Communication method and related apparatus

Abstract

A communication method and a related apparatus, relating to the technical field of communications. The method comprises: when a first trigger condition is satisfied, a relay node releases a configuration of a backhaul link. The backhaul link is a backhaul link between the relay node and a first donor node. The method clearly provides the trigger condition for releasing the configuration of the backhaul link. Thus, the relay node can release the configuration of the backhaul link in a timely fashion when the first trigger condition is satisfied, so that the configuration of the backhaul link which is not used temporarily is released, and can be used by other nodes, thereby increasing the resource utilization rate. In addition, in the embodiments of the present application, a situation in which two backhaul links are allocated to an IAB node can be avoided, so that conflicts in backhaul link configuration can be avoided, and signaling overhead in an MT migration process can be reduced.

Description

Communication method and related device

[0001] This application claims priority to the Chinese patent application with application number 202311288668.6 filed with the State Intellectual Property Office of China on September 27, 2023, and priority to the Chinese patent application with the invention name “Communication Methods and Related Devices”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a communication method and related devices. Background Art

[0003] Compared to the fourth-generation mobile communication system, the fifth-generation (5G) and future mobile communication systems impose even more stringent requirements on various network performance indicators. For example, 5G boasts a 1,000-fold increase in capacity compared to 4G, requiring wider coverage, ultra-high reliability, and ultra-low latency. Given the abundance of high-frequency carrier frequency resources, the use of high-frequency small cell networks is becoming increasingly popular in hotspots to meet the ultra-high capacity requirements of 5G. Due to the poor propagation characteristics of high-frequency carriers, severe attenuation due to obstruction, and limited coverage, a large number of small cells need to be deployed densely. However, providing fiber backhaul for these densely deployed small cells is costly and difficult to implement, necessitating the need for economical and convenient backhaul solutions. Furthermore, to meet the need for wide coverage, fiber deployment is challenging and expensive in remote areas, necessitating the design of flexible and convenient access and backhaul solutions. Integrated access and backhaul (IAB) technology provides a solution to the above two problems: its access link (access link) and backhaul link (backhaul link, BL) both adopt wireless transmission solutions, reducing the deployment of optical fibers.

[0004] In an IAB network, a relay node (RN), also known as an IAB node, provides wireless access services and forwards service data for user equipment (UE). The UE's service data is transmitted by the IAB node via a wireless backhaul link to an IAB donor, also known as a donor node or donor gNodeB (DgNB). An IAB node consists of a mobile termination (MT) and a distributed unit (DU). When facing its parent node, the IAB node acts as a terminal device, i.e., the MT. When facing its child node (which may be another IAB node or a UE), it is considered a network device, i.e., the DU. A donor base station (DgNB) can be an access network element with full base station functionality, or an access network element with a separate centralized unit (CU) and distributed unit (DU). The host base station is connected to the core network element (e.g., connected to the 5G core network) serving the UE and provides wireless backhaul functionality for the IAB node.

[0005] In an IAB network, during mobile equipment (MT) migration on an IAB node, the target CU assigns backhaul link configurations to the IAB node by default, including the default backhaul adaptation protocol (BAP) configuration, BAP address, and IP address. After the MT migration is complete, the IAB node also obtains backhaul link configurations when it transitions from an unauthorized state to an authorized state. If the MT migration is completed in an unauthorized state and then subsequently transitions to an authorized state, the IAB node may have two sets of backhaul link configurations, increasing signaling overhead.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a communication method and related apparatus, which can reduce the signaling overhead during the migration of an IAB node MT.

[0008] In the application, the CU (or host) to which the MT is connected and the CU (or host) to which the DU is connected refer to logical connections, which do not represent direct physical connections. For example, the MT has a radio resource control (RRC) connection with the CU to which it is connected, and the DU has an F1 interface connection with the CU to which it is connected. Moreover, the logical connection may be in a state that is about to be established (for example, the DU has determined that an F1 connection will be established with a certain CU, but the F1 interface has not yet been established, and the establishment of the F1 interface is about to be initiated), or in a state that has already been established (for example, the DU has already established an F1 interface with the CU to which it is connected). In this application, the migration of a relay node generally refers to the migration of a DU in a relay node.

[0009] In a first aspect, embodiments of the present application provide a communication method that can be performed by a communication device. The communication device can be a device, or a chip (system) or circuit for a device, which is not limited in this application. The method is applied to a relay node and includes:

[0010] The relay node releases the configuration of the backhaul link when the first trigger condition is met; the backhaul link is the backhaul link between the relay node and the first host node;

[0011] The first trigger condition includes:

[0012] The relay node performs mobile terminal MT migration; and the relay node is in an unauthorized state; and the relay node receives first configuration information from the first host node, where the first configuration information is used to indicate the configuration of the backhaul link.

[0013] The present application provides a communication method in which, upon satisfying a first trigger condition, a relay node releases the configuration of a backhaul link between the relay node and a first host node. The first trigger condition includes the relay node being in an unauthorized state. This allows the backhaul link configuration, which is not currently in use by the relay node, to be released promptly and potentially used by other nodes, thereby reducing resource waste and improving resource utilization.

[0014] The relay node in the embodiments of the present application can be a device equipped with a processor / chip capable of executing computer-executable instructions, or a processor / chip capable of executing computer-executable instructions. The relay node in the embodiments of the present application includes a terminal-side portion facing the parent node and a network-side portion facing the child node. For example, it can include a MT and a DU, or it can include an MT and a gNB, and the embodiments of the present application are not limited in this regard. The DU migration and MT migration of the relay node are completely decoupled, so the host node connected to the MT of the relay node and the host node connected to the DU can be different or the same. For example, the MT and DU of the relay node are both connected to the first host node. For another example, the MT of the relay node is connected to the second host node, and the DU of the relay node is connected to the first host node. When the communication method in the embodiments of the present application is applied to an IAB network, the relay node can be an IAB node, the MT of the IAB node is connected to the first host node, and the host node connected to the DU of the IAB node is not limited in this embodiment of the present application, and can be, for example, the first host node or the second host node.

[0015] The first host node in the embodiments of the present application may be a device equipped with a processor / chip capable of executing computer-executable instructions, or may be a processor / chip capable of executing computer-executable instructions. The first host node in the embodiments of the present application is the target CU corresponding to the MT of the relay node, and after the relay node performs MT migration, the first host node is connected to the MT of the relay node. When the communication method in the embodiments of the present application is applied to an IAB network, the relay node may be an IAB node, and the first host node may be connected to the MT of the IAB node.

[0016] The second host node in the embodiments of the present application can be a device equipped with a processor / chip capable of executing computer-executable instructions, or a processor / chip capable of executing computer-executable instructions. The second host node in the embodiments of the present application is the host node before the MT migration. When the communication method in the embodiments of the present application is applied to an IAB network, the relay node can be an IAB node, and the second host node can connect to the MT of the IAB node.

[0017] The configuration of releasing the backhaul link in the embodiment of the present application can be understood as the configuration failure of the backhaul link, or the configuration of not occupying the backhaul link, or the configuration of not using the backhaul link, or the construction of the backhaul link has been completed based on the configuration of the backhaul link, and then the backhaul link that has been constructed is released, etc. The configuration of releasing the backhaul link should not be understood only as the construction of the backhaul link has been completed according to the configuration of the backhaul link, and then the backhaul link that has been constructed is released. Optionally, after the relay node releases the configuration of the backhaul link, a message can be sent to the first host node, such as an RRC message, for informing the first host node that the relay node has released the backhaul link configuration, or for triggering the first host node side to release the backhaul link configuration. After receiving the message, the first host node releases the backhaul link configuration if the backhaul link configuration has not been released.

[0018] The first triggering condition in the embodiments of the present application includes, but is not limited to: the relay node performing MT migration; the relay node being in an unauthorized state; and the relay node receiving first configuration information from the first host node, the first configuration information being used to indicate the configuration of the backhaul link.

[0019] The relay node performs MT migration, which may refer to the first host node receiving information indicating MT migration, for example, the first host node receives MT migration indication information (for example, HANDOVER REQUEST message) from the second host node.

[0020] Among them, the relay node is in an unauthorized state, which may mean that the relay node is in an unauthorized state under the second host node, or it may mean that the relay node is in an unauthorized state under the first host node, or it may mean that the relay node is only allowed to be in an unauthorized state in the current situation (for example, a specific time period, or a specific space, etc.), etc. The implementation method of this application does not impose any restrictions on this.

[0021] The relay node being in an unauthorized state may also be understood as the relay node being about to be determined to be in an unauthorized state, or the relay node being indicated as being in an unauthorized state by other indication information.

[0022] For example, the handover request information (HANDOVER REQUEST message) sent by the second donor node to the first donor node includes information indicating that the relay node is in an unauthorized state.

[0023] For another example, the access and mobility management function (AMF) sends information to the first host node indicating that the relay node is in an unauthorized state. Specifically, the AMF sends a PATH SWITCH REQUEST ACK message to the first host node, and the relay node authorization information carried indicates that the relay node is in an unauthorized state.

[0024] For another example, the AMF directly sends information to the MT of the relay node indicating that the relay node is in an unauthorized state. Specifically, the AMF sends a NAS message to the MT of the relay node, and the NAS message carries the information of the MT authorization status of the relay node. The authorization status information indicates that the MT of the relay node is in an unauthorized state.

[0025] The first configuration information is used to indicate the configuration of a backhaul link, which is a backhaul link between the relay node and the first host node. The configuration of the backhaul link is used to establish a backhaul link for communication. The configuration of the backhaul link may include one or more of the following: a default BAP configuration, a BAP address, and an IP address.

[0026] Optionally, the first configuration information may be carried in an RRC message, such as an RRC reconfiguration message RRCReconfiguration.

[0027] In the IAB network, during the MT migration process of the IAB node, the target CU will assign the relevant configuration of the backhaul link to the IAB node by default, for example, including one or more of the following: default BAP configuration, BAP address and IP address, etc. After the MT migration is completed, when the state changes from the unauthorized state to the authorized state, the IAB node will perform the network access process and obtain the relevant configuration of the backhaul link once. For example, during the migration of the MT of the IAB node to the first host node, the first host node will usually default the MT of the IAB node to the authorized state and assign the relevant configuration of the backhaul link to the MT of the IAB node. After the MT switching of the IAB node is completed, the AMF will send the authorization information of the IAB node (including the authorized state or the unauthorized state) to the first host node. For example, the NAS message sent by the AMF to the IAB node carries the authorization information of the IAB node. The authorization information can be an IAB Authorized information element or a Mobile IAB Authorized information element (hereinafter referred to as the mIAB Authorized information element). This embodiment of the present application is not limited to this.

[0028] If an IAB node's mobile operator (MT) is in an unauthorized state, the issue of how to handle the backhaul link configuration already assigned to the MT is a challenge. Furthermore, if an IAB node's MT subsequently changes from an unauthorized state to an authorized state, the IAB node will re-enter the network and obtain a new backhaul link configuration. At this point, the question of whether the IAB node should use the new backhaul link configuration or the old one remains unresolved. Furthermore, assigning two backhaul link configurations to the IAB node can lead to usage conflicts and increased signaling overhead.

[0029] However, the embodiments of this application clearly define the trigger conditions for releasing the backhaul link configuration. This allows the relay node to promptly release the backhaul link configuration when the first trigger condition is met, freeing up the backhaul link configuration that is not currently in use and making it available for use by other nodes, thereby improving resource utilization. Furthermore, the embodiments of this application can also avoid the situation where two sets of backhaul link configurations are allocated to an IAB node, thereby avoiding conflicts in backhaul link configurations and reducing signaling overhead during MT migration.

[0030] In one possible implementation, the backhaul link configuration is not released if the following trigger conditions are met: the relay node performs mobile terminal MT migration; the relay node is in an authorized state; and the relay node receives first configuration information from the first host node, where the first configuration information is used to indicate the backhaul link configuration.

[0031] In a possible implementation manner of the first aspect, the first configuration information includes at least one of the following: a default Backhaul Adaptation Layer Protocol (BAP) configuration, a BAP address, and an Internet Protocol (IP) address.

[0032] In the embodiments of the present application, a possible specific implementation of a first configuration is provided. Specifically, in an MT migration scenario of an IAB node, the first host node sends a first configuration to the IAB node. The first configuration may include at least one of the following: a default BAP configuration, a BAP address, and an IP address. It should be noted that the first configuration information may be carried in a single RRC message or in multiple RRC messages, which is not limited in the embodiments of the present application.

[0033] In another possible implementation manner of the first aspect, the method further includes:

[0034] When the relay node switches to the authorized state, it receives second configuration information from the first host node, where the second configuration information is used to indicate the configuration of the backhaul link.

[0035] Among them, the relay node switching to the authorized state may refer to the AMF sending an indication message to the first host node, indicating that the relay node is in the authorized state, and the indication message may be carried by the PATH SWITCH REQUEST ACK message in the switching process. Alternatively, the indication message may be carried by the UE CONTEXT MODIFICATION REQUEST message. It may also refer to the AMF sending a non-access layer NAS message to the MT of the IAB node, indicating that the IAB node is in the authorized state. It may also refer to the NAS layer of the IAB node sending an indication message to the AS layer, indicating that the IAB node is in the authorized state. The embodiment of the present application does not limit which specific state the relay node switches to.

[0036] Optionally, the message indicating the authorization status of the relay node may be an IAB Authorized information element or an mIAB Authorized information element, which is not limited in this embodiment of the present application.

[0037] The relay node receives the second configuration information from the first host node, and accordingly, the first host node generates / sends the second configuration information. The second configuration information is configuration information of the backhaul link, which is the backhaul link between the relay node and the first host node.

[0038] Optionally, the second configuration information includes at least one of the following: a default BAP configuration, a BAP address, and an Internet Protocol IP address, which is not limited in the implementation manner of the present application.

[0039] It should be noted that the second configuration information can be carried in one RRC message or in multiple RRC messages, and this embodiment of the present application does not limit this.

[0040] In the implementation manner of the present application, a possible specific implementation manner of a relay node is provided, specifically, in a scenario where the relay node switches from an unauthorized state to an authorized state, the relay node receives second configuration information from the first host node for building a backhaul link for communication. It can be understood that in the implementation manner of the present application, if the relay node is in an unauthorized state, the configuration information (first configuration information) assigned to the relay node will be released. When the relay node switches from an unauthorized state to an authorized state, there will not be a situation where two sets of backhaul link configurations exist at the same time, which can avoid configuration conflicts of the backhaul link and reduce signaling overhead. In addition, the second configuration information is the configuration information of the backhaul link assigned to the relay node by the first host node after the relay node is re-authorized. This information can enable the backhaul link configuration to be based on the latest resource status, thereby improving the performance of resource allocation.

[0041] In another possible implementation of the first aspect, the second configuration information includes an IP address.

[0042] It should be noted that, in the embodiments of this application, "the second configuration information includes an IP address" generally means that the second configuration information includes only one IP address. In other words, when the relay node switches from an unauthorized state to an authorized state, the configuration information received by the relay node includes only one IP address. That is, the second configuration information may also include a default BAP configuration or BAP address, but only one IP address, not multiple IP addresses.

[0043] In the implementation manner of the present application, a specific implementation manner of the second configuration information is provided, specifically, in a scenario where the relay node switches from an unauthorized state to an authorized state, the relay node receives the second configuration information from the first host node for building a backhaul link and communicating. The second configuration information includes only one IP address, not multiple IP addresses. It is understandable that building a backhaul link requires one or more IP addresses, but the IP address resources that can be allocated by the host node are limited. By allocating an IP address to the relay node, the demand for building a backhaul link can be met. In the case where the relay node needs more IP addresses, it requests more IP addresses from the first host node.

[0044] Optionally, one IP address in the second configuration information may be carried in an RRC message, for example, an RRCReconfiguration message.

[0045] Optionally, one of the IP addresses in the second configuration information may be used for a control plane protocol (F1-C), which can manage the interface between the relay node and the first host node, manage the DU of the relay node, and perform UE context-related configuration.

[0046] In the implementation manner of the present application, the second configuration information includes only one IP address, which can save IP address resources and fully utilize the limited IP address resources in the first host node.

[0047] In another possible implementation of the first aspect, the relay node sends second information to the first host node, where the second information is used to request at least one IP address.

[0048] In the implementation manner of the present application, the second information is used to request at least one IP address. Accordingly, the first host node allocates at least one IP address to the relay node according to the second information.

[0049] The present application does not limit the use of the above IP address. For example, it can be used for F1-C or user plane protocol F1-U.

[0050] Optionally, the second information may be carried in an RRC message, such as IABOtherInformation.

[0051] Optionally, if the relay node needs more IP addresses, the second message is sent to the first host node. The embodiments of this application do not limit why the relay node needs more IP addresses or the purpose of the IP addresses. For example, if the relay node needs to backhaul more traffic, it may need more IP addresses.

[0052] In an embodiment of the present application, a specific implementation of the second information is provided. Specifically, in a scenario where a relay node needs more IP addresses, the relay node sends the second information to the first host node. It is understood that the first host node will allocate at least one IP address to the relay node based on the second information, allowing the relay node to implement / complete the corresponding task. This method of allocating IP addresses to relay nodes based on their needs can avoid allocating unused IP addresses, thereby conserving IP address resources and improving IP address utilization.

[0053] In another possible implementation of the first aspect, the second configuration information does not include an IP address; and the method further includes:

[0054] When the second trigger condition is met, the relay node sends third information to the first host node, where the third information is used to request an IP address;

[0055] The second trigger condition includes at least one of the following:

[0056] The second configuration information includes a default BAP configuration; or, the second configuration information includes a BAP address; or, the relay node receives fourth information, where the fourth information is used to indicate that the relay node is in an authorized state.

[0057] The second trigger condition in the implementation manner of the present application includes but is not limited to one or more of the following: the second configuration information includes a default BAP configuration; or, the second configuration information includes a BAP address; or, the relay node receives fourth information, which is used to indicate that the relay node is in an authorized state.

[0058] The relay node receiving the fourth information generally refers to the relay node receiving the fourth information from the AMF. Accordingly, the AMF sends the fourth information to the relay node. Typically, the AMF sends the fourth information to the NAS layer of the relay node, or the NAS layer of the relay node sends the fourth information to the AS layer. That is, the relay node receiving the fourth information from the AMF can be understood as the relay node receiving the fourth information from the AMF via the NAS layer, or, after the NAS layer receives authorization information from the AMF, the relay node receiving the fourth information from the NAS layer via the AS layer.

[0059] Optionally, the fourth information is used to indicate that the relay node is in an authorized state. For example, the fourth information may indicate that the IAB Authorized value is equal to authorized. The fourth information may also indicate that the mIAB Authorized value is equal to authorized. This embodiment of the present application does not limit this.

[0060] In an embodiment of the present application, when the second trigger condition is met, the relay node sends the third information to the first host node. Accordingly, the first host node also receives the third information from the relay node and sends one or more IP addresses to the relay node based on the third information.

[0061] The IP addresses requested through the third information include at least one IP address for F1-C.

[0062] Optionally, the IP address of the third information request may also include an IP address for F1-U.

[0063] The embodiments of the present application provide a possible implementation of the third information. Specifically, in a scenario where the second trigger condition is met, or in a scenario where the relay node requires an IP address, the relay node sends the third information to the first host node to request an IP address. It is understandable that in the embodiments of the present application, when the first host node sends the backhaul link configuration to the relay node, it does not assign an IP address to the relay node by default. Only when the second trigger condition is met does the relay node send the third information to the first host node and request one or more IP addresses.

[0064] In another possible implementation of the first aspect, the fourth information comes from a non-access stratum NAS or an access stratum AS of the relay node.

[0065] In the embodiments of the present application, a possible specific implementation of the fourth information is provided. Specifically, the fourth information is from the NAS layer or the AS layer of the relay node. It is understood that the AMF is responsible for authenticating the authorization status of the relay node. After authentication, the AMF sends the authentication result to the relay node. For example, the AMF sends authorization status indication information to the NAS layer of the relay node to indicate the authorization status of the relay node. For another example, the NAS layer of the relay node sends indication information to the AS layer to indicate the authorization status of the relay node.

[0066] Optionally, the indication information sent by the AMF to the NAS layer can be carried in a NAS message.

[0067] In a second aspect, an embodiment of the present application provides a communication method, which can be performed by a communication device. The communication device can be a device, or a chip (system) or circuit for a device, which is not limited in this application. The method is applied to a first host node, including:

[0068] When the relay node meets the third trigger condition, the first host node sends second configuration information to the relay node, where the second configuration information is used to indicate the configuration of the backhaul link between the relay node and the first host node; the second configuration information includes an IP address;

[0069] The third trigger condition includes:

[0070] The relay node performs mobile terminal MT migration; and the relay node switches to an authorized state.

[0071] In a third aspect, an embodiment of the present application provides a communication method, which can be performed by a communication device. The communication device can be a device, or a chip (system) or circuit for a device, which is not limited in this application. The method is applied to a first host node, including:

[0072] When the relay node meets the third trigger condition, the first host node sends second configuration information to the relay node, where the second configuration information is used to indicate the configuration of the backhaul link between the relay node and the first host node; the second configuration information does not include an IP address;

[0073] The third trigger condition includes:

[0074] The relay node performs mobile terminal MT migration; and the relay node switches to an authorized state.

[0075] In a fourth aspect, an embodiment of the present application provides a communication method, which can be performed by a communication device. The communication device can be a device, or a chip (system) or circuit for a device, which is not limited in this application. The method is applied to a relay node and includes:

[0076] The relay node saves third configuration information of the backhaul link when the fourth trigger condition is met; the backhaul link is a backhaul link between the relay node and the first host node;

[0077] The fourth trigger condition includes:

[0078] The relay node performs MT migration; and, the relay node is in an unauthorized state; and, the relay node receives the third configuration information from the first host node, where the third configuration information is used to indicate the configuration information of the backhaul link.

[0079] An embodiment of the present application provides a communication method, wherein a relay node can save configuration information of a backhaul link, which is a backhaul link between the relay node and a first host node, when a fourth trigger condition is met. The backhaul link is a backhaul link between the relay node and a first host node. The fourth trigger condition includes the relay node being in an unauthorized state. This allows the relay node to directly activate the saved backhaul link configuration when the relay node is adjusted to an authorized state, without having to request the backhaul link configuration from the relay node again. This facilitates rapid startup of the relay node after it changes from an unauthorized state to an authorized state.

[0080] For the relevant introduction of the relay node, the first host node and the second host node in the embodiment of the present application, please refer to the description of the first aspect above, which will not be repeated here.

[0081] The configuration information of the backhaul link stored in the embodiment of the present application may be stored, for example, in a memory of the relay node, or in other devices from which the relay node can quickly obtain the configuration information. The embodiment of the present application does not limit this.

[0082] The fourth trigger condition in the embodiment of the present application includes but is not limited to:

[0083] The relay node performs MT migration. The relay node is in an unauthorized state. The relay node receives third configuration information from the first host node, where the third configuration information is used to indicate configuration of a backhaul link.

[0084] The relay node performs MT migration, which may refer to the first host node receiving information indicating MT migration, for example, the first host node receives MT migration indication information (for example, HANDOVER REQUEST message) from the second host node.

[0085] Among them, the relay node is in an unauthorized state, which may mean that the relay node is in an unauthorized state under the second host node, or it may mean that the relay node is in an unauthorized state under the first host node, or it may mean that the relay node is only allowed to be in an unauthorized state in the current situation (for example, a specific time period, or a specific space, etc.), etc. The implementation method of this application does not impose any restrictions on this.

[0086] The relay node being in an unauthorized state may also be understood as the relay node being about to be determined to be in an unauthorized state, or the relay node being indicated as being in an unauthorized state by other indication information.

[0087] For example, the handover request information (HANDOVER REQUEST message) sent by the second donor node to the first donor node includes information indicating that the relay node is in an unauthorized state.

[0088] For another example, the AMF sends information to the first host node indicating that the relay node is in an unauthorized state. Specifically, the AMF sends a PATH SWITCH REQUEST ACK message to the first host node, and the relay node authorization information carried indicates that the relay node is in an unauthorized state.

[0089] For another example, the AMF directly sends information to the MT of the relay node indicating that the relay node is in an unauthorized state. Specifically, the AMF sends a NAS message to the MT of the relay node, and the NAS message carries the information of the MT authorization status of the relay node. The authorization status information indicates that the MT of the relay node is in an unauthorized state.

[0090] The third configuration information is used to indicate the configuration of the backhaul link, which is a backhaul link between the relay node and the first host node. The configuration of the backhaul link is used to build a backhaul link for communication.

[0091] In an IAB network, during the MT migration process of an IAB node, the second host node may send an indication of the relay node's authorization status to the first host node. For example, this indication may be carried in a Handover Request message (HANDOVER REQUEST). It is understood that the authorization status indicated by this indication generally refers to the relay node's authorization status under the second host node. For example, if the relay node is authorized under the second host node, the indication indicates that the relay node is authorized. For another example, if the relay node is unauthorized under the second host node, the indication indicates that the relay node is unauthorized. If the first host node receives a notification that the relay node is unauthorized, it may not send backhaul link configuration information to the relay node. However, whether the relay node is ultimately authorized depends on the indication from the AMF. If the relay node is authorized after AMF authentication, then sending the backhaul link configuration to the relay node by the first host node will affect the startup speed of the relay node.

[0092] However, in the embodiments of the present application, the trigger conditions for saving the backhaul link configuration are clearly provided. Therefore, when the fourth trigger condition is met, the relay node will save the backhaul link configuration and use it for rapid startup after the relay node is authorized. Furthermore, because the saved backhaul link configuration in the embodiments of the present application is used for rapid startup after the relay node is authorized, there is no need to resend the backhaul link configuration information to the relay node when the relay node switches to the authorized state. This reduces the signaling overhead during MT migration and avoids conflicts in the backhaul link configuration.

[0093] In one possible implementation, the third configuration information of the backhaul link is still stored if the following conditions are met: the relay node performs MT migration; the relay node is in an authorized state; and the relay node receives the third configuration information from the first host node, where the third configuration information is used to indicate the configuration information of the backhaul link.

[0094] In a possible implementation of the fourth aspect, the method further includes:

[0095] The relay node receives fifth information, where the fifth information is used to indicate that the relay node is in an authorized state; the relay node performs backhaul link transmission based on the configuration information, where the backhaul link transmission includes establishing an F1 interface of the relay node.

[0096] In the embodiments of the present application, a possible specific implementation of the fifth information is provided. Specifically, the fifth information is used to indicate that the relay node is in an authorized state. The fifth information can come from the AMF. For example, the AMF sends the fifth information to the relay node via an NAS message. Alternatively, after the AMF sends authorization information to the relay node via an NAS message, the NAS layer of the relay node sends the fifth information to the AS layer. It is understood that after the relay node transitions from an unauthorized state to an authorized state, the relay node performs backhaul link transmission based on the above configuration information, allowing the relay node to quickly start up and avoiding backhaul link configuration conflicts.

[0097] The backhaul link transmission includes establishing the relay node's F1 interface. For example, using the backhaul link established with the aforementioned configuration information, the relay node sends an F1 application protocol (F1AP) message to the relay node's F1 anchor CU. Specifically, an F1 interface message can be sent to the F1 anchor CU via the established backhaul link to request establishment of the relay node's F1 interface.

[0098] In a fifth aspect, an embodiment of the present application provides a communication method, which can be performed by a communication device. The communication device can be a device, or a chip (system) or circuit for a device, which is not limited in this application. The method is applied to a first host node, including:

[0099] The first host node retains configuration information of a backhaul link when the fourth condition is met; the backhaul link is a backhaul link between the relay node and the first host node;

[0100] The fourth condition includes:

[0101] The first host node receives sixth information from the access and mobility management function network element AMF, where the sixth information is used to indicate that the relay node is in an unauthorized state; and the relay node is connected to the first host node.

[0102] The implementation manner of the present application provides a possible specific implementation manner of configuration information. Specifically, the first host node retains the above configuration information when the fourth condition is met. The fourth information includes the seventh information from the AMF indicating that the relay node is in an unauthorized state, so that when the relay node is in an unauthorized state, the first host node ignores the indication information of the AMF and still saves the configuration of the backhaul link. This facilitates the direct use of the configuration of the backhaul link when the relay node switches to an authorized state, thereby achieving the effect of quickly enabling the relay node. In addition, since the first host node saves the configuration information, it can also ensure that the first host node no longer sends the configuration of the backhaul link to the relay node when the relay node switches to an authorized state, thereby avoiding conflicts in the backhaul link configuration.

[0103] For the introduction of the relay node, the first host node and the second host node in the implementation manner of the present application, please refer to the relevant description of the first aspect above, and will not be repeated here.

[0104] The sixth information is used to indicate that the relay node is in an unauthorized state, and the sixth information may be carried in a UE CONTEXT MODIFICATION REQUEST message. The sixth information may also be carried in a NAS message sent to the relay node, the NAS message carrying the relay node's authorization state as "authorized".

[0105] The above-mentioned connection between the relay node and the first host node usually means that the relay node and the first host node are not disconnected, specifically, it means that the MT of the relay node remains connected to the first host node, for example, the backhaul link between the MT of the relay node and the first host node is not disconnected, or the MT of the relay node has not performed a new MT migration, etc.

[0106] In one possible implementation, the first host node retains the configuration information if the following conditions are met: the first host node receives indication information from the AMF indicating that the relay node is in an authorized state; and the relay node connects to the first host node.

[0107] In an IAB network, during the MT migration process of an IAB node, the second host node may send an indication of the relay node's authorization status to the first host node. For example, this indication may be carried in a Handover Request message (HANDOVER REQUEST). It is understood that the authorization status indicated by this indication generally refers to the relay node's authorization status under the second host node. For example, if the relay node is authorized under the second host node, the indication indicates that the relay node is authorized. For another example, if the relay node is unauthorized under the second host node, the indication indicates that the relay node is unauthorized. If the first host node receives a notification that the relay node is unauthorized, it may not send backhaul link configuration information to the relay node. However, whether the relay node is ultimately authorized depends on the indication from the AMF. If the relay node is authorized after AMF authentication, then sending the backhaul link configuration to the relay node by the first host node will affect the startup speed of the relay node.

[0108] The embodiment of the present application clearly provides a processing method for the first host node when the AMF indicates that the relay node is in an unauthorized state. Specifically, the first host node ignores the indication information of the AMF, that is, it does not consider whether the indication information from the AMF indicates that the relay node is in an authorized state, and directly sends the configuration information of the backhaul link to the relay node. So that, when the authentication result of the AMF is that the relay node is in an authorized state, the relay node directly uses the configuration information of the backhaul link. On the one hand, it can achieve the effect of quickly enabling the relay node. On the other hand, the first host node does not need to send the configuration information of the backhaul link to the relay node again when the relay node switches to an authorized state, thereby avoiding conflicts in the backhaul link configuration.

[0109] In a possible implementation of the fifth aspect, the method further includes:

[0110] The first host node receives the seventh information from the second host node, and sends configuration information of the backhaul link to the relay node;

[0111] The seventh information is used to indicate that the relay node is in an unauthorized state.

[0112] An embodiment of the present application provides a communication method, wherein a first host node receives seventh information from a second host node and sends backhaul link configuration information to a relay node. The seventh information is used to indicate that the relay node is in an unauthorized state. The first host node ignores the authorization indication information from the second host node, allowing the relay node to establish a backhaul link based on the configuration information when the AMF authentication result is an authorized state, thereby achieving the effect of quickly enabling the relay node.

[0113] It is understandable that the first host node receives the seventh information from the second host node, and accordingly, the second host node generates / sends the seventh information. The first host node sends the configuration information of the backhaul link, and accordingly, the second host node also receives the configuration information of the backhaul link.

[0114] It should be noted that the first host node receiving the seventh information should not be understood as a condition that triggers the first host node to send the backhaul link configuration to the relay node. Instead, it should be understood that the first host node can send the backhaul link configuration information to the relay node when receiving the sixth information.

[0115] Optionally, the seventh information may be carried in a MT migration request message of the relay node, for example, a HANDOVER REQUEST message.

[0116] Optionally, the configuration information of the backhaul link may be carried in a radio resource control (RRC) message, for example, an RRCReconfiguration message.

[0117] Optionally, the configuration information of the backhaul link may include one or more of the following: default BAP configuration, BAP address, IP address, etc.

[0118] Optionally, the above IP address can be used for at least F1-C.

[0119] The embodiment of the present application clearly provides a processing method for the first host node when the second host node indicates that the relay node is in an unauthorized state. Specifically, the first host node ignores the indication information of the second host node, that is, it does not consider whether the indication information from the second host node indicates that the relay node is in an authorized state, and directly sends the configuration information of the backhaul link to the relay node. So that, when the authentication result of the AMF is that the relay node is in an authorized state, the relay node directly uses the configuration information of the backhaul link. On the one hand, it can achieve the effect of quickly enabling the relay node. On the other hand, the first host node does not need to send the configuration information of the backhaul link to the relay node again when the relay node switches to an authorized state, thereby avoiding conflicts in the backhaul link configuration.

[0120] In a possible implementation, when the first host node receives indication information from the second host node indicating that the relay node is in an authorized state, the first host node still sends configuration information of the backhaul link to the relay node.

[0121] In a possible implementation of the fifth aspect, the method further includes:

[0122] When the relay node is disconnected from the first host node, the configuration information is deleted.

[0123] The present application provides a possible specific implementation method for deleting backhaul link configuration information. Specifically, when a relay node is disconnected from a first host node, the backhaul link configuration information of the first host node is deleted. This allows unused backhaul link configurations to be released in a timely manner and, if possible, reused by other nodes, thereby improving resource utilization.

[0124] It can be understood that the relay reception is disconnected from the first host node, which may mean that the MT of the relay node is disconnected from the first host node, or that the backhaul link between the MT of the relay node and the first host node is disconnected, or that the MT of the relay node has undergone MT migration, etc.

[0125] The above-mentioned deletion of configuration information by the first host node may refer to releasing the configuration information, or may refer to adjusting the configuration information to configuration information that can be used by other nodes.

[0126] In a sixth aspect, an embodiment of the present application provides a communication device, which includes a unit for executing the method as described in any one of the first aspects.

[0127] In one possible design, the apparatus includes:

[0128] A processing unit, configured to release a configuration of a backhaul link when the relay node satisfies a first trigger condition; the backhaul link is a backhaul link between the relay node and the first host node;

[0129] The first trigger condition includes:

[0130] The relay node performs mobile terminal MT migration; and the relay node is in an unauthorized state; and the relay node receives first configuration information from the first host node, where the first configuration information is used to indicate the configuration of the backhaul link.

[0131] In one possible implementation, the device further includes:

[0132] A communication unit is configured to receive second configuration information from the first host node when the relay node switches to an authorized state, where the second configuration information is used to indicate a configuration of the backhaul link.

[0133] In a possible implementation, the communication unit is further configured to send second information, where the second information is used to request at least one IP address.

[0134] In a possible implementation manner, the communication unit is further configured to send third information, where the third information is used to request an IP address.

[0135] The methods performed by the above-mentioned processing unit and communication unit can refer to the methods corresponding to the above-mentioned first aspect, and will not be repeated here.

[0136] Regarding the technical effects brought about by the sixth aspect and any possible implementation method, please refer to the introduction of the technical effects corresponding to the first aspect and the corresponding implementation method.

[0137] In a seventh aspect, an embodiment of the present application provides a communication device, which includes a unit for executing the method as described in any one of the second aspects.

[0138] In one possible design, the apparatus includes:

[0139] a communication unit, configured for the relay node to send, when a third trigger condition is met, second configuration information from the first host node to the relay node, the second configuration information being used to indicate a configuration of a backhaul link between the relay node and the first host node; the second configuration information including an IP address;

[0140] The third trigger condition includes:

[0141] The relay node performs mobile terminal MT migration; and the relay node switches to an authorized state.

[0142] In one possible design, the device further includes:

[0143] A processing unit is used to generate the above-mentioned second configuration information.

[0144] The methods performed by the above-mentioned processing unit and communication unit can refer to the methods corresponding to the above-mentioned second aspect, and will not be repeated here.

[0145] Regarding the technical effects brought about by the seventh aspect and any possible implementation method, please refer to the introduction of the technical effects corresponding to the second aspect and the corresponding implementation method.

[0146] In an eighth aspect, an embodiment of the present application provides a communication device, which includes a unit for executing the method as described in any one of the third aspects.

[0147] In one possible design, the apparatus includes:

[0148] a communication unit, configured for the relay node to send, when a third trigger condition is met, second configuration information by the first host node to the relay node, where the second configuration information is used to indicate a configuration of a backhaul link between the relay node and the first host node; the second configuration information does not include an IP address;

[0149] The third trigger condition includes:

[0150] The relay node performs mobile terminal MT migration; and the relay node switches to an authorized state.

[0151] In one possible design, the device further includes:

[0152] A processing unit is used to generate the above-mentioned second configuration information.

[0153] The methods performed by the above-mentioned processing unit and communication unit can refer to the methods corresponding to the above-mentioned third aspect, and will not be repeated here.

[0154] Regarding the technical effects brought about by the eighth aspect and any possible implementation method, please refer to the introduction of the technical effects corresponding to the third aspect and the corresponding implementation method.

[0155] In a ninth aspect, an embodiment of the present application provides a communication device comprising a unit for executing the method as described in any one of the fourth aspects.

[0156] In one possible design, the apparatus includes:

[0157] a processing unit, configured for the relay node to save third configuration information of a backhaul link when a fourth trigger condition is satisfied; the backhaul link being a backhaul link between the relay node and the first host node;

[0158] The fourth trigger condition includes:

[0159] The relay node performs MT migration; and, the relay node is in an unauthorized state; and, the relay node receives the third configuration information from the first host node, where the third configuration information is used to indicate the configuration information of the backhaul link.

[0160] In one possible design, the device further includes:

[0161] The communication unit is configured to receive the third configuration information.

[0162] The methods performed by the above-mentioned processing unit and communication unit can refer to the methods corresponding to the above-mentioned fourth aspect, and will not be repeated here.

[0163] Regarding the technical effects brought about by the ninth aspect and any possible implementation method, please refer to the introduction of the technical effects corresponding to the fourth aspect and the corresponding implementation method.

[0164] In the tenth aspect, an embodiment of the present application provides a communication device, which includes a unit for executing the method as described in any one of the fifth aspects.

[0165] In one possible design, the apparatus includes:

[0166] a processing unit, configured to retain configuration information of a backhaul link when the first host node satisfies a fourth condition; the backhaul link being a backhaul link between the relay node and the first host node;

[0167] The fourth condition includes:

[0168] The first host node receives sixth information from the access and mobility management function network element AMF, where the sixth information is used to indicate that the relay node is in an unauthorized state; and the relay node is connected to the first host node.

[0169] In one possible design, the device further includes:

[0170] a communication unit, configured to receive seventh information from the second host node and send configuration information of the backhaul link to the relay node;

[0171] The seventh information is used to indicate that the relay node is in an unauthorized state.

[0172] The methods executed by the above-mentioned processing unit and communication unit can refer to the methods corresponding to the above-mentioned fifth aspect, which will not be repeated here.

[0173] Regarding the technical effects brought about by the tenth aspect and any possible implementation method, please refer to the introduction of the technical effects corresponding to the fifth aspect and the corresponding implementation method.

[0174] Optionally, in the communication device described in any one of the sixth to tenth aspects and any possible implementation manner:

[0175] In one implementation, the communication apparatus is a communication device. When the communication apparatus is a communication device, the communication unit may be a transceiver or an input / output interface; and the processing unit may be at least one processor. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input / output interface may be an input / output circuit.

[0176] In another implementation, the communication device is a chip (system) or circuit used in a communication device. When the communication device is a chip (system) or circuit used in a communication device, the communication unit may be a communication interface (input / output interface), interface circuit, output circuit, input circuit, pin, or related circuit on the chip (system) or circuit; and the processing unit may be at least one processor, processing circuit, or logic circuit.

[0177] In an eleventh aspect, an embodiment of the present application provides a communication device, comprising a processor. The processor is coupled to a memory and can be configured to execute instructions in the memory to implement the method of any of the first to fifth aspects and any possible implementation methods described above. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

[0178] In a twelfth aspect, an embodiment of the present application provides a communication device, comprising: a logic circuit and a communication interface. The communication interface is configured to receive or send information; the logic circuit is configured to receive or send information via the communication interface, so that the communication device executes the method of any one of the first to fifth aspects and any possible implementation thereof.

[0179] In the thirteenth aspect, an embodiment of the present application provides a computer-readable storage medium, which is used to store a computer program (also referred to as code, or instructions); when the computer program is run on a computer, the method of any one of the above-mentioned aspects from the first to the fifth aspect and any possible implementation method is implemented.

[0180] In the fourteenth aspect, an embodiment of the present application provides a computer program product, which includes: a computer program (also referred to as code, or instructions); when the computer program is run, it enables the computer to execute any one of the above-mentioned aspects 1 to 5 and any possible implementation method.

[0181] In a fifteenth aspect, an embodiment of the present application provides a chip, comprising a processor configured to execute instructions. When the processor executes the instructions, the chip performs the method of any one of the first to fifth aspects and any possible implementation manner described above. Optionally, the chip further comprises a communication interface configured to receive or send signals.

[0182] In the sixteenth aspect, an embodiment of the present application provides a communication system, which includes at least one communication device as described in aspects six to ten, or the communication device described in aspect eleven, or the communication device described in aspect twelfth, or the chip described in aspect fifteen.

[0183] In the seventeenth aspect, an embodiment of the present application provides a communication system, which includes at least one of a relay node and a first host node, the relay node is used to execute the method of the first aspect or the fourth aspect and any possible implementation method, and the second host node is used to execute the method of the second aspect or the third aspect or the fifth aspect and any possible implementation method.

[0184] In addition, in the process of executing the method described in any one of the first to fifth aspects and any possible implementation methods, the process of sending information and / or receiving information in the above method can be understood as the process of the processor outputting information and / or the process of the processor receiving input information. When outputting information, the processor can output the information to the transceiver (or communication interface, or sending module) so that it can be transmitted by the transceiver. After the information is output by the processor, it may also need to undergo other processing before it reaches the transceiver. Similarly, when the processor receives input information, the transceiver (or communication interface, or sending module) receives the information and inputs it into the processor. Furthermore, after the transceiver receives the information, the information may need to undergo other processing before it is input into the processor.

[0185] Based on the above principles, for example, the sending of information mentioned in the above method can be understood as the processor outputting information. For another example, the receiving of information can be understood as the processor receiving input information.

[0186] Optionally, for the operations such as transmission, sending and receiving involved in the processor, if there is no special explanation, or if they do not conflict with their actual functions or internal logic in the relevant description, they can be more generally understood as processor output, reception, input and other operations.

[0187] Optionally, in the process of executing the method described in any aspect of the first to fifth aspects and any possible implementation method, the processor may be a processor specifically used to execute these methods, or a processor that executes these methods by executing computer instructions in a memory, such as a general-purpose processor. The memory may be a non-transitory memory, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or may be separately provided on different chips. The embodiments of the present application do not limit the type of memory and the configuration of the memory and the processor.

[0188] In a possible implementation, the at least one memory is located outside the device.

[0189] In yet another possible implementation, the at least one memory is located within the device.

[0190] In another possible implementation, part of the at least one memory is located inside the device, and another part of the memory is located outside the device.

[0191] In this application, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together.

[0192] In the embodiments of this application, the trigger conditions for releasing the backhaul link configuration are clearly defined. This allows the relay node to promptly release the backhaul link configuration when the first trigger condition is met. This allows the backhaul link configuration that is not currently in use to be released and made available to other nodes, thereby improving resource utilization. Furthermore, this prevents the situation where two sets of backhaul link configurations are allocated to an IAB node, thereby avoiding conflicts in backhaul link configurations and reducing signaling overhead during MT migration. BRIEF DESCRIPTION OF THE DRAWINGS

[0193] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0194] FIG1 is a schematic diagram of the structure of an IAB system provided in an embodiment of the present application;

[0195] FIG2 is a schematic diagram of the structure of an IAB node provided in an embodiment of the present application;

[0196] FIG3 is a schematic diagram of the structure of an IAB network provided in an embodiment of the present application;

[0197] FIG4 is a schematic diagram of a control plane protocol architecture in an IAB network provided in an embodiment of the present application;

[0198] FIG5 is a schematic diagram of a user plane protocol architecture in an IAB network provided in an embodiment of the present application;

[0199] FIG6 is an example of an IAB network architecture diagram provided in an embodiment of the present application;

[0200] FIG7 is an example of a BAP topology of an IAB network provided in an embodiment of the present application;

[0201] FIG8 is a schematic diagram of an IAB node accessing a network according to an embodiment of the present application;

[0202] FIG9 is a flow chart of a communication method provided in an embodiment of the present application;

[0203] FIG10 is a flow chart of another communication method provided in an embodiment of the present application;

[0204] FIG11 is a flow chart of another communication method provided in an embodiment of the present application;

[0205] FIG12 is a flow chart of another communication method provided in an embodiment of the present application;

[0206] FIG13 is a flow chart of another communication method provided in an embodiment of the present application;

[0207] FIG14 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0208] FIG15 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0209] FIG16 is a schematic diagram of the structure of a chip provided in an embodiment of the present application. DETAILED DESCRIPTION

[0210] In order to make the purpose, technical solutions and advantages of this application clearer, the embodiments of this application will be described below in conjunction with the drawings in the embodiments of this application.

[0211] The terms "first" and "second" in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to the process, method, product, or device.

[0212] The “embodiment” mentioned herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It can be understood explicitly and implicitly by those skilled in the art that in the various embodiments of the present application, unless otherwise specified and there is a logical conflict, the terms and / or descriptions between the various embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form a new embodiment according to their inherent logical relationship.

[0213] It should be understood that in the present application, "at least one (item)" refers to one or more, "more than one" refers to two or more, "at least two (items)" refers to two or three and more than three, and "and / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0214] It should be noted that in this application, "indication" can include direct indication, indirect indication, explicit indication, and implicit indication. When describing that a certain indication information is used to indicate A, it can be understood that the indication information carries A, directly indicates A, or indirectly indicates A.

[0215] In this application, the information indicated by the indication information is referred to as the information to be indicated. In specific implementations, there are many ways to indicate the information to be indicated. For example, but not limited to, the information to be indicated can be directly indicated, such as the information to be indicated itself or an index of the information to be indicated. The information to be indicated can also be indirectly indicated by indicating other information, where the other information is associated with the information to be indicated. Alternatively, only a portion of the information to be indicated can be indicated, while the rest of the information to be indicated is known or agreed upon in advance. For example, the indication of specific information can be achieved by using a pre-agreed (e.g., protocol-specified) order of the various information, thereby reducing indication overhead to a certain extent. The information to be indicated can be sent as a whole or divided into multiple sub-information and sent separately. The transmission period and / or transmission timing of these sub-information can be the same or different. The specific transmission method is not limited in this application. The transmission period and / or transmission timing of these sub-information can be pre-defined, for example, according to a protocol, or can be configured by the transmitting device sending configuration information to the receiving device.

[0216] It should be noted that in this application, "send" can be understood as "output" and "receive" can be understood as "input". "Send information to A", where "to A" only indicates the direction of information transmission, A is the destination, and does not limit "sending information to A" to direct transmission on the air interface. "Sending information to A" includes sending information directly to A, and also includes sending information indirectly to A through a transmitter, so "sending information to A" can also be understood as "outputting information to A". Similarly, "receiving information from A" indicates that the source of the information is A, including receiving information directly from A, and also including receiving information indirectly from A through a receiver, so "receiving information from A" can also be understood as "inputting information from A".

[0217] Before introducing the present application, some of the terms used in the embodiments of the present application are briefly explained to facilitate understanding by those skilled in the art.

[0218] 1) Terminal side device is a device that provides voice and / or data connectivity to users. In the embodiments of the present application, the terminal side device may be referred to as user equipment (UE), terminal device, terminal, mobile station (MS), mobile terminal (MT), etc. For example, the terminal side device may include a handheld device with a wireless connection function, or a communication device connected to a wireless modem. The terminal side device can communicate with the core network via the radio access network (RAN) and exchange voice and / or data with the RAN.

[0219] Some examples of terminal-side devices include: mobile stations (MS), subscriber units, cellular phones, smart phones, wireless data cards, personal digital assistants (PDAs), computers, tablet computers, wireless modems, handsets, laptop computers, machine type communication (MTC) terminals, wearable devices, and vehicle-mounted terminal devices. Terminal-side devices also include restricted devices, such as devices with low power consumption, limited storage capacity, or limited computing power. Terminal-side devices also include information sensing devices such as barcodes, radio frequency identification (RFID), sensors, global positioning systems (GPS), and laser scanners.

[0220] The functions of the terminal-side device can be implemented by hardware components inside the terminal device, and the above-mentioned hardware components can be a processor and / or a programmable chip inside the above-mentioned terminal device. Optionally, the chip can be implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD). The above-mentioned PLD can be any one of a complex programmable logical device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), and a system on a chip (SOC), or any combination thereof.

[0221] 2) Donor gNodeB, also known as the donor node, can access the core network through the donor node. In other words, the donor base station is a device in the communication system that connects the terminal side device to the core network. The donor base station is generally connected to the core network through a wired link (such as an optical fiber cable). The donor base station can be responsible for receiving data from the core network and forwarding it to the wireless backhaul device (such as an IAB node), or receiving data from the wireless backhaul device and forwarding it to the core network. The donor base station can generally be connected to the network via a wired connection.

[0222] As an example, the donor base station may include a radio network controller (RNC), a node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved NodeB, or home Node B, HNB), a base band unit (BBU), etc., and may also include an evolved base station (NodeB or eNB or e-NodeB, evolutionary Node B) in an evolved LTE system (LTE-Advanced, LTE-A), or may also include a next generation node B (gNB) in a fifth generation mobile communication technology (5G) new radio (NR) system. As another example, the donor base station may include a centralized unit (CU) (abbreviated as Donor-CU or gNB-CU in this application) and a distributed unit (DU) (abbreviated as Donor-DU or gNB-DU in this application). The gNB-CU and gNB-DU are connected via the F1 interface, which may further include a control plane interface (F1-C) and a user plane interface (F1-U). The donor-CU and the core network are connected via a next-generation (NG) interface. A gNB-CU or donor-CU may exist with a separate user plane (UP) (referred to herein as CU-UP) and control plane (CP) (referred to herein as CU-CP). Specifically, a gNB-CU or donor-CU consists of a CU-CP and a CU-UP. A gNB-CU may include one gNB-CU-CP and at least one gNB-CU-UP. Alternatively, a donor-CU may include one donor-CU-CP and at least one donor-CU-UP.

[0223] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, CU may also be called O-CU (Open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the convenience of description, this application uses CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0224] The functions of the donor base station may be implemented by hardware components within the donor base station, such as a processor and / or programmable chip within the donor base station. For example, the chip may be implemented using an ASIC or a programmable logic device (PLD). The PLD may be any one of a CPLD, an FPGA, a GAL, and a SOC, or any combination thereof.

[0225] This application provides a communication method, which is applied to the field of communication technology, such as communication in an IAB network. In order to more clearly describe the solution of this application, some knowledge related to IAB is first introduced below.

[0226] In an IAB network, an IAB node can establish a wireless backhaul link with one or more upper-level nodes and access the core network through the upper-level node. The upper-level node can perform certain control on the relay node through various signaling (for example, data scheduling, timing modulation, power control, etc.). In addition, the relay node can establish an access link with one or more lower-level nodes and provide access services for one or more lower-level nodes. The upper-level node of the relay node can be a base station or another relay node. The lower-level node of the relay node can be a terminal or another relay node. In some cases, the upper-level node of an IAB node can also be referred to as its upstream node or parent node, and the lower-level node of the IAB node can also be referred to as its downstream node or child node.

[0227] Please refer to FIG1 , which is a schematic structural diagram of an IAB system provided in an embodiment of the present application.

[0228] As shown in Figure 1, an IAB node provides wireless access and wireless backhaul for UEs. An IAB donor node provides wireless backhaul functionality to the IAB node and provides an interface between the UE and the core network. The IAB node connects to the IAB donor node via a wireless backhaul link, connecting the UE served by the IAB node to the core network.

[0229] Please refer to FIG. 2 , which is a schematic diagram of the structure of an IAB node provided in an embodiment of the present application.

[0230] As shown in Figure 2, the IAB node in NR can be divided into two parts: the Mobile Equipment Unit (MT) and the User Equipment Unit (DU). The MT can also be understood as a component similar to a UE. In an IAB node, the MT is referred to as a function residing on the IAB node. Since the MT functions similarly to a regular UE, it can be understood that the MT is used for communication between the IAB node and its upper-level nodes. The DU, in contrast to the CU function of network equipment, is used for communication between the IAB node and its lower-level nodes. It should be understood that the upper-level node can be a base station or other IAB node, and the lower-level node can be a UE or other IAB node.

[0231] The communication method provided in the embodiments of the present application can be applied to various communication systems including relay nodes, such as NR systems, LTE systems, LTE-A systems, worldwide interoperability for microwave access (WiMAX), or wireless local area networks (WLAN). In LTE, relay nodes are generally referred to as RNs. In NR, relay nodes are generally referred to as IAB nodes. In some embodiments, relay nodes may also be referred to as relay devices, or relay transmission and reception points (rTRPs), and the upper node of the relay node may be a network device (including a DU of a network device, or including a CU of a network device, etc.).

[0232] Please refer to FIG3 , which is a schematic diagram of the structure of an IAB network provided in an embodiment of the present application.

[0233] As shown in Figure 3, the IAB network includes multiple UEs and multiple IAB nodes. Figure 3 takes two UEs and five IAB nodes as an example. Among them, the two UEs are UE1 and UE2, and the five IAB nodes are IAB nodes 1 to IAB nodes 5. It should be understood that the thick line in Figure 3 indicates the access link, and the thin line indicates the backhaul link. Among them, UE2 can be connected to the host base station via IAB node 5, IAB node 2, and IAB node 1. UE2 can also be connected to the host base station via IAB node 4, IAB node 2, and IAB node 1. Alternatively, UE2 can also be connected to the host base station via IAB node 4, IAB node 3, and IAB node 1. UE1 can be connected to the host base station via IAB node 4, IAB node 3, and IAB node 1. UE1 can be connected to the host base station via IAB node 4, IAB node 2, and IAB node 1.

[0234] It should be noted that the communication system shown in Figure 3 is only an example and does not limit the application scenarios applicable to the embodiments of the present application. It should be understood that the use of IAB nodes in the embodiments of the present application is only for descriptive purposes and does not mean that the solution of the embodiments of the present application is only used in NR scenarios. In the embodiments of the present application, IAB nodes can generally refer to any node or device with a relay function. The use of IAB nodes and relay nodes in the implementation of this application should be understood to have the same meaning.

[0235] In an IAB network, an IAB node is connected to the core network via an IAB host node. For example, in a standalone (SA) 5G architecture, an IAB node is connected to the 5G core network (5GC / 5GCN) via an IAB host node. For another example, in a dual connectivity (DC) or multi-connectivity (MC) 5G architecture (e.g., non-standalone, NSA scenarios), on the primary path, an IAB node can be connected to the evolved packet core (EPC) via an evolved NodeB (eNB), or to the 5G core network via an IAB host.

[0236] In the IAB network, a transmission path between the UE and the IAB host may include one or more IAB nodes. Each IAB node needs to maintain a wireless backhaul link towards the parent node, and also needs to maintain a wireless link with the child node. If the child node of the IAB node is a UE, there is a wireless access link between the IAB node and its child node (i.e., the UE). If the child node of the IAB node is another IAB node, there is a wireless backhaul link between the IAB node and its child node (i.e., the other IAB node). For example, referring to Figure 3, in the path "UE1→IAB node 4→IAB node 3→IAB node 1→IAB host", UE1 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 the IAB host node through a wireless backhaul link.

[0237] In the embodiment of the present application, the access IAB node refers to the IAB node accessed by the UE, and the intermediate IAB node refers to the IAB node that provides wireless backhaul services for the UE or IAB node. For example, referring to Figure 3, in the path "UE1→IAB node 4→IAB node 3→IAB node 1→IAB host", IAB node 4 is the access IAB node, and IAB node 3 and IAB node 1 are intermediate IAB nodes. It should be noted that an IAB node is an access IAB node for the UE accessing the IAB node; it is an intermediate IAB node for the UE accessing other IAB nodes. Therefore, whether an IAB node is an access IAB node or an intermediate IAB node is not fixed and can be determined according to the specific application scenario.

[0238] It should be noted that the communication system shown in Figure 3 is only an example and does not limit the application scenarios applicable to the embodiments of the present application. It should be understood that the use of the IAB node in the embodiments of the present application is only for descriptive purposes and does not mean that the solution of the embodiments of the present application is only used in new radio (NR) scenarios.

[0239] An F1 interface exists between the DU of the IAB node and the CU of the IAB host. This F1 interface may include a control plane and a user plane. The user plane is maintained between the IAB-DU and the IAB donor CU-UP, while the control plane is maintained between the IAB-DU and the IAB donor CU-CP. This F1 interface may also be referred to as an F1* interface, and this embodiment of the application does not impose any restrictions on the name of this interface. This document will refer to this interface as the F1 interface as an example.

[0240] The F1 interface supports user plane protocols (F1-U / F1*-U) and control plane protocols (F1-C / F1*-C). The user plane protocols include one or more of the following protocol layers: the General Packet Radio Service (GPRS) Tunneling Protocol User Plane (GTP-U), the User Datagram Protocol (UDP), and the Internet Protocol (IP). The control plane protocols include one or more of the following protocol layers: the F1 Application Protocol (F1AP), the Stream Control Transport Protocol (SCTP), and the IP. The control plane of the F1 / F1* interface enables interface management, IAB-DU management, and UE context configuration between the IAB node and the IAB host. The user plane of the F1 / F1* interface enables user plane data transmission and downlink transmission status feedback between the IAB node and the IAB host.

[0241] For example, please refer to Figures 4 and 5, where Figure 4 is a schematic diagram of a control plane protocol architecture in an IAB network provided in an embodiment of the present application, and Figure 5 is a schematic diagram of a user plane protocol architecture in an IAB network provided in an embodiment of the present application.

[0242] On the control plane, as shown in Figure 4, a Uu interface is established between UE1 and IAB2-DU. The corresponding protocol layers include the radio link control protocol (RLC), media access control (MAC), and physical layer (PHY). An F1-C interface is established between the IAB2-DU and IAB donor CU 1. The corresponding protocol layers include the F1AP and SCTP layers. IAB donor DU 1 and IAB donor CU 1 are connected via a wired connection. The corresponding protocol layers include the Internet Protocol (IP), Layer 2, and Layer 1. BLs are established between IAB Node 2 and IAB Node 3, between IAB Node 3 and IAB Node 1, and between IAB Node 1 and IAB donor DU 1. The corresponding protocol layers include the Backhaul Adaptation Protocol (BAP), RLC, MAC, and PHY layers. In addition, a peer-to-peer radio resource control (RRC) layer and packet data convergence protocol (PDCP) layer are established between UE1 and IAB donor CU 1, and a peer-to-peer IP layer is established between IAB2-DU and IAB donor DU 1.

[0243] As can be seen, compared to the control plane protocol stack for a single air interface, the DU connected to the IAB node implements the functions of a single air interface gNB-DU (i.e., establishing peer RLC, MAC, and PHY layers with the UE, and establishing peer F1AP and SCTP layers with the CU). In other words, the DU connected to the IAB node in the IAB network implements the functions of a single air interface gNB-DU, while the IAB donor CU implements the functions of a single air interface gNB-CU.

[0244] On the control plane, RRC messages are encapsulated in F1AP messages for transmission between the access IAB node and the IAB donor CU. Specifically, in the uplink, UE1 encapsulates the RRC message in a PDCP protocol data unit (PDU), which is processed sequentially by the RLC, MAC, and PHY layers before being sent to the IAB2-DU. The IAB2-DU is processed sequentially by the PHY, MAC, and RLC layers to obtain a PDCP PDU. This PDCP PDU is then encapsulated in a F1AP message and processed sequentially by the SCTP and IP layers to obtain an IP packet. The IAB2-MT processes the IP packet through the BAP, RLC, MAC, and PHY layers before sending it to the IAB3-DU. The IAB3-DU is processed sequentially by the PHY, MAC, RLC, and BAP layers to obtain an IP packet. The IAB3-MT then uses similar operations as the IAB2-MT to send the IP packet to the IAB1-DU. Similarly, the IAB1-MT sends the IP packet to the IAB donor DU 1. After IAB donor DU 1 parses the IP packet, it sends it to IAB donor CU 1. IAB donor CU 1 processes the IP packet through the SCTP layer, the F1AP layer, and the PDCP layer, obtaining an RRC message. The downlink direction is similar and will not be described here.

[0245] For the user plane, as shown in Figure 5, a Uu interface is established between UE1 and IAB2-DU. The peer protocol layers include the RLC layer, MAC layer, and PHY layer. An F1-U interface is established between the IAB2-DU and IAB donor CU 1. The peer protocol layers include the GTP-U layer and the User Datagram Protocol (UDP) layer. IAB donor DU 1 and IAB donor CU 1 are connected via a wired connection. The peer protocol layers include the IP layer, L2, and L1. A BL is established between IAB node 2 and IAB node 3, between IAB node 3 and IAB node 1, and between IAB node 1 and IAB donor DU 1. The peer protocol layers include the BAP layer, RLC layer, MAC layer, and PHY layer. Furthermore, the peer SDAP layer and PDCP layer are established between UE1 and IAB donor CU 1, and the peer IP layer is established between the IAB2-DU and IAB donor DU 1.

[0246] As can be seen, compared to the user plane protocol stack of a single air interface, the IAB access node DU implements some of the functions of a single air interface gNB-DU (i.e., establishing peer RLC, MAC, and PHY layers with the terminal, and establishing peer GTP-U and UDP layers with the IAB donor CU 1). It can be understood that the IAB access node DU implements the functions of a single air interface gNB-DU, while the IAB donor CU implements the functions of a single air interface gNB-CU.

[0247] On the user plane, PDCP packets are encapsulated and transmitted in a GTP-U tunnel between the access IAB node and the IAB donor CU. The GTP-U tunnel is established on the F1-U interface.

[0248] The communication method provided in this application is primarily applicable to IAB networks, including standalone (SA) and non-standalone (NSA) IAB networks. An IAB node consists of a mobile operator (MT) and a user-defined unit (DU). An IAB donor can be further divided into a DU and a user-defined unit (CU). The CU can also be divided into a CU-CP and a CU-UP.

[0249] Please refer to FIG. 6 , which is an example of an IAB network architecture diagram provided in an embodiment of the present application.

[0250] Figure 6 shows an example of an IAB node connected to an IAB donor via a wireless backhaul link. Figure 6 uses a scenario involving one UE, two IAB nodes, and two IAB donors. The two IAB nodes are IAB node 1 and IAB node 2, each consisting of an MT and a DU. The two IAB donors are IAB donor 1 and IAB donor 2. Each IAB donor can be further divided into a DU and a CU, and the CU can be further divided into a CU-CP and a CU-UP. In Figure 6, the MT of IAB node 2 and the DU of IAB node 1, the MT of IAB node 1 and the DU of IAB donor 1, and the MT of IAB node 1 and the DU of IAB donor 2 all communicate through a wireless backhaul (BH) link; a Uu interface is established between the UE and the IAB2-DU; an F1-C interface is established between the IAB donor DU and the IAB donor CU-CP, and an F1-U interface is established between the IAB donor DU and the IAB donor CU-UP; the DU of IAB donor 2 and the CU of IAB donor 1 are connected through an Internet protocol (IP) network.

[0251] When the IAB node operates in SA mode, the IAB node can be connected to one parent node or two parent nodes. The two parent nodes can be controlled by the same IAB donor or by different IAB donors. An F1 interface is established between the DU part of the IAB node and an IAB donor. The IAB donor can be connected to the 5G core network, which is the dotted line part in Figure 6. The IAB-donor-CU-CP is connected to the control plane network elements (such as access and mobility management functions) in the 5GC through the NG control plane interface (NG-C), and the IAB-donor-CU-UP is connected to the user plane network elements (such as user plane functions) in the 5GC through the NG user plane interface (NG-U).

[0252] When the IAB node works in NSA mode, the IAB-donor-CU-UP can be connected to the EPC (for example, connected to the serving gateway (SGW)) through the S1 user plane interface (S1-U), there is an LTE Uu air interface connection between the MeNB and the MT of the IAB node, there is an X2-C interface between the MeNB and the IAB-donor-CU-CP, and the MeNB is connected to the EPC through the S1 interface (including the S1 interface user plane and the S1 interface control plane), which is the dotted line part in Figure 6.

[0253] In another possible scenario, the MeNB in ​​Figure 6 can be replaced with a 5G gNB. The LTE-Uu interface in Figure 6 is correspondingly replaced with an NR-Uu interface. The gNB can establish user plane and / or control plane interfaces with the 5GC. The gNB and IAB-donor provide dual connectivity services for the IAB node. The gNB can act as the primary base station or secondary base station for the IAB node.

[0254] The above is an example of an application scenario of the technical solution of the embodiment of the present application. It should be understood that the technical solution of the embodiment of the present application is not limited to application only in the network architecture shown in Figure 6.

[0255] In the IAB network, IAB nodes are mobile, such as vehicle-mounted IAB nodes. For example, a mobile IAB node can be called a mobile IAB node (mIAB). As shown in Figure 7, the mIAB node can switch from IAB donor 1 to IAB donor 2 during movement. Since the coverage of the donor CU1 is limited, it is impossible to maintain the F1 connection with the mIAB-DU all the time. Therefore, the F1 connection of the mIAB-DU needs to be migrated from Donor-CU1 to Donor-CU2. In this scenario, the way in which the mIAB-DU needs to migrate the RRC connection and the F1 connection from Donor-CU1 to Donor-CU2 can be called full migration.

[0256] For example, in the IAB network, in order to enhance network robustness and achieve more refined load balancing and topology management, the mAB node can perform a partial migration process, that is, the MT of the mAB node (IAB-MT2 in Figure 7) switches from one parent node (IAB-node1 in Figure 7) to another parent node (IAB-node3 in Figure 7). The two parent nodes belong to topologies controlled by different host CUs, that is, IAB-node1 in Figure 7 belongs to the topology controlled by Donor-CU1 (the solid box part in Figure 7), and IAB-node3 belongs to the topology controlled by Donor-CU2 (the dotted box part in Figure 7). During the partial migration process, the RRC connection of IAB-MT2 is switched from CU1 to CU2, but the F1 connection of IAB-DU2 is still terminated in CU1 (as shown by the solid arrow in Figure 7), and is not migrated to CU2 along with IAB-MT2. It is understandable that the F1 connection of the child node IAB node 4 of the IAB node 2 may also be terminated at CU1 (as indicated by the dotted arrow in FIG7 ).

[0257] For example, the F1 interface of IAB node 2 is terminated at CU1, and IAB host 1 can be referred to as the F1-terminating IAB-donor of IAB node 2. CU2 has an RRC connection with IAB node 2, but the F1 connection of IAB node 2 is not terminated at CU2, and IAB host 2 can be referred to as the non-F1-terminating IAB-donor of IAB node 2.

[0258] After IAB node 2 switches from the CU1 topology to the CU2 topology, the 3rd Generation Partnership Project (3GPP) Release-17 standard (R17) introduces the IAB Transport Migration Management process to migrate the data traffic of IAB node 2 from the CU1 topology to the CU2 topology. That is, CU1 can perform the IAB Transport Migration Management process to migrate the data traffic of IAB node 2 to CU2 through the Xn interface between CU1 and CU2. The IAB Transport Migration Management process is as follows:

[0259] Step S701: CU1 sends an IAB Transport Migration Management request message to CU2. Correspondingly, CU2 receives the IAB Transport Migration Management request message.

[0260] CU1 is the F1-terminating IAB-donor of IAB node 2, and CU2 is the non-F1-terminating IAB-donor of IAB node 2. The IAB transport migration management request message is used to request migration of data traffic of IAB node 2 to CU2.

[0261] Step S702: CU2 sends an IAB Transport Migration Management response message to CU1. Correspondingly, CU1 receives the IAB Transport Migration Management response message.

[0262] The IAB transmission migration management response message is used to respond to the IAB transmission migration management request message, so as to migrate the data traffic of the IAB node 2 to the CU2.

[0263] The details of the above-mentioned "IAB Transport Migration Management" process can be referred to the 3GPP protocol TS 38.423R17, but it is not limited to the method described in the above-mentioned protocol. In the above-mentioned "IAB Transport Migration Management" process, CUs realize the transfer (offloading) of data traffic by exchanging the quality of service (QoS) of data traffic and the corresponding integrated access and backhaul (IAB) configuration information. The R17 standard defines that this process is initiated by the F1-terminating IAB-donor (i.e., CU1 in Figure 7) to the Non-F1-terminating IAB-donor (i.e., CU2 in Figure 7).

[0264] In an IAB network, the IAB node network access (IAB integration) process includes IAB-MT network access and IAB-DU network access. Since the IAB-DU network access process requires the backhaul link established between the IAB-MT and the host node, the IAB-DU network access must be completed after the IAB-MT network access is completed.

[0265] Please refer to Figure 8, which is a schematic diagram of an IAB node network access provided in an embodiment of the present application, including: IAB-donor2 (IAB node), IAB-donor1, IAB-donor (host node), and core network. For simplicity, the network access process is described using IAB-donor2 as an example. The IAB node mentioned below generally refers to IAB-donor2, the host node generally refers to IAB-donor, which is the host node for the IAB node to access the network, and the core network generally refers to the 5G core network (5GC).

[0266] The IAB node network access process may include the following steps:

[0267] Step 1. IAB-MT setup.

[0268] Typically, an IAB-MT needs to access a cell in a similar manner to a normal UE, establish an RRC connection with the donor node, and indicate that it is an IAB node when establishing the RRC connection. For example, the RRCSetupComplete message carries the IAB node indication information.

[0269] After the RRC connection between the donor node and the IAB-MT is established, the donor node may send the indication information of the IAB-MT to the AMF network element of the core network, so that the AMF can authenticate the IAB-MT and determine whether the IAB-MT is in an authorized state. Specifically, the indication information of the IAB-MT may be carried in the UE initial message (e.g., INITIAL UE MESSAGE) sent by the CU of the donor node to the AMF network element of the core network.

[0270] Optionally, the AMF network element may also return authentication information (e.g., IAB Authorized information element) to the host node. The authentication information may be carried in the UE initial context message of the IAB-MT. For example, the IAB Authorized information element may be carried in the INITIAL CONTEXT SETUP REQUEST message.

[0271] If the indication information returned by the AMF network element indicates that the IAB-MT is in the authorized state (the value of IAB Authorized is authorized), the subsequent network access process is executed. If the indication information returned by the AMF network element indicates that the IAB-MT is in the unauthorized state (the value of IAB Authorized is not authorized), the subsequent network access process is not performed. Optionally, if the host node has already allocated the configuration information of the backhaul link to the IAB-MT, the host node can delete the configuration information of the backhaul link.

[0272] In some possible scenarios, whether to allow IAB node authorization may also be related to time and space. For example, only some IABs are allowed to provide services during the morning rush hour. For another example, IAB nodes have their own specific service range. Therefore, when the authorization status of an IAB node changes, the AMF will also send a UE context modification request (e.g., UE CONTEXT MODIFICATION REQUEST) message to the host node. This message can carry the latest authorization status of the IAB node.

[0273] In one possible implementation, after receiving the authorization status indication of the IAB node from the AMF, the host node will allow the IAB node to provide services or not allow the IAB node to provide services through its own implementation according to the indication information (the value of IAB Authorized).

[0274] To introduce the subsequent network access process, it is assumed that the network element is in the authorized state, that is, the value of IAB Authorized is authorized.

[0275] Step 2-1. Establish a return link RLC channel.

[0276] When the IAB node is in the authorized state, the donor node configures the backhaul link RLC channel and performs routing configuration through RRC messages. At this time, only a default backhaul radio link control channel (default BH RLC CH) and a default routing ID (default routing ID) are configured for use when the F1 interface is initially established.

[0277] Step 2-2. Update routing.

[0278] In addition to configuring the routes of the IAB node, the routes of the nodes between the IAB node and the host node are also updated. As shown in Figure 8, IAB-donor1 is the node between IAB-donor2 and IAB-donor. After configuring the routes of IAB-donor2, the routes of IAB-donor1 are also updated. This informs the intermediate nodes (for example, IAB-donor1) how to select the next-hop link and next-hop RLC channel when receiving or sending packets from IAB-donor2.

[0279] Step 3.IAB-DU settings.

[0280] The DU of the IAB node can use the default configuration obtained in step 2-1 (for example, the default BH RLC CH and default routing ID) to send a request message to the migrated host node to establish the F1 interface. Optionally, the request message may include the configuration information of the cell under the DU of the IAB node. After receiving the request message, the host node can return information to the IAB node indicating that the establishment of the F1 interface is complete. For example, this information can be carried in the F1 interface message, and the cell is activated to complete the migration of the IAB-DU. At this point, the IAB node has completed network access and can provide services for the UE and the next-hop IAB-MT.

[0281] The above content provides an exemplary introduction to the network access process of an IAB node. After the IAB node completes the network access, there may be migration of the IAB node, including migration of IAB-MT and IAB-DU.

[0282] In some possible scenarios, during the IAB-MT migration process, the AMF network element will send the IAB node's authorization status information to the host node during the handover process. For example, the RAN3 meeting has agreed that during the IAB-MT migration process, the IAB node's authorization information will be carried in the PATH SWITCH REQUEST ACK message. The PATH SWITCH REQUEST-PATH SWITCH REQUEST ACK message is the information exchanged between the host node and the AMF, used to inform the AMF that the IAB node has been switched to the host node, allowing the AMF to send UE downlink data to the host node.

[0283] In other possible scenarios, during the IAB-MT handover request phase, the source host node sends the IAB node authorization status indication information to the target host node. Compared to sending the IAB node authorization status information to the target host node in a PATH SWITCH REQUEST ACK message, this method enables the target host node to obtain the IAB node authorization status more quickly. For example, during the IAB-MT handover request phase, the source host node sends the IAB node authorization status indication information in a HANDOVER REQUEST message.

[0284] After the target host node receives the authorization status indication information (HANDOVER REQUEST) from the IAB node, if the authorization status indication information in the information indicates that the IAB node is in an unauthorized state, the target host node may not send the backhaul link configuration information (including: default BAP configuration, BAP address or IP address, etc.) to the IAB node.

[0285] However, the authorization status of an IAB node is usually related to time, space, etc. The authorization status of an IAB node under the source host node is usually not equal to the authorization status of the IAB node under the target host node. For example, the authorization status of an IAB node under the source host node is authorized, while the authorization status of the IAB node under the target host node may be not authorized. The authorization of the IAB node is ultimately subject to the authentication result of the AMF network element, for example, the authorization indication information in the PATH SWITCH REQUEST ACK message received by the target host node.

[0286] Therefore, under normal circumstances, the target host node will default the IAB node to the authorized state and send the backhaul link configuration (including: default BAP configuration, BAP address or IP address, etc.) to the IAB node during the IAB-MT migration process. For example, the backhaul link configuration information is carried in the RRC message and sent to the IAB node.

[0287] However, the IAB node migrated to the target host node may still be in an unauthorized state. When the IAB node switches from an unauthorized state to an authorized state, the IAB node should access the network according to the network access process shown in Figure 8, obtain the configuration information of the backhaul link, and establish the F1 interface. It is understandable that in this case, the relay node obtains the backhaul link configuration information twice, during the IAB-MT migration process and after switching to the authorized state. There is currently no clear solution for how to process / use the backhaul link configuration information obtained twice. If no further processing is performed, two sets of backhaul link configurations may appear, which may cause conflicts in the backhaul link configuration and high signaling overhead.

[0288] It should be noted that all IAB indication information in the embodiments of the present application can be replaced with Mobile IAB indication information. For example, IAB authorization information can include IAB authorization information and Mobile IAB authorization information. For example, the IAB Authorized information element can be used to carry IAB authorization information, and the mAB Authorized information element can be used to carry IAB node authorization information. For example, if the IAB node is mAB, the mAB Authorized information element is used to carry the IAB node's authorization status; otherwise, the IAB Authorized information element can be used to carry the IAB node's authorization status.

[0289] In view of this, an embodiment of the present application provides a new communication method that can avoid the situation where two sets of backhaul link configurations appear, thereby ensuring that there will be no conflict in the backhaul link configuration and no additional signaling overhead.

[0290] Please refer to Figure 9, which is a flow chart of a communication method provided in an embodiment of the present application. The communication method is applied to the field of communication technology, such as communication in an IAB network, and includes but is not limited to the following steps:

[0291] S901: The relay node releases the configuration of the backhaul link.

[0292] S902: The first host node sends second configuration information to the relay node. Correspondingly, the relay node receives the second configuration information from the first host node.

[0293] It can be understood that the relay node in the embodiment of the present application can be a device equipped with a processor / chip that can be used to execute computer-executable instructions, or it can be a processor / chip that can be used to execute computer-executable instructions, and the embodiment of the present application is not limited to this. The relay node in the embodiment of the present application includes a terminal-side part facing the parent node and a network-side part facing the child node, for example, it can include MT and DU, or it can include MT and gNB, and the embodiment of the present application is not limited to this. Among them, the DU migration and MT migration of the relay node are completely decoupled, so the host node connected to the MT of the relay node and the host node connected to the DU can be different. The MT of the relay node is connected to the first host node, and the DU of the relay node is connected to the third host node. Optionally, when the communication method in the embodiment of the present application is applied to the IAB network, the relay node can be an IAB node, the MT of the IAB node is connected to the first host node, and the DU of the IAB node is connected to the third host node. Exemplarily, the relay node can be an mIAB node, for example, the relay node composed of IAB-MT2 and IAB-DU2 in Figure 7, which is used to execute the communication method in the embodiment of the present application, and can avoid the situation of two sets of backhaul link configurations, thereby ensuring that there will be no conflict in the backhaul link configuration and no additional signaling overhead.

[0294] It can be understood that the first host node in the embodiment of the present application can be a device equipped with a processor / chip that can be used to execute computer-executable instructions, or it can be a processor / chip that can be used to execute computer-executable instructions, and the embodiment of the present application is not limited to this. The first host node in the embodiment of the present application is the target CU corresponding to the MT of the relay node, and the first host node is connected to the MT of the relay node. Optionally, when the communication method in the embodiment of the present application is applied to the IAB network, the relay node can be an IAB node, and the first host node can be connected to the MT of the IAB node. Exemplarily, the first host node can be CU2 in Figure 7 above, which is used to execute the communication method in the embodiment of the present application, which can avoid the situation of two sets of backhaul link configurations, thereby ensuring that there will be no conflicts in the backhaul link configuration and no additional signaling overhead.

[0295] It is understandable that the second host node in the embodiment of the present application can be a device equipped with a processor / chip that can be used to execute computer-executable instructions, or it can be a processor / chip that can be used to execute computer-executable instructions, and the embodiment of the present application is not limited to this. The second host node in the embodiment of the present application is the source CU corresponding to the MT of the relay node. It is understandable that the MT of the relay node is migrated from the second host node to the first host node. Optionally, when the communication method in the embodiment of the present application is applied to the IAB network, the relay node can be an IAB node, and the second host node can be the source CU corresponding to the MT of the IAB node. It is understandable that the MT of the IAB node is migrated from the second host node to the first host node. Exemplarily, the first host node can be CU1 in Figure 7 above, which is used to execute the communication method in the embodiment of the present application, which can avoid the situation of two sets of backhaul link configurations, thereby ensuring that there will be no conflict in the backhaul link configuration and no additional signaling overhead.

[0296] Specifically, the above S901 and / or S902 are executed when the following triggering conditions are met:

[0297] When the first trigger condition is met, the relay node releases the configuration of the backhaul link. The first trigger condition at this time can be understood as a condition that triggers the relay node to release the configuration of the backhaul link.

[0298] The first trigger condition includes, but is not limited to, any one or more of the following:

[0299] (1) The relay node performs mobile terminal MT migration.

[0300] (2) The relay node is in an unauthorized state.

[0301] (3) The relay node receives first configuration information from the first host node, where the first configuration information is used to indicate the configuration of the backhaul link.

[0302] In the embodiments of the present application, releasing the backhaul link configuration can be understood as the configuration failure of the backhaul link, or the configuration of not occupying the backhaul link, or the configuration of not using the backhaul link, or the release of the constructed backhaul link after the backhaul link has been constructed based on the backhaul link configuration. Releasing the backhaul link configuration should not be understood as simply releasing the constructed backhaul link after the backhaul link has been constructed based on the backhaul link configuration.

[0303] Optionally, the relay node performing MT migration may refer to after the first host node receives MT migration indication information (eg, HANDOVER REQUEST message) from the second host node and before the MT re-establishes the F1 interface through the first host node.

[0304] Optionally, the relay node being in the unauthorized state may be that the handover request information (HANDOVER REQUEST message) sent by the second host node to the first host node includes information indicating that the relay node is in the unauthorized state.

[0305] It can also be that the access and mobility management function (AMF) sends information to the first host node indicating that the relay node is in an unauthorized state. Specifically, the AMF sends a PATH SWITCH REQUEST ACK message to the first host node, and the relay node authorization information carried indicates that the relay node is in an unauthorized state.

[0306] It is also possible that the AMF directly sends information to the MT of the relay node indicating that the relay node is in an unauthorized state. Specifically, the AMF sends a NAS message to the MT of the relay node, where the NAS message carries information about the authorization status of the MT of the relay node, and the authorization status information indicates that the MT of the relay node is in an unauthorized state.

[0307] Optionally, the first configuration information may be carried in an RRC message, such as an RRC reconfiguration message RRCReconfiguration, and may include one or more of the following: default BAP configuration, BAP address, IP address, and the like.

[0308] In an IAB network, during the migration of a mobile operator (MT) on an IAB node, the target CU will, by default, assign backhaul link configurations to the IAB node, including one or more of the following: default BAP configuration, BAP address, and IP address. After the MT migration is complete, if it changes from an unauthorized state to an authorized state, the IAB node will perform a network access process and obtain backhaul link configurations. For example, during the migration of a MT on an IAB node to a first host node, the first host node will typically default the MT to an authorized state and assign backhaul link configurations to the MT. After the MT handover is complete, the AMF will send the MT's authorization information (including authorized or unauthorized status) to the first host node. If the MT on the IAB node is in an unauthorized state, the issue of how to handle the backhaul link configurations already assigned to the MT on the IAB node remains unresolved. Furthermore, if the MT on the IAB node subsequently changes from an unauthorized state to an authorized state, the IAB node will re-enter the network access process and obtain a new backhaul link configuration. At this point, the IAB node needs to decide whether to use the new backhaul link configuration or the old one. At the same time, allocating two sets of backhaul link configurations to the IAB node may cause usage conflicts and increase signaling overhead.

[0309] However, the embodiments of this application clearly define the trigger conditions for releasing the backhaul link configuration. This allows the relay node to promptly release the backhaul link configuration when the first trigger condition is met. This allows the backhaul link configuration that is not currently in use to be released and made available to other nodes, improving resource utilization. Furthermore, this prevents the situation where two sets of backhaul link configurations are allocated to an IAB node, thereby avoiding conflicts in backhaul link configurations and reducing signaling overhead during MT migration.

[0310] In one possible implementation, the backhaul link configuration is not released if the following trigger conditions are met: the relay node performs mobile terminal MT migration; the relay node is in an authorized state; and the relay node receives first configuration information from the first host node, where the first configuration information is used to indicate the backhaul link configuration.

[0311] In a possible implementation manner, the first configuration information includes at least one of the following: a default backhaul link adaptation layer protocol (BAP) configuration, a BAP address, and an Internet Protocol (IP) address.

[0312] In the embodiments of the present application, a possible specific implementation of a first configuration is provided. Specifically, in an MT migration scenario of an IAB node, the first host node sends a first configuration to the IAB node. The first configuration may include at least one of the following: a default BAP configuration, a BAP address, and an IP address. It should be noted that the first configuration information may be carried in a single RRC message or in multiple RRC messages, which is not limited in the embodiments of the present application.

[0313] In a possible implementation, the above method further includes:

[0314] When the relay node switches to the authorized state, the first host node sends second configuration information to the relay node. Correspondingly, the relay node receives the second configuration information from the first host node. The second configuration information is used to indicate the configuration of the backhaul link.

[0315] The relay node switching to an authorized state may refer to the AMF sending an indication message to the first host node, indicating that the relay node is in an authorized state. The indication message may be carried by a PATH SWITCH REQUEST ACK message in the switching process. It may also refer to the AMF sending a non-access stratum (NAS) message to the MT of the IAB node, indicating that the IAB node is in an authorized state. It may also refer to the NAS layer of the IAB node sending an indication message to the AS layer, indicating that the IAB node is in an authorized state. The embodiments of the present application do not limit the specific state in which the relay node switches to an authorized state.

[0316] The relay node receives the second configuration information from the first host node, and accordingly, the first host node generates / sends the second configuration information. The second configuration information is configuration information of the backhaul link, which is the backhaul link between the relay node and the first host node.

[0317] Optionally, the second configuration information includes at least one of the following: a default BAP configuration, a BAP address, and an Internet Protocol IP address, which is not limited in the implementation manner of the present application.

[0318] It should be noted that the second configuration information can be carried in one RRC message or in multiple RRC messages, and this embodiment of the present application does not limit this.

[0319] In the implementation manner of the present application, a possible specific implementation manner of a relay node is provided, specifically, in a scenario where the relay node switches from an unauthorized state to an authorized state, the relay node receives second configuration information from the first host node for building a backhaul link for communication. It can be understood that in the implementation manner of the present application, if the relay node is in an unauthorized state, the configuration information (first configuration information) assigned to the relay node will be released. When the relay node switches from an unauthorized state to an authorized state, there will not be a situation where two sets of backhaul link configurations exist at the same time, which can avoid configuration conflicts of the backhaul link and reduce signaling overhead. In addition, the second configuration information is the configuration information of the backhaul link assigned to the relay node by the first host node after the relay node is re-authorized. This information can enable the backhaul link configuration to be based on the latest resource status, thereby improving the performance of resource allocation.

[0320] In a possible implementation manner, the second configuration information includes an IP address.

[0321] It should be noted that, in the embodiments of this application, "the second configuration information includes an IP address" generally means that the second configuration information includes only one IP address. In other words, when the relay node switches from an unauthorized state to an authorized state, the configuration information received by the relay node includes only one IP address. That is, the second configuration information may also include a default BAP configuration or BAP address, but only one IP address, not multiple IP addresses.

[0322] It is understandable that in the scenario where the relay node switches from an unauthorized state to an authorized state, the relay node receives the second configuration information from the first host node for building a backhaul link and communicating. Among them, the second configuration information includes only one IP address, not multiple IP addresses. It is understandable that building a backhaul link requires one or more IP addresses, but the IP address resources that can be allocated by the host node are limited. By allocating an IP address to the relay node, the demand for building a backhaul link can be met. In the case where the relay node needs more IP addresses, it requests more IP addresses from the first host node.

[0323] Optionally, one IP address in the second configuration information may be carried in an RRC message.

[0324] Optionally, one of the IP addresses in the second configuration information may be used for a control plane protocol (F1-C), which can manage the interface between the relay node and the first host node, manage the DU of the relay node, and perform UE context-related configuration.

[0325] In the implementation manner of the present application, the second configuration information includes only one IP address, which can save IP address resources and fully utilize the limited IP address resources in the first host node.

[0326] In a possible implementation, the relay node sends the second information to the first host node. Correspondingly, the first host node receives the second information from the relay node, where the second information is used to request at least one IP address.

[0327] In the implementation manner of the present application, the second information is used to request at least one IP address. Accordingly, the first host node allocates at least one IP address to the relay node according to the second information.

[0328] The present application does not limit the use of the above IP address. For example, it can be used for F1-C or user plane protocol F1-U.

[0329] Optionally, the second information may be carried in an RRC message, such as IABOtherInformation.

[0330] Optionally, if the relay node needs more IP addresses, the second message is sent to the first host node. The embodiments of this application do not limit why the relay node needs more IP addresses or the purpose of the IP addresses. For example, if the relay node needs to backhaul more traffic, it may need more IP addresses.

[0331] In an embodiment of the present application, a specific implementation of the second information is provided. Specifically, in a scenario where a relay node needs more IP addresses, the relay node sends the second information to the first host node. It is understood that the first host node will allocate at least one IP address to the relay node based on the second information, allowing the relay node to implement / complete the corresponding task. This method of allocating IP addresses to relay nodes based on their needs can avoid allocating unused IP addresses, thereby conserving IP address resources and improving IP address utilization.

[0332] In a possible implementation manner, the second configuration information does not include an IP address; and the method further includes:

[0333] When the second trigger condition is met, the relay node sends third information to the first host node. Accordingly, the first host node receives the third information from the relay node, where the third information is used to request an IP address.

[0334] The second trigger condition includes at least one of the following:

[0335] The second configuration information includes a default BAP configuration; or, the second configuration information includes a BAP address; or, the relay node receives fourth information, and the fourth information is used to indicate that the relay node is in an authorized state.

[0336] The second trigger condition in the implementation manner of the present application includes but is not limited to one or more of the following: the second configuration information includes a default BAP configuration; or, the second configuration information includes a BAP address; or, the relay node receives fourth information, which is used to indicate that the relay node is in an authorized state.

[0337] The relay node receiving the fourth information generally refers to the relay node receiving the fourth information from the AMF. Accordingly, the AMF sends the fourth information to the relay node. Typically, the AMF sends the fourth information to the NAS layer of the relay node, or the NAS layer of the relay node sends the fourth information to the AS layer. That is, the relay node receiving the fourth information from the AMF can be understood as the relay node receiving the fourth information from the AMF via the NAS layer, or the relay node receiving the fourth information from the NAS layer via the AS layer after receiving authorization information from the AMF at the NAS layer.

[0338] In an embodiment of the present application, when the second trigger condition is met, the relay node sends the third information to the first host node. Accordingly, the first host node also receives the third information from the relay node and sends one or more IP addresses to the relay node based on the third information.

[0339] The IP addresses requested through the third information include at least one IP address for F1-C.

[0340] Optionally, the IP address of the third information request may also include an IP address for F1-U.

[0341] The embodiments of the present application provide a possible implementation of the third information. Specifically, in a scenario where the second trigger condition is met, or in a scenario where the relay node requires an IP address, the relay node sends the third information to the first host node to request an IP address. It is understandable that in the embodiments of the present application, when the first host node sends the backhaul link configuration to the relay node, it does not assign an IP address to the relay node by default. Only when the second trigger condition is met does the relay node send the third information to the first host node and request one or more IP addresses.

[0342] In a possible implementation manner, the fourth information comes from the non-access stratum NAS or the access stratum AS of the relay node.

[0343] It is understood that the AMF is responsible for authenticating the authorization status of the relay node. After authentication, the AMF will send the authentication result to the relay node. For example, the AMF sends authorization status indication information to the NAS layer of the relay node to indicate the authorization status of the relay node. For another example, the NAS layer of the relay node will send indication information to the AS layer to indicate the authorization status of the relay node.

[0344] Optionally, the indication information sent by the AMF to the NAS layer can be carried in a NAS message.

[0345] Please refer to Figure 10, which is a flowchart illustrating another communication method provided in an embodiment of the present application. It is understood that the steps in the embodiment of the present application can be considered as reasonable variations or supplements to the embodiment in Figure 9 above; alternatively, it is understood that the communication method in the embodiment of the present application can also be considered as an embodiment that can be executed independently, and this application does not limit this. The communication method provided in the embodiment of the present application is applicable to the field of communication technology, such as communication in an IAB network.

[0346] It can be understood that the CU1 involved in the communication method provided in the embodiment of the present application can refer to the first host node in the communication method shown in Figure 9 above, and the IAB (including IAB-DU and IAB-MT) involved in the communication method provided in the embodiment of the present application can refer to the relay node in the communication method shown in Figure 9 above, which will not be repeated here.

[0347] The communication method includes but is not limited to the following steps:

[0348] Step 1: CU1 sends first configuration information to IAB-MT. In response, IAB-MT receives the first configuration information from CU1. The first configuration information is used to establish a backhaul link between CU1 and IAB-MT. The first configuration information can be carried in an RRC message, such as an RRC reconfiguration message.

[0349] Step 2: The IAB node releases the backhaul link configuration, which is the backhaul link configuration indicated by the first configuration information.

[0350] Optionally, the AMF sends a NAS message to the IAB node indicating that the IAB node is in an unauthorized state, or the NAS layer of the IAB node sends an indication message to the AS layer indicating that the IAB node is in an unauthorized state. The IAB node releases the above-mentioned backhaul link configuration information.

[0351] It is understood that if the AMF sends a NAS message to the IAB node indicating that the IAB node is in an authorized state, or the NAS layer of the IAB node sends an indication message to the AS layer indicating that the IAB node is in an authorized state, the IAB node may not release the above-mentioned backhaul link configuration information.

[0352] Step 3-1: The AMF sends authorization indication information to CU1. For example, the AMF sends a UE CONTEXT MODIFICATION REQUEST message to CU1. In response, CU1 receives a UE CONTEXT MODIFICATION REQUEST message from the AMF. The UE CONTEXT MODIFICATION REQUEST message carries the authorization indication information of the IAB node, and the authorization indication information indicates that the IAB node is in an authorized state. Specifically, the authorization status of the IAB node may be indicated by the IAB Authorized information element in the UE CONTEXT MODIFICATION REQUEST message, or by the mIAB Authorized information element in the UE CONTEXT MODIFICATION REQUEST message. This embodiment of the present application is not limited to this.

[0353] Step 3-2: The AMF sends authorization indication information to the relay node. For example, the AMF directly sends a NAS message to the IAB node. In response, the IAB node receives a NAS message from the AMF, which carries information indicating that the IAB node is in an authorized state. Specifically, the authorization status of the IAB node may be indicated by an IAB Authorized information element in the NAS message, or by an mIAB Authorized information element in the NAS message. This embodiment of the present application is not limited to this.

[0354] It should be understood that the execution order of the above steps 3-1 and 3-2 is not limited in this embodiment of the application. For example, step 3-1 may be executed first, and then step 3-2. Alternatively, step 3-2 may be executed first, and then step 3-1.

[0355] Step 4: CU1 sends second configuration information to the IAB-MT. In response, the IAB-MT receives the second configuration information from CU1. This second configuration information is used to establish a backhaul link between CU1 and the IAB-MT. This second configuration information can be carried in an RRC message, such as an RRC reconfiguration message. This configuration information includes one or more of the following: a default BAP configuration and a BAP address.

[0356] Step 5: IAB-MT requests an IP address from CU1 (Option 1, an IP address is assigned by default).

[0357] Optionally, before the IAB-MT requests an IP address from CU1, CU1 may send an IP address to the IAB-MT. For example, CU1 may include the IP address in an RRC message sent to the IAB-MT. Optionally, the RRC message used to send the IP address may be combined with the RRC message in step 4. This means that CU1 assigns an IP address to the IAB-MT by default.

[0358] Optionally, one of the above IP addresses can be used for F1-C.

[0359] When the IAB-MT needs more IP addresses, it can send a request message to CU1 to request more IP addresses. The request message can be carried in an RRC message, such as IABOtherInformation.

[0360] It should be noted that the solution shown in step 5 and the subsequent step 6 are two parallel solutions. In step 5, CU1 will assign an IP address to IAB-MT by default for use by F1-C. In step 6, CU1 will not assign an IP address to IAB-MT by default. If the trigger conditions are met, IAB-MT can apply for an IP address from CU1.

[0361] Step 6: IAB-MT requests an IP address from CU1 (Option 2, no default IP address allocation).

[0362] When the following triggering conditions are met, the IAB-MT requests an IP address from CU1 (for example, the request information is carried in an RRC message, such as IABOtherInformation). The triggering conditions include one or more of the following:

[0363] (1) IAB-MT receives the default BAP configuration.

[0364] (2) IAB-MT receives the BAP address.

[0365] (3) Receive indication information (indicating that the IAB node is in the authorized state) through the NAS layer.

[0366] (4) The NAS layer sends an indication message to the AS layer (indicating that the IAB node is in the authorized state).

[0367] The IP addresses requested by the IAB-MT to CU1 include at least one IP address for F1-C.

[0368] This embodiment of the present application clarifies that during IAB-MT migration, if the IAB node is in an unauthorized state, the configuration information obtained by the IAB node is directly released. This prevents the IAB node from having two backhaul link configurations, avoids backhaul link configuration conflicts, and reduces signaling overhead. Furthermore, the second configuration information is the backhaul link configuration information assigned to the IAB node by CU1 after the IAB node is reauthorized. This information ensures that the backhaul link configuration is based on the latest resource status, thereby improving resource allocation performance.

[0369] Please refer to Figure 11, which is a flowchart of another communication method provided in an embodiment of the present application. It is understandable that the steps in the embodiment of the present application can be regarded as reasonable variations or supplements of the embodiments in Figures 9 or 10 above; or, it is understandable that the communication method in the embodiment of the present application can also be regarded as an embodiment that can be executed independently, and the present application does not limit this. The communication method provided in the embodiment of the present application is applied to the field of communication technology, such as communication of an IAB network, and the communication method includes but is not limited to the following steps:

[0370] S1101: The relay node saves the configuration of the backhaul link. Accordingly, the first host node generates / sends the configuration of the backhaul link.

[0371] S1102: The first host node sends fifth information to the relay node. Correspondingly, the relay node receives the fifth information from the first host node.

[0372] It can be understood that the relay node in the embodiment of the present application can be a device equipped with a processor / chip that can be used to execute computer-executable instructions, or it can be a processor / chip that can be used to execute computer-executable instructions, and the embodiment of the present application is not limited to this. The relay node in the embodiment of the present application includes a terminal-side part facing the parent node and a network-side part facing the child node, for example, it can include MT and DU, or it can include MT and gNB, and the embodiment of the present application is not limited to this. Among them, the DU migration and MT migration of the relay node are completely decoupled, so the host node connected to the MT of the relay node and the host node connected to the DU can be different. The MT of the relay node is connected to the first host node, and the DU of the relay node is connected to the third host node. Optionally, when the communication method in the embodiment of the present application is applied to the IAB network, the relay node can be an IAB node, the MT of the IAB node is connected to the first host node, and the DU of the IAB node is connected to the third host node. Exemplarily, the relay node can be an mIAB node, for example, the relay node composed of IAB-MT2 and IAB-DU2 in Figure 7, which is used to execute the communication method in the embodiment of the present application, and can avoid the situation of two sets of backhaul link configurations, thereby ensuring that there will be no conflict in the backhaul link configuration and no additional signaling overhead.

[0373] It can be understood that the first host node in the embodiment of the present application can be a device equipped with a processor / chip that can be used to execute computer-executable instructions, or it can be a processor / chip that can be used to execute computer-executable instructions, and the embodiment of the present application is not limited to this. The first host node in the embodiment of the present application is the target CU corresponding to the MT of the relay node, and the first host node is connected to the MT of the relay node. Optionally, when the communication method in the embodiment of the present application is applied to the IAB network, the relay node can be an IAB node, and the first host node can be connected to the MT of the IAB node. Exemplarily, the first host node can be CU2 in Figure 7 above, which is used to execute the communication method in the embodiment of the present application, which can avoid the situation of two sets of backhaul link configurations, thereby ensuring that there will be no conflicts in the backhaul link configuration and no additional signaling overhead.

[0374] It is understandable that the second host node in the embodiment of the present application can be a device equipped with a processor / chip that can be used to execute computer-executable instructions, or it can be a processor / chip that can be used to execute computer-executable instructions, and the embodiment of the present application is not limited to this. The second host node in the embodiment of the present application is the source CU corresponding to the MT of the relay node. It is understandable that the MT of the relay node is migrated from the second host node to the first host node. Optionally, when the communication method in the embodiment of the present application is applied to the IAB network, the relay node can be an IAB node, and the second host node can be the source CU corresponding to the MT of the IAB node. It is understandable that the MT of the IAB node is migrated from the second host node to the first host node. Exemplarily, the first host node can be CU1 in Figure 7 above, which is used to execute the communication method in the embodiment of the present application, which can avoid the situation of two sets of backhaul link configurations, thereby ensuring that there will be no conflicts in the backhaul link configuration and no additional signaling overhead.

[0375] Specifically, the above S1101 and / or S1102 are executed when the following triggering conditions are met:

[0376] When the fourth trigger condition is met, the relay node saves the configuration of the backhaul link. The fourth trigger condition can be understood as a condition that triggers the relay node to save the configuration of the backhaul link. Alternatively, it can be understood that when the fourth trigger condition is met, the configuration of the backhaul link is still saved.

[0377] The fourth trigger condition includes, but is not limited to, any one or more of the following:

[0378] (1) The relay node performs MT migration.

[0379] (2) The relay node is in an unauthorized state.

[0380] (3) The relay node receives third configuration information from the first host node, where the third configuration information is used to indicate configuration information of the backhaul link.

[0381] The configuration of the backhaul link in the embodiment of the present application can be stored in, for example, a memory of the relay node, or in other devices from which the relay node can quickly obtain the configuration information. The embodiment of the present application does not limit this.

[0382] Optionally, the relay node performing MT migration may refer to after the first host node receives MT migration indication information (eg, HANDOVER REQUEST message) from the second host node and before the MT re-establishes the F1 interface through the first host node.

[0383] Optionally, the relay node being in an unauthorized state may be that the handover request information (HANDOVER REQUEST message) sent by the second host node to the first host node includes information indicating that the relay node is in an unauthorized state. Specifically, the IAB Authorized information element in the HANDOVER REQUEST message may indicate the authorization status of the relay node, or the mIAB Authorized information element in the HANDOVER REQUEST message may indicate the authorization status of the relay node. This embodiment of the present application is not limited to this.

[0384] It can also be that the access and mobility management function (AMF) sends information to the first host node indicating that the relay node is in an unauthorized state. Specifically, the AMF sends a PATH SWITCH REQUEST ACK message to the first host node, and the relay node authorization information carried is used to indicate that the relay node is in an unauthorized state.

[0385] Alternatively, the AMF directly sends information to the MT of the relay node indicating that the relay node is in an unauthorized state. Specifically, the AMF sends a NAS message to the MT of the relay node, where the NAS message carries information about the authorization status of the MT of the relay node, and the authorization status information indicates that the MT of the relay node is in an unauthorized state.

[0386] Optionally, the third configuration information may be carried in an RRC message, such as an RRC reconfiguration message, and may include one or more of the following: default BAP configuration, BAP address, IP address, etc.

[0387] In an IAB network, during the migration of a mobile operator (MT) on an IAB node, the target CU will, by default, assign backhaul link configurations to the IAB node, including one or more of the following: default BAP configuration, BAP address, and IP address. After the MT migration is complete, if it changes from an unauthorized state to an authorized state, the IAB node will perform a network access process and obtain backhaul link configurations. For example, during the migration of a MT on an IAB node to a first host node, the first host node will typically default the MT to an authorized state and assign backhaul link configurations to the MT. After the MT handover is complete, the AMF will send the MT's authorization information (including authorized or unauthorized status) to the first host node. If the MT on the IAB node is in an unauthorized state, the issue of how to handle the backhaul link configurations already assigned to the MT on the IAB node remains unresolved. Furthermore, if the MT on the IAB node subsequently changes from an unauthorized state to an authorized state, the IAB node will re-enter the network access process and obtain a new backhaul link configuration. At this point, the IAB node needs to decide whether to use the new backhaul link configuration or the old one. At the same time, allocating two sets of backhaul link configurations to the IAB node may cause usage conflicts and increase signaling overhead.

[0388] It can be understood that the difference between the embodiment shown in Figure 11 and the embodiment shown in Figure 9 is that the embodiment shown in Figure 11 does not consider whether the relay node is authorized (for example, whether the relay node is in an authorized state or an unauthorized state), and the relay node saves the received backhaul link configuration information. Unlike the embodiment shown in Figure 9, the backhaul link configuration information received by the relay node is saved only when the relay node is in an authorized state. The embodiments shown in Figure 11 and Figure 9 can both avoid conflicts in backhaul link configuration and reduce signaling overhead during MT migration. The difference is that the embodiment shown in Figure 11 can enable the relay node based on the saved backhaul link configuration as soon as the relay node obtains authorization, thereby achieving the effect of quickly enabling the relay node. The embodiment shown in Figure 9 can release unused backhaul link configurations in a timely manner, improving resource utilization. In addition, the embodiment shown in Figure 9 can obtain the backhaul link configuration generated based on the latest resource status after the relay node obtains authorization, thereby improving resource allocation performance.

[0389] In one possible implementation, the third configuration information of the backhaul link is still preserved when the following conditions are met, including: the relay node performs MT migration; and the relay node is in an authorized state; and the relay node receives the third configuration information from the first host node, where the third configuration information is used to indicate the configuration information of the backhaul link.

[0390] In a possible implementation, the above method further includes:

[0391] The relay node receives fifth information, where the fifth information is used to indicate that the relay node is in an authorized state. The relay node performs backhaul link transmission based on the configuration information, where the backhaul link transmission includes establishing an F1 interface of the relay node.

[0392] In the embodiments of the present application, a possible specific implementation of the fifth information is provided. Specifically, the fifth information is used to indicate that the relay node is in an authorized state. The fifth information can come from the AMF. For example, the AMF sends the fifth information to the relay node via an NAS message, or the fifth information is carried in the indication information sent from the NAS layer of the relay node to the AS layer. It is understood that after the relay node transitions from an unauthorized state to an authorized state, the relay node performs backhaul link transmission based on the above configuration information, allowing the relay node to quickly start up and avoiding backhaul link configuration conflicts.

[0393] The backhaul link transmission includes establishing the F1 interface of the relay node. For example, using the backhaul link established with the configuration information above, the relay node sends an F1 application protocol (F1AP) message to the F1 anchor CU of the relay node. Specifically, an F1 interface message can be sent to the F1 anchor CU via the established backhaul link to request the establishment of the F1 interface of the relay node.

[0394] Please refer to Figure 12, which is a flow chart of another communication method provided in an embodiment of the present application. It is understandable that the steps in the embodiment of the present application can be regarded as reasonable variations or supplements of the embodiments in Figures 9, 10, or 11 above; or, it is understandable that the communication method in the embodiment of the present application can also be regarded as an embodiment that can be executed independently, and the present application does not limit this. The communication method provided in the embodiment of the present application is applied to the field of communication technology, such as communication of an IAB network, and the communication method includes but is not limited to the following steps:

[0395] S1201: The second host node sends seventh information to the first host node, and correspondingly, the first host node receives the seventh information from the second host node. The seventh information is used to indicate that the relay node is in an unauthorized state.

[0396] S1202: The first host node sends the configuration of the backhaul link to the relay node. Correspondingly, the relay node receives the configuration of the backhaul link from the first host node.

[0397] In the embodiment of the present application, for the relevant description of the first host node, the second host node and the relay node, please refer to the relevant description in the above Figure 11, which will not be repeated here.

[0398] Optionally, the seventh information may be carried in a MT migration request message of the relay node, for example, a HANDOVER REQUEST message.

[0399] Optionally, the configuration information of the backhaul link may be carried in a radio resource control (RRC) message, for example, an RRCReconfiguration message.

[0400] Optionally, the configuration information of the backhaul link may include one or more of the following: default BAP configuration, BAP address, IP address, etc.

[0401] Optionally, the above IP address can be used for at least F1-C.

[0402] In an IAB network, during the MT migration process of an IAB node, the second host node may send indication information of the authorization status of the relay node to the first host node. For example, the indication information may be carried in a handover request message HANDOVER REQUEST. It is understandable that the authorization status indicated by the indication information generally refers to the authorization status of the relay node under the second host node. For example, if the relay node is in an authorized state under the second host node, the indication information indicates that the relay node is in an authorized state. For another example, if the relay node is in an unauthorized state under the second host node, the indication information indicates that the relay node is in an unauthorized state. Specifically, the IAB Authorized information element in the HANDOVER REQUEST message may indicate the authorization status of the IAB node under the second host node, or the mAB Authorized information element in the HANDOVER REQUEST message may indicate the authorization status of the IAB node under the second host node. This embodiment of the present application does not limit this.

[0403] If the first host node receives a message indicating that the relay node is in an unauthorized state, it may not send the backhaul link configuration information to the relay node. However, whether the relay node is ultimately authorized depends on the AMF's instructions. If the relay node is authorized after AMF authentication, and the first host node sends the backhaul link configuration to the relay node again, it will affect the speed of the relay node startup.

[0404] However, the embodiment of the present application clearly provides a processing method for the first host node when the second host node indicates that the relay node is in an unauthorized state. Specifically, the first host node ignores the indication information of the second host node, that is, it does not consider whether the indication information from the second host node indicates that the relay node is in an authorized state, and directly sends the configuration information of the backhaul link to the relay node. So that, when the authentication result of the AMF is that the relay node is in an authorized state, the relay node directly uses the configuration information of the backhaul link. On the one hand, it can achieve the effect of quickly enabling the relay node. On the other hand, there is no need for the first host node to send the configuration information of the backhaul link to the relay node again when the relay node switches to an authorized state, thereby avoiding conflicts in the backhaul link configuration.

[0405] In the embodiment shown in Figure 12, the first host node does not consider whether the relay node is authorized (for example, the relay node is in an authorized state or an unauthorized state). After receiving the MT migration request from the relay node, the first host node sends the backhaul link configuration information to the relay node. Corresponding to the embodiment shown in Figure 11, regardless of whether the relay node is authorized (for example, the relay node is in an authorized state or an unauthorized state), the relay node saves the received backhaul link configuration information. In the specific implementation process, the embodiments shown in Figures 11 and 12 work together to quickly enable the relay node when the relay node switches to an authorized state.

[0406] In a possible implementation, when the first host node receives indication information from the second host node indicating that the relay node is in an authorized state, the first host node still sends configuration information of the backhaul link to the relay node.

[0407] In a possible implementation, the above method further includes:

[0408] The first host node retains the configuration information when the fourth condition is met;

[0409] The fourth condition mentioned above includes:

[0410] The first host node receives sixth information from the access and mobility management function network element AMF, where the sixth information is used to indicate that the relay node is in an unauthorized state; and the relay node is connected to the first host node.

[0411] Among them, the sixth information is used to indicate that the relay node is in an unauthorized state, and the sixth information can be carried in the UE CONTEXT MODIFICATION REQUEST message. The sixth information can also be carried in a NAS message sent to the relay node, and the NAS message carries information that the authorization state of the relay node is "authorized". Specifically, it can be the IAB Authorized information element in the UE CONTEXT MODIFICATION REQUEST message indicating that the IAB node is in an authorized state, or it can be the mAB Authorized information element in the UE CONTEXT MODIFICATION REQUEST message indicating that the IAB node is in an authorized state, or it can be the IAB Authorized information element in the NAS message indicating that the IAB node is in an authorized state, or it can be the mAB Authorized information element in the NAS message indicating that the IAB node is in an authorized state, and the embodiment of the present application does not limit this.

[0412] The above-mentioned connection between the relay node and the first host node usually means that the relay node and the first host node are not disconnected, specifically, it means that the MT of the relay node remains connected to the first host node, for example, the backhaul link between the MT of the relay node and the first host node is not disconnected, or the MT of the relay node has not performed a new MT migration, etc.

[0413] In one possible implementation, the first host node retains the configuration information if the following conditions are met: the first host node receives indication information from the AMF indicating that the relay node is in an authorized state; and the relay node connects to the first host node.

[0414] In a possible implementation, the above method further includes:

[0415] When the relay node is disconnected from the first host node, the configuration information is deleted.

[0416] The present application provides a possible specific implementation method for deleting backhaul link configuration information. Specifically, when a relay node is disconnected from a first host node, the backhaul link configuration information of the first host node is deleted. This allows unused backhaul link configurations to be released in a timely manner and, if possible, reused by other nodes, thereby improving resource utilization.

[0417] It can be understood that the relay reception is disconnected from the first host node, which may mean that the MT of the relay node is disconnected from the first host node, or that the backhaul link between the MT of the relay node and the first host node is disconnected, or that the MT of the relay node has undergone MT migration, etc.

[0418] The above-mentioned deletion of configuration information by the first host node may refer to releasing the configuration information, or may refer to adjusting the configuration information to configuration information that can be used by other nodes.

[0419] Please refer to Figure 13, which is a flowchart illustrating another communication method provided in an embodiment of the present application. It is understood that the steps in the embodiment of the present application can be considered as reasonable variations or supplements to the embodiment in Figure 9 above; alternatively, it is understood that the communication method in the embodiment of the present application can also be considered as an embodiment that can be executed independently, and this application does not limit this. The communication method provided in the embodiment of the present application is applicable to the field of communication technology, such as communication in an IAB network.

[0420] It can be understood that the CU1 involved in the communication method provided in the embodiment of the present application can refer to the first host node in the communication method shown in Figure 11 or Figure 12 above, the CU2 involved in the communication method provided in the embodiment of the present application can refer to the second host node in the communication method shown in Figure 11 or Figure 12 above, and the IAB (including IAB-DU and IAB-MT) involved in the communication method provided in the embodiment of the present application can refer to the relay node in the communication method shown in Figure 11 or Figure 12 above, which will not be repeated here.

[0421] The communication method includes but is not limited to the following steps:

[0422] Step 1: CU1 sends a handover request to CU2, and accordingly, CU2 receives the handover request from CU1. For example, the handover request information can be carried in a Handover Request message. Optionally, the handover request information can include the authorization status of the IAB-MT under CU1. Specifically, it can be the IAB Authorized information element in the Handover Request message that indicates that the IAB node is in an authorized state, or it can be the mIAB Authorized information element in the Handover Request message that indicates that the IAB node is in an authorized state. This embodiment of the present application does not limit this.

[0423] Step 2: CU2 sends backhaul link configuration information to the IAB-MT. In response, the IAB-MT receives the backhaul link configuration information from CU2. For example, the backhaul link configuration information can be carried in an RRC message, such as an RRCReconfiguration message. Specifically, the RRC message can be forwarded to the IAB-MT via CU1. For example, the RRC message transmission path is CU2-CU1-DU1-IAB-MT.

[0424] Optionally, the configuration information includes one or more of the following: default BAP configuration, BAP address, IP address, etc.

[0425] Normally, if CU2 receives an indication from CU1 that the IAB node is in an unauthorized state, CU2 will not send configuration information to the IAB node. However, in an embodiment of the present application, CU2 ignores the indication from CU1. Even if CU1 indicates that the IAB node is in an unauthorized state, it still allocates configuration information to the IAB-MT, so as to quickly enable the IAB node when receiving an indication from the AMF that the IAB node is in an authorized state.

[0426] Step 3: The IAB node saves the backhaul link configuration information. Even if the IAB node knows it is in an unauthorized state, it still saves the backhaul link configuration information obtained in step 2. Similarly, if the IAB node knows it is in an authorized state, it also saves the backhaul link configuration information obtained in step 2.

[0427] Step 4: IAB-MT performs handover and establishes an RRC connection between IAB-MT and CU2. CU2 sends a UE initial message (e.g., INITIAL UE MESSAGE) to the AMF network element. Optionally, the RRCSetupComplete message and the INITIAL UE MESSAGE message may carry indication information of the IAB node. Specifically, the RRCSetupComplete message and the INITIAL UE MESSAGE message may carry indication information of the IAB node, and the RRCSetupComplete message and the INITIAL UE MESSAGE message may carry indication information of the mIAB node, which is not limited in this embodiment of the present application.

[0428] Step 5: AMF sends IAB node authorization indication information to CU2. Correspondingly, CU2 receives the IAB node authorization indication information from AMF, and the authorization indication information is used to indicate that the IAB node is in an unauthorized state. For example, the authorization indication information is carried in the PATH SWITCH REQUEST ACK message sent by AMF to CU2, and indicates that the IAB node is in an unauthorized state. Specifically, it can be the IAB Authorized information element in the PATH SWITCH REQUEST ACK message that indicates that the IAB node is in an authorized state, or it can be the mIAB Authorized information element in the PATH SWITCH REQUEST ACK message that indicates that the IAB node is in an authorized state. This embodiment of the present application does not limit this.

[0429] Step 6: Even if the AMF indicates that the IAB node is in an unauthorized state, CU2 still saves the configuration information of the backhaul link. It should be noted that CU2 can save the configuration information of the backhaul link before the next MT migration of IAB-MT.

[0430] Step 7-1: AMF sends IAB node authorization indication information to CU2. Accordingly, CU2 receives the IAB node authorization indication information from AMF, and the authorization indication information is used to indicate that the IAB node is in an authorized state. For example, the authorization indication information is carried in the UE CONTEXT MODIFICATION REQUEST message sent by AMF to CU2, and indicates that the IAB node is in an authorized state. Specifically, it can be the IAB Authorized information element in the UE CONTEXT MODIFICATION REQUEST message that indicates that the IAB node is in an authorized state, or it can be the mIAB Authorized information element in the UE CONTEXT MODIFICATION REQUEST message that indicates that the IAB node is in an authorized state. This embodiment of the present application does not limit this.

[0431] Step 7-2: The AMF sends authorization indication information to the IAB node. For example, the AMF sends a NAS message to the IAB node. Correspondingly, the IAB node receives the NAS message from the AMF. The NAS message is used to indicate that the IAB node is in an authorized state.

[0432] Step 8: Establish a backhaul link between the IAB-MT and CU2. The IAB node performs backhaul link transmission based on the backhaul link configuration information saved in Step 3. For example, the IAB-DU uses the saved backhaul link information to initiate the establishment of the F1 interface to the F1 anchor CU (the F1 anchor CU is the terminating CU of the IAB-DU's F1 interface and can be a different CU or the same CU as CU2) through the topology under CU2.

[0433] In this embodiment, the triggering conditions and circumstances for the IAB node and CU2 to save backhaul link configuration information are clearly defined. This backhaul link configuration information saved by the IAB node and CU2 is then used to establish a backhaul link between the IAB node and CU2. This allows for rapid activation of the IAB node and eliminates the need for CU2 to resend the backhaul link configuration information to the IAB node when the IAB node switches to an authorized state, thus avoiding conflicts in the backhaul link configuration.

[0434] It can be understood that Figure 13 can be used as a specific description of the embodiments shown in Figures 11 and 12, and shows in detail the possible steps in Figures 11 or 12, so it has the beneficial effects corresponding to Figures 11 and 12. The embodiments shown in Figures 9 and 10 above show that when the relay node is in an unauthorized state, the relay node releases the backhaul link configuration, thereby achieving the effect of improving resource utilization. The embodiments shown in Figures 11, 12 and 13 above show that the relay node and / or the first host node ignore the authorization state of the relay node, the relay node saves the received backhaul link configuration, and the first host node saves the backhaul link configuration sent to the relay node. When the relay node switches to the authorized state, the saved backhaul link configuration is used to quickly enable the relay node.

[0435] Optionally, if IAB-MT undergoes MT migration, the backhaul link configuration information saved by CU2 needs to be released / deleted. Unused resources can be released and, if possible, used to build backhaul links on other nodes, thereby improving resource utilization.

[0436] The above describes in detail the methods of the embodiments of the present application. The following provides an apparatus for implementing any method in the embodiments of the present application. For example, an apparatus is provided that includes units (or means) for implementing each step performed by the device in any of the above methods.

[0437] As shown in Figure 14, the communication device 140 may include a communication unit 1401 and a processing unit 1402. The communication unit 1401 and the processing unit 1402 may be software, hardware, or a combination of software and hardware.

[0438] The communication unit 1401 can implement a sending function and / or a receiving function, and can also be described as a transceiver unit. The communication unit 1401 can also be a unit that integrates an acquisition unit and a transmission unit, wherein the acquisition unit is used to implement the receiving function and the transmission unit is used to implement the transmission function. Optionally, the communication unit 1401 can be used to receive information sent by other devices, and can also be used to send information to other devices.

[0439] In one possible design, the communication device 140 may correspond to the relay node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above. For example, the communication device 140 may be a relay node or a chip in a relay node. The communication device 140 may include a unit for executing the operations performed by the relay node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above, and each unit in the communication device 140 is respectively for implementing the operations performed by the relay node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above. The description of each unit is as follows:

[0440] The processing unit 1402 is configured to release the configuration of the backhaul link when a first trigger condition is met; the backhaul link is a backhaul link between the relay node and the first host node;

[0441] The first trigger condition includes:

[0442] The relay node performs mobile terminal MT migration; and the relay node is in an unauthorized state; and the relay node receives first configuration information from the first host node, where the first configuration information is used to indicate the configuration of the backhaul link.

[0443] or,

[0444] The processing unit 1402 is configured to, when the relay node satisfies a fourth trigger condition, save third configuration information of a backhaul link; the backhaul link is a backhaul link between the relay node and the first host node;

[0445] The fourth trigger condition includes:

[0446] The relay node performs MT migration; and, the relay node is in an unauthorized state; and, the relay node receives the third configuration information from the first host node, where the third configuration information is used to indicate the configuration information of the backhaul link.

[0447] In one possible implementation, the device further includes:

[0448] The communication unit 1401 is configured to receive second configuration information from the first host node.

[0449] or,

[0450] The communication unit 1401 is configured to receive second configuration information from the first host node when the relay node switches to the authorized state.

[0451] or,

[0452] The communication unit 1401 is configured to send second information to the first host node, where the second information is used to request at least one IP address.

[0453] or,

[0454] The communication unit 1401 is configured to send, by the relay node, third information to the first host node when a second trigger condition is met, where the third information is used to request an IP address;

[0455] The second trigger condition includes at least one of the following:

[0456] The second configuration information includes a default BAP configuration; or, the second configuration information includes a BAP address; or, the relay node receives fourth information, where the fourth information is used to indicate that the relay node is in an authorized state.

[0457] or,

[0458] The communication unit 1401 is configured to receive fifth information, where the fifth information is used to indicate that the relay node is in an authorized state; and the relay node performs backhaul link transmission based on the configuration information.

[0459] In one possible design, the communication device 140 may correspond to the first host node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above, such as the communication device 140 may be the first host node or a chip in the first host node. The communication device 140 may include a unit for executing the operations performed by the first host node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above, and each unit in the communication device 140 is respectively for implementing the operations performed by the first host node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above. The description of each unit is as follows:

[0460] The processing unit 1402 is configured to retain the configuration information of the backhaul link when the fourth condition is met; the backhaul link is a backhaul link between the relay node and the first host node;

[0461] The fourth condition includes:

[0462] The first host node receives sixth information from the access and mobility management function network element AMF, where the sixth information is used to indicate that the relay node is in an unauthorized state; and the relay node is connected to the first host node.

[0463] or,

[0464] The processing unit 1402 is configured to delete the configuration information when the relay node is disconnected from the first host node.

[0465] In one possible implementation, the device further includes:

[0466] The communication unit 1401 is configured to receive seventh information from the second host node and send configuration information of the backhaul link to the relay node;

[0467] The seventh information is used to indicate that the relay node is in an unauthorized state.

[0468] Regarding the technical effects brought about by any of the above designs and any possible implementation methods, please refer to the introduction of the technical effects of the corresponding methods in Figures 9, 10, 11, 12, and 13 above, which will not be repeated here.

[0469] Optionally, in the communication device described in any of the foregoing designs and any of the possible implementations:

[0470] In one implementation, the communication apparatus is a communication device. When the communication apparatus is a communication device, the communication unit may be a transceiver or an input / output interface; and the processing unit may be at least one processor. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input / output interface may be an input / output circuit.

[0471] In another implementation, the communication device is a chip (system) or circuit used in a communication device. When the communication device is a chip (system) or circuit used in a communication device, the communication unit may be a communication interface (input / output interface), interface circuit, output circuit, input circuit, pin, or related circuit on the chip (system) or circuit; and the processing unit may be at least one processor, processing circuit, or logic circuit.

[0472] According to an embodiment of the present application, each unit in the device shown in Figure 14 can be separately or all merged into one or several other units to constitute, or a certain (some) unit therein can also be split into multiple smaller units to constitute, which can achieve the same operation without affecting the realization of the technical effects of the embodiments of the present application. The above-mentioned units are divided based on logical functions. In practical applications, the function of a unit can also be realized by multiple units, or the function of multiple units can be realized by one unit. In other embodiments of the present application, other units can also be included based on electronic equipment. In practical applications, these functions can also be implemented with the assistance of other units, and can be implemented by collaboration of multiple units.

[0473] It should be noted that the implementation of each unit may also refer to the corresponding description of the method embodiments shown in the above-mentioned Figures 9, 10, 11, 12, and 13.

[0474] In the communication device 140 depicted in FIG14 , the IAB node can promptly release unused backhaul link configurations or save received backhaul link configurations for use in establishing a backhaul link. This prevents conflicts between two backhaul link configurations and reduces signaling overhead.

[0475] Please refer to FIG15 , which is a schematic structural diagram of a communication device provided in an embodiment of the present application.

[0476] It should be understood that the communication device 150 shown in Figure 15 is only an example. The communication device of the embodiment of the present application may also include other components, or include components with similar functions to the various components in Figure 15, or not include all the components in Figure 15.

[0477] The communication device 150 includes a communication interface 1501 and at least one processor 1502 .

[0478] The communication device 150 may correspond to any node or device among the first host node, the relay node, the third host node, and the fourth host node. The communication interface 1501 is used to send and receive signals, and the at least one processor 1502 executes program instructions so that the communication device 150 implements the corresponding process of the method executed by the corresponding device in the above method embodiment.

[0479] In one possible design, the communication device 150 may correspond to the first host node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above. For example, the communication device 150 may be the first host node or a chip in the first host node. The communication device 150 may include components for executing the operations performed by the first host node in the above method embodiments, and each component in the communication device 150 is respectively for implementing the operations performed by the first host node in the above method embodiments. Specifically, it may be as follows:

[0480] The processing unit 1402 is configured to release the configuration of the backhaul link when a first trigger condition is met; the backhaul link is a backhaul link between the relay node and the first host node;

[0481] The first trigger condition includes:

[0482] The relay node performs mobile terminal MT migration; and the relay node is in an unauthorized state; and the relay node receives first configuration information from the first host node, where the first configuration information is used to indicate the configuration of the backhaul link.

[0483] or,

[0484] Processor 1502 is configured to, when a fourth trigger condition is satisfied, enable the relay node to save third configuration information of a backhaul link; the backhaul link is a backhaul link between the relay node and the first host node;

[0485] The fourth trigger condition includes:

[0486] The relay node performs MT migration; and, the relay node is in an unauthorized state; and, the relay node receives the third configuration information from the first host node, where the third configuration information is used to indicate the configuration information of the backhaul link.

[0487] In one possible implementation, the device further includes:

[0488] The communication interface 1501 is configured to receive second configuration information from the first host node.

[0489] or,

[0490] The communication interface 1501 is configured to receive second configuration information from the first host node when the relay node switches to the authorized state.

[0491] or,

[0492] The communication interface 1501 is used to send second information to the first host node, where the second information is used to request at least one IP address.

[0493] or,

[0494] Communication interface 1501, configured for the relay node to send third information to the first host node when a second trigger condition is met, wherein the third information is used to request an IP address;

[0495] The second trigger condition includes at least one of the following:

[0496] The second configuration information includes a default BAP configuration; or, the second configuration information includes a BAP address; or, the relay node receives fourth information, where the fourth information is used to indicate that the relay node is in an authorized state.

[0497] or,

[0498] The communication interface 1501 is configured to receive fifth information, where the fifth information is used to indicate that the relay node is in an authorized state; and the relay node performs backhaul link transmission based on the configuration information.

[0499] In one possible design, the communication device 150 may correspond to the first host node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above, such as the communication device 150 may be the first host node or a chip in the first host node. The communication device 150 may include a unit for executing the operations performed by the first host node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above, and each unit in the communication device 150 is respectively for implementing the operations performed by the first host node in the method embodiments shown in Figures 9, 10, 11, 12, and 13 above. The description of each unit is as follows:

[0500] Processor 1502 is configured to retain configuration information of a backhaul link when a fourth condition is met; the backhaul link is a backhaul link between the relay node and the first host node;

[0501] The fourth condition includes:

[0502] The first host node receives sixth information from the access and mobility management function network element AMF, where the sixth information is used to indicate that the relay node is in an unauthorized state; and the relay node is connected to the first host node.

[0503] or,

[0504] The processor 1502 is configured to delete the configuration information when the relay node is disconnected from the first host node.

[0505] In one possible implementation, the device further includes:

[0506] The communication interface 1501 is configured to receive seventh information from the second host node and send configuration information of the backhaul link to the relay node;

[0507] The seventh information is used to indicate that the relay node is in an unauthorized state.

[0508] The methods executed by the processor 1502 and the communication interface 1501 can refer to the methods corresponding to Figures 9, 10, 11, 12, and 13 above, and will not be repeated here.

[0509] Regarding the technical effects brought about by any of the above designs and any possible implementation methods, please refer to the introduction of the technical effects of the corresponding methods in Figures 9, 10, 11, 12, and 13 above, which will not be repeated here.

[0510] In the communication device 140 depicted in FIG14 , the IAB node can promptly release unused backhaul link configurations or save received backhaul link configurations for use in establishing a backhaul link. This prevents conflicts between two backhaul link configurations and reduces signaling overhead.

[0511] It should be understood that when the communication device 150 is a relay node / first host node, it includes a CU and a DU. The CU may include a communication interface, a processor, and optionally a memory. The communication interface may be used to communicate with the CU of the host node or the DU of the IAB node. The DU may also include a communication interface, a processor, and a memory, as well as a bus connecting the communication interface, the processor, and the memory. The communication interface is used to communicate with the MT of the IAB node.

[0512] For the case where the communication device may be a chip or a chip system, reference may be made to the schematic structural diagram of the chip shown in FIG16 .

[0513] As shown in Figure 16 , chip 160 includes a processor 1601 and an interface 1602. There may be one or more processors 1601, and there may be multiple interfaces 1602. It should be noted that the functions corresponding to processor 1601 and interface 1602 can be implemented through hardware design, software design, or a combination of hardware and software, without limitation.

[0514] Optionally, the chip 160 may further include a memory 1603 , which is used to store necessary program instructions and data.

[0515] In the present application, processor 1601 may be configured to call from memory 1603 an implementation program for the communication method provided in one or more embodiments of the present application on one or more devices or nodes in the first host node, the second host node, or the first node, and execute the instructions contained in the program. Interface 1602 may be configured to output the execution results of processor 1601. In the present application, interface 1602 may be specifically configured to output various messages or information from processor 1601.

[0516] Regarding the communication method provided by one or more embodiments of the present application, reference may be made to the embodiments shown in Figures 9, 10, 11, 12, and 13 above, which will not be repeated here.

[0517] The processor in the embodiments of the present application may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0518] The memory in the embodiments of the present application is used to provide storage space, in which data such as an operating system and computer programs can be stored. The memory includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM).

[0519] According to the method provided in the embodiment of the present application, the embodiment of the present application also provides a computer-readable storage medium, in which a computer program is stored. When the computer program runs on one or more processors, the method shown in Figures 9, 10, 11, 12, and 13 can be implemented.

[0520] According to the method provided in the embodiment of the present application, the embodiment of the present application also provides a computer program product, which includes a computer program. When the computer program runs on a processor, it can implement the methods shown in Figures 9, 10, 11, 12, and 13.

[0521] An embodiment of the present application also provides a system, which includes at least one communication device 140 or communication device 150 or chip 160 as described above, and is used to execute the steps executed by the corresponding device in any of the embodiments of Figures 9, 10, 11, 12, and 13.

[0522] An embodiment of the present application also provides a system, which includes at least one of a relay node, a first host node, a second host node, and an AMF server. The relay node is used to execute the steps executed by the relay node in any of the above-mentioned Figures 9, 10, 11, 12, and 13. The first host node is used to execute the steps executed by the first host node in any of the above-mentioned Figures 9, 10, 11, 12, and 13. The second host node is used to execute the steps executed by the relay node in any of the above-mentioned Figures 12 and 13. The AMF server is used to execute the steps executed by the third host node in any of the above-mentioned Figures 9, 10, 11, 12, and 13.

[0523] An embodiment of the present application further provides a processing device, including a processor and an interface; the processor is used to execute the method in any of the above method embodiments.

[0524] It should be understood that the above-mentioned processing device can be a chip. For example, the processing device can be a field programmable gate array (FPGA), a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, a system on chip (SoC), a central processing unit (CPU), a network processor (NP), a digital signal processing circuit (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chip. The various methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0525] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0526] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. 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 via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disc (SSD)).

[0527] The units in the above-mentioned various apparatus embodiments completely correspond to the electronic devices in the method embodiments, and the corresponding modules or units perform the corresponding steps. For example, the communication unit (transceiver) performs the receiving or sending steps in the method embodiments, and other steps except sending and receiving can be performed by the processing unit (processor). The functions of the specific units can be referred to the corresponding method embodiments. Among them, there can be one or more processors.

[0528] It is understood that in the embodiments of the present application, the electronic device can perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples, and the embodiments of the present application can also perform other operations or variations of various operations. In addition, the various steps can be performed in a different order than those presented in the embodiments of the present application, and it is possible that not all operations in the embodiments of the present application need to be performed.

[0529] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0530] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0531] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0532] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0533] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0534] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0535] The above is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the scope of protection of the present application.

Claims

1. A communication method, characterized in that: The method comprises: The relay node releases the configuration of the backhaul link when the first trigger condition is met; the backhaul link is a backhaul link between the relay node and the first host node; The first trigger condition includes: The relay node performs mobile terminal MT migration; and, the relay node is in an unauthorized state; and, the relay node receives first configuration information from the first host node, where the first configuration information is used to indicate the configuration of the backhaul link.

2. The method according to claim 1, characterized in that The first configuration information includes at least one of the following: Default Backhaul Link Adaptation Layer Protocol (BAP) configuration, BAP address, and Internet Protocol (IP) address.

3. The method according to claim 1 or 2, characterized in that: The method further comprises: When the relay node switches to the authorized state, second configuration information is received from the first host node, where the second configuration information is used to indicate the configuration of the backhaul link.

4. The method according to claim 3, characterized in that The second configuration information includes an IP address.

5. The method according to claim 4, characterized in that The one IP address is used for the control plane protocol F1-C.

6. The method according to any one of claims 3 to 5, characterized in that: The method further comprises: The relay node sends second information to the first host node, where the second information is used to request at least one IP address.

7. The method according to claim 3, characterized in that The second configuration information does not include an IP address; and the method further includes: When the second trigger condition is met, the relay node sends third information to the first host node, where the third information is used to request an IP address; The second trigger condition includes at least one of the following: The second configuration information includes a default BAP configuration; or, the second configuration information includes a BAP address; or, the relay node receives fourth information, and the fourth information is used to indicate that the relay node is in an authorized state.

8. The method according to claim 7, characterized in that The fourth information comes from the non-access layer NAS or the access layer AS of the relay node.

9. A communication method, characterized in that: The method comprises: The relay node saves third configuration information of a backhaul link when a fourth trigger condition is met; the backhaul link is a backhaul link between the relay node and the first host node; Wherein, the fourth trigger condition includes: The relay node performs MT migration; and, the relay node is in an unauthorized state; and, the relay node receives the third configuration information from the first host node, wherein the third configuration information is used to indicate the configuration information of the backhaul link.

10. The method according to claim 9, characterized in that The method further comprises: The relay node receives fifth information, where the fifth information is used to indicate that the relay node is in an authorized state; and the relay node performs backhaul link transmission based on the configuration information.

11. A communication method, characterized in that: The method comprises: The first host node retains configuration information of a backhaul link when the fourth condition is met; the backhaul link is a backhaul link between the relay node and the first host node; The fourth condition includes: The first host node receives sixth information from an access and mobility management function network element AMF, where the sixth information is used to indicate that the relay node is in an unauthorized state; and the relay node is connected to the first host node.

12. The method according to claim 11, characterized in that The method further comprises: The first host node receives the seventh information from the second host node, and sends configuration information of the backhaul link to the relay node; The seventh information is used to indicate that the relay node is in an unauthorized state.

13. The method according to claim 11 or 12, characterized in that: The method further comprises: When the relay node is disconnected from the first host node, the configuration information is deleted.

14. A communication device, characterized in that: Comprising means for performing the method as claimed in any one of claims 1 to 13.

15. A communication device, characterized in that: comprising a processor for executing the method as claimed in any one of claims 1 to 13.

16. A communication device, characterized in that: comprising a logic circuit and an interface, wherein the logic circuit and the interface are coupled; The interface is used for inputting and / or outputting information, and the logic circuit is used for executing the method according to any one of claims 1 to 13.

17. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program. When the computer program is executed, the method according to any one of claims 1 to 13 is performed.

18. A communication system, characterized in that: include: Relay node, first host node; The relay node is used to execute the method according to any one of claims 1 to 10, and the first host node is used to execute the method according to any one of claims 11 to 13.

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