 8, characterized in that the method further comprises:

the first network device receiving a measurement report of the at least one second network device, the measurement report comprising a signal quality between the wireless backhaul node and the at least one second network device;

the first network device selecting a target second network device from the at least one second network device as the SN of the wireless backhaul node according to the capability information of the at least one second network device, including:

and the first network device selects the target second network device from the at least one second network device as the SN of the wireless backhaul node according to the capability information of the at least one second network device and the measurement report.

10. The method according to any of claims 1-9, wherein the first network device configuring the dual connectivity mode of the F1 interface of the wireless backhaul node comprises:

and the first network equipment sends first indication information to the wireless backhaul node, wherein the first indication information indicates a dual-connection mode of the F1 interface.

11. The method of claim 10, wherein the first indication information is default backhaul radio link control (BH RLC) channel configuration information.

12. The method according to claim 10 or 11, characterized in that the method further comprises:

the first network device sends the first indication information to the wireless backhaul node through the target second network device.

13. The method according to any one of claims 1-12, further comprising:

the first network equipment broadcasts the capability information of the first network equipment;

the first network device receives access request information from the wireless backhaul node.

14. A method of communication, the method comprising:

the target second network equipment sends the capability information of the target second network equipment, wherein the capability information indicates whether the target second network equipment has the capability of accessing the return-transmission integrated IAB host and/or whether the target second network equipment supports the transmission of F1AP (application protocol) messages of an F1 interface through an air interface;

and the target second network equipment receives access request information from the wireless backhaul node, wherein the target second network equipment is an auxiliary node SN of the wireless backhaul node.

15. The method according to claim 14, wherein the dual connectivity for the F1 interface comprises the F1AP message being transmitted over an air interface and the F1 interface data for the user plane being transmitted over a backhaul link.

16. The method of claim 15, wherein the F1AP message is transmitted over an air interface, and wherein the transmitting comprises:

the F1AP message is transmitted to the target second network equipment through an air interface between the wireless backhaul node and first network equipment, wherein the first network equipment is a main node MN of the wireless backhaul node; alternatively, the first and second electrodes may be,

17. The method according to claim 15 or 16, wherein the backhaul link is a backhaul link between the wireless backhaul node and the first network device or the target second network device.

18. The method according to claim 14, wherein the F1AP message and the F1 interface data of the user plane are transmitted over a backhaul link between the wireless backhaul node and the first network device and the target second network device.

19. The method according to any of claims 14-18, wherein the target second network device sending capability information of the target second network device comprises:

the target second network equipment sends the capability information of the target second network equipment to the first network equipment;

the method further comprises the following steps:

and the target second network equipment sends whether an Xn interface between the target second network equipment and the first network equipment supports F1AP message transmission through an XnAP message.

20. The method according to any of claims 14-18, wherein the target second network device sending capability information of the target second network device comprises:

the target second network device broadcasts capability information of the target second network device.

21. The method according to any one of claims 14-20, further comprising:

and the target second network device sends second indication information to the wireless backhaul node, where the second indication information is used to indicate a dual connectivity mode of the F1 interface.

22. The method of claim 21, wherein the second indication information comprises default backhaul radio link control (BH RLC) channel configuration information.

23. The method according to claim 21 or 22, further comprising:

and the target second network equipment sends the second indication information to the wireless backhaul node through the first network equipment.

24. A method of communication, the method comprising:

the wireless backhaul node acquires capability information of at least one network device, wherein the capability information is used for indicating whether the wireless backhaul node has the capability of accessing a backhaul integrated IAB host and/or whether the wireless backhaul node supports transmission of F1AP messages through an air interface;

the wireless backhaul node accesses a first network device based on the capability information of the at least one network device, wherein the first network device is a main node MN of the wireless backhaul node;

the wireless backhaul node receiving first configuration information, where the first configuration information is used to configure a target second network device as an auxiliary node SN of the wireless backhaul node;

and the wireless backhaul node receives second configuration information, wherein the second configuration information is used for configuring a dual connectivity mode of an F1 interface of the wireless backhaul node.

25. The method according to claim 24, wherein the dual connectivity mode includes the F1AP message being transmitted over an air interface and F1 interface data of a user plane being transmitted over a backhaul link.

26. The method according to claim 24, wherein the F1AP message and the F1 interface data of the user plane are transmitted over a backhaul link between the wireless backhaul node and the first network device and the target second network device.

27. The method according to claim 25 or 26, wherein the second configuration information comprises default backhaul radio link control, BH, RLC channel configuration information.

28. The method of claim 27, further comprising:

the wireless backhaul node sends an F1AP message over a backhaul link between the wireless backhaul node and the first network device or the target second network device.

29. A communications device comprising means for performing a method as claimed in any one of claims 1 to 13, or means for performing a method as claimed in any one of claims 14 to 23, or means for performing a method as claimed in any one of claims 24 to 28.

30. A communications apparatus, comprising: comprises a processor and a memory; the memory is for storing one or more computer programs that, when executed, cause the method of any of claims 1-13 to be performed, or cause the method of any of claims 14-23 to be performed, or cause the method of any of claims 24-28 to be performed.

31. A communication system comprising means for performing the method of any of claims 1-13, means for performing the method of any of claims 14-23, and means for performing the method of any of claims 24-28.

32. A computer-readable storage medium for storing a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 1-13, or causes the computer to perform the method of any one of claims 14-23, or causes the computer to perform the method of any one of claims 24-28.

33. A computer program product, the computer program product comprising: computer program code for implementing a method according to any one of claims 1-13, or for implementing a method according to any one of claims 14-23, or for implementing a method according to any one of claims 24-28, when said computer program code is run.