CN117545025A

CN117545025A - Communication method and device based on access backhaul integrated IAB

Info

Publication number: CN117545025A
Application number: CN202210915840.5A
Authority: CN
Inventors: 朱世超; 孙飞; 朱元萍; 史玉龙
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-08-01
Filing date: 2022-08-01
Publication date: 2024-02-09
Also published as: WO2024027390A1

Abstract

A communication method and device based on access backhaul integration IAB can be applied to an IAB network to support the realization of the full migration of IAB nodes. The method comprises the following steps: the first hosting node centralized unit Donor-CU1 sends a first message to the second hosting node centralized unit Donor-CU2 requesting IP address configuration and/or BAP configuration. The Donor-CU2 receives the first message and sends X sets of first IP address configurations and/or Y first BAP configurations to the Donor-CU 1. The Donor-CU1 then sends the X sets of first IP address configurations and/or Y first BAP configurations to the first IAB node via a second message. Wherein one of the X sets of first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2.

Description

Communication method and device based on access backhaul integrated IAB

Technical Field

The embodiment of the application relates to the field of communication, in particular to a communication method and device based on access backhaul integrated IAB.

Background

The fifth generation (5th generation,5G) mobile communication system puts more stringent requirements on various performance indexes of the network than the fourth generation mobile communication system. To meet the performance requirements of 5G systems, a large number of densely deployed small stations are required on the one hand, and network coverage is required for remote areas on the other hand. However, the cost of providing the optical fiber backhaul is high and the construction difficulty is high in both scenes, so that an economical and convenient access backhaul integrated (integrated access and backhaul, IAB) technology is generated.

In an IAB network, an IAB-node (IAB-node) may provide a radio access service for a User Equipment (UE), and traffic data of the UE is sent by the IAB node to an IAB-home (IAB-node) via a radio backhaul link. In some scenarios, an IAB node may migrate, i.e., handover from one IAB host to another IAB host.

Generally, the migration of the IAB node may be classified into a Full migration (Full migration) and a partial migration (Partial migration). However, the design of complete migration is not perfect at present, so that it is necessary to design the relevant implementation of complete migration of the IAB node.

Disclosure of Invention

The application provides a communication method based on access backhaul integrated IAB, which can support the realization of full migration of IAB nodes.

In a first aspect, a communication method based on access backhaul integrated IAB is provided, where the method includes: the first home node centralized unit Donor-CU1 sends a first message to the second home node centralized unit Donor-CU2 requesting an internet protocol IP address configuration and/or a backhaul adaptation protocol BAP configuration for the first IAB node. And receiving the X sets of first IP address configurations and/or Y first BAP configurations from the Donor-CU2, and sending a second message to the first IAB node, wherein the second message comprises the X sets of first IP address configurations and/or Y first BAP configurations, and X, Y is a positive integer. Wherein one of the X sets of first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2.

Based on this scheme, the Donor-CU1 requests IP address configuration and/or BAP configuration from the Donor-CU2 for the first IAB node. The X set of IP address configuration and/or Y BAP configuration returned by the Donor-CU2 enables the F1 connection between the Donor-CU2 and the first DU of the first IAB node to be established after the MT of the first IAB node is switched from the Donor-CU1 to the Donor-CU2, thereby enabling the Donor-CU2 and the first IAB node to perform F1-C and F1-U communication, supporting implementation of a full migration scheme and enabling traffic of the terminal device to migrate to a target path transmission between the Donor-CU2 and the first IAB node.

In one possible design, the method further comprises: the Donor-CU1 receives third information from the Donor-CU2, the third information indicating DUs of the first IAB node to which each of the X sets of first IP address configurations and each of the Y first BAP configurations belong.

Based on this possible design, the Donor-CU2 indicates each set of first IP address configuration and/or each first BAP configuration of the DU, which enables the first IAB node to accurately use the IP address configuration and the first BAP configuration of the respective DU, thereby being consistent with the Donor-CU2 side understanding, and further enabling the F1 connection between the subsequent Donor-CU2 and the first DU of the first IAB node to be properly established.

In one possible design, the method further comprises: the Donor-CU1 sends a third message to the first IAB node. The third message includes a second IP address configuration and a second BAP configuration. The second IP address configuration and the second BAP configuration are used to establish a cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node via the first home node distributed unit Donor-DU 1.

Based on the possible design, according to the second IP address configuration and the second BAP configuration, a cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node through the Donor-CU1 can be established, so that the terminal device can be switched to the first DU of the first IAB node, and further full migration of the IAB node is achieved.

In one possible design, the method further comprises: donor-CU1 receives fourth information from Donor-CU 2. The fourth information indicates that the second handover command message sent by the Donor-CU1 to the first IAB node carries a handover condition of the MT of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

In one possible design, the method further comprises: donor-CU1 receives fourth information from Donor-CU 2. The fourth information indicates the Donor-CU1 to send a first switching command message to at least one terminal device under a second DU of the first IAB node, and then send a second switching command message to the first IAB node; the first handover command message instructs the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second handover command message instructs the MT of the first IAB node to perform handover.

Based on the possible design, the Donor-CU1 can be instructed to send a second handover command message to the first IAB node after sending the first handover command message to the at least one terminal device, so that the migration of the IAB node conforms to the flow of the Full new migration.

In one possible design, the Donor-CU1 sends a second message to the first IAB node, including: the Donor-CU1 sends a second message to the first IAB node after sending the first handover command message to at least one terminal device under the second DU of the first IAB node. The first handover command message indicates the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second message indicates the MT of the first IAB node to perform handover.

In one possible design, the method further comprises: donor-CU1 receives fourth information from Donor-CU 2. The fourth information indicates that the Donor-CU1 sends a second switching command message to the first IAB node after receiving the notification message from the Donor-CU 2; the notification message is used for notifying the Donor-CU2 of receiving a handover complete message of at least one terminal device under a second DU of the first IAB node, the handover complete message indicates that the terminal device completes handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

Based on the possible design, the Donor-CU1 sends a second switching command message to the first IAB node after receiving the switching completion message of at least one terminal device from the Donor-CU2, so that the migration of the IAB node accords with the flow of the Gradual Bottom-up migration.

In one possible design, the Donor-CU1 sends a second message to the first IAB node, including: after receiving the notification message from the Donor-CU2, the Donor-CU1 sends a second message to the first IAB node, where the second message instructs the MT of the first IAB node to perform handover. The notification message is used for notifying the Donor-CU2 of receiving a handover complete message of at least one terminal device under the second DU of the first IAB node.

In a second aspect, a communication method based on access backhaul integrated IAB is provided, where the method includes: the second home node centralized unit Donor-CU2 receives a first message from the first home node centralized unit Donor-CU1 requesting IP address configuration and/or BAP configuration for the first IAB node, and sends the X set of first IP address configuration and Y first BAP configurations to the Donor-CU1, X, Y being a positive integer. Wherein one of the X sets of first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2.

Based on the scheme, the Donor-CU2 returns an X set of IP address configuration and/or Y BAP configurations to the Donor-CU1 based on the request of the Donor-CU1, so that after the MT of the first IAB node is switched from the Donor-CU1 to the Donor-CU2, an F1 connection between the Donor-CU2 and the first DU of the first IAB node can be established, thereby enabling the Donor-CU2 and the first IAB node to conduct F1-C and F1-U communication, supporting implementation of the full migration scheme, and enabling traffic of the terminal device to migrate to a target path transmission between the Donor-CU2 and the first IAB node.

In one possible design, the method further comprises: the Donor-CU2 sends third information to the Donor-CU1, the third information indicating DUs of the first IAB node to which each of the X sets of first IP address configurations and each of the Y first BAP configurations belong.

In one possible design, the method further comprises: the Donor-CU2 sends fourth information to the Donor-CU 1. The fourth information indicates that the second handover command message sent by the Donor-CU1 to the first IAB node carries a handover condition of the MT of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

In one possible design, the method further comprises: the Donor-CU2 sends fourth information to the Donor-CU 1. The fourth information indicates the Donor-CU1 to send a first switching command message to at least one terminal device under a second DU of the first IAB node, and then send a second switching command message to the first IAB node; the first handover command message instructs the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second handover command message instructs the MT of the first IAB node to perform handover.

In one possible design, the method further comprises: the Donor-CU2 sends fourth information to the Donor-CU 1. The fourth information indicates that the Donor-CU1 sends a second switching command message to the first IAB node after receiving the notification message from the Donor-CU 2; the notification message is used for notifying the Donor-CU2 of receiving a handover complete message of at least one terminal device under a second DU of the first IAB node, the handover complete message indicates that the terminal device completes handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

In one possible design, the method further comprises: and after receiving the fifth information from the Donor-CU1, the Donor-CU2 sends back link resource configuration information to the intermediate node. The intermediate node includes a second home node distributed unit, donor-DU2, and an IAB node between the first IAB node and the Donor-CU 2. The fifth information is context information or quality of service QoS information of the terminal equipment under the first IAB node. The backhaul link resource configuration information is used to establish a backhaul radio link control RLC channel for a first DU of the first IAB node.

In one possible design, the method further comprises: and after receiving the fourth message from the Donor-CU1, the Donor-CU2 sends back link resource configuration information to the intermediate node. Or, the Donor-CU2 sends the backhaul link resource configuration information to the intermediate node after sending the fifth message to the Donor-CU 1. Wherein the fourth message is for requesting to migrate an F1 connection between the Donor-CU1 and a second DU of the first IAB node; the fifth message is a response message of the fourth message; the backhaul link resource configuration information is used to establish a backhaul RLC channel for a first DU of the first IAB node; the intermediate node includes a Donor-DU2 and an IAB node between the first IAB node and the Donor-CU 2.

The technical effects of any possible design in the second aspect may refer to the technical effects of the corresponding design in the first aspect, which are not described herein.

With reference to the first aspect or the second aspect, in one possible design, the first message includes first information. The first information indicates a number of IP address configurations and/or BAP configurations requested by the Donor-CU1 for the first IAB node.

With reference to the first aspect or the second aspect, in one possible design, the first message includes the second information. The second information indicates at least one DU of the first IAB node, an IP address configuration requested by the Donor-CU1 and/or a BAP configuration for the at least one DU.

With reference to the first aspect or the second aspect, in one possible design, the first message is configured to request an IP address configuration and/or a BAP configuration for the first IAB node, including: the first message is for requesting a set of IP address configurations and/or a set of BAP configurations for a first DU of the first IAB node.

With reference to the first aspect or the second aspect, in one possible design, the second message is a handover command message for the MT of the first IAB node.

With reference to the first aspect or the second aspect, in one possible design, the second message further includes a second IP address configuration, a second BAP configuration, and a handover condition of the MT of the first IAB node. Wherein the second IP address configuration and the second BAP configuration are used for establishing a cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node through the Donor-DU 1.

With reference to the first aspect or the second aspect, in one possible design, the handover condition of the MT of the first IAB node includes: a first handover command message is sent to at least one terminal device under the second DU of the first IAB node, the first handover command message instructing the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node. Or, receiving a handover complete message of at least one terminal device under the second DU of the first IAB node, where the handover complete message indicates that the terminal device completes handover from the second DU of the first IAB node to the first DU of the first IAB node.

With reference to the first aspect or the second aspect, in one possible design, one of the set of X first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node is handed over from the Donor-CU1 to the Donor-CU2, and is also used to migrate the F1 connection between the Donor-CU1 and the second DU of the first IAB node.

With reference to the first aspect or the second aspect, in one possible design, one set of the X sets of first IP address configurations and one first BAP configuration of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node is handed over from the Donor-CU1 to the Donor-CU2, and the other set of first IP address configurations and the one first BAP configuration are used to migrate the F1 connection between the Donor-CU1 and the second DU of the first IAB node.

With reference to the first aspect or the second aspect, in one possible design, one of the set of X first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU2, and the other one of the set of first IP address configurations and the Y first BAP configurations is used to migrate an F1 connection between the Donor-CU1 and the second DU of the first IAB node.

With reference to the first aspect or the second aspect, in one possible design, one of the X sets of first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU2, and the other of the X sets of first IP address configurations and the other of the Y first BAP configurations is used to migrate an F1 connection between the Donor-CU1 and the second DU of the first IAB node.

With reference to the first aspect or the second aspect, in one possible design, the first message is configured to request an IP address configuration and/or a BAP configuration for the first IAB node, including: the first message is for requesting X sets of IP address configurations and Y BAP configurations for a first DU and a second DU of the first IAB node, X being equal to 1 or 2, Y being equal to 1 or 2.

In a third aspect, a communication method based on access backhaul integrated IAB is provided, where the method includes: the first IAB node receives sixth information from the first home node centralized unit Donor-CU1, and starts a first DU of the first IAB node according to the sixth information. Wherein the sixth information comprises at least one set of IP address configuration and/or at least one set of BAP configuration, the at least one set of IP address configuration and the at least one set of BAP configuration being used to establish an F1 connection between the second home node centralized unit Donor-CU2 and the first DU of the first IAB node.

Based on the scheme, after receiving the IP address configuration and/or the BAP configuration for establishing the F1 connection between the Donor-CU2 and the first DU of the first IAB node, the first DU of the first IAB node is started, so that the terminal equipment can be switched from the second DU of the IAB node to the first DU, and the implementation of the full migration scheme is ensured.

In one possible design, the first IAB node receives the sixth information from the Donor-CU1, including: the first IAB node receives a second handover command message from the Donor-CU1, the second handover command message including sixth information, the second handover command message instructing the mobile terminal MT of the first IAB node to perform a handover.

In one possible design, the second handover command message further includes a handover condition of the MT of the first IAB node.

In one possible design, the handoff condition of the MT of the first IAB node includes: a first handover command message is sent to at least one terminal device under the second DU of the first IAB node, the first handover command message instructing the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node. Or, receiving a handover complete message of at least one terminal device under the second DU of the first IAB node, where the handover complete message indicates that the terminal device completes handover from the second DU of the first IAB node to the first DU of the first IAB node.

In a fourth aspect, a communications apparatus is provided for implementing various methods. The communication device may be the first host node in the first aspect, or a device comprised in the first host node, such as a chip or a system-on-chip; alternatively, the communication device may be the second host node in the second aspect, or a device comprised in the second host node, such as a chip or a chip system; alternatively, the communication device may be the first IAB node in the third aspect, or a device comprised in the first IAB node, such as a chip or a system-on-chip. The communication device comprises a module, a unit or means (means) for implementing the method, and the module, the unit or the means can be implemented by hardware, software or implemented by hardware for executing corresponding software. The hardware or software includes one or more modules or units corresponding to the functions.

In some possible designs, the communication device may include a processing module and a transceiver module. The processing module may be configured to implement the processing functions of any of the aspects described above and any possible implementation thereof. The transceiver module may comprise a receiving module and a transmitting module for implementing the receiving function and the transmitting function, respectively, in any of the above aspects and any possible implementation thereof.

In some possible designs, the transceiver module may be formed by a transceiver circuit, transceiver, or communication interface.

In a fifth aspect, there is provided a communication apparatus comprising: a processor and a memory; the memory is for storing computer instructions which, when executed by the processor, cause the communications device to perform the method of any of the aspects. The communication device may be the first host node in the first aspect, or a device comprised in the first host node, such as a chip or a system-on-chip; alternatively, the communication device may be the second host node in the second aspect, or a device comprised in the second host node, such as a chip or a chip system; alternatively, the communication device may be the first IAB node in the third aspect, or a device comprised in the first IAB node, such as a chip or a system-on-chip.

In a sixth aspect, there is provided a communication apparatus comprising: a processor and a communication interface; the communication interface is used for receiving and/or transmitting signals; the processor is configured to execute a computer program or instructions to cause the communication device to perform the method of any of the aspects. The communication device may be the first host node in the first aspect, or a device comprised in the first host node, such as a chip or a system-on-chip; alternatively, the communication device may be the second host node in the second aspect, or a device comprised in the second host node, such as a chip or a chip system; alternatively, the communication device may be the first IAB node in the third aspect, or a device comprised in the first IAB node, such as a chip or a system-on-chip.

In a seventh aspect, there is provided a communication apparatus comprising: at least one processor; the processor is configured to execute a computer program or instructions stored in the memory to cause the communication device to perform the method of any of the aspects. The memory may be coupled to the processor or may be separate from the processor. The communication device may be the first host node in the first aspect, or a device comprised in the first host node, such as a chip or a system-on-chip; alternatively, the communication device may be the second host node in the second aspect, or a device comprised in the second host node, such as a chip or a chip system; alternatively, the communication device may be the first IAB node in the third aspect, or a device comprised in the first IAB node, such as a chip or a system-on-chip.

In an eighth aspect, there is provided a computer readable storage medium having stored therein a computer program or instructions which, when run on a communication device, cause the communication device to perform the method of any of the aspects.

In a ninth aspect, there is provided a computer program product comprising instructions which, when run on a communications apparatus, cause the communications apparatus to perform the method of any of the aspects.

In a tenth aspect, there is provided a communications device (e.g. which may be a chip or a system of chips) comprising a processor for carrying out the functions referred to in any of the aspects.

In some possible designs, the communication device includes a memory for holding necessary program instructions and data.

In some possible designs, the device may be a system-on-chip, may be formed from a chip, or may include a chip and other discrete devices.

It is to be understood that when the communication device provided in any one of the fourth to tenth aspects is a chip or a chip system, the transmitting action/function of the communication device may be understood as outputting information, and the receiving action/function of the communication device may be understood as inputting information.

The technical effects of any one of the design manners of the fourth aspect to the tenth aspect may be referred to as the technical effects of the different design manners of the first aspect, the second aspect or the third aspect, and are not described herein.

Drawings

Fig. 1 is a schematic structural diagram of an IAB network provided in the present application;

fig. 2 is a schematic diagram of an interface between an IAB node and an IAB host provided herein;

fig. 3 is a schematic diagram of a control plane protocol stack in an IAB network provided in the present application;

fig. 4 is a schematic diagram of a user plane protocol stack in an IAB network provided in the present application;

fig. 5 is a schematic diagram of an IAB node migration provided in the present application;

fig. 6 is a schematic diagram of a partial migration of an IAB node provided herein;

fig. 7a is a schematic flow chart of an IAB node total migration provided in the present application;

fig. 7b is a schematic flow chart of another IAB node full migration provided in the present application;

fig. 7c is a schematic flow chart of yet another IAB node full migration provided in the present application;

fig. 8 is a schematic structural diagram of a communication system provided in the present application;

fig. 9 is a flow chart of an IAB-based communication method provided in the present application;

FIG. 10 is a flow chart of another exemplary IAB-based communication method provided herein;

FIG. 11 is a flow chart of yet another IAB-based communication method provided herein;

FIG. 12 is a flow chart of yet another IAB-based communication method provided herein;

fig. 13 is a schematic structural diagram of a communication device provided in the present application;

fig. 14 is a schematic structural diagram of another communication device provided in the present application.

Detailed Description

In the description of the present application, unless otherwise indicated, "/" means that the associated object is an "or" relationship, e.g., a/B may represent a or B; the term "and/or" in this application is merely an association relation describing an association object, and means that three kinds of relations may exist, for example, a and/or B may mean: there are three cases, a alone, a and B together, and B alone, wherein a, B may be singular or plural.

In the description of the present application, unless otherwise indicated, "a plurality" means two or more than two. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b, or c may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or plural.

In addition, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second", and the like are used to distinguish the same item or similar items having substantially the same function and effect. It will be appreciated by those of skill in the art that the words "first," "second," and the like do not limit the amount and order of execution, and that the words "first," "second," and the like do not necessarily differ.

In the embodiments of the present application, words such as "exemplary" or "such as" are used to mean serving as examples, illustrations, or descriptions. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion that may be readily understood.

It is appreciated that reference throughout this specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the various embodiments are not necessarily all referring to the same embodiment throughout the specification. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present application, the sequence number of each process does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

It should be understood that, in the present application, "…" and "if" refer to a process that is performed under some objective condition, and are not limited in time, nor do they require a judgment action when implemented, nor are they meant to be limiting.

It can be appreciated that some optional features of the embodiments of the present application may be implemented independently in some scenarios, independent of other features, such as the scheme on which they are currently based, to solve corresponding technical problems, achieve corresponding effects, or may be combined with other features according to requirements in some scenarios. Accordingly, the apparatus provided in the embodiments of the present application may also implement these features or functions accordingly, which is not described herein.

Throughout this application, unless specifically stated otherwise, identical or similar parts between the various embodiments may be referred to each other. In the various embodiments and the various implementation/implementation methods in the various embodiments in this application, if no special description and logic conflict exist, terms and/or descriptions between different embodiments and between the various implementation/implementation methods in the various embodiments may be consistent and may be mutually referred to, technical features in the different embodiments and the various implementation/implementation methods in the various embodiments may be combined to form new embodiments, implementations, implementation methods, or implementation methods according to their inherent logic relationships. The embodiments of the present application described below do not limit the scope of the present application.

In an access backhaul integrated (integrated access and backhaul, IAB) network, an IAB node (IAB-node) and an IAB host (IAB-node) are included. The IAB node may provide a radio access service for a User Equipment (UE), and traffic data of the UE is sent by the IAB node to an IAB host via a radio backhaul link. The IAB node may access the IAB host and may also connect to the IAB host through other IAB nodes.

The IAB node may include at least one Mobile Terminal (MT) and at least one Distributed Unit (DU). An IAB node may be an entity, e.g. comprising 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 may communicate with each other, e.g. via a network cable.

When the IAB node faces to its parent node (the parent node may be an IAB host or other IAB node), the IAB node may serve as a terminal device, i.e. a 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 to its child node (the child node may be another IAB node or a terminal device), the IAB node may be used as a network device, i.e. a network device role of the IAB node. In this case, it is the DU function or DU entity that provides the network device role for the IAB node.

The IAB host is an access network element with complete base station functionality. The IAB host may include one Centralized Unit (CU) and at least one Distributed Unit (DU). The interface between the CU and the DU is an F1 interface. The two ends of the F1 interface are CU and DU respectively, the opposite end of the F1 interface of the CU is DU, and the opposite end of the F1 interface of the DU is CU.

For convenience of description, in the following embodiments of the present application, MT of an IAB node is abbreviated as IAB-MT, and DU of an IAB node is abbreviated as IAB-DU. An IAB-hosted CU is abbreviated as a host CU (Donor-CU), and an IAB-hosted DU is abbreviated as a host DU (Donor-DU).

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 for which backhaul service is provided as a parent node, and accordingly, the IAB node may be treated as a child node of its parent node. The terminal device may regard the IAB node to which it is connected as a parent node, and correspondingly, the IAB node may also regard the terminal device connected to itself as a child node. The IAB node to which the terminal directly accesses may be referred to as an access IAB node. The IAB node may consider its own IAB host to be a parent node, and correspondingly, the IAB host may consider its own IAB node to be a child node.

Illustratively, as shown in FIG. 1, the parent node of IAB node 1 comprises an IAB host. IAB node 1 is in turn the parent node of IAB node 2 or IAB node 3. The parent node of the terminal device 1 comprises an IAB node 4. The child node of the IAB node 4 comprises a terminal device 1 or a terminal device 2. The IAB node 4 is an access IAB node for the terminal device 1 and the terminal device 2. The IAB node 5 is an access IAB node of the terminal device 2.

As shown in fig. 1, there are various possibilities for the transmission path between the IAB host and the terminal device 2, for example, transmission path 1"IAB host-IAB node 1-IAB node 2-IAB node 5-terminal device 2", transmission path 2"IAB host-IAB node 1-IAB node 2-IAB node 4-terminal device 2", and transmission path 3"IAB host-IAB node 1-IAB node 3-IAB node 4-terminal device 2".

One or more IAB nodes may be included on a transmission path between the terminal device and the IAB host. Each IAB node needs to maintain a parent-oriented wireless Backhaul Link (BL) and a child-oriented wireless link. If the sub-node of the IAB node is a terminal device, the radio link between the IAB node and the sub-node (i.e., the terminal device) is a radio Access Link (AL). If the sub-node of the IAB node is another IAB node, the radio link between the IAB node and the sub-node (i.e., the other IAB node) is a radio backhaul link.

Illustratively, as shown in fig. 1, in the transmission path "terminal device 1→iabnode 4→iabnode 3→iabnode 1→iab IAB host", the terminal device 1 accesses IAB node 4 through a wireless access link, IAB node 4 is connected to IAB node 3 through a wireless backhaul link, IAB node 3 is connected to IAB node 1 through a wireless backhaul link, and IAB node 1 is connected to IAB host through a wireless backhaul link.

As shown in FIG. 2, the IAB-DU is logically connected to the Donor-CU through the F1 interface. In practice, the connection of an IAB-DU to a Donor-CU is achieved through the Uu interface between the MT of each hop IAB node and the IAB-DU of its parent node on the transmission path. But since the final IAB-DU can communicate with the Donor-CU, it can be considered that there is logically an F1 interface between the IAB-DU and the Donor-CU.

The F1 interface includes an F1 interface control plane (F1-C) and an F1 interface user plane (F1-U). Through F1-C, IAB host can carry out interface management, configuration relevant to terminal equipment context, management of IAB-DU, etc. to IAB node. Through F1-U, IAB host and IAB node can carry out user plane data transmission, down transmission status feedback, etc.

Fig. 3 and fig. 4 are a schematic diagram of a control plane protocol stack and a schematic diagram of a user plane protocol stack in an IAB network according to an embodiment of the present application. A wireless backhaul link (an interface is a Uu interface) is established between the IAB node 2 and the IAB node 1 in fig. 3 and fig. 4, and between the IAB node 1 and the IAB-hosted DU. Peer-to-peer protocol stacks on both sides of the wireless backhaul link may include a backhaul adaptation protocol (backhaul adaptation protocol, BAP) layer, a radio link control (radio link control, RLC) layer, a medium access control (medium access control, MAC) layer, and a Physical (PHY) layer. There is a Uu interface between the terminal equipment and the IAB host in fig. 3 and 4. One end of the Uu interface is positioned at the terminal equipment, and the other end is positioned at the IAB host.

As shown in fig. 3, the control plane protocol stacks peer to peer across the Uu interface between the terminal device and the IAB host include a radio resource control (radio resource control, RRC) layer, a packet data convergence (packet data convergence protocol, PDCP) layer, an RLC layer, a MAC layer, and a PHY layer. When the IAB host includes a CU and a DU, the control plane protocol stack of the Uu interface at the end of the IAB may be located in the DU and the CU, respectively. For example, PHY layer, MAC layer and RLC layer are located in DUs, RRC layer and PDCP layer are located in CUs.

An F1-C interface exists between the DU of IAB node 2 and the IAB-hosted CU. One end of the F1-C interface is positioned at the DU of the IAB node 2, and the other end is positioned at the CU of the IAB host. The F1-C interface peer-to-peer control plane protocol stack includes at least one of an F1 application protocol (F1 application protocol, F1 AP) layer, a stream control transmission protocol (stream control transmission protocol, SCTP) layer, and an internet protocol (internet protocol, IP) layer.

As shown in fig. 4, the user plane protocol stacks peer to peer at both ends of the Uu interface between the terminal equipment and the IAB host include a service data adaptation protocol (service data adaptation protocol, SDAP) layer, a PDCP layer, an RLC layer, a MAC layer, and a PHY layer. When the IAB host includes a CU and a DU, the user plane protocol stack of the Uu interface at the end of the IAB host may be located in the DU and the CU, respectively. For example, the PHY layer, MAC layer and RLC layer are located in DUs, and the SDAP layer and PDCP layer are located in CUs.

There is an FI-U interface between the DU and the IAB host of IAB node 2. One end of the F1-U interface is positioned at the DU of the IAB node 2, and the other end is positioned at the CU of the IAB host. The user plane protocol layers peer to peer at both ends of the F1-U interface include at least one of a general packet radio service user plane tunneling protocol (general packet radio service tunnelling protocol for the user plane, GTP-U) layer, a user datagram protocol (user datagram protocol, UDP) layer, and an IP layer.

The BAP layer is a new protocol layer introduced by the wireless backhaul link in the IAB network. As shown in fig. 3 or fig. 4, the starting and stopping points of the BAP layer may be located in the DUs of the IAB node and the DUs of the IAB host counted by the terminal device. The BAP layer can be used for realizing the functions of routing of data packets on a wireless backhaul link, bearer mapping and the like. The Donor-CU may assign a unique BAP address (BAP address) to each IAB node and Donor-DU it controls for uniquely identifying each IAB node and Donor-DU in the network. In addition, the IAB node needs to have an IP address, and the IP address of the IAB-DU side is related to the Donor-DU.

In the case where the IAB node and the Donor-DU are located in a plurality of transmission paths, the BAP address of the IAB node or the Donor-DU may be associated with a plurality of BAP path Identifications (IDs). The BAP address and BAP path identification (BAP path ID) may be collectively referred to as a BAP route identification (BAP routing ID). The BAP layer protocol stack of the source node (downlink Donor-DU, uplink access IAB node) may add a BAP header to the packet. The BAP header may include a target BAP address and a BAP path identification indicating the BAP address of the target node (downstream access IAB node, upstream Donor-DU) and the path taken to reach the target node, respectively.

The Donor-CU may configure a routing table for each IAB node it controls. The routing table includes a mapping relationship between the BAP routing address and the BAP address of the next hop. After the IAB node receives the data packet, the routing table can be searched to determine the next-hop node, and the data packet is forwarded to the next-hop IAB node.

In addition to the routing function, the BAP layer may also be used to implement mapping between ingress backhaul RLC channels (backhaul RLC channel, BH RLC CH) and egress BH RLC CH. The mapping rule between ingress BH RLC CH and egress BH RLC CH may be configured by the Donor-CU. The mapping between the ingress BH RLC CH and the egress BH RLC CH can be understood as essentially a finer granularity route, further selecting the BH RLC CH based on determining the BAP address of the next hop node.

In some scenarios, such as load balancing or mobility scenarios, the parent node and the IAB host to which the IAB node is connected may change. Illustratively, as shown in FIG. 5, IAB node 3 may be handed over from a source parent node (IAB node 1) to a target parent node (IAB node 2), e.g., IAB-MT3 may be handed over from a cell under IAB-DU1 to a cell under IAB-DU 2. In addition, the IAB host to which the IAB node is connected is changed from the IAB host 1 to the IAB host 2, and it can be considered that the IAB node 3 is switched from the source IAB host (IAB host 1) to the target IAB host (IAB host 2). This scenario may be referred to as a migration of the IAB node, or across hosts, or across Donor-CUs. The IAB node where migration occurs may be referred to as a boundary node (boundary node), for example, the IAB node 3 in fig. 5 may be referred to as a boundary node.

Currently, IAB node migration across Donor-CUs can be divided into two implementations, partial migration (partial migration) and full migration (full migration). Briefly, in partial migration, the IAB-MT makes a handoff across the Donor-CU, but the IAB-DU remains F1 connected to the source Donor-CU. In full migration, the IAB-MT makes a handover across the Donor-CU, and the IAB-DU needs to establish an F1 connection with the target Donor-CU. In partial migration, a source Donor-CU may be referred to as an F1 endpoint CU (F1-terminating CU), and a target Donor-CU may be referred to as a non-F1 endpoint CU (non-F1-terminating CU). The F1 connection is understood to be a connection on the F1 interface.

The partial migration is mainly directed to the scenario for load balancing purposes. When the moving range of the boundary node is large, it is not suitable for the boundary node to still keep the F1 connection with the source Donor-CU, and the anchor point of the F1 connection of the boundary node needs to be migrated to the target Donor-CU, so that the full migration is mainly oriented to migration caused by the movement of the boundary node. Of course, the partial migration and the full migration may also be applied to migration caused by other reasons, which is not particularly limited in this application.

Fig. 6 is a schematic diagram of a partial migration according to an embodiment of the present application. Before the partial migration, there is an RRC connection between IAB-MT2 and Donor-CU1, there is an F1 interface between IAB-DU2 and Donor-CU1, and the communication path between IAB-DU2 and Donor-CU1 is the source path: After partial migration, IAB-MT2 and DAn RRC connection is established between the onor-CU2, the F1 interface between the IAB-DU2 and the Donor-CU1 still exists, and the F1 interface does not exist between the IAB-DU2 and the Donor-CU 2. Thus, after the partial migration, the communication path between IAB-DU2 and Donor-CU1 becomes the target path: />/>Wherein the target path may be understood as a cross-topology path, which may refer to: including the paths of two Donor-CU managed IAB nodes.

After partial migration, the data is not transmitted over the destination path through the Donor-CU2, and the Donor-CU1 and the Donor-DU2 communicate over the IP network. Although the data transfer on the target path does not pass through the Donor-CU2, the Donor-DU2, IAB-MT3, IAB-DU3, IAB-MT2 are controlled by the Donor-CU2, and the configuration thereon for servicing the cross-topology traffic is done by the Donor-CU 2. Among them, the cross-topology traffic can be understood as traffic (traffic) transmitted through the cross-topology path.

Because the IP address of the IAB-DU side is related to the Donor-DU, when the boundary node migrates across the Donor-CU, the Donor-DU changes, and the IP address of the IAB-DU side needs to change accordingly. In the example shown in FIG. 6, the IP address of the IAB-DU2 anchor (anchor) under the Donor-DU2 may be issued by the Donor-CU2 to the Donor-CU1 and then by the Donor-CU1 to the IAB node 2.

In addition, when the boundary node migrates across the Donor-CU, the BAP address and BAP configuration of the boundary node connected Donor-CU need to be transformed correspondingly because the boundary node connected Donor-CU transforms. In the example shown in FIG. 6, the IAB node 2's BAP address and default BAP configuration may be issued by the Donor-CU2 to the Donor-CU1 and then issued by the Donor-CU1 to the IAB node 2. Wherein the default BAP configuration is used to interact the first F1-C message between the IAB node 2 and the Donor-CU1 via the target path. The Donor-CU2 can send the Donor-CU1 more BAP configurations of the user plane data in the target path and then the Donor-CU1 sends the configuration to the IAB node 2 via the cross-topology F1-C interface between the Donor-CU1 and the IAB node 2. The cross-topology F1 interface can be understood as: the F1 interface (or F1 connection) is implemented by crossing topology paths.

Full migration can be divided into three implementations, full Nested, gradual Bottom-up, gradual Top-Down. Fig. 7a, fig. 7b, and fig. 7c are schematic flow diagrams of these three implementations provided in the embodiments of the present application, respectively. In fig. 7a, 7b, and 7c, it is assumed that the border node (IAB node 3) has two (logical) DUs (denoted IAB-DU3a and IAB-DU3 b). Prior to full migration, there is an RRC connection between IAB-MT3 and Donor-CU1, and there is an F1 interface between IAB-DU3a and Donor-CU 1. The curves in fig. 7a, 7b, and 7c represent possible transmission paths in the respective steps.

As shown in fig. 7a, in Full new, a cross-topology F1-C connection (a cross-topology F1-U connection is not established, and a cross-topology traffic transmission is not performed) between the IAB-DU3b and the Donor-CU2 is established through step 0, so that the terminal device under the IAB-DU3a can be switched to the IAB-DU3b. After sending a Handover (HO) command (Com) to the terminal device under the IAB-DU3a in step 1, the terminal device performs handover in step 2. In steps 3 to 5, the Donor-CU1 sends a handover command to the IAB point 3, causes the IAB-MT3 to handover from the IAB-DU1 to the IAB-DU2, and sends a handover complete (HO complete) message to the Donor-CU2. In step 6, a handover complete message of the terminal device is sent to the Donor-CU2 through the IAB-DU3b.

As shown in fig. 7b, in the data Bottom-up, a cross-topology F1-C connection and a cross-topology F1-U connection between the IAB-DU3b and the Donor-CU2 are established through step 0, so that the terminal device under the IAB-DU3a can be switched to the IAB-DU3b, and cross-topology control plane and user plane communication between the IAB-DU3b and the Donor-CU2 are implemented. In steps 1 to 3, the denor-CU 1 sends a handover command to the terminal device, and after the terminal device performs handover, a handover complete message is transmitted to the denor-CU 2 through a cross-topology path between the IAB-DU3b and the denor-CU 2. Thereafter, in steps 4 to 6, the Donor-CU1 transmits a handover command to the IAB point 3, causes the IAB-MT3 to handover from the IAB-DU1 to the IAB-DU2, and transmits a handover complete message to the Donor-CU2.

As shown in FIG. 7C, the Gradual Top-Down is similar to the partial migration, first performing a handoff of IAB-MT3, establishing a cross-topology F1-C connection and F1-U connection between IAB-DU3 and Donor-CU1, and an F1-C connection and F1-U connection between IAB-DU3b and Donor-CU 2. And then, the Donor-CU1 sends a switching command to the terminal equipment through the cross-topology connection between the IAB-DU3 and the Donor-CU1, so that the terminal equipment can be switched from the IAB-DU3a to the IAB-DU3 b.

For the full migration, the flow shown in fig. 7a, 7b and 7c is only generally presented, and implementation details thereof are not discussed. Based on the information, the application provides a communication method based on IAB, which designs the implementation details of the whole migration and ensures the implementation of the whole migration scheme.

Fig. 8 is a schematic structural diagram of a communication system to which the method provided in the present application is applicable. The communication system includes a first home node, a second home node, and a first IAB node. The first IAB is first connected to the first home node, after which the first IAB node may migrate to connect to the second home node. Further, the communication system may further comprise at least one terminal device accessing the first IAB node.

Alternatively, one or more IAB nodes may exist between the first IAB node and the first host node, and one IAB node 1 is illustrated in fig. 8, and the IAB node 1 includes an IAB-MT1 and an IAB-DU1 as an example. One or more IAB nodes may also be present between the first IAB node and the second host node, fig. 8 illustrates one IAB node 2, and the IAB node 2 includes an IAB-MT2 and an IAB-DU 2.

Alternatively, the first host node or the second host node may include, but is not limited to: a next generation base station (gNB), an evolved Node B (eNB), a radio network controller (radio network controller, RNC), a Node B (Node B, NB), a base station controller (base station controller, BSC), a base transceiver station (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 Road Side Unit (RSU) with a base station function, a baseband unit (BBU), a remote radio unit (Remote Radio Unit, RRU), an active antenna unit (active antenna unit, AAU), one or a group of antenna panels, or a Node with a base station function in a subsequent evolution system, etc.

Alternatively, the first host node may include a host CU function and a host DU function, in which case the first host node may be understood as one entity. Alternatively, the first host node may include a host CU entity and a host DU entity, in which case the first host node may be split into two entities. The second host node may refer to the first host node, and will not be described herein.

For convenience of description, the following embodiments refer to a host CU function or a host CU entity of the first host node as a first host node centralized unit Donor-CU1, and refer to a host DU function or a host DU entity of the first host node as a first host node distributed unit Donor-DU1. The hosting CU function or hosting CU entity of the second hosting node is referred to as a second hosting node centralized unit Donor-CU2, and the hosting DU function or hosting DU entity of the second hosting node is referred to as a second hosting node distributed unit Donor-DU2. In addition, the first host node may also be referred to as a first IAB host, and the second host node may also be referred to as a second IAB host, all of the features of the previously described IAB hosts being applicable to both the first host node and the second host node.

Alternatively, the first IAB node may be an entity comprising an MT function, a first DU function, and a second DU function. Alternatively, the first IAB node may include an MT entity, a first DU entity, and a second DU entity. The first DU entity and the second DU entity may share hardware resources, i.e. use one DU entity to implement the functionality of two logical DUs; alternatively, the first DU entity and the second DU entity may use different hardware resources, which is not specifically limited in this application.

For convenience of description, the following embodiments of the present application refer to the MT function or MT entity of the first IAB node simply as the MT of the first IAB node, refer to the first DU function or first DU entity of the first IAB node simply as the first DU of the first IAB node, and refer to the second DU function or second DU entity of the first IAB node simply as the second DU of the first IAB node. Furthermore, all of the features of the foregoing IAB node apply to the first IAB node.

Alternatively, the terminal device is sometimes also referred to as a User Equipment (UE), a mobile station, a terminal, etc. Terminal devices may be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-device (vehicle to everything, V2X) communication, machine-type communication (MTC), internet of things (internet of things, ioT), virtual reality, augmented reality, industrial control, autopilot, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal equipment can be a mobile phone, a tablet personal computer, a computer with a wireless receiving and transmitting function, a wearable device, a vehicle, an unmanned aerial vehicle, a helicopter, an airplane, a ship, a robot, a mechanical arm, intelligent household equipment and the like. The specific name and implementation form of the terminal device are not limited in the present application.

The method provided in the embodiment of the present application will be described in detail below by taking interaction among a first host node, a second host node, and a first IAB node as an example with reference to the accompanying drawings.

It is to be understood that in the embodiments of the present application, the execution subject may perform some or all of the steps in the embodiments of the present application, these steps or operations are only examples, and the embodiments of the present application may also perform other operations or variations of various operations. Furthermore, the various steps may be performed in a different order presented in accordance with embodiments of the present application, and it is possible that not all of the operations in the embodiments of the present application may be performed.

It should be noted that, in the embodiments described below, a name of a message between functions or entities or a name of each information in a message is only an example, and may be other names in a specific implementation, which is not specifically limited in the embodiments of the present application.

As shown in fig. 9, an IAB-based communication method provided in an embodiment of the present application includes the following steps:

s901, the Donor-CU1 sends a first message to the Donor-CU 2. Accordingly, the Donor-CU2 receives the first message from the Donor-CU 1.

Wherein the first message is used to request IP address configuration and/or BAP configuration for the first IAB node. Illustratively, the IP address configuration may include IP addresses at traffic granularity (i.e., per traffic). The BAP configuration may include a BAP address and a default BAP (default BAP) configuration, which may include an RLC channel identification indicating an RLC channel that may be used for interaction between the first IAB node and the Donor-CU 2.

Prior to this step S901, the first IAB node is connected to the Donor-CU1 or the first IAB node is controlled by the Donor-CU 1. There is an F1 interface between the second DU of the first IAB node and the Donor-CU1, which F1 interface may be referred to as a topology-with-F1 interface. The topology F1 interface can be understood as: the F1 interface (or F1 connection) is implemented through a common topology path. The co-topological path may refer to: the IAB nodes are all comprised of paths managed by the same Donor-CU. Illustratively, as shown in FIG. 8, prior to this step S901, the co-topology path of the second DU of the first IAB node and the Donor-CU1 is:

optionally, prior to step S901, the MT of the first IAB node may send a measurement report (measurement report, MR) to the Donor-CU 1. After the Donor-CU1 receives the measurement report, it can determine whether the MT of the first IAB node needs handover according to the measurement report. In case it is determined that the MT of the first IAB node needs to switch from the Donor-CU1 to the Donor-CU2, the first message is sent to the Donor-CU2.

Further, the Donor-CU1 may perform a handover preparation procedure with respect to the MT of the first IAB node in case it is determined that the MT of the first IAB node needs to be handed over from the Donor-CU1 to the Donor-CU2, for example, the Donor-CU1 may send a handover request with respect to the MT of the first IAB node to the Donor-CU2 for requesting to handover the MT of the first IAB node to the Donor-CU2. The Donor-CU2 can send a switching response to the Donor-CU1 after receiving the switching request, and the switching response can carry the IP address of the Donor-CU2.

Optionally, the first message may be sent in the handover preparation procedure of the MT related to the first IAB node, or may be sent before or after the handover preparation procedure, which is not specifically limited in this application.

S902, the Donor-CU2 sends X sets of first IP address configurations and/or Y first BAP configurations to the Donor-CU 1. Accordingly, donor-CU1 receives the X sets of first IP addresses and/or Y first BAP configurations from Donor-CU 2. X, Y is a positive integer.

For example, a set of IP address configurations may include at least one IP address that corresponds one-to-one to at least one type (or class) of traffic (traffic). I.e. a set of IP address configurations comprises IP addresses with granularity of traffic.

Optionally, when the Donor-CU2 sends the X set of first IP address configurations and the Y first BAP configurations to the Donor-CU1, a correspondence exists between the X set of first IP address configurations and the Y first BAP configurations, where the correspondence indicates that a certain set of IP address needs to be used in combination with the corresponding first BAP configuration. For example, if the IP address of a certain DU of the first IAB node is the IP address in the first IP address configuration #1, the BAP configuration of the DU is the first BAP configuration corresponding to the first IP address configuration # 1.

Wherein one of the X sets of first IP address configurations and one of the Y BAP configurations is used to establish an F1 connection (or F1 interface) between the Donor-CU2 and the first DU of the first IAB node after the MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2. In other words, the set of first IP address configurations and the one first BAP configuration are used to establish a topology F1 connection between the Donor-CU2 and the first DU of the first IAB node.

Optionally, the X sets of first IP address configurations and/or Y first BAP configurations may be determined by negotiation between the Donor-CU2 and the Donor-DU 2. Or, the first IP address configuration of the X set can be determined by the Donor-DU2 and then sent to the Donor-CU 2; the Y first BAP configurations may be determined by the Donor-CU2, which is not specifically limited in this application.

S903, the Donor-CU1 sends a second message to the first IAB node. Accordingly, the first IAB node receives the second message from the Donor-CU 1. The second message includes the above X sets of first IP address configurations and/or Y first BAP configurations.

Alternatively, the second message may be a handover command message for the MT of the first IAB node. Alternatively, the second message may be another RRC message other than the handover command message, which is not specifically limited in the present application.

S904, the first IAB node starts a first DU of the first IAB node.

The triggering conditions of the first DU start of the first IAB node are as follows: the first IAB node receives the sixth information. In other words, after the first IAB node receives the sixth information, the first DU of the first IAB node is started according to the sixth information. Wherein the sixth information comprises at least one set of IP addresses and/or at least one set of BAP configurations. The at least one set of IP address configurations and the at least one set of BAP configurations are used to establish an F1 connection (or F1 interface) between the Donor-CU2 and the first DU of the first IAB node (co-topology or cross-topology).

It should be noted that, the method provided in the embodiment of the present application further relates to the first information to the fifth information, which will be described in the subsequent embodiments, and are not repeated herein.

Based on the triggering condition, the first IAB node may determine whether the second message includes the sixth information after receiving the second message. Because of the X sets of first IP address configurations and/or the Y first BAP configurations in the second message, there is a set of first IP address configurations and/or one first BAP configuration for establishing a cross-topology F1 connection (or an F1 interface) between the Donor-CU2 and the first DU of the first IAB node, the first IAB node may start the first DU of the first IAB node after receiving the second message.

Alternatively, the first DU for starting the first IAB node may be described as: the first DU of the first IAB node is turned on or enabled or validated or activated.

Optionally, the starting the first DU of the first IAB node may include: the first DU managed cell is activated or prepared or validated. Illustratively, the operations management and maintenance network element (operation administration and maintenance, OAM) may pre-configure the first IAB node with two sets of cells, one set of cells being managed by a first DU of the first IAB node and the other set being managed by a second DU of the first IAB node, each DU managed cell being activated or validated at the start-up of the DU. Further, the cells under the first DU activated or prepared or validated at the start of the first DU of the first IAB node may specifically be indicated by the Donor-CU2, i.e. the Donor-CU2 may indicate which cells under the first DU are activated or prepared or validated.

Based on the above scheme provided by the application, the Donor-CU1 requests the IP address configuration and/or the BAP configuration from the Donor-CU2 for the first IAB node. And the X set of IP address configuration and/or Y BAP configuration returned by the Donor-CU2 enable the F1 connection between the Donor-CU2 and the first DU of the first IAB node to be established after the MT of the first IAB node is switched from the Donor-CU1 to the Donor-CU2, so that the Donor-CU2 and the first IAB node can carry out F1-C and F1-U communication, the implementation of a full migration scheme is ensured, and the traffic of the terminal equipment can be migrated to a target path transmission between the Donor-CU2 and the first IAB node.

In addition, after receiving the IP address configuration and/or the BAP configuration for establishing the F1 connection between the Donor-CU2 and the first DU of the first IAB node, the first DU of the first IAB node is started, so that the terminal device can be switched from the second DU to the first DU of the IAB node, and implementation of the full migration scheme is ensured as well.

The following describes a migration flow of Full Nested provided in the present application, taking the implementation of the method shown in FIG. 9 as an example. As shown in fig. 10, the flow includes the steps of:

s1001, the MT of the first IAB node sends a measurement report to the Donor-CU 1. Accordingly, the Donor-CU1 receives the measurement report from the MT of the first IAB node.

Optionally, after the Donor-CU1 receives the measurement report, it can determine whether the MT of the first IAB node needs to be handed over according to the measurement report. In the case where it is determined that the MT of the first IAB node needs to switch from the Donor-CU1 to the Donor-CU2, the following steps S1002 and S1003 are performed.

S1002, the Donor-CU1 and the Donor-CU2 execute a handover preparation procedure concerning the MT of the first IAB node. Reference may be made to the above description of the handover preparation procedure, and the description thereof will not be repeated here.

S1003, the Donor-CU1 sends a first message to the Donor-CU 2. Accordingly, the Donor-CU2 receives the first message from the Donor-CU 1. The first message may refer to the related description in step S901, which is not described herein.

Alternatively, step S1002 and step S1003 are not strictly performed in order. Step S1002 may be performed first and then step S1003 may be performed; alternatively, step S1003 may be performed first and then step S1003 may be performed; alternatively, step S1002 and step S1003 may be performed simultaneously, and in this scenario, the first message may be considered as a certain message in the handover preparation flow for the MT.

Optionally, when the Donor-CU1 requests the IP address configuration and/or the BAP configuration for the first IAB node, the number of the requested IP address configuration and/or BAP configuration may be indicated, and/or a body corresponding to the requested IP address configuration and/or BAP configuration may be indicated, that is, which DU of the first IAB node requests the IP address configuration and/or the BAP configuration.

As a first possible implementation, the first message may include the first information and/or the second information. In this scenario, the first message may be an existing XN message of some kind.

Wherein the first information indicates the number of IP address configurations and/or BAP configurations requested by the Donor-CU1 for the first IAB node. For example, for Full Nested, the first information may instruct the Donor-CU1 to request a set of IP address configurations and/or a BAP configuration for the first IAB node.

Illustratively, the first message may include cell 1 and cell 2 for indicating the number of IP address configurations requested by the Donor-CU1 and the number of BAP configurations, respectively. Alternatively, the first message may include cell 3 for jointly indicating the number of scheduling IP address configurations and the number of BAP configurations requested by the Donor-CU 1. For example, when cell 3 has a value of 1, the Donor-CU1 is instructed to request a set of IP address configuration and a BAP configuration for the first IAB node.

Wherein the second information indicates at least one DU of the first IAB node. The IP address configuration and/or BAP configuration requested by the Donor-CU1 is used for at least one DU indicated by the second information. For example, for Full Nested, the second information may indicate a first DU of the first IAB node for which the IP address configuration and/or BAP configuration requested by Donor-CU1 is indicated. In other words, the first DU, which indicates that the Donor-CU1 requests the IP address configuration and/or the BAP configuration for the first IAB node.

Illustratively, the first message may include a cell 4 in which an identity of the first DU is carried to indicate the first DU of the first IAB node.

Alternatively, the Donor-CU2 may learn that the first IAB node will perform full migration instead of partial migration after receiving the first message and obtaining the second information from the first message.

As a second possible implementation, the first message may be a newly defined XN message, which itself may have the aforementioned number and/or body indication function.

The newly defined XN message may be used, for example, to request a set of IP address configurations and/or a BAP configuration for the first DU of the first IAB node.

S1004, the Donor-CU2 sends X sets of first IP address configurations and/or Y first BAP configurations to the Donor-CU 1. Accordingly, donor-CU1 receives the X sets of first IP addresses and/or Y first BAP configurations from Donor-CU 2. X, Y is a positive integer.

For example, for Full Nested, the Donor-CU2 may send a set of first IP address configurations and/or a first BAP configuration to the Donor-CU1 for establishing a cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node.

Optionally, in the case where the Donor-CU2 sends the X set of first IP address configurations and the Y first BAP configurations to the Donor-CU1, the X set of first IP address configurations and the Y first BAP configurations may be carried in one message or may be carried in multiple messages. For example, X sets of first IP address configurations are carried in one message, and Y first BAP configurations are carried in another message; alternatively, the first IP address configuration and/or the first BAP configuration of the first DU for the first IAB node is carried in one message, and the first IP address configuration and/or the first BAP configuration of the second DU for the first IAB node is carried in another message, which is not specifically limited herein.

Optionally, the Donor-CU2 may also send third information to the Donor-CU 1. Accordingly, the Donor-CU1 can receive the third information from the Donor-CU 2. Wherein the third information indicates a DU of the first IAB node to which each of the X sets of first IP address configurations sent by the Donor-CU2 belongs, and/or indicates a DU of the first IAB node to which each of the Y first BAP configurations belongs. In other words, the third information may indicate to which DU of the first IAB node each set of first IP addresses it sends is configured for, and/or to which DU of the first IAB node each first BAP configuration it sends is configured for.

For example, for Full Nested, the third information may indicate a set of IP address configurations and/or a BAP configuration sent by the Donor-CU2 pertaining to the first DU of the first IAB node, i.e. the first DU configuration for the first IAB node.

Optionally, the Donor-CU2 may also send fourth information to the Donor-CU 1. Accordingly, the Donor-CU1 can receive this fourth information from the Donor-CU 2.

As a first possible implementation, the fourth information may instruct the Donor-CU1 to send the second handover command message to the first IAB node after sending the first handover command message to at least one terminal device under the second DU of the first IAB node. The present application does not limit the at least one terminal device to certain specific terminal devices, and the term "at least one terminal device" is used herein only to limit the number of terminal devices. For example, assuming that there are 10 terminal devices in total under the second DU of the first IAB node, when the "at least one terminal device" indicated by the fourth information is 8 terminal devices, it may be indicated that the Donor-CU1 sends the first handover command message to any 8 terminal devices under the second DU of the first IAB node, and then sends the second handover command message to the first IAB node. Of course, the at least one terminal device may also refer to all terminal devices. That is, the fourth information may instruct the Donor-CU1 to transmit the second handover command message after transmitting the first handover command message to all terminal apparatuses under the second DU of the first IAB node.

The first handover command message indicates that the terminal device is handed over from the second DU of the first IAB node to the first DU of the first IAB node, or indicates that the terminal device is handed over from the second DU of the first IAB node to the first DU of the first IAB node. The second handover command message instructs the MT of the first IAB node to perform a handover, or the second handover command message is a handover command message for the MT of the first IAB node.

As a second possible implementation, the fourth information indicates a handover condition of the MT of the first IAB node in a second handover command message sent by the Donor-CU1 to the first IAB node.

Illustratively, the handoff condition of the MT of the first IAB node may include: the first handover command message is sent (to the first IAB node or to the second DU of the first IAB node) to at least one terminal device under the second DU of the first IAB node. The present application does not limit the at least one terminal device to some specific terminal devices, and furthermore, the at least one terminal device may be replaced by all terminal devices, that is, the handover condition of the MT of the first IAB node may include: (the first IAB node or the second DU of the first IAB node) sends a first handover command message to all terminal devices under the second DU of the first IAB node. Reference may be made to a description of the at least one terminal device in the first possible implementation of the fourth information, which is not described in detail herein.

Alternatively, the above-described step S1003 and step S1004 may be performed in the same flow, and for example, the above-described step S1003 and step S1004 may be performed in a handover preparation flow with respect to MT.

Alternatively, the above information sent by the Donor-CU2 to the Donor-CU1 may be carried in the same message or may be carried in multiple messages, which is not specifically limited in this application.

S1005, the Donor-CU1 sends a second message to the first IAB node. Accordingly, the first IAB node receives the second message from the Donor-CU 1. The second message includes the above X sets of first IP address configurations and/or Y first BAP configurations.

As a first possible implementation, the second message may be another RRC message than the handover command message for the MT. In other words, the second message is not a handover command message for the MT.

Optionally, in this first possible implementation, the second message may further include a second IP address configuration and/or a second BAP configuration. The second IP address configuration and the second BAP configuration are configured to establish a cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node via the Donor-DU 1. In other words, the second IP address configuration and the second BAP configuration are configured to establish an F1 connection between the Donor-CU2 and the first DU of the first IAB node before the MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2. Illustratively, for Full Nested, the F1 connection herein may be an F1-C connection.

Alternatively, the second IP address configuration and the second BAP configuration may be determined by a negotiation between the Donor-CU1 and the Donor-DU 1. Alternatively, the second IP address configuration may be determined by the Donor-DU1 and the second BAP configuration may be determined by the Donor-CU 1.

As a second possible implementation, the second message may be a handover command message for the MT of the first IAB node, and the second message further includes a handover condition of the MT of the first IAB node. And, the Donor-CU1 also sends a third message to the first IAB node, the third message including the second IP address configuration and the second BAP configuration. The third message is another RRC message other than the handover command message for the MT. In addition, the third message is sent to the first IAB node before the second message.

The handover conditions of the MT of the first IAB node may refer to the description related to the second possible implementation of the fourth information, which is not described herein.

Optionally, in this second possible implementation, the sending, by the Donor-CU1, the second message to the first IAB node may include: the Donor-CU1 sends a second message to the first IAB node after sending the first handover command message to at least one terminal device under the second DU of the first IAB node. The present application does not limit the at least one terminal device to certain specific terminal devices. The at least one terminal device may be replaced by all terminal devices, and reference may be made to the description related to the at least one terminal device in the first possible implementation of the fourth information, which is not described herein. Further, in this possible implementation, the second message may also be referred to as a second handover command message.

As a third possible implementation, the second message may be a handover command message for the MT of the first IAB node, and the second message further includes a second IP address configuration, a second BAP configuration, and a handover condition of the MT of the first IAB node. The handover condition of the MT of the first IAB node may refer to the description related to the second possible implementation of the fourth information, which is not described herein. Further, in this possible implementation, the second message may also be referred to as a second handover command message.

Alternatively, the handover condition of the MT of the first IAB node may be understood as a validation condition of the handover command indicated by the second message. The handover command indicated by the second message is a handover command for the MT of the first IAB node.

S1006, the first IAB node starts a first DU of the first IAB node.

The triggering conditions of the first DU start of the first IAB node are as follows: the first IAB node receives the sixth information. Wherein the sixth information comprises at least one set of IP addresses and/or at least one set of BAP configurations. The at least one set of IP address configurations and the at least one set of BAP configurations are used to establish an F1 connection (co-topology or cross-topology) between the Donor-CU2 and the first DU of the first IAB node. The description of the first DU for starting the first IAB node may refer to the related description in step S904, which is not repeated here.

For the first implementation and the third implementation of the second message in step S1005, the sixth information includes at least one of a first IP address configuration, a first BAP configuration, a second IP address configuration, or a second BAP configuration. Wherein the first IP address configuration and the first BAP configuration are configured to establish a topology F1 connection between the Donor-CU2 and the first DU of the first IAB node. The second IP address configuration and the second BAP configuration are used to establish a cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node.

For the second implementation of the second message in step S1005, the sixth information includes a second IP address configuration and/or a second BAP configuration. I.e. the first IAB node may start the first DU of the first IAB node after receiving the third message.

Alternatively, for the second implementation and the third implementation of the second message in step S1005, the sixth information may be considered to be carried in the second message (or referred to as the second handover command message). That is, the first IAB node receives the sixth information from the Donor-CU1, may include: the first IAB node receives a second message (or called a second handover command message) from the Donor-CU1, which includes the sixth information.

S1007, a cross topology F1-C connection is established between the Donor-CU2 and the first DU of the first IAB node.

Wherein a second IP address configuration and a second BAP configuration may be used in this step S1007. The manner of establishing the cross-topology F1-C connection is not particularly limited in the present application.

S1008, the Donor-CU1 sends fifth information to the Donor-CU 2. Accordingly, donor-CU2 receives the fifth information from Donor-CU 1.

Wherein the fifth information is context information or quality of service (quality of service, qoS) information of the terminal device under the first IAB node (e.g., the second DU of the first IAB node).

Optionally, the fifth information may be carried in a handover request (handover request) message for the terminal device, or may be carried in another message, which is not specifically limited in this application. In case the fifth information is carried in other messages, the Donor-CU1 needs to send a handover request message for the terminal device to the Donor-CU2 in this step S1008. Fig. 10 illustrates an example in which the fifth information is carried in the handover request message for the terminal device.

S1009, the Donor-CU2 sends back link resource configuration information to the intermediate node.

Alternatively, the Donor-CU2 may perform this step S1009 after receiving the fifth information. In other words, the trigger condition for the Donor-CU2 to send back the link resource configuration information to the intermediate node may be that the Donor-CU2 receives the context information or QoS information of the terminal device.

Wherein the intermediate node comprises a Donor-DU2 and an IAB node between the first IAB node and the Donor-CU2 (e.g. the IAB node 2 shown in fig. 8). It will be appreciated that fig. 8 is only an example of an embodiment where one IAB node exists between the first IAB node and the Donor-CU2, and in practical application, multiple IAB nodes may exist between the first IAB node and the Donor-CU2, and the Donor-CU2 may send backhaul link resource configuration information to the multiple IAB nodes respectively. In addition, the backhaul link resource configuration information sent by the Donor-CU2 to different IAB nodes may be the same or different, which is not specifically limited in this application.

Wherein the backhaul link resource configuration information is used to establish a backhaul RLC channel (BL RLC CH) for a first DU of the first IAB node.

S1010, the Donor-CU2 sends a handover response (handover response) message for the terminal device to the Donor-CU 1. Accordingly, the Donor-CU1 receives the handover response message from the Donor-CU 2.

The step S1010 and the step S1009 are not strictly sequential. Step S1009 may be performed first and then step S1010 may be performed; alternatively, step S1010 may be performed first and then step S1009 may be performed; alternatively, step S1009 and step S1010 may be performed simultaneously. The present application is not particularly limited thereto.

S1011, the Donor-CU1 sends a first handover command message to the terminal equipment under the second DU of the first IAB node. Correspondingly, the terminal device receives a first handover command message from the Donor-CU 1.

Alternatively, the first handover command message may be sent to the terminal device via the Donor-DU1, the IAB node 1, the MT of the first IAB node, and the second DU of the first IAB node.

S1012, the terminal equipment initiates random access to a first DU of the first IAB node, and executes a random access procedure.

Optionally, when the second message of step S1005 adopts the first possible implementation manner, the process may further include the following step S1013a. When the second message of step S1005 described above adopts the second possible implementation manner or the third possible implementation manner, the process may further include the following step S1013b.

S1013a, the Donor-CU1 determines to send a first handover command message to at least one terminal device under a second DU of the first IAB node, and then sends a second handover command message to the first IAB node.

S1013b, after the first IAB node determines to send the first handover command message to at least one terminal device under the second DU of the first IAB node, it is determined that the handover condition of the MT of the first IAB node is satisfied, or that the handover command indicated by the second message is validated.

It should be noted that the present application is not limited to at least one terminal device in the steps S1013a and S1013b described above being some specific terminal devices. In addition, the at least one terminal device may be replaced by all terminal devices, and the description of the at least one terminal device in the first possible implementation of the fourth information may be referred to, which is not described herein.

After step S1013a or step S1013b, the following steps S1014 and S1015 may be continuously performed.

S1014, the MT of the first IAB node initiates random access to the target cell, and executes a random access procedure.

The target cell is a cell managed by a DU of a target parent node of the first IAB node. The target parent node is managed by the Donor-CU 2. Illustratively, as shown in fig. 8, the target parent node may be an IAB node 2, and the target cell is a DU-managed cell of the IAB node 2.

S1015, establishing a connection with topology F1 between the Donor-CU2 and the first DU of the first IAB node.

Optionally, since the Donor-CU2 establishes the BL RLC CH for the first DU of the first IAB node at the intermediate node in step S1009, and the first BAP configuration is received in step S1005, the first DU of the first IAB node may initiate the F1-C connection establishment request to the Donor-CU2 through the intermediate node after the MT handover of the first IAB node is completed. Thereafter, a User Plane (UP) configuration update issued by the Donor-CU2 via the F1-C message may be received, such as an IAB user plane configuration update (IAB UP configuration update) message.

To this end, the first DU of the first IAB node may communicate with the Donor-CU2 through the intermediate node with the F1 control plane and the user plane, in other words, the Full new migration of the first IAB node is completed.

In the above scheme, implementation details of Full Nested migration are designed from the aspects of IP address configuration of the first DU, BAP configuration, sending time or effective time of a handover command message of the MT, starting time of the first DU of the first IAB node, configuration time of BL RLC CH and the like, so that implementation of the Full Nested migration scheme can be ensured.

The following describes a migration flow of the Gradual Bottom-up provided in the present application, taking the implementation of the method shown in FIG. 9 applied to full migration as an example. As shown in fig. 11, the flow includes the steps of:

s1101 to S1102 are the same as step S1001 and step S1002, and reference is made to the description of step S1001 and step S1002, which will not be repeated here.

S1103, the Donor-CU1 sends a first message to the Donor-CU 2. Accordingly, the Donor-CU2 receives the first message from the Donor-CU 1.

The same as in step S1003 described above. For the Gradual Bottom-up, the first information may also instruct the Donor-CU1 to request a set of IP address configurations and/or a BAP configuration for the first IAB node. The second information may also indicate a first DU of the first IAB node, indicating that the Donor-CU1 requests an IP address configuration and/or a BAP configuration for the first DU of the first IAB node. Reference is made to the related description in the above step S1003, and the description is omitted here.

S1104, the Donor-CU2 sends X sets of first IP address configurations and/or Y first BAP configurations to the Donor-CU 1. Accordingly, donor-CU1 receives the X sets of first IP addresses and/or Y first BAP configurations from Donor-CU 2. X, Y is a positive integer.

This step S1104 is identical to the step S1004 described above. For the Gradual from-up, the Donor-CU2 may also send a set of first IP address configurations and/or a first BAP configuration to the Donor-CU1 for establishing a cross topology F1 connection between the Donor-CU2 and the first DU of the first IAB node. The third information may also indicate a set of IP address configurations and/or a BAP configuration sent by the Donor-CU2 as belonging to the first DU of the first IAB node.

For the Gradual Bottom-up, the Donor-CU2 may also send fourth information to the Donor-CU 1. Unlike Full new, in the data from up procedure, as a first possible implementation, the fourth information may instruct the Donor-CU1 to send a second handover command message to the first IAB node after receiving the notification message from the Donor-CU 2.

The notification message is used for notifying the Donor-CU2 of receiving a handover complete message of at least one terminal device under the second DU of the first IAB node. The handover complete message indicates that the terminal device completes the handover from the second DU of the first IAB node to the first DU of the first IAB node. The handover complete message may be a response message to the first handover command. The second handover command message may refer to the related description in the flow shown in fig. 10, and will not be described herein.

The present application is not limited to at least one terminal device in the flow shown in fig. 11 being some specific terminal device. In addition, except for the specific description, the "at least one terminal device" may be replaced by "all terminal devices" in the flow shown in fig. 11, and the detailed description of the at least one terminal device may refer to the related description in the flow shown in fig. 10, which is not repeated here.

As a second possible implementation, the fourth information may indicate a handover condition of the MT of the first IAB node in a second handover command message sent by the Donor-CU1 to the first IAB node.

For example, for a Gradual Bottom-up, the handoff conditions of the MT of the first IAB node may include: and (the first IAB node or the second DU of the first IAB node) receives the switching completion message of at least one terminal equipment under the second DU of the first IAB node.

S1105, the Donor-CU1 sends a second message to the first IAB node. Accordingly, the first IAB node receives the second message from the Donor-CU 1.

This step S1105 is similar to the above step S1005, except that: in a second possible implementation of the second message, the Donor-CU1 sends the second message to the first IAB node, which may include: the Donor-CU1 sends a second message to the first IAB node after receiving the notification message from the Donor-CU 2. The notification message is used to notify the Donor-CU2 of the handover complete message of the at least one terminal device under the second DU of the first IAB node. The rest of the description refers to the related description in step S1005, and is not repeated here.

S1106, the first IAB node starts a first DU of the first IAB node. The same as the step S1006, reference is made to the description of the step S1006, and the description is omitted here.

S1107, a cross-topology F1-C and F1-U connection between the Donor-CU2 and the first DU of the first IAB node is established.

S1108-S1112, which are the same as the above-mentioned steps S1108-S1112, refer to the relevant descriptions of steps S1108-S1112, and are not repeated here.

Optionally, when the second message of the step S1105 uses the first possible implementation manner, the process may further include the following step S1113a. When the second message of the above step S1105 adopts the second possible implementation manner or the third possible implementation manner, the process may further include the following step S1113b.

S1113a, donor-CU1 receives the notification message from Donor-CU2 and then sends a second handover command message to the first IAB node.

Alternatively, the Donor-CU2 may send the notification message to the Donor-CU1 after receiving the handover complete message of the at least one terminal device under the second DU of the first IAB node.

S1113b, after the first IAB node receives the handover complete message of at least one terminal device under the second DU of the first IAB node, it determines that the handover condition of the MT of the first IAB node is satisfied, or that the handover command indicated by the second message is validated.

After step S1113a or step S1113b, step S1114 and step S1115 may be continuously performed. Step S1114 and step S1115 are the same as step S1014 and step S1015, respectively, and reference is made to the above description, which is not repeated here.

To this end, the first DU of the first IAB node may perform communication between the F1 control plane and the user plane through the intermediate node and the Donor-CU2, in other words, the data Bottom-up migration of the first IAB node is completed.

In the above scheme, implementation details of the Gradual Bottom-up migration are designed from the aspects of IP address configuration of the first DU, BAP configuration, sending time or effective time of a switching command message of the MT, starting time of the first DU of the first IAB node, configuration time of BL RLC CH and the like, so that implementation of the Gradual Bottom-up migration scheme can be ensured.

The following describes a migration flow of the Gradual Top-Down provided in the present application, taking the implementation of the method shown in FIG. 9 applied to full migration as an example. As shown in fig. 12, the flow includes the steps of:

S1201-S1202, which are the same as step S1001 and step S1002 described above, refer to the description of step S1001 and step S1002, and are not described here again.

S1203, donor-CU1 sends a first message to Donor-CU 2. Accordingly, the Donor-CU2 receives the first message from the Donor-CU 1.

This step S1203 is similar to the step S1003 described above, except that: for the Gradual Top-down, in a first possible implementation, the first information and the second information may be implemented as follows:

1) The first information indicates that the Donor-CU1 requests two sets of IP address configurations and two BAP configurations for the first IAB node.

The second information indicates a first DU and a second DU of the first IAB node. That is, the first information and the second information may jointly indicate: a set of IP address configurations and a BAP configuration are requested for a first DU of a first IAB node and a set of IP address configurations and a BAP configuration are requested for a second DU of the first IAB node.

2) The first information indicates that the Donor-CU1 requests two sets of IP address configurations and one BAP configuration for the first IAB node.

The second information indicates a first DU and a second DU of the first IAB node. That is, the first information and the second information may jointly indicate: a set of IP address configurations is requested for the first DU and the second DU of the first IAB node, respectively, and a common BAP configuration is requested for the first DU and the second DU of the first IAB node.

3) The first information indicates that the Donor-CU1 requests a set of IP address configurations and two BAP configurations for the first IAB node.

The second information indicates a first DU and a second DU of the first IAB node. That is, the first information and the second information may jointly indicate: one BAP configuration is requested for the first DU and the second DU of the first IAB node, respectively, and a set of common IP address configurations is requested for the first DU and the second DU of the first IAB node.

4) The first information indicates that the Donor-CU1 requests a set of IP address configurations and a BAP configuration for the first IAB node. In this scenario, the first DU and the second DU of the first IAB node share a set of IP address configurations and share one BAP configuration. At this time, the first message may not include the second information; alternatively, the second information may be 1-bit indication information indicating the first DU and the second DU of the first IAB node or indicating that the first DU and the second DU of the first IAB node share the IP address configuration and the BAP configuration.

Wherein the IP address configuration and/or BAP configuration requested by the first IAB node for the second DU of the first IAB node is used to migrate the F1 connection between the Donor-CU1 and the second DU of the first IAB node. Exemplary, in particular for migrating an F1 connection between a Donor-CU1 and a second DU of a first IAB node from a source path to a target path. Based on the communication system shown in fig. 8, the source path is The target path is->

It will be appreciated that the migration of F1 between the Donor-CU1 and the second DU of the first IAB node to the target path is to effect a handoff of the terminal device under the second DU of the first IAB node.

In a second possible implementation, the first message may be a newly defined XN message that may be used to request X sets of IP address configurations and/or Y BAP configurations for the first DU and the second DU of the first IAB node, X being equal to 1 or 2, Y being equal to 1 or 2.

Alternatively, in connection with the flows shown in FIGS. 10 and 11 above, the Donor-CU2 may differentiate between Full New/Graded Bottom-up and Graded Top-Down based on the number of IP address configurations and/or BAP configurations requested by the Donor-CU 1.

S1204, the Donor-CU2 sends X sets of first IP address configurations and/or Y first BAP configurations to the Donor-CU 1. Accordingly, donor-CU1 receives the X sets of first IP addresses and/or Y first BAP configurations from Donor-CU 2. X, Y is a positive integer.

This step S1204 is similar to the step S1004 described above, except that: for a Gradual Top-Down, the Donor-CU2 may send to the Donor-CU 1:

1) Two sets of first IP address configurations and/or two first BAP configurations.

Wherein the set of first IP addresses and the first BAP are configured to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2. The further set of first IP addresses and the further first BAP configuration are also used for migrating the F1 connection between the Donor-CU1 and the second DU of the first IAB node.

2) Two sets of first IP address configurations and/or one first BAP configuration.

Wherein the set of first IP address configuration and the one first BAP configuration are configured to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the MT of the first IAB node is switched from the Donor-CU1 to the Donor-CU 2. Another set of first IP address configurations and the one first BAP configuration are used to migrate an F1 connection between the Donor-CU1 and a second DU of the first IAB node.

3) A set of first IP address configurations and/or two first BAP configurations.

Wherein the set of first IP addresses and the first BAP are configured to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2. The set of first IP address configurations and the further first BAP configuration are used to migrate an F1 connection between the Donor-CU1 and a second DU of the first IAB node.

4) A set of first IP address configurations and/or a first BAP configuration.

Wherein the set of first IP addresses and the first BAP are configured to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2. The set of first IP address configurations and the one first BAP configuration are also used to migrate an F1 connection between the Donor-CU1 and a second DU of the first IAB node.

Optionally, the Donor-CU2 may further send third information to the Donor-CU1 to indicate the DUs of the first IAB node to which each set of first IP address configurations belongs, and/or the DUs of the first IAB nodes to which each first BAP configuration belongs. Reference may be made to the relevant description in the flow shown in fig. 10, and will not be repeated here.

Alternatively, the Donor-CU2 can also send fourth information to the Donor-CU1, which instructs the Donor-CU1 to immediately issue a handover command message for the MT. Of course, the Donor-CU2 may not send the fourth information, and default to issue the handover command message for the MT immediately after receiving the IP address configuration and/or BAP configuration of the Donor-CU 2.

S1205, the Donor-CU1 sends a second message to the first IAB node. Accordingly, the first IAB node receives the second message from the Donor-CU 1. The second message includes the above X sets of first IP address configurations and/or Y first BAP configurations.

For the grade Top-down, the second message in this step S1205 is a handover command message for the MT of the first IAB node.

S1206, the first IAB node starts a first DU of the first IAB node.

The triggering conditions of the first DU start of the first IAB node are as follows: the first IAB node receives the sixth information. For a Gradual Top-Down, the sixth information includes a first IP address configuration and/or a first BAP configuration for establishing a cross-topology F1 connection between the Donor-CU2 and a first DU of the first IAB node.

S1207, the MT of the first IAB node initiates random access to the target cell, and executes a random access procedure. Reference is made to the related description in the above step S1014, and the description is omitted here.

S1208, migrate F1-U and F1-C connections between the Donor-CU1 and the second DU of the first IAB node. In other words, a cross-topology F11-U and F1-C connection is established between the Donor-CU1 and the second DU of the first IAB node.

S1209, establishing the connection with topology F1-U and F1-C between the Donor-CU2 and the first DU of the first IAB node.

Alternatively, for this step S1209, the Donor-CU2 may send back link resource configuration information to the intermediate node after receiving the fourth message from Donor-CU 1. Alternatively, the Donor-CU2 may send the backhaul link resource configuration information to the intermediate node after sending the fifth message to the Donor-CU 1.

Wherein the fourth message is for requesting to migrate an F1 connection between the Donor-CU1 and the second DU of the first IAB node. For example, the fourth message may be an IAB transport migration request (IAB transport migration request) message. The fifth message is a response message to the fourth message. For example, the fifth message may be an IAB transport migration response (IAB transport migration response) message.

The backhaul link resource configuration information is used to establish a BL RLC CH for a first DU of the first IAB node. The intermediate node includes a Donor-DU2 and an IAB node between the first IAB node and the Donor-CU 2. Reference is made to the related description in the above step S1009, and the description thereof is omitted here.

S1210, switching the terminal equipment under the second DU of the first IAB node to the first DU of the first IAB node.

Alternatively, the Donor-CU1 can send the handover command to the terminal device under the second DU via a cross-topology F1 connection between the Donor-CU1 and the second DU of the first IAB node. After receiving the switching command, the terminal equipment initiates random access to the second DU and executes a random access procedure. Thereafter, a handover complete message may be sent over the same topology F1 connection between the first DU of the first IAB node and the Donor-CU 2.

After the terminal device switches to the second DU, communication may be performed with the topology F1 connection between the first DU of the first IAB node and the Donor-CU 2. So far, the grade Top-down migration of the first IAB node is completed.

In the above scheme, implementation details of Gradual Top-Down migration are designed from the aspects of IP address configuration of the first DU, BAP configuration, start timing of the first DU of the first IAB node at transmission timing of the handover command message of the MT, establishment timing of connection with topology F1 between the Donor-CU2 and the first DU, and the like, so that implementation of Gradual Top-Down migration scheme can be ensured.

The foregoing has mainly described the solutions provided in this application. Correspondingly, the application also provides a communication device, which is used for realizing the methods, or can realize the functions of the first host node, the second host node or the first IAB node. The communication device may be the first host node in the above-described method embodiments, or a component, such as a chip or a chip system, that may be used for the first host node; alternatively, the communication device may be the second host node in the above-described method embodiment, or a component, such as a chip or a chip system, that may be used for the second host node; alternatively, the communication device may be the first IAB node in the above method embodiment, or a component that may be used for the first IAB node.

It will be appreciated that the communication device, in order to achieve the above-described functions, comprises corresponding hardware structures and/or software modules performing the respective functions. Those of skill in the art will readily appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is implemented as hardware or computer software driven hardware depends upon the particular application and design constraints imposed on the solution. 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.

The embodiment of the application may divide the functional modules of the communication device according to the embodiment of the method, for example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The integrated modules may be implemented in hardware or in software functional modules. It should be noted that, in the embodiment of the present application, the division of the modules is schematic, which is merely a logic function division, and other division manners may be implemented in actual implementation.

Communication device fig. 13 shows a schematic configuration of a communication device 130. The communication device 130 includes a processing module 1301 and a transceiver module 1302. The communication device 130 may be configured to implement the functions of the first home node, the second home node, or the first IAB node.

In some embodiments, the communications device 130 may also include a memory module (not shown in fig. 13) for storing program instructions and data.

In some embodiments, the transceiver module 1302, which may also be referred to as a transceiver unit, is configured to implement transmit and/or receive functions. The transceiver module 1302 may be formed of transceiver circuitry, a transceiver, or a communication interface.

In some embodiments, the transceiver module 1302 may include a receiving module and a transmitting module, configured to perform the steps of receiving and transmitting the class performed by the first host node, the second host node, or the first IAB node in the above-described method embodiments, respectively, and/or to support other processes of the techniques described herein; processing module 1301 may be configured to perform the steps of the processing class (e.g., determining, etc.) performed by the first host node, the second host node, or the first IAB node in the above-described method embodiments, and/or to support other processes of the techniques described herein.

The communication device 130 is configured to implement the functions of the first host node:

a processing module 1301 configured to send a first message to the Donor-CU2 through the transceiver module 1302, where the first message is used to request an IP address configuration and/or a BAP configuration for the first IAB node. The processing module 1301 is further configured to receive X sets of first IP address configurations and/or Y first BAP configurations from the Donor-CU2 through the transceiver module 1302. The processing module 1301 is further configured to send a second message to the first IAB node through the transceiver module 1302, where the second message includes X sets of first IP address configurations and/or Y first BAP configurations, and X, Y is a positive integer. Wherein one of the X sets of first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first DU of the first IAB node after the MT of the first IAB node is switched from the Donor-CU1 to the Donor-CU 2.

Optionally, the processing module 1301 is further configured to receive, through the transceiver module 1302, third information from the Donor-CU2, where the third information indicates a DU of the first IAB node to which each of the X sets of first IP address configurations and each of the Y first BAP configurations belong.

Optionally, the processing module 1301 is further configured to send a third message to the first IAB node through the transceiver module 1302. The third message includes a second IP address configuration and a second BAP configuration. The second IP address configuration and the second BAP configuration are used to establish a cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node via the first home node distributed unit Donor-DU 1.

Optionally, the processing module 1301 is further configured to receive fourth information from the Donor-CU2 through the transceiver module 1302. The fourth information indicates that the second handover command message sent by the Donor-CU1 to the first IAB node carries a handover condition of the MT of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

Optionally, the processing module 1301 is further configured to receive fourth information from the Donor-CU2 through the transceiver module 1302. The fourth information indicates the Donor-CU1 to send a first switching command message to at least one terminal device under a second DU of the first IAB node, and then send a second switching command message to the first IAB node; the first handover command message instructs the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second handover command message instructs the MT of the first IAB node to perform handover.

Optionally, the processing module 1301 is specifically configured to send, after sending the first handover command message to at least one terminal device under the second DU of the first IAB node, the second message to the first IAB node through the transceiver module 1302. The first handover command message indicates the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second message indicates the MT of the first IAB node to perform handover.

Optionally, the processing module 1301 is further configured to receive fourth information from the Donor-CU2 through the transceiver module 1302. The fourth information indicates that the Donor-CU1 sends a second switching command message to the first IAB node after receiving the notification message from the Donor-CU 2; the notification message is used for notifying the Donor-CU2 of receiving a handover complete message of at least one terminal device under a second DU of the first IAB node, the handover complete message indicates that the terminal device completes handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

Optionally, the processing module 1301 is specifically configured to send, through the transceiver module 1302, a second message to the first IAB node after receiving the notification message from the Donor-CU2, where the second message instructs the MT of the first IAB node to perform handover. The notification message is used for notifying the Donor-CU2 of receiving a handover complete message of at least one terminal device under the second DU of the first IAB node.

The communication device 130 is configured to implement the function of the second host node:

a processing module 1301 is configured to receive, through the transceiver module 1302, a first message from the Donor-CU1, where the first message is used to request an IP address configuration and/or a BAP configuration for the first IAB node. The processing module 1301 is further configured to send the X sets of first IP address configurations and Y first BAP configurations to the Donor-CU1 through the transceiver module 1302, where X, Y is a positive integer. Wherein one of the X sets of first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2.

Optionally, the processing module 1301 is further configured to send third information to the Donor-CU1 through the transceiver module 1302, where the third information indicates a DU of the first IAB node to which each of the X sets of first IP address configurations and each of the Y first BAP configurations belong.

Optionally, the processing module 1301 is further configured to send fourth information to the Donor-CU1 through the transceiver module 1302. The fourth information indicates that the second handover command message sent by the Donor-CU1 to the first IAB node carries a handover condition of the MT of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

Optionally, the processing module 1301 is further configured to send fourth information to the Donor-CU1 through the transceiver module 1302. The fourth information indicates the Donor-CU1 to send a first switching command message to at least one terminal device under a second DU of the first IAB node, and then send a second switching command message to the first IAB node; the first handover command message instructs the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second handover command message instructs the MT of the first IAB node to perform handover.

Optionally, the processing module 1301 is further configured to send fourth information to the Donor-CU1 through the transceiver module 1302. The fourth information indicates that the Donor-CU1 sends a second switching command message to the first IAB node after receiving the notification message from the Donor-CU 2; the notification message is used for notifying the Donor-CU2 of receiving a handover complete message of at least one terminal device under a second DU of the first IAB node, the handover complete message indicates that the terminal device completes handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

Optionally, the processing module 1301 is further configured to send backhaul link resource configuration information to the intermediate node through the transceiver module 1302 after receiving the fifth information from the Donor-CU 1. The intermediate node includes a second home node distributed unit, donor-DU2, and an IAB node between the first IAB node and the Donor-CU 2. The fifth information is context information or quality of service QoS information of the terminal equipment under the first IAB node. The backhaul link resource configuration information is used to establish a backhaul radio link control RLC channel for a first DU of the first IAB node.

Optionally, the processing module 1301 is further configured to send backhaul link resource configuration information to the intermediate node through the transceiver module 1302 after receiving the fourth message from the Donor-CU 1. Or, the processing module 1301 is further configured to send, after sending the fifth message to the Donor-CU1, backhaul link resource configuration information to the intermediate node through the transceiver module 1302. Wherein the fourth message is for requesting to migrate an F1 connection between the Donor-CU1 and a second DU of the first IAB node; the fifth message is a response message of the fourth message; the backhaul link resource configuration information is used to establish a backhaul RLC channel for a first DU of the first IAB node; the intermediate node includes a Donor-DU2 and an IAB node between the first IAB node and the Donor-CU 2.

Optionally, the first message includes first information. The first information indicates a number of IP address configurations and/or BAP configurations requested by the Donor-CU1 for the first IAB node.

Optionally, the first message includes second information. The second information indicates at least one DU of the first IAB node, an IP address configuration requested by the Donor-CU1 and/or a BAP configuration for the at least one DU.

Optionally, the first message is configured to request IP address configuration and/or BAP configuration for the first IAB node, including: the first message is for requesting a set of IP address configurations and/or a set of BAP configurations for a first DU of the first IAB node.

Optionally, the second message is a handover command message for the MT of the first IAB node.

Optionally, the second message further includes a second IP address configuration, a second BAP configuration, and a handover condition of the MT of the first IAB node. Wherein the second IP address configuration and the second BAP configuration are used for establishing a cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node through the Donor-DU 1.

Optionally, the handoff condition of the MT of the first IAB node includes: a first handover command message is sent to at least one terminal device under the second DU of the first IAB node, the first handover command message instructing the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node. Or, receiving a handover complete message of at least one terminal device under the second DU of the first IAB node, where the handover complete message indicates that the terminal device completes handover from the second DU of the first IAB node to the first DU of the first IAB node.

Optionally, one of the set of X first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU2, and is also used to migrate the F1 connection between the Donor-CU1 and the second DU of the first IAB node.

Optionally, one of the X sets of first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU2, and the other set of first IP address configurations and the one first BAP configuration is used to migrate the F1 connection between the Donor-CU1 and the second DU of the first IAB node.

Optionally, one of the set of X first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU2, and the other one of the set of first IP address configurations and the Y first BAP configurations is used to migrate an F1 connection between the Donor-CU1 and the second DU of the first IAB node.

Optionally, one of the X sets of first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and the first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU2, and the other of the X sets of first IP address configurations and the other of the Y first BAP configurations is used to migrate the F1 connection between the Donor-CU1 and the second DU of the first IAB node.

Optionally, the first message is configured to request IP address configuration and/or BAP configuration for the first IAB node, including: the first message is for requesting X sets of IP address configurations and Y BAP configurations for a first DU and a second DU of the first IAB node, X being equal to 1 or 2, Y being equal to 1 or 2.

The communication device 130 is configured to implement the function of the first IAB node:

a processing module 1301 is configured to receive, through the transceiver module 1302, sixth information from the first host node centralized unit Donor-CU 1. Processing module 1301 is further configured to start the first DU of the first IAB node according to the sixth information. Wherein the sixth information comprises at least one set of IP address configuration and/or at least one set of BAP configuration, the at least one set of IP address configuration and the at least one set of BAP configuration being used to establish an F1 connection between the second home node centralized unit Donor-CU2 and the first DU of the first IAB node.

Optionally, the processing module 1301 is configured to include, by the transceiver module 1302: a processing module 1301 is configured to receive, through the transceiver module 1302, a second handover command message from the Donor-CU1, where the second handover command message includes sixth information, and the second handover command message instructs the mobile terminal MT of the first IAB node to perform handover.

Optionally, the second handover command message further includes a handover condition of the MT of the first IAB node.

All relevant contents of each step related to the above method embodiment may be cited to the functional description of the corresponding functional module, which is not described herein.

Optionally, in this application, the processing module receives/sends information through the transceiver module, which can be also understood as: the processing module controls the transceiver module to receive/transmit information. Alternatively, the processing module sends information through the transceiver module, which can be understood as: the processing module outputs information to the receiving and transmitting module, and the receiving and transmitting module transmits the information; the processing module receives the information through the transceiver module, and can be understood as: the transceiver module receives the information and inputs the information to the processing module.

In this application, the communication device 130 may be presented in the form of an integrated manner dividing the respective functional modules. "module" herein may refer to an application-specific integrated circuit (ASIC), a circuit, a processor and memory that execute one or more software or firmware programs, an integrated logic circuit, and/or other devices that can provide the described functionality.

In some embodiments, when the communication device 130 in fig. 13 is a chip or a chip system, the functions/implementation of the transceiver module 1302 may be implemented through an input/output interface (or a communication interface) of the chip or the chip system, and the functions/implementation of the processing module 1301 may be implemented through a processor (or a processing circuit) of the chip or the chip system.

Since the communication device 130 provided in this embodiment can perform the above method, the technical effects obtained by the method can be referred to the above method embodiment, and will not be described herein.

As one possible product form, the first host node, the second host node, or the first IAB node according to the embodiments of the present application may be implemented using the following: one or more field programmable gate arrays (field programmable gate array, FPGA), programmable logic devices (programmable logic device, PLD), controllers, state machines, gate logic, discrete hardware components, any other suitable circuit or combination of circuits capable of performing the various functions described throughout this application.

As yet another possible product form, the first host node, the second host node, or the first IAB node in the present application may employ the constituent structure shown in fig. 14, or include the components shown in fig. 14. Fig. 14 is a schematic diagram of a communication device 1400 provided in the present application.

As shown in fig. 14, the communication device 1400 includes at least one processor 1401. Optionally, the communication device further comprises a communication interface 1402.

The program instructions in question, when executed in the at least one processor 1401, may cause the apparatus 1400 to implement the communication method provided by any of the embodiments described above and any of the possible designs thereof. Alternatively, the processor 1401 is configured to implement the communication method and any of the possible designs provided in any of the foregoing embodiments by logic circuitry or executing code instructions.

Communication interface 1402 may be used to receive program instructions and transmit them to the processor, or communication interface 1402 may be used to communicatively interact with other communication devices, such as interactive control signaling and/or traffic data, etc., by communication apparatus 1400. Illustratively, the communication interface 1402 may be used to receive signals from other devices than the device 1400 and transmit to the processor 1401 or send signals from the processor 1401 to other communication devices than the device 1400.

Alternatively, the communication interface 1402 may be a code and/or data read-write interface circuit, or the communication interface 1402 may be a signal transmission interface circuit between a communication processor and a transceiver, or a pin of a chip.

Optionally, the communication device 1400 may further comprise at least one memory 1403, which memory 1403 may be used for storing the required program instructions and/or data involved. Note that the memory 1403 may exist separately from the processor 1401 or may be integrated with the processor 1401. Memory 1403 may be located within communication device 1400 or external to communication device 1400, without limitation.

Optionally, the communication device 1400 may also include a power circuit 1404, the power circuit 1404 may be used to power the processor 1401. The power supply circuit 1404 may be located in the same chip as the processor 1401 or in another chip outside the chip in which the processor 1401 is located.

Optionally, the communication device 1400 may also include a bus 1405, and various components of the communication device 1400 may be interconnected by the bus 1405.

Alternatively, the processor in the present application may be a central processing unit (central processing unit, CPU), which may also be other general purpose processor, digital signal processor (digital signal processor, DSP), application specific integrated circuit (application specific integrated circuit, ASIC), off-the-shelf programmable gate array (field programmable gate array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, or the like. A general purpose processor may be a microprocessor, or the processor may be any conventional processor or the like.

Alternatively, the memory in the present application may be volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The nonvolatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. The volatile memory may be random access memory (random access memory, RAM) which acts as an external cache. By way of example but not limitation, many forms of random access memory (random access memory, RAM) are available, such as Static RAM (SRAM), dynamic random access memory (dynamic random access memory, DRAM), synchronous Dynamic Random Access Memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced Synchronous Dynamic Random Access Memory (ESDRAM), synchronous Link DRAM (SLDRAM), or direct memory bus RAM (DR RAM).

Optionally, the power supply circuit according to the embodiments of the present application includes, but is not limited to, at least one of the following: a power supply line, a power supply system, a power management chip, a power consumption management processor, or a power consumption management control circuit.

In some embodiments, in a hardware implementation, one skilled in the art will appreciate that the communication device 130 may take the form of the communication device 1400 shown in fig. 14.

As an example, the functions/implementation of the processing module 1301 in fig. 13 may be implemented by the processor 1401 in the communication apparatus 1400 shown in fig. 14 invoking computer-executed instructions stored in the memory 1403. The functions/implementations of the transceiver module 1302 in fig. 13 may be implemented by the communication interface 1402 in the communication device 1400 shown in fig. 14.

The configuration shown in fig. 14 is not limited to the first host node, the second host node, or the first IAB node. For example, in other embodiments of the present application, the first home node, the second home node, or the first IAB node may include more or fewer components than shown, or may combine certain components, or split certain components, or may have a different arrangement of components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

In some embodiments, the embodiments of the present application further provide a communication device, where the communication device includes a processor, for implementing the method in any of the method embodiments described above.

As a possible implementation, the communication device further comprises a memory. The memory is used for storing necessary computer programs and data. The computer program may comprise instructions which the processor may invoke the instructions in the computer program stored in the memory to instruct the communication device to perform the method in any of the method embodiments described above. Of course, the memory may not be in the communication device.

As another possible implementation, the communication apparatus further includes an interface circuit, which is a code/data read/write interface circuit, for receiving computer-executable instructions (the computer-executable instructions are stored in a memory, may be read directly from the memory, or may be transmitted to the processor via other devices).

As a further possible implementation, the communication device further comprises a communication interface, which may be used for communication with modules outside the communication device.

It will be appreciated that the communication device may be a chip or a chip system, and when the communication device is a chip system, the communication device may be formed by a chip, or may include a chip and other discrete devices, which are not specifically limited in this embodiment of the present application.

The present application also provides a computer readable storage medium having stored thereon a computer program or instructions which when executed by a computer, performs the functions of any of the method embodiments described above.

The present application also provides a computer program product which, when executed by a computer, implements the functions of any of the method embodiments described above.

Those skilled in the art will understand that, for convenience and brevity, the specific working process of the system, apparatus and unit described above may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.

It will be appreciated that the systems, apparatus, and methods described herein may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate components may or may not be physically separate, i.e. may be located in one place, or may be distributed over a plurality of network elements. The components shown as units may or may not be physical units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using a software program, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in accordance with embodiments of the present application are produced in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device including one or more servers, data centers, etc. that can be integrated with the medium. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like. In an embodiment of the present application, the computer may include the apparatus described above.

Although the present application has been described herein in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a review of the figures, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Although the present application has been described in connection with specific features and embodiments thereof, it will be apparent that various modifications and combinations thereof can be made without departing from the scope of the application. Accordingly, the specification and drawings are merely exemplary illustrations of the present application as defined in the appended claims and are considered to cover any and all modifications, variations, combinations, or equivalents that fall within the scope of the present application. It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims and the equivalents thereof, the present application is intended to cover such modifications and variations.

Claims

1. A communication method based on access backhaul integration IAB, the method comprising:

the first home node centralized unit Donor-CU1 sends a first message to the second home node centralized unit Donor-CU2, wherein the first message is used for requesting Internet protocol IP address configuration and/or backhaul adaptation protocol BAP configuration for the first IAB node;

the Donor-CU1 receives X sets of first IP address configurations and/or Y first BAP configurations from the Donor-CU2, wherein X, Y is a positive integer;

the Donor-CU1 sends a second message to the first IAB node, wherein the second message comprises the X sets of first IP address configurations and/or the Y first BAP configurations;

wherein one of the X sets of first IP address configurations and one of the Y first BAP configurations is used to establish an F1 connection between the Donor-CU2 and a first distributed unit DU of the first IAB node after the mobile terminal MT of the first IAB node switches from the Donor-CU1 to the Donor-CU 2.

2. The method of claim 1, wherein the first message includes first information indicating a number of IP address configurations and/or BAP configurations requested by the Donor-CU1 for the first IAB node.

3. The method according to claim 1 or 2, wherein the first message comprises second information indicating at least one DU of the first IAB node for which the requested IP address configuration and/or BAP configuration of the Donor-CU1 is used.

4. A method according to any one of claims 1-3, wherein the method further comprises:

the Donor-CU1 receives third information from the Donor-CU2, the third information indicating a DU of the first IAB node to which each of the X sets of first IP address configurations and each of the Y first BAP configurations belong.

5. The method of claim 1, wherein the first message is configured to request an IP address configuration and/or a BAP configuration for the first IAB node, comprising:

the first message is for requesting a set of IP address configurations and/or a set of BAP configurations for a first DU of the first IAB node.

6. The method according to any of claims 1-5, characterized in that the second message is a handover command message for the MT of the first IAB node.

7. The method of claim 6, wherein the method further comprises:

The Donor-CU1 sends a third message to the first IAB node, wherein the third message comprises a second IP address configuration and a second BAP configuration, and the second IP address configuration and the second BAP configuration are used for establishing cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node through a first host node distributed unit Donor-DU 1.

8. The method of claim 6 wherein the second message further comprises a second IP address configuration, a second BAP configuration, and a handoff condition of the MT of the first IAB node;

the second IP address configuration and the second BAP configuration are used for establishing a cross-topology F1 connection between the Donor-CU2 and the first DU of the first IAB node through the Donor-DU 1.

9. The method of any one of claims 1-6, or 8, further comprising: the Donor-CU1 receives fourth information from the Donor-CU 2;

the fourth information indicates that a second handover command message sent by the Donor-CU1 to the first IAB node carries a handover condition of the MT of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

10. The method according to claim 8 or 9, wherein the handover conditions of the MT of the first IAB node comprise:

a first handover command message is sent to at least one terminal device under a second DU of the first IAB node, the first handover command message instructing the terminal device to handover from the second DU of the first IAB node to the first DU of the first IAB node;

or, receiving a handover complete message of at least one terminal device under the second DU of the first IAB node, where the handover complete message indicates that the terminal device completes handover from the second DU of the first IAB node to the first DU of the first IAB node.

11. The method according to any one of claims 1-7, further comprising: the Donor-CU1 receives fourth information from the Donor-CU 2;

the fourth information indicates that the Donor-CU1 sends a first switching command message to at least one terminal device under a second DU of the first IAB node, and then sends a second switching command message to the first IAB node; the first handover command message instructs the terminal device to handover from a second DU of the first IAB node to a first DU of the first IAB node, and the second handover command message instructs the MT of the first IAB node to perform handover.

12. The method of any of claims 1-7, or 11, wherein the Donor-CU1 sends a second message to the first IAB node, comprising:

the Donor-CU1 sends a first switching command message to at least one terminal device under a second DU of the first IAB node, and then sends the second message to the first IAB node;

wherein the first handover command message instructs the terminal device to handover from a second DU of the first IAB node to a first DU of the first IAB node, and the second message instructs the MT of the first IAB node to perform handover.

13. The method according to any one of claims 1-7, further comprising: the Donor-CU1 receives fourth information from the Donor-CU 2;

the fourth information indicates that the Donor-CU1 sends a second switching command message to the first IAB node after receiving the notification message from the Donor-CU 2; the notification message is configured to notify the Donor-CU2 that a handover complete message of at least one terminal device under a second DU of the first IAB node is received, where the handover complete message indicates that the terminal device completes a handover from the second DU of the first IAB node to the first DU of the first IAB node, and the second handover command message indicates that the MT of the first IAB node performs handover.

14. The method of any of claims 1-7, or 13, wherein the Donor-CU1 sends a second message to the first IAB node, comprising:

after receiving the notification message from the Donor-CU2, the Donor-CU1 sends the second message to the first IAB node, where the second message instructs the MT of the first IAB node to perform handover;

the notification message is used for notifying the Donor-CU2 to receive a handover complete message of at least one terminal device under the second DU of the first IAB node.

15. The method of any of claims 1-4, wherein the set of first IP address configurations and the one first BAP configuration are further for migrating an F1 connection between the Donor-CU1 and a second DU of the first IAB node.

16. The method of any of claims 1-4, wherein the other one of the X sets of first IP address configurations and the one first BAP configuration are used to migrate an F1 connection between the Donor-CU1 and a second DU of the first IAB node.

17. The method of any of claims 1-4, wherein the set of first IP address configurations and another one of the Y first BAP configurations are used to migrate an F1 connection between the doser-CU 1 and a second DU of the first IAB node.

18. The method of any of claims 1-4, wherein another one of the X sets of first IP address configurations and another one of the Y first BAP configurations is used to migrate an F1 connection between the Donor-CU1 and a second DU of the first IAB node.

19. The method according to any of claims 1-4, or 15-18, wherein the first message is for requesting an IP address configuration and/or a BAP configuration for the first IAB node, comprising:

the first message is used to request X sets of IP address configurations and Y BAP configurations for a first DU and a second DU of the first IAB node, X being equal to 1 or 2, Y being equal to 1 or 2.

20. A communication method based on access backhaul integration IAB, the method comprising:

the second home node centralized unit Donor-CU2 receives a first message from the first home node centralized unit Donor-CU1, wherein the first message is used for requesting Internet protocol IP address configuration and/or backhaul adaptation protocol BAP configuration for the first IAB node;

the Donor-CU2 sends X sets of first IP address configurations and Y first BAP configurations to the Donor-CU1, wherein X, Y is a positive integer;

21. The method of claim 20, wherein the method further comprises:

after receiving the fifth information from the Donor-CU1, the Donor-CU2 sends back link resource configuration information to an intermediate node, wherein the intermediate node comprises a second host node distributed unit Donor-DU2 and an IAB node between the first IAB node and the Donor-CU 2;

wherein, the fifth information is context information or quality of service QoS information of the terminal equipment under the first IAB node; the backhaul link resource configuration information is used to establish a backhaul radio link control RLC channel for a first DU of the first IAB node.

22. The method of claim 20, wherein the method further comprises:

after receiving the fourth message from the Donor-CU1, the Donor-CU2 sends back link resource configuration information to the intermediate node; or,

After the Donor-CU2 sends a fifth message to the Donor-CU1, the Donor-CU sends back link resource configuration information to the intermediate node;

wherein the fourth message is used to request migration of an F1 connection between the Donor-CU1 and a second DU of the first IAB node; the fifth message is a response message of the fourth message; the backhaul link resource configuration information is used to establish a backhaul RLC channel for the first DU of the first IAB node; the intermediate node includes a Donor-DU2, and an IAB node between the first IAB node and the Donor-CU 2.

23. A communication method based on access backhaul integration IAB, the method comprising:

the first IAB node receives sixth information from the first home node centralized unit Donor-CU1, the sixth information comprising at least one set of IP address configuration and/or at least one set of BAP configuration for establishing an F1 connection between the second home node centralized unit Donor-CU2 and the first DU of the first IAB node;

the first IAB node starts the first DU of the first IAB node according to the sixth information.

24. The method of claim 23, wherein the first IAB node receives sixth information from the Donor-CU1, comprising:

The first IAB node receives a second handover command message from the Donor-CU1, where the second handover command message includes the sixth information, and the second handover command message instructs the mobile terminal MT of the first IAB node to perform handover.

25. The method of claim 24 wherein the second handover command message further includes a handover condition of the MT of the first IAB node.

26. The method of claim 25 wherein the handoff condition of the MT of the first IAB node comprises:

27. A communication device comprising means for implementing the method of any one of claims 1 to 26.

28. A communication device, comprising: at least one processor configured to enable the method of any one of claims 1 to 26 to be performed and a communication interface for receiving and/or transmitting signals.

29. A computer readable storage medium, having stored therein computer program instructions which, when executed by a processor, cause the method of any of claims 1 to 26 to be implemented.

30. A computer program product comprising program instructions which, when executed by a processor, cause the method of any one of claims 1 to 26 to be implemented.