Communication method and communication apparatus

Abstract

A communication method and a communication apparatus, which can be applied in an IAB network comprising a mobile relay node, and are conducive to improving the communication performance of the IAB network. The method may comprise: a first donor node determining a second donor node for a first mobile relay node, wherein the second donor node supports a first operation mode, and the first operation mode indicates that the first mobile relay node operates as a mobile relay node; and sending a request message to the second donor node, wherein the request message is used for requesting the switching or redirection of the first mobile relay node to the second donor node, or the request message is used for requesting the addition of the second donor node as a secondary node. Thus, the flexible deployment of a first mobile relay node can be supported, thereby helping to improve the performance utilization rate of the first mobile relay node, and thus helping to improve the communication performance of an IAB network.

Description

Communication method and communication device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 31, 2024, with application number 202410142355.8 and application name “Communication Method and Communication Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of communication technology, and in particular, to a communication method and a communication device. Background Art

[0003] Integrated access and backhaul (IAB) not only meets the needs of densely deployed base stations, but also meets the needs of flexible fiber deployment and saves fiber deployment costs. IAB is a relay solution that can include an IAB node (IAB node) and an IAB donor (IAB donor). The IAB donor is the host node of the IAB node. Among them, an IAB node can also be called a relay node or relay device, etc. The child node of an IAB node can be another IAB node or user equipment (UE), and the parent node of an IAB node can be another IAB node or another IAB donor. An IAB node consists of a mobile terminal (MT) and a distributed unit (DU), which can be represented as IAB-MT and IAB-DU, respectively. When an IAB node faces its parent node, it acts as an IAB-MT; when it faces its child node, it acts as an IAB-DU. An IAB donor can also be called a host device, a host node, or a donor base station (donor gNodeB, DgNB), etc. The IAB donor consists of a centralized unit (CU) part and a DU part, which can be represented as donor-CU and donor-DU respectively.

[0004] With the development of communication technology, IAB nodes can move within the network. Such IAB nodes can be called mobile IAB nodes. During the movement of mobile IAB nodes, their host devices may be replaced. During the process of replacing the host device of a mobile IAB node, how to improve the communication performance of the IAB network is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The embodiments of the present application provide a communication method and a communication device, which are helpful in improving the communication performance of an IAB network.

[0006] In a first aspect, an embodiment of the present application provides a communication method that can be applied to a first host node. That is, the method can be executed by the first host node, or by a device that matches the first host node, such as a processor or chip. The method may include: determining a second host node, the second host node supporting a first working mode, the first working mode indicating that the first mobile relay node operates as a mobile relay node; sending a request message to the second host node, the request message being used to request that the first mobile relay node be switched or redirected to the second host node, or the request message being used to request that the second host node be added as a secondary node.

[0007] The first host node can be understood as the source host node in a switching or redirection scenario, and the second host node can be understood as the target host node in the scenario. In this case, the request message is used to request that the first mobile relay node be switched or redirected to the second host node. Alternatively, the first host node can be understood as the primary node in a dual-connection scenario, and the second host node can be understood as the secondary node in the dual-connection scenario. In this case, the request message is used to request that the second host node be added as a secondary node.

[0008] It can be seen that the first host node determines a second host node that supports the first working mode for the first mobile relay node, so that the first mobile relay node can switch or redirect from the first host node to the second host node, or so that the second host node can support the first working mode of the first mobile relay node as an auxiliary node in a dual-connection scenario, thereby supporting flexible deployment of the first mobile relay node, helping to improve the performance utilization of the first mobile relay node, and thus helping to improve the communication performance of the IAB network.

[0009] It can be understood that in the embodiment of the present application, for a certain host node, it supports the first working mode, which may be only supporting the first working mode and not supporting the second working mode; or it may be supporting not only the first working mode but also the second working mode.

[0010] In one possible implementation, when a first mobile relay node is connected to a first host node, the first mobile relay node is authorized to operate in a second operating mode, which instructs the first mobile relay node to operate as a relay node. The mobile relay node has two identities, one of which it operates in. These two identities are a relay node identity and a mobile relay node identity. The mobile relay node identity can be considered an upgraded version of the relay node identity, and the two identities support different capabilities.

[0011] Optionally, when the first mobile relay node is authorized to operate in the second working mode, the first host node may determine a second host node. That is, when the first mobile relay node is authorized to operate in a lower version working mode, the first host node may determine a second host node to support the first mobile relay node in switching to a higher version working mode, thereby improving the performance utilization of the first mobile relay node.

[0012] In a possible implementation, the method further includes: receiving first indication information, where the first indication information instructs the first host node to determine the second host node. In other words, the first host node may determine the second host node based on the first indication information.

[0013] Optionally, the first indication information comes from a core network device, and the core network device serves the first mobile relay node, for example, it may serve the MT of the first mobile relay node. It is understandable that the core network device may determine whether to determine a second host node for the first mobile relay node, and if so, instruct the first host node to determine the second host node through the first indication information.

[0014] Optionally, the first indication information comes from the first mobile relay node. For example, the first mobile relay node may determine whether to switch the working mode, and if so, instruct the first host node to determine the second host node through the first indication information.

[0015] In one possible implementation, determining the second host node may include: obtaining a working mode supported by a neighboring area and / or a candidate host node, which working mode is a first working mode and / or a second working mode, and then the first host node determines a second host node that supports the first working mode based on the working mode supported by the neighboring area and / or the candidate host node. Among them, the neighboring area refers to the neighboring area of ​​the service cell of the first mobile relay node, and the candidate host node refers to the neighboring host node of the service host node of the first mobile relay node. Taking the candidate host node as an example, the working mode it supports may be the first working mode or the second working mode, or it may support both working modes, depending on its capabilities. This method can be understood as the first host node determining the second host node based on Xn interaction.

[0016] Optionally, the first host node determines the second host node based on the working mode supported by the neighboring area and / or candidate host node, and the premise is that the first host node supports the first working mode, so that the first host node can read the supported working mode indicated by it through the Xn interaction information.

[0017] In one possible implementation, determining the second host node may include: receiving a measurement report from the first mobile relay node, and determining, based on the measurement report, a second host node that supports the first working mode. This approach can be understood as the first host node determining the second host node based on the measurement report. In this approach, the first host node may only support the second working mode or the first working mode (including only supporting the first working mode and not supporting the second working mode, or supporting both the first working mode and the second working mode).

[0018] Optionally, the measurement report is a measurement report of a candidate neighboring cell, and the candidate neighboring cell supports the first operating mode. The number of candidate neighboring cells is one or more. That is, the measurement report only includes measurement reports of neighboring cells that support the first operating mode, and does not include measurement reports of other neighboring cells that only support the second operating mode. On the one hand, this helps reduce the bit overhead of the measurement report, and on the other hand, it helps the first host node quickly determine the second host node.

[0019] In one possible implementation, determining the second host node may include: receiving identification information of at least one candidate host node, at least one candidate host node supporting the first operating mode, and determining the second host node from the at least one candidate host node. In this manner, the first host node may support only the second operating mode or the first operating mode (including supporting only the first operating mode and not the second operating mode, or supporting both the first operating mode and the second operating mode).

[0020] Optionally, the identification information of the at least one candidate host node comes from a core network device, and the core network device serves the first mobile relay node, for example, serves the MT of the first mobile relay node. In other words, the core network device determines at least one candidate host node that supports the first working mode, and notifies the first host node of the identification information of the at least one candidate host node, so that the first host node can determine the second host node.

[0021] Optionally, the identification information of the at least one candidate host node comes from the first mobile relay node. It is understandable that the first mobile relay node determines at least one candidate host node that supports the first working mode based on the broadcast information of the neighboring area, and informs the first host node of the identification information of the at least one candidate host node so that the first host node can determine the second host node.

[0022] In one possible implementation, the method further includes: the first donor node may receive second indication information from a core network device, the second indication information indicating that the first mobile relay node is authorized to operate in the first operating mode, i.e., updating the authorized operating mode of the first mobile relay node from the second operating mode to the first operating mode to support the first mobile relay node to operate as a mobile relay node. The core network device serves the first mobile relay node.

[0023] Optionally, the second indication information further indicates to deauthorize the second working mode to prevent the first mobile relay node from continuing to work as a relay node, thereby reducing conflicts with the first working mode.

[0024] Optionally, in response to the received second indication information, the first host node may inform the first mobile relay node that it is authorized to operate in the first working mode.

[0025] In one possible implementation, the method further includes: sending third indication information to a core network device, the third indication information indicating that the first mobile relay node's desired operating mode is the first operating mode, and that the core network device serves the first mobile relay node. The first host node sends the third indication information to the core network device so that the core network device learns the desired operating mode of the first mobile relay node, or in other words, so that the core network device learns that the accessed terminal device is a mobile relay node, and can then determine whether the first host node needs to determine a second host node to support the core network device in authorizing the first mobile relay node to operate in the first operating mode.

[0026] Optionally, when the first donor node receives indication information from the first mobile relay node, where the indication information indicates the desired working mode of the first mobile relay node, the first donor node sends third indication information to the core network device.

[0027] In one possible implementation, in a dual-connectivity scenario, the first host node may migrate traffic from the first mobile relay node, when operating in the first operating mode, to the second host node. This process can be understood as an IAB traffic migration management process. This process enables the transition of the operating mode of the first mobile relay node without service interruption, thereby improving service continuity for terminal devices.

[0028] In one possible implementation, the first host node may also send fourth indication information to the second host node, where the fourth indication information indicates that the first mobile relay node is authorized to operate in the first working mode, so that the second host node provides services to the first mobile relay node based on the first working mode.

[0029] In one possible implementation, in a dual-connectivity scenario, in response to receiving a release request message from a first mobile relay node, the F1 connection with the first mobile relay node is released to save wireless resources and wireless signaling. In this approach, the first mobile relay node initiates the F1 connection release process. Optionally, the first host node may also initiate the F1 connection release process, for example, by sending a release request message to the first mobile relay node to release the F1 connection with the first mobile relay node.

[0030] In a second aspect, an embodiment of the present application provides a communication method, which can be applied to a first mobile relay node. That is, the method can be executed by the first mobile relay node, or by a device matching the first mobile relay node, such as a processor or chip. The method may include: receiving broadcast information of a neighboring area, the broadcast information indicating whether the neighboring area supports the first working mode, and the first working mode indicating that the first mobile relay node works as a mobile relay node; based on the broadcast information of the neighboring area, determining a candidate neighboring area, and the candidate neighboring area supports the first working mode; sending a measurement report to the first host node, the measurement report is a measurement report of the candidate neighboring area, and the measurement report is used by the first host node to determine a second host node that supports the first working mode; or, sending identification information of at least one candidate host node to the first host node, at least one candidate host node supports the first working mode, and the identification information of at least one candidate host node is used by the first host node to determine a second host node that supports the first working mode; wherein the first mobile relay node has established a connection with the first host node (including a radio resource control (RRC) connection and / or an F1 connection).

[0031] The first host node can be understood as the source host node in a handover or redirection scenario, and the second host node can be understood as the target host node in the scenario. Alternatively, the first host node can be understood as the primary node in a dual-connection scenario, and the second host node can be understood as the secondary node in the dual-connection scenario. The number of candidate neighboring cells can be one or more.

[0032] It can be seen that when the first mobile relay node determines the candidate neighboring area that supports the first working mode, it can feedback the measurement report of the candidate neighboring area that supports the first working mode to the first host node, or feedback the identifier of the candidate host node to the first host node so that the first host node can determine the second host node that supports the first working mode, so that the first mobile relay node can switch or redirect from the first host node to the second host node, or in a dual-connection scenario, the second host node supports the first working mode of the first mobile relay node as an auxiliary node. In this way, the flexible deployment of the first mobile relay node can be supported, which helps to improve the performance utilization of the first mobile relay node, and thus helps to improve the communication performance of the IAB network. In addition, the measurement report only includes the measurement report of the candidate neighboring area that supports the first working mode, which is beneficial to reducing the bit overhead of the measurement report on the one hand, and is beneficial to the first host node to quickly determine the second host node on the other hand.

[0033] It can be understood that in the embodiment of the present application, for a certain host node, it supports the first working mode, which may be only supporting the first working mode and not supporting the second working mode; or it may be supporting not only the first working mode but also the second working mode.

[0034] In one possible implementation, when a first mobile relay node is connected to a first host node, the first mobile relay node is authorized to operate in a second operating mode, which instructs the first mobile relay node to operate as a relay node. The mobile relay node has two identities, one of which it operates in. These two identities are a relay node identity and a mobile relay node identity. The mobile relay node identity can be considered an upgraded version of the relay node identity, and the two identities support different capabilities.

[0035] In one possible implementation, sending the measurement report to the first host node may include: in response to determining that the operating mode is the first operating mode, sending the measurement report to the first host node, so that the first host node can quickly determine the second host node based on the measurement report. That is, when the first mobile relay node determines that its operating mode is the first operating mode, the measurement report is sent to the first host node. The first mobile relay node determining that its operating mode is the first operating mode may be determining to switch its operating mode from the second operating mode to the first operating mode.

[0036] Optionally, in response to the determined working mode being the first working mode and the first host node not supporting the first working mode, the measurement report is sent to the first host node.

[0037] In one possible implementation, sending identification information of at least one candidate host node to the first host node may include: in response to determining that the working mode is the first working mode, sending identification information of at least one candidate host node to the first host node, so that the first host node can quickly determine the second host node based on the identification information of these candidate host nodes. That is, when the first mobile relay node determines that its working mode is the first working mode, the identification information of the above-mentioned candidate host node is sent to the first host node. The first mobile relay node determines that its working mode is the first working mode, which may be a determination to convert its working mode from the second working mode to the first working mode.

[0038] Optionally, in response to the determined working mode being the first working mode and the first host node not supporting the first working mode, identification information of at least one candidate host node is sent to the first host node.

[0039] In one possible implementation, the first mobile relay node further sends fifth indication information, where the fifth indication information indicates that the first mobile relay node's desired operating mode is the first operating mode. In other words, the first mobile relay node indicates its desired operating mode through the fifth indication information so as to determine a second host node that supports the first operating mode.

[0040] Optionally, the first mobile relay node sends the fifth indication information to the core network device through the first host node. That is, the first mobile relay node first sends the fifth indication information to the first host node, and the first host node then sends the third indication information to the core network device, where the third indication information includes the fifth indication information.

[0041] In one possible implementation, the above method also includes: the first mobile relay node receives indication information from the core network device through the first host node, and the indication information indicates that the first mobile relay node is authorized to be in the first working mode, so that the first mobile relay node can operate based on the first working mode.

[0042] In one possible implementation, the method further includes: establishing, by the first mobile relay node, an RRC connection and / or an F1 connection with the second donor node. Regarding establishing the RRC connection and the F1 connection, in a dual-connectivity scenario, the first mobile relay node and the second donor node may establish an RRC connection and an F1 connection. In a handover scenario, the first mobile relay node and the second donor node may establish an RRC connection.

[0043] In one possible implementation, the method further includes: in response to the first mobile relay node and the second host node having established an F1 connection, sending a release request message to the first host node, where the release request message is used to request release of the F1 connection between the first mobile relay node and the first host node. Alternatively, the first host node may also initiate an F1 connection release process, for example, the first host node sending a release request message to the first mobile relay node to release the F1 connection between the first host node and the first mobile relay node.

[0044] In a third aspect, embodiments of the present application provide a communication method that can be applied to a core network device, where the core network device serves a first mobile relay node. That is, the method can be executed by the core network device, or by a device compatible with the core network device, such as a processor or chip. The method can include: obtaining an operating mode supported by at least one host node, where the operating mode is a first operating mode and / or a second operating mode, where the first operating mode indicates that the first mobile relay node operates as a mobile relay node, and the second operating mode indicates that the first mobile relay node operates as a relay node; determining at least one candidate host node based on the operating mode supported by the at least one host node, where the at least one candidate host node supports the first operating mode; and sending identification information of the at least one candidate host node to the first host node, where the first mobile relay node has established a connection with the first host node, where the identification information of the at least one candidate host node is used by the first host node to determine a second host node, where the second host node supports the first operating mode.

[0045] The first host node can be understood as the source host node in a handover or redirection scenario, and the second host node can be understood as the target host node in the scenario. Alternatively, the first host node can be understood as the primary node in a dual-connection scenario, and the second host node can be understood as the secondary node in the dual-connection scenario.

[0046] It can be seen that the core network device provides the first host node with identification information of at least one candidate host node that supports the first working mode, so that the first host node can determine the second host node that supports the first working mode, so that the first mobile relay node can be switched or redirected from the first host node to the second host node, or in a dual-connection scenario, the second host node can serve as a secondary node to support the first working mode of the first mobile relay node. In this way, flexible deployment of the first mobile relay node can be supported, which helps to improve the performance utilization of the first mobile relay node, and thus helps to improve the communication performance of the IAB network.

[0047] In one possible implementation, sending identification information of at least one candidate host node to the first host node may include: in response to determining that the operating mode of the first mobile relay node is the first operating mode, sending identification information of at least one candidate host node to the first host node. That is, when the core network device determines that the operating mode of the first mobile relay node is the first operating mode, sending identification information of at least one candidate host node to the first host node. Alternatively, when the core network device determines that the first mobile relay node is authorized to operate in the first operating mode, sending identification information of at least one candidate host node to the first host node.

[0048] In one possible implementation, after the core network device authorizes the first working mode to the first mobile relay node, it may send second indication information to the first host node, where the second indication information indicates that the first mobile relay node is authorized to the first working mode to support the first mobile relay node to operate as a mobile relay node.

[0049] Optionally, the second indication information further indicates to deauthorize the second working mode to prevent the first mobile relay node from continuing to work as a relay node, thereby reducing conflicts with the first working mode.

[0050] In one possible implementation, determining at least one candidate host node based on the working mode supported by at least one host node may include: in response to the first host node not supporting the first working mode, determining at least one candidate host node based on the working mode supported by the at least one host node; and / or, in response to the first mobile relay node being authorized for the second working mode, determining at least one candidate host node based on the working mode supported by the at least one host node. That is, when the first mobile relay node is connected to the first host node, if the first host node does not support the first working mode and / or the first mobile relay node is authorized for the second working mode, the core network device may select at least one candidate host node that supports the first working mode, so as to send identification information of the at least one candidate host node to the first host node.

[0051] In a possible implementation, the method further includes: receiving third indication information from the first host node, where the third indication information indicates that the desired working mode of the first mobile relay node is the first working mode.

[0052] In a fourth aspect, embodiments of the present application provide a communication method, which can be applied to a core network device serving a first mobile relay node. That is, the method can be executed by the core network device, or by a device compatible with the core network device, such as a processor or chip. The method can include: receiving a first handover request from a first host node, the first handover request including identification information of a third host node, the first handover request being used to request handover of the first mobile relay node to the third host node; in response to the third host node not supporting the first operating mode and / or in response to the first mobile relay node being authorized for the second operating mode, determining a second host node based on operating modes supported by at least one host node, the at least one host node supporting the first operating mode and / or the second operating mode, the first operating mode indicating that the first mobile relay node operates as a mobile relay node, and the second operating mode indicating that the first mobile relay node operates as a relay node; and sending a second handover request to the second host node, the second handover request being used to request handover of the first mobile relay node to the second host node.

[0053] The third host node may be understood as the target host node determined by the first host node, and the second host node may be understood as the target host node determined by the core network device.

[0054] It can be seen that when the target host node determined by the first host node does not support the first working mode, and / or when the first mobile relay node is connected to the first host node, the first mobile relay node is authorized to operate in the second working mode, the core network device can re-determine a target host node that supports the first working mode and send a handover request to the target host node to handover the first mobile relay node to the target host node. Thus, the flexible deployment of the first mobile relay node can be supported, which helps to improve the performance utilization of the first mobile relay node, and further helps to improve the communication performance of the IAB network.

[0055] In one possible implementation, the first handover request also includes identification information of a first protocol data unit (PDU) session. The first donor node establishes a PDU session for the first mobile relay node, and the PDU session is the first PDU session. The second handover request also includes the identification information of the first PDU session. This allows the second donor node to notify the core network device of its air interface configuration and the admission status of the first PDU session.

[0056] In one possible implementation, upon receiving the air interface configuration of the second host node and the admission status of the first PDU session, the core network device may send an indication message to the first host node, instructing the first host node to switch or redirect the first mobile relay node.

[0057] In a fifth aspect, an embodiment of the present application provides a communication device, which may be a first host node, or a device in the first host node, or a device that can be used in conjunction with the first host node. The communication device may also be a chip system. The communication device may execute the method described in the first aspect. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module may be software and / or hardware. The operations and beneficial effects performed by the communication device may refer to the method and beneficial effects described in the first aspect above.

[0058] In a sixth aspect, an embodiment of the present application provides a communication device, which may be a first mobile relay node, or a device in the first mobile relay node, or a device that can be used in combination with the first mobile relay node. The communication device may also be a chip system. The communication device may execute the method described in the second aspect. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module may be software and / or hardware. The operations and beneficial effects performed by the communication device may refer to the method and beneficial effects described in the second aspect above.

[0059] In a seventh aspect, an embodiment of the present application provides a communication device, which may be a core network device, a device in a core network device, or a device that can be used in conjunction with a core network device. The communication device may also be a chip system. The communication device may execute the method described in the third or fourth aspect above. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module may be software and / or hardware. The operations and beneficial effects performed by the communication device may refer to the methods and beneficial effects described in the third or fourth aspect above.

[0060] In an eighth aspect, an embodiment of the present application provides a communication device, comprising a processor coupled to a memory, the memory being used to store programs or instructions. When the programs or instructions are executed by the processor, the communication device executes the method described in any one of the first to fourth aspects.

[0061] In the ninth aspect, an embodiment of the present application provides a communication device, which includes a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor is used to implement the method described in any one of the first to fourth aspects through a logic circuit or executing code instructions.

[0062] In the tenth aspect, an embodiment of the present application provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed by a communication device, the method described in any one of the first to fourth aspects is implemented.

[0063] In the eleventh aspect, an embodiment of the present application provides a computer program product comprising instructions, which, when a communication device reads and executes the instructions, enables the communication device to execute any method in any one of the first to fourth aspects.

[0064] In the twelfth aspect, an embodiment of the present application provides a communication system, which includes a first host node, a first mobile relay node and a core network device, the first host node is used to execute the method provided by the first aspect, the first mobile relay node is used to execute the method provided by the second aspect, and the core network device is used to execute the method provided by the third aspect or the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is a schematic diagram of a wireless relay scenario;

[0066] FIG2 is a schematic diagram of the network access process of an IAB node;

[0067] FIG3 is a diagram illustrating an exemplary system architecture using an embodiment of the present application;

[0068] FIG4 is a flow chart of a communication method provided in an embodiment of the present application;

[0069] FIG5 is a flow chart of another communication method provided in an embodiment of the present application;

[0070] FIG6 is a flow chart of another communication method provided in an embodiment of the present application;

[0071] FIG7 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0072] FIG8 is a schematic structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0073] In this application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit differences. "And / or" describes the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0074] It should be understood that, in this application, "at least one" refers to one or more, and "a plurality" refers to two or more. Furthermore, in this application, "equal to" can be used in conjunction with "greater than" or "less than." When "equal to" and "greater than" are used together, the technical solution of "greater than" is adopted; when "equal to" and "less than" are used together, the technical solution of "less than" is adopted.

[0075] In this application, "sending information to... (e.g., a terminal device)" can be understood as the destination of the information being the terminal device. This can include sending information to the terminal device directly or indirectly. "Receiving information from... (e.g., a terminal device)" or "receiving information from... (e.g., a terminal device)" can be understood as the source of the information being the terminal device, which can include receiving information from the terminal device directly or indirectly. The information may be processed as necessary between the source and destination of the information, such as format changes, but the destination can understand the valid information from the source. Similar expressions in this application can be understood similarly and will not be elaborated on here.

[0076] The following first explains the relevant names or terms involved in this application to facilitate understanding by those skilled in the art.

[0077] 1. IAB Network

[0078] In an IAB network, an IAB node (also known as a relay node (RN) or relay device) provides wireless access services to UEs. The UE's service data is transmitted from the IAB node to the IAB donor via a backhaul link.

[0079] An IAB node consists of an IAB-MT and an IAB-DU. When an IAB node faces its parent node, it functions as an IAB-MT. When an IAB node faces its child node (which may be another IAB node or a UE), it functions as a network device, acting as an IAB-DU.

[0080] The IAB donor consists of a donor-CU and a donor-DU. The IAB donor can be an access network device with complete base station functions or an access network device with a separate CU and DU. The IAB donor is connected to the core network device that provides services to the UE (for example, to the 5G core network (5G core, 5GC) network element) and provides wireless backhaul functions for the IAB node. The donor-CU may be in a form with a separate control plane (CP) and user plane (UP). For example, the donor-CU can be composed of a donor-CU-CP and one (or more) donor-CU-UPs.

[0081] In an IAB network, a transmission path between a UE and an IAB donor may include one or more IAB nodes. Each IAB node maintains not only a backhaul link to its parent node, but also an access link to its child nodes. If the child of an IAB node is a UE, the link between the IAB node and the UE is an access link. If the child of an IAB node is another IAB node, the link between the IAB node and the other IAB nodes is a backhaul link. For example, referring to the wireless relay scenario shown in Figure 1, in the path "UE1 → IAB node 4 → IAB node 3 → IAB node 1 → IAB donor," UE1 accesses IAB node 4 via an access link, IAB node 4 connects to IAB node 3 via a backhaul link, IAB node 3 connects to IAB node 1 via a backhaul link, and IAB node 1 connects to the IAB donor via a backhaul link. In Figure 1, black bidirectional arrows represent backhaul links, and gray bidirectional arrows represent access links.

[0082] IAB nodes can be divided into access IAB nodes and intermediate IAB nodes. An access IAB node is an IAB node that a UE accesses, while an intermediate IAB node is an IAB node that provides wireless backhaul services to the UE or IAB node. For example, referring to Figure 1, in the path "UE1 → IAB node 4 → IAB node 3 → IAB node 1 → IAB donor," IAB node 4 is an access IAB node, while IAB node 3 and IAB node 1 are intermediate IAB nodes.

[0083] The host node in the embodiment of the present application may be an IAB donor, and the CU and DU of the IAB donor may adopt a separate architecture or not, depending on the specific situation.

[0084] The CU may be a device under an open radio access network (O-RAN) architecture, such as an open CU. The DU (e.g., IAB-DU) may also be a device under an O-RAN architecture, such as an open DU.

[0085] 2. IAB node integration process

[0086] The IAB node network access process refers to the IAB node's access to the network through an IAB donor. For example, the IAB node network access process is shown in Figure 2. Figure 2 uses the network access of IAB node 2 as an example. IAB node 1 is its parent node and IAB node 1 is already connected to the network. The network access process shown in Figure 2 includes the following stages:

[0087] Phase 1: IAB-MT 2 setup

[0088] The IAB donor carries the iab-Support information element in the broadcast information of cells that support access by IAB-MT 2 (i.e., the MT of IAB node 2). The broadcast information can be, for example, system information block 1 (SIB1). In other words, SIB1 can broadcast the iab-Support information element. IAB-MT 2 will only choose to access cells that broadcast the iab-Support information element in SIB1. IAB-MT 2 accesses the cell in a manner similar to how a UE accesses a cell, establishes an RRC connection with the IAB donor, and indicates that it is an IAB node when establishing the RRC connection. For example, the RRC Setup Complete message (i.e., Msg5) sent by IAB-MT 2 to the donor-CU carries the iab-NodeIndication information element, which indicates that the sender of the message is an IAB node.

[0089] In response to the received Msg5 message, the donor-CU sends an Initial UE Message to the core network device. This message also carries the IAB Node Indication information element, which indicates that the device requesting access is an IAB node. In response to the received UE Initial Message, the core network device authenticates IAB-MT 2 and instructs the donor-CU to establish a UE initial context for IAB-MT 2. This indication can be, for example, an Initial Context Setup Request message carrying the IAB Authorized information element. If IAB-MT 2 is authenticated successfully, the value of the IAB Authorized information element is "authorized," indicating that IAB node 2 is authenticated as an IAB node. If IAB-MT 2 is not authenticated successfully, the value of the IAB Authorized information element is "not authorized," indicating that IAB node 2 is not authenticated as an IAB node. Based on the assumption that authentication is successful, the subsequent stages are executed.

[0090] Phase 2-1: Backhaul (BH) Radio Link Control (RLC) Channel Establishment

[0091] The donor-CU configures BH RLC channels and routes for IAB node 2 using RRC messages. The donor-CU configures a default BH RLC channel and a default route for use during the initial F1 interface establishment (Phase 3). After the F1 interface is established, the donor-CU can configure more BH RLC channels and routes for the IAB node using F1-C messages for subsequent F1-C messages and F1-U user plane data.

[0092] Phase 2-2: Routing Update

[0093] The donor-CU may also perform routing updates on nodes between IAB node 2 and the IAB donor (eg, IAB node 1), informing IAB node 1 how to select the next-hop link and next-hop RLC channel when receiving a data packet from IAB node 2 or sending a data packet to IAB node 2.

[0094] Phase 3: IAB-DU 2 access

[0095] IAB-DU 2 uses the default configuration obtained in stage 2-1 (i.e., the default BH RLC channel and default route) to send an F1 Setup Request message to the donor-CU. This message may carry the configuration information of the cell under IAB-DU 2 and is used to request the establishment of the F1 interface. In response to the F1 Setup Request message, the donor-CU feeds back an F1 Setup Response message to IAB-DU 2 to activate the cell under IAB-DU 2 and complete the establishment of the F1 interface. In response to the F1 Setup Response message, IAB-DU 2 activates the cell under IAB-DU 2, so that IAB-DU 2 can provide services for the UE and the next-hop IAB-MT. Establishing the F1 interface can also be described as establishing an F1 connection. The subsequent embodiments take the establishment of the F1 connection as an example.

[0096] The core network device in Figure 2 serves IAB node 2. The core network device may be, for example, an access and mobility management function (AMF) in a 5G core network.

[0097] 3. Mobile IAB node

[0098] With the advancement of communication technology, IAB nodes can be mobile within the network. Such IAB nodes can be called mobile IAB nodes. In the 3rd Generation Partnership Project (3GPP) Release 18 (R18), mobile IAB nodes can support various features, such as continuous partial migration, distributed unit migration (DU migration), and migration of the mobile unit (MT) and distributed unit (DU) of a mobile IAB node to different donor-CUs. However, R18 also discards some IAB node features in 3GPP Release 16 (R16) and Release 17 (R17). For example, in R18, mobile IAB nodes do not support dual connectivity and cannot serve as the parent node of other IAB nodes. Although the mobile IAB node in R18 does not support dual connections and service sub-nodes, the features in R18 rely on the support of the entire network. Therefore, R18 is still backward compatible with R16 / R17. The mobile IAB node in R18 can be regarded as an enhanced or upgraded version of the IAB node in R16 / R17.

[0099] The IAB node access process shown in Figure 2 applies to IAB nodes in Release 16 / 17. The mobile IAB node access process is similar, except that the IAB node in Figure 2 is replaced with a mobile IAB node. According to the standard, mobile IAB nodes and IAB nodes are considered two different types of nodes. To support the features of mobile IAB nodes in Release 18, both core network devices and IAB donors need to be upgraded to provide services for mobile IAB nodes. Therefore, the mobileIAB-Support information element is introduced in SIB1, and the mobileIAB-NodeIndication information element is introduced in the Msg5 message. In response to the received Msg5 message, the donor-CU searches for a core network device that supports mobile IAB nodes and sends a UE Initial Message to the core network device. This message carries the Mobile IAB Node Indication information element, indicating that the device requesting access is a mobile IAB node. If authentication is successful, the core network device includes the Mobile IAB Authorized information element with the value "authorized" in the Initial Context Setup Request message.

[0100] It's understandable that a mobile IAB node has two identities, but operates under one of them. The mobile IAB node identity can be considered an upgraded version of the IAB node identity, and the two identities support different capabilities.

[0101] Therefore, a mobile IAB node can have two operating modes: one in which the mobile IAB node operates as a mobile IAB node, and the other in which the mobile IAB node operates as an IAB node. For ease of distinction, in this embodiment of the application, the operating mode in which the mobile IAB node operates as the first operating mode is referred to as the first operating mode, and the operating mode in which the mobile IAB node operates as the IAB node is referred to as the second operating mode.

[0102] It is understood that if a mobile IAB node operates in the first operating mode, after the core network device authenticates the mobile IAB node, it will include the Mobile IAB Authorized information element in the Initial Context Establishment Request message. In this case, the IAB donor accessed by the mobile IAB node must also support the first operating mode, meaning that the mobileIAB-Support information element must be broadcast in the SIB1 of its cell. Alternatively, if the IAB donor supports only the first operating mode, the mobileIAB-Support information element can be broadcast in the SIB1 of its cell. Alternatively, if the IAB donor supports both the first and second operating modes, the mobileIAB-Support information element and the iab-Support information element must be broadcast in the SIB1 of its cell. If a mobile IAB node operates in the second operating mode, the core network device, after authenticating the mobile IAB node, includes the IAB Authorized information element in the Initial Context Setup Request message. In this case, the IAB donor connected to the mobile IAB node only supports the second operating mode, and the iab-Support information element is broadcast in the SIB1 of its cell. The IAB donor can support the second operating mode only, or both the first and second operating modes.

[0103] Optionally, the first working mode may also be described as a working mode of a mobile IAB node in 3GPP R18, or a mobile IAB node being authorized as a mobile IAB node, etc.; the second working mode may also be described as a working mode of a mobile IAB node in 3GPP R16 / R17, or a mobile IAB node being authorized as an IAB node, etc.

[0104] The working mode of the mobile IAB node has the following characteristics:

[0105] 1. The mobile IAB node can reside on or connect to an IAB donor that supports the second working mode;

[0106] In other words, if a mobile IAB node wants to access a cell that only broadcasts the iab-Support information element in SIB1 and not the mobileIAB-Support information element, it can do so. However, after accessing the cell, its operating mode will be the second operating mode, which does not support the features in Release 18. This feature indicates that the mobile IAB node can fall back from the first operating mode to the second operating mode.

[0107] Second, the mobile IAB node can know its desired working mode and can then indicate the desired working mode to the IAB donor via the Msg5 message;

[0108] However, when indicating its desired operating mode, the mobile IAB node can only indicate the first operating mode or the second operating mode, but not both. The final operating mode of the mobile IAB node is determined by the core network equipment, and the final operating mode may or may not be the same as the desired operating mode.

[0109] 3. For cells that only support the first working mode, the mobileIAB-Support information element is broadcast in SIB1, and the iab-Support information element is not broadcast; for cells that support the first working mode and the second working mode, the mobileIAB-Support information element and the iab-Support information element are broadcast in SIB1.

[0110] The following is an introduction to the application scenarios and system architecture of this application.

[0111] For a mobile IAB node, its IAB donor may change during mobility. If the mobile IAB node wishes to switch from the second operating mode to the first operating mode, but the replaced IAB donor does not support the first operating mode, the mobile IAB node's Release 18 features cannot be utilized, impacting the flexible deployment of the mobile IAB node and the communication performance of the IAB network. Alternatively, the mobile IAB node's currently connected IAB donor supports the first operating mode, but due to coverage and / or load reasons, the mobile IAB node needs to be switched to another IAB donor. Whether this IAB donor supports the first operating mode will affect the flexible deployment of the mobile IAB node and the communication performance of the IAB network. Therefore, improving the communication performance of the IAB network is a pressing technical issue.

[0112] In view of this, embodiments of the present application provide a communication method and a communication device, which can support flexible deployment of mobile IAB nodes, help improve the performance utilization of mobile IAB nodes, and further help improve the communication performance of the IAB network.

[0113] In one implementation, the embodiments of the present application can be applied to a switching or redirection scenario, i.e., switching or redirecting the IAB donor connected to the mobile IAB node from the source IAB donor to the target IAB donor. The switching scenario can also be understood as switching the cell connected to the mobile IAB node from the cell under the source IAB donor to the cell under the target IAB donor. In the switching or redirection scenario, the IAB donor connected to the RRC connection of the mobile IAB node is switched, and the IAB donor connected to the F1 connection may or may not be switched. If both the RRC connection and the F1 connection are switched, the IAB donors after the switch may or may not be the same.

[0114] In another implementation, embodiments of the present application can be applied to a dual-connectivity scenario, where a mobile IAB node is connected to two IAB donors, one serving as a primary node and the other as a secondary node. In this dual-connectivity scenario, if an IAB donor that does not support the first operating mode serves as the primary node and an IAB donor that supports the first operating mode is added as the secondary node, then after the mobile IAB node establishes an RRC connection and an F1 connection with the secondary node, the F1 connection between the mobile IAB node and the primary node can be disconnected.

[0115] The embodiments of the present application are not only applicable to the IAB system, but also to the access network system including the CU-DU separation architecture.

[0116] Please refer to FIG3 , which is a diagram illustrating an exemplary system architecture for applying an embodiment of the present application. The system architecture shown in FIG3 includes a first mobile relay node 301 , a first donor node 302 , and a core network device 303 .

[0117] Among them, the first mobile relay node 301 can be any relay node with mobility in the IAB network, and can move with a physical device (such as a vehicle-mounted device, etc.). The first mobile relay node 301 can provide access and backhaul services for the UE, but cannot serve other relay nodes as a parent node. In an embodiment of the present application, the first mobile relay node 301 has two identities, one is a mobile relay node identity, and the other is a relay node identity, and works with one of these identities. The working mode of the first mobile relay node 301 can be a first working mode, corresponding to a mobile relay node identity; or it can be a second working mode, corresponding to a relay node identity.

[0118] The first host node 302 is the host node to which the first mobile relay node 301 is currently connected. Currently refers to before switching or redirection, or before adding a secondary node. The first host node 302 can be an F1-terminating IAB donor, that is, a host node that establishes an F1 connection with the DU of the first mobile relay node 301; it can also be an RRC-terminating IAB donor, that is, a host node that establishes an RRC connection with the MT of the first mobile relay node 301. In an embodiment of the present application, the first host node 302 may support the first working mode, may support the second working mode, or may support the first working mode and the second working mode. For a certain host node, its support for the first working mode may mean that it only supports the first working mode, or it may mean that it supports the first working mode and the second working mode.

[0119] The core network device 303 can be used to perform authentication, mobility management, PDU session management, etc. for the UE, and may include, for example, functional entities or network elements such as the AMF and user plane function (UPF) in the 5G core network. In an embodiment of the present application, the core network device 303 serves the first mobile relay node 301. The core network device 303 can be the AMF in the 5G core network, or it can be a device that is the same as the AMF in a future communication system. The core network device 303 can be understood as an upgraded version of the AMF to support the first mobile relay node 301 to operate in the first working mode.

[0120] Optionally, there may be one or more intermediate nodes between the first mobile relay node 301 and the first host node 302, that is, a multi-hop backhaul scenario. FIG3 takes the case where the first mobile relay node 301 directly accesses the first host node 302 as an example.

[0121] The system architecture shown in Figure 3 can also be included in an O-RAN, cloud radio access network (CRAN), or wireless fidelity (WiFi) system. The system architecture shown in Figure 3 can also be a communication system that integrates two or more of the above systems.

[0122] The communication method provided in the embodiments of the present application is described in detail below in conjunction with the system architecture shown in Figure 3. For ease of description, the first mobile relay node is taken as mobile IAB node 1, the first host node is taken as IAB donor 1, the second host node is taken as IAB donor 2, and the core network device is taken as AMF, which provides services for mobile IAB node 1.

[0123] Please refer to FIG4 , which is a flowchart of a communication method provided in an embodiment of the present application. The method may include but is not limited to the following steps:

[0124] 401. IAB donor 1 determines IAB donor 2. IAB donor 2 supports a first working mode. The first working mode instructs mobile IAB node 1 to work as a mobile IAB node.

[0125] In other words, IAB donor 1 is determined by mobile IAB node 1 to support the first operating mode, so that mobile IAB node 1 can operate in the first operating mode. For example, IAB donor 2 is used as an example of an IAB donor determined by IAB donor 1. IAB donor 2 supports the first operating mode, either only the first operating mode or both the first and second operating modes.

[0126] In one implementation, when mobile IAB node 1 is connected to IAB donor 1 and mobile IAB node 1 is authorized for the second operating mode, IAB donor 1 determines IAB donor 2. Mobile IAB node 1 connects to IAB donor 1 through a network access process. The value of the IAB Authorized information element carried in the Initial Context Establishment Request message sent by the AMF to IAB donor 1 is "authorized," indicating that mobile IAB node 1 is authorized for the second operating mode. In this case, IAB donor 1 can determine IAB donor 2.

[0127] In another implementation, when IAB donor 1 receives the first indication information, the first indication information instructs IAB donor 1 to determine IAB donor 2, and in response to the first indication information, determines IAB donor 2. Optionally, the first indication information may come from mobile IAB node 1. For example, when mobile IAB node 1 intends to operate in the first operating mode, it sends the first indication information to IAB donor 1 to instruct IAB donor 1 to determine IAB donor 2. Mobile IAB node 1 intends to operate in the first operating mode, which may mean it intends to switch from the second operating mode to the first operating mode, or to switch to another IAB donor that supports the first operating mode, and may send the first indication information to IAB donor 1. Optionally, the first indication information may come from an AMF. The AMF may determine whether to select an IAB donor that supports the first operating mode for mobile IAB node 1, and if so, send the first indication information to IAB donor 1. For example, when the AMF determines that it wants mobile IAB node 1 to switch from the second operating mode to the first operating mode, or when the AMF determines that mobile IAB node 1 connected to IAB donor 1 is authorized for the second operating mode, it determines that an IAB donor that supports the first operating mode can be selected for mobile IAB node 1, and then sends first indication information to IAB donor 1 to instruct IAB donor 1 to determine IAB donor 2.

[0128] In another implementation, when mobile IAB node 1 is connected to IAB donor 1, mobile IAB node 1 is authorized to operate in the second operating mode, and receives first indication information, IAB donor 1 determines IAB donor 2. This embodiment of the present application does not limit the order in which the AMF authorizes mobile IAB node 1 to operate in the second operating mode and sends the first indication information; the two may be performed simultaneously. The first indication information may also be sent by mobile IAB node 1.

[0129] The above three implementations can be understood as the timing for IAB donor 1 to determine IAB donor 2. These three implementations are for example only and do not constitute a limitation on the embodiments of the present application.

[0130] IAB donor 1 can identify IAB donor 2 in one or more of the following ways:

[0131] In method 1, IAB donor 1 determines IAB donor 2 based on Xn interaction.

[0132] Based on Xn interaction, IAB donor 1 obtains the operating modes supported by neighboring cells and / or candidate IAB donors, which may be the first operating mode and / or the second operating mode. Based on the operating modes supported by neighboring cells and / or candidate IAB donors, IAB donor 1 determines IAB donor 2.

[0133] The neighboring cell refers to the neighboring cell of the serving cell of mobile IAB node 1, which is the cell under IAB donor 1. The candidate IAB donor refers to the neighboring IAB donor of IAB donor 1.

[0134] The operating modes supported by neighboring cells and / or candidate IAB donors can be included in Xn interaction information. For example, when IAB donor 1 establishes an Xn interface with IAB donor 2 or subsequently updates the Xn interface configuration, they can exchange information about the operating modes supported by each cell and / or their respective cells. Alternatively, IAB donor 1 can send an Xn request message to its neighboring IAB donor, requesting that it provide an Xn response message. The Xn response message can include the operating modes supported by the neighboring IAB donor and / or its cell. Method 1 assumes that IAB donor 1 supports the first operating mode. Thus, IAB donor 1 can read the indicated supported operating modes through Xn interaction information. If IAB donor 1 only supports the second operating mode and a candidate IAB donor supports the first operating mode, IAB donor 1 may be unable to read or decode the supported operating modes provided by the candidate IAB donor. Therefore, Method 1 assumes that IAB donor 1 supports the first operating mode.

[0135] In mode 2, IAB donor 1 determines IAB donor 2 based on the measurement report sent by mobile IAB node 1.

[0136] Mobile IAB node 1 sends a measurement report to IAB donor 1, and IAB donor 1 can determine IAB donor 2 based on the measurement report.

[0137] Optionally, the measurement report includes measurement reports of all neighboring cells of the serving cell. IAB donor 1 may select an IAB donor with better signal quality and supporting the first working mode as IAB donor 2 based on the measurement report and Xn interaction information.

[0138] Optionally, the measurement report includes a measurement report of a candidate neighboring cell, and the candidate neighboring cell supports the first working mode. The number of candidate neighboring cells is one or more. When mobile IAB node 1 measures a neighboring cell, it determines a candidate neighboring cell that supports the first working mode based on the broadcast information of the neighboring cell. For the broadcast information of a certain neighboring cell, for example, the SIB1 of the neighboring cell, if it broadcasts a mobileIAB-Support information element, it indicates that the neighboring cell supports the first working mode; if it broadcasts only an iab-Support information element, it indicates that the neighboring cell only supports the second working mode. Optionally, when mobile IAB node 1 measures a neighboring cell, it can also determine the gNB ID of the IAB donor to which the neighboring cell belongs, that is, the gNB ID of the candidate IAB donor, based on the cell identifier in the broadcast information of the neighboring cell, such as the new radio cell global identifier (NCGI) and the node identifier length, such as the gNB ID length. For the broadcast information of a neighboring cell, such as the SIB1 of the neighboring cell, which includes the NCGI and the gNB ID length, and broadcasts the mobileIAB-Support information element, then the neighboring cell supports the first operating mode, and mobile IAB node 1 can determine the gNB ID of the IAB donor to which the neighboring cell belongs based on the NCGI and the gNB ID length.

[0139] Mode 3: IAB donor 1 determines IAB donor 2 based on identification information of at least one candidate IAB donor.

[0140] IAB donor 1 receives identification information of at least one candidate IAB donor and determines IAB donor 2 based on the identification information of the at least one candidate IAB donor. For a candidate IAB donor, its identification information may include one or more of the following information: gNB ID, cell global identifier (CGI), physical cell identifier (PCI), NCGI, logical cell identifier, internet protocol (IP) address, etc.

[0141] Optionally, the identification information of the at least one candidate IAB donor comes from mobile IAB node 1. Mobile IAB node 1 determines at least one candidate IAB donor supporting the first working mode based on the broadcast information of the neighboring cell, and notifies IAB donor 1 of the identification information of the at least one candidate IAB donor.

[0142] Optionally, the identification information of the at least one candidate IAB donor comes from the AMF. Based on the NG interaction information, the AMF obtains the operating modes supported by the at least one IAB donor, determines at least one candidate IAB donor that supports the first operating mode based on the operating modes supported by the at least one IAB donor, and notifies IAB donor 1 of the identification information of the at least one candidate IAB donor.

[0143] The above-mentioned methods 1 to 3 are for example only and do not limit the embodiments of the present application. IAB donor 1 may also use other methods to determine IAB donor 2.

[0144] 402, IAB donor 1 sends a request message to IAB donor 2. Correspondingly, IAB donor 2 receives the request message from IAB donor 1.

[0145] In response to IAB donor 1 identifying IAB donor 2, IAB donor 1 sends a request message to IAB donor 2.

[0146] Optionally, the request message is used to request that mobile IAB node 1 be handed over or redirected to IAB donor 2. That is, in a handover or redirection scenario, IAB donor 1 identifies IAB donor 2 to hand over or redirect mobile IAB node 1 from IAB donor 1 to IAB donor 2, for example, to hand over the IAB donor to which mobile IAB node 1 is connected via RRC from IAB donor 1 to IAB donor 2. IAB donor 1 can be understood as a source IAB donor, and IAB donor 2 can be understood as a target IAB donor.

[0147] Optionally, the request message is used to request the addition of IAB donor 2 as a secondary node. That is, in a dual-connectivity scenario, IAB donor 1 determines to add IAB donor 2 as a secondary node to support the first operating mode of mobile IAB node 1. IAB donor 1 can be considered the primary node, and IAB donor 2 can be considered the secondary node.

[0148] In the embodiment shown in FIG4 , IAB donor 1 determines IAB donor 2 that supports the first working mode for mobile IAB node 1, so that mobile IAB node 1 can be switched or redirected from IAB donor 1 to IAB donor 2, or so that IAB donor 2 can support the first working mode of mobile IAB node 1 as a secondary node in a dual-connectivity scenario. This supports flexible deployment of mobile IAB node 1, helps improve performance utilization of mobile IAB node 1, and further helps improve communication performance of the IAB network.

[0149] Figure 4 illustrates the communication method provided by the embodiment of the present application from an overall perspective, without distinguishing different scenarios. The communication method provided by the embodiment of the present application will be described below in two scenarios.

[0150] Scenario 1: Switching scenes

[0151] Please refer to FIG5 , which is a flowchart of another communication method provided in an embodiment of the present application. The method may include but is not limited to the following steps:

[0152] 501, mobile IAB node 1 sends Msg5 message to IAB donor 1. Correspondingly, IAB donor 1 receives Msg5 message from mobile IAB node 1.

[0153] During the network access process, mobile IAB node 1 sends a Msg5 message to IAB donor 1. For example, during the network access process, the MT of mobile IAB node 1 sends a Msg5 message to IAB donor 1. The Msg5 message indicates the desired operating mode of mobile IAB node 1, thereby informing IAB donor 1.

[0154] The Msg5 message carries the iab-NodeIndication information element, indicating that the desired working mode of mobile IAB node 1 is the second working mode. The Msg5 message carries the mobileIAB-NodeIndication information element, indicating that the desired working mode of mobile IAB node 1 is the first working mode.

[0155] Optionally, when joining the network, mobile IAB node 1 can select an IAB donor 1 that supports the first operating mode based on the SIB1 broadcast by each IAB donor. In other words, mobile IAB node 1 can select an IAB donor 1 that supports the first operating mode, which helps improve the performance utilization of mobile IAB node 1 and allows IAB donor 1 to read Xn interaction information from other IAB donors that support the first operating mode.

[0156] 502. IAB donor 1 sends a first NGAP message to the AMF. Correspondingly, the AMF receives the first NGAP message from IAB donor 1.

[0157] In response to the received Msg5 message, IAB donor 1 sends a first NGAP message to the AMF. The first NGAP message may be, for example, a UE-initialized message, which may indicate the desired working mode of mobile IAB node 1.

[0158] Optionally, when the Msg5 message indicates that the desired working mode of mobile IAB node 1 is the first working mode or the second working mode, IAB donor 1 selects an AMF that supports the second working mode and carries the IAB Node Indication information element in the first NGAP message.

[0159] Optionally, when the Msg5 message indicates that the desired working mode of the mobile IAB node 1 is the first working mode, the IAB donor 1 selects an AMF that supports the first working mode and carries the Mobile IAB Node Indication information element in the first NGAP message.

[0160] In the embodiment of the present application, the IAB node 1 selects an AMF that supports the first working mode and the second working mode as an example.

[0161] 503: AMF authorizes mobile IAB node 1 to operate in the second working mode.

[0162] In this embodiment of the present application, the AMF authorizes the second working mode to mobile IAB node 1 when mobile IAB node 1 is connected to IAB donor 1 as an example.

[0163] 504. The AMF sends a second NGAP message to IAB donor 1. In response, IAB donor 1 receives the second NGAP message from the AMF.

[0164] The second NGAP message may be, for example, an initial context establishment request message, which carries an IAB Authorized information element, the value of which is "authorized", indicating that the mobile IAB node 1 is authorized to operate in the second working mode.

[0165] Optionally, the second NGAP message also includes first indication information, where the first indication information instructs IAB donor 1 to determine IAB donor 2. That is, the second NGAP message also instructs IAB donor 1 to select a target IAB donor that supports the first working mode when subsequently performing a handover or redirection process on mobile IAB node 1. Alternatively, the second NGAP message also includes identification information of at least one candidate IAB donor, where the at least one candidate IAB donor is an IAB donor that supports the first working mode determined by the AMF. The AMF can obtain the working modes supported by other IAB donors based on NG interactions, and then determine at least one candidate IAB donor that supports the first working mode. The AMF obtains the working modes supported by other IAB donors based on the NG interaction. This can be performed before the judgment step 503, for example, based on the NG interface establishment or update interaction process, and for example, the AMF sends an NG request message to the other IAB donor to obtain the working modes supported by the other IAB donors and / or the cells of the other IAB donors; it can also be performed after the judgment step 503, for example, after triggering the NG interface update interaction process to obtain the working modes supported by other IAB donors, and for example, the AMF sends an NG request message to the other IAB donor to request the other IAB donor to feedback an NG response message, and the NG response message may include the working modes supported by the other IAB donors and / or the cells of the other IAB donors.

[0166] 505, IAB donor 1 sends an RRC message to mobile IAB node 1. Correspondingly, mobile IAB node 1 receives the RRC message from IAB donor 1.

[0167] The RRC message may be, for example, an RRC reconfiguration message, which may indicate that mobile IAB node 1 is authorized to operate in the second working mode. That is, IAB donor 1 notifies mobile IAB node 1 through the RRC message that mobile IAB node 1 is authorized to operate in the second working mode.

[0168] Optionally, upon receiving the RRC message, mobile IAB node 1 may determine to switch its operating mode from the second operating mode to the first operating mode.

[0169] IAB donor 2 can be determined by IAB donor 1, mobile IAB node 1, or AMF. Methods for determining IAB donor 2 may include one or more of the following:

[0170] In method a, IAB donor 1 determines IAB donor 2 based on Xn interaction.

[0171] 506a, IAB donor 1 determines IAB donor 2 based on the working modes supported by neighboring cells and / or candidate IAB donors.

[0172] The implementation process of method a can be found in the detailed description of method 1 in the embodiment shown in FIG4 , which will not be repeated here. After step 506a, IAB donor 1 sends a request message to IAB donor 2, requesting that mobile IAB node 1 be switched or redirected to IAB donor 2.

[0173] Alternatively, when the number of candidate IAB donors is one, IAB donor 1 may use the candidate IAB donor as IAB donor 2.

[0174] In method b, IAB donor 1 determines IAB donor 2 based on the measurement report sent by mobile IAB node 1.

[0175] 506b, mobile IAB node 1 sends a measurement report to IAB donor 1. Correspondingly, IAB donor 1 receives the measurement report from mobile IAB node 1.

[0176] In 507b, IAB donor 1 determines IAB donor 2 based on the measurement report.

[0177] The implementation process of method b can be found in the detailed description of method 2 in the embodiment shown in FIG4 , which will not be repeated here. After step 507b, IAB donor 1 sends a request message to IAB donor 2, requesting that mobile IAB node 1 be switched or redirected to IAB donor 2.

[0178] Optionally, in 506b, mobile IAB node 1 sends identification information of at least one candidate IAB donor to IAB donor 1;

[0179] Optionally, in 507b, IAB donor 1 determines IAB donor 2 based on identification information of at least one candidate IAB donor.

[0180] When the number of candidate IAB donors is one, IAB donor 1 only needs to use the candidate IAB donor as IAB donor 2, and there is no need to perform a determination operation.

[0181] In mode c, the target IAB donor (assuming it is IAB donor 3) determined by IAB donor 1 does not support the first working mode. Upon receiving the NGAP message from IAB donor 3, the AMF determines at least one candidate IAB donor and informs IAB donor 3 of the identification information of the at least one candidate IAB donor so that IAB donor 3 can determine IAB donor 2.

[0182] In 506c, IAB donor 1 and IAB donor 3 perform a handover process.

[0183] IAB donor 3 is the target IAB donor determined by IAB donor 1. For example, IAB donor 1 determines the target IAB donor based on the neighboring cell measurement report reported by the MT of mobile IAB node 1. This target IAB donor may or may not support the first operating mode. Method c is used as an example of a target IAB donor that does not support the first operating mode. The neighboring cell measurement report includes measurement reports for all neighboring cells of the serving cell, not just measurement reports for candidate neighboring cells that support the first operating mode.

[0184] After determining IAB donor 3 as the target IAB donor, IAB donor 1 performs a handover procedure with IAB donor 3 to handover mobile IAB node 1 to IAB donor 3. After the handover, mobile IAB node 1 and IAB donor 3 may establish an RRC connection.

[0185] In step 507c, IAB donor 3 sends a third NGAP message to the AMF. In response, the AMF receives the third NGAP message from IAB donor 3.

[0186] The third NGAP message may be, for example, a Path Switch Request message, which is used to request an update of the tunnel information of the data plane between the core network and the AMF. In response to the third NGAP message, the AMF determines whether the IAB donor 3 supports the first working mode. If it is determined that the IAB donor 3 does not support the first working mode, the AMF may obtain the working modes supported by other IAB donors based on NG interaction, and then determine at least one candidate IAB donor that supports the first working mode based on the working modes supported by these IAB donors, and then execute steps 508c to 510c. If it is determined that the IAB donor 3 supports the first working mode, the AMF does not need to determine at least one candidate IAB donor, nor does it need to execute steps 508c to 510c. The embodiment of the present application does not limit the specific method by which the AMF determines whether a certain IAB donor supports the first working mode.

[0187] In step 508c, the AMF sends identification information of at least one candidate IAB donor to IAB donor 3. Correspondingly, IAB donor 3 receives identification information of at least one candidate IAB donor from the AMF.

[0188] The AMF sends identification information of at least one candidate IAB donor to the IAB donor 3, so that the IAB donor 3 can determine the IAB donor 2 from the at least one candidate IAB donor.

[0189] Optionally, the AMF sends a fourth NGAP message to the IAB donor 3. The fourth NGAP message may be, for example, a Path Switch Request Acknowledge message, which may carry identification information of at least one candidate IAB donor.

[0190] Optionally, in 509c, IAB donor 3 determines IAB donor 2 from at least one candidate IAB donor.

[0191] When the number of candidate IAB donors is one, the IAB donor 3 may simply use the candidate IAB donor as the IAB donor 2, and does not need to perform a determination operation.

[0192] In step 510c, IAB donor 3 sends a request message to IAB donor 2. In response, IAB donor 2 receives the request message from IAB donor 3. The request message is used to request that mobile IAB node 1 be switched from IAB donor 3 to IAB donor 2.

[0193] When the RRC connection established by mobile IAB node 1 is switched from IAB donor 1 to IAB donor 3, IAB donor 1 is the source IAB donor and IAB donor 3 is the target IAB donor. When the RRC connection established by mobile IAB node 1 is switched from IAB donor 3 to IAB donor 2, IAB donor 3 is the source IAB donor and IAB donor 2 is the target IAB donor. In step 508c, the AMF sends the identification information of at least one candidate IAB donor to IAB donor 3, which can be understood as the AMF sending the identification information of at least one candidate IAB donor to the source IAB donor.

[0194] Mode d: IAB donor 1 determines the target IAB donor (assuming it is IAB donor 4). When the AMF determines that IAB donor 4 does not support the first working mode, it determines IAB donor 2.

[0195] In step 506d, IAB donor 1 sends a first handover request message to the AMF. Accordingly, the AMF receives the first handover request message from IAB donor 1.

[0196] The first handover request (Handover Required) message carries identification information of IAB donor 4. The first handover request message is used to request handover of mobile IAB node 1 to IAB donor 4. IAB donor 4 is a target IAB donor determined by itself, for example, a target IAB donor determined by IAB donor 1 based on a neighboring cell measurement report reported by the MT of mobile IAB node 1. This target IAB donor may or may not support the first working mode. Mode d is used as an example in which the target IAB donor does not support the first working mode.

[0197] Optionally, the first handover request message further carries identification information of a first PDU session. IAB donor 1 establishes a resource PDU session for mobile IAB node 1, and this PDU session is the first PDU session. The identification information may include one or more of a session ID, a data radio bearer (DRB) ID, a quality of service (QoS) flow identifier, and the like.

[0198] The AMF receives the first handover request message and determines whether IAB donor 4 supports the first working mode. If it is determined that IAB donor 4 does not support the first working mode, the AMF can obtain the working modes supported by other IAB donors based on NG interaction. Based on the working modes supported by these IAB donors, the AMF determines that IAB donor 2 supports the first working mode, and then executes steps 507d and 508d. The AMF can obtain the working modes supported by other IAB donors based on NG interaction before or after determining that IAB donor 4 does not support the first working mode. For details, please refer to the description of the AMF obtaining the working modes supported by other IAB donors based on NG interaction in step 504, which will not be repeated here. If it is determined that IAB donor 4 supports the first working mode, there is no need to determine IAB donor 2, nor is there a need to execute steps 507d and 508d. This embodiment of the application does not limit the specific method by which the AMF determines whether a particular IAB donor supports the first working mode.

[0199] 507d, the AMF sends a second handover request message to IAB donor 2. Correspondingly, IAB donor 1 receives the second handover request message from the AMF.

[0200] The second handover request (Handover Request) may be an NGAP message. The second handover request message is used to request handover of the mobile IAB node 1 to the IAB donor 2.

[0201] Optionally, the second handover request message also includes identification information of the first PDU session, so that IAB donor 2 can inform the AMF of its air interface configuration and the admission status of the first PDU session. For example, IAB donor 2 may send its air interface configuration and the admission status of the first PDU session to the AMF via a Handover Request Acknowledge message.

[0202] 508d, the AMF sends a handover command message to IAB donor 1. Correspondingly, IAB donor 1 receives the handover command message from the AMF.

[0203] The handover command message may instruct the IAB donor 1 to hand over the MT of the mobile IAB node 1, for example, instructing the MT of the mobile IAB node 1 to establish an RRC connection with the IAB donor 2 and disconnect the RRC connection with the IAB donor 1.

[0204] In the above-mentioned methods b to d, the IAB donor 1 may support only the second working mode or the first working mode.

[0205] In mode e, the AMF determines that mobile IAB node 1 is authorized to operate in the first working mode, but IAB donor 1 does not support the first working mode. The AMF determines at least one candidate IAB donor and informs IAB donor 1 of the identification information of the at least one candidate IAB donor, so that IAB donor 1 can determine IAB donor 2.

[0206] Optionally, in 506e, mobile IAB node 1 sends fifth indication information to IAB donor 1, and IAB donor 1 sends third indication information to the AMF. Accordingly, IAB donor 1 receives the fifth indication information from mobile IAB node 1, and the AMF receives the third indication information from IAB donor 1. The third indication information and the fifth indication information indicate that mobile IAB node 1's desired operating mode is the first operating mode.

[0207] In one implementation, mobile IAB node 1 sends a Msg5 message to IAB donor 1, where the Msg5 message carries a mobileIAB-NodeIndication information element, i.e., the fifth indication information. In response to the Msg5 message, IAB donor 1 sends an NGAP message to the AMF, where the NGAP message carries a Mobile IAB Node Indication information element, i.e., the third indication information.

[0208] In another implementation, mobile IAB node 1 sends a Msg5 message to IAB donor 1. The Msg5 message carries a non-access stratum (NAS) message, and the NAS message carries a mobileIAB-NodeIndication information element, i.e., the fifth indication information. Upon receiving the Msg5 message, IAB donor 1 does not parse the NAS message, but instead carries it in an NGAP message. The NGAP message includes the NAS message, and the NAS message carries the mobileIAB-NodeIndication information element, which is referred to as the third indication information.

[0209] 507e: AMF determines to authorize mobile IAB node 1 to operate in the first mode.

[0210] The AMF determines that mobile IAB node 1 is authorized for the first operating mode by setting the value of the Mobile IAB Authorized information element for mobile IAB node 1 to "authorized." The AMF may also determine whether IAB donor 1 supports the first operating mode. If it is determined that IAB donor 1 does not support the first operating mode, the AMF may obtain the operating modes supported by other IAB donors based on NG interactions. Based on the operating modes supported by these IAB donors, the AMF may determine at least one candidate IAB donor that supports the first operating mode, and then execute steps 508e to 510e. The AMF may obtain the operating modes supported by other IAB donors based on NG interactions before or after determining that IAB donor 1 does not support the first operating mode. For details, refer to the description of the AMF obtaining the operating modes supported by other IAB donors based on NG interactions in step 504, which is not repeated here. If it is determined that IAB donor 1 supports the first operating mode, the AMF does not need to determine at least one candidate IAB donor and does not need to execute steps 508e to 510e.

[0211] In step 508e, the AMF sends identification information of at least one candidate IAB donor to IAB donor 1. Correspondingly, IAB donor 1 receives identification information of at least one candidate IAB donor from the AMF.

[0212] Optionally, the AMF sends an NGAP message to the IAB donor 1. The NGAP message may be, for example, a downlink NAS transport message, which may carry identification information of at least one candidate IAB donor.

[0213] Optionally, the NGAP message may further indicate that the mobile IAB node 1 is authorized to operate in the first working mode. For example, the NAS-PDU in the NGAP message may indicate that the mobile IAB node 1 is authorized to operate in the first working mode.

[0214] Optionally, in 509e, IAB donor 1 determines IAB donor 2 from at least one candidate IAB donor.

[0215] When the number of candidate IAB donors is one, IAB donor 1 only needs to use the candidate IAB donor as IAB donor 2, and there is no need to perform a determination operation.

[0216] After determining the IAB donor 2, the IAB donor 1 may send a request message to the IAB donor 2 to request that the mobile IAB node 1 be switched from the IAB donor 1 to the IAB donor 2.

[0217] In 510e, IAB donor 1 sends an RRC message to mobile IAB node 1. In response, mobile IAB node 1 receives the RRC message from IAB donor 1.

[0218] The RRC message may indicate that the mobile IAB node 1 is authorized to operate in the first working mode.

[0219] The above methods a to e are for illustrative purposes only and do not constitute a limitation on the embodiments of the present application.

[0220] In the embodiment shown in FIG5 , in a handover scenario, flexible deployment of the mobile IAB node 1 can be supported, which helps to improve the performance utilization of the mobile IAB node 1 and further helps to improve the communication performance of the IAB network.

[0221] The embodiment shown in FIG5 takes the handover scenario as an example. The redirection scenario is similar to the handover scenario and will not be described in detail here.

[0222] Scenario 2: Dual Connection Scenario

[0223] Please refer to Figure 6, which is a flowchart of another communication method provided by an embodiment of the present application. In a dual-connectivity scenario, IAB donor 1 serves as a master node (MN), IAB donor 2 serves as a secondary node (SN), and mobile IAB node 1 can specifically be the mobile operator (MT) of mobile IAB node 1. The method may include, but is not limited to, the following steps:

[0224] 601, mobile IAB node 1 sends a Msg5 message to the MN. Correspondingly, the MN receives the Msg5 message from mobile IAB node 1. The Msg5 message indicates the desired working mode of mobile IAB node 1.

[0225] 602. The MN sends a first NGAP message to the AMF. Correspondingly, the AMF receives the first NGAP message from the MN.

[0226] 603: AMF authorizes mobile IAB node 1 to operate in the second working mode.

[0227] 604. The AMF sends a second NGAP message to the MN. Correspondingly, the MN receives the second NGAP message from the AMF.

[0228] 605: The MN sends an RRC message to the mobile IAB node 1. Correspondingly, the mobile IAB node 1 receives the RRC message from the MN.

[0229] The implementation process of steps 601 to 605 can refer to the specific description of steps 501 to 505 in the embodiment shown in FIG5 , which will not be repeated here.

[0230] Optionally, upon receiving the RRC message, mobile IAB node 1 may determine to switch its operating mode from the second operating mode to the first operating mode.

[0231] Methods for determining the SN may include one or more of the following:

[0232] In method A, the AMF determines the candidate IAB donor and the MN determines the SN.

[0233] 606A: The AMF sends identification information of at least one candidate IAB donor to the MN. Correspondingly, the MN receives identification information of at least one candidate IAB donor from the AMF.

[0234] The AMF can obtain the working modes supported by other IAB donors based on the NG interaction, and then determine at least one candidate IAB donor that supports the first working mode based on the working modes supported by these IAB donors. The AMF can obtain the working modes supported by other IAB donors based on the NG interaction before determining that the MN does not support the first working mode, or after determining that the MN does not support the first working mode. Alternatively, the AMF can obtain the working modes supported by other IAB donors based on the NG interaction before determining step 603, or after determining step 603. For details, please refer to the description of the AMF obtaining the working modes supported by other IAB donors based on the NG interaction in step 504, which will not be repeated here.

[0235] Optionally, the AMF sends an NGAP message to the MN, where the NGAP message may carry identification information of at least one candidate IAB donor. The NGAP message may be the second NGAP message or another NGAP message independent of the second NGAP message.

[0236] Optionally, after determining to convert the working mode of mobile IAB node 1 from the second working mode to the first working mode, the AMF sends a UE Configuration Update message to the MN, where the message may carry identification information of at least one candidate IAB donor.

[0237] Optionally, in 607A, the MN determines a SN from at least one candidate IAB donor.

[0238] When the number of candidate IAB donors is one, the MN only needs to use the candidate IAB donor as the SN, and does not need to perform a determination operation.

[0239] In mode B, mobile IAB node 1 determines the candidate IAB donor, and MN determines the SN.

[0240] 606B, mobile IAB node 1 determines a candidate neighboring cell based on the broadcast information of the neighboring cell.

[0241] When measuring neighboring cells, mobile IAB node 1 determines candidate neighboring cells that support the first operating mode based on the neighboring cell's broadcast information. For a neighboring cell's broadcast information, such as the neighboring cell's SIB1, if the broadcast includes the mobileIAB-Support information element, it indicates that the neighboring cell supports the first operating mode. If the broadcast includes only the iab-Support information element, it indicates that the neighboring cell supports only the second operating mode.

[0242] Optionally, when measuring a neighboring cell, mobile IAB node 1 may also determine the gNB ID of the IAB donor to which the neighboring cell belongs, i.e., the gNB ID of the candidate IAB donor, based on the cell identifier, such as the NCGI, and the node identifier length, such as the gNB ID length, in the neighboring cell's broadcast information. If the broadcast information of a neighboring cell, such as the SIB1 of the neighboring cell, includes the NCGI and the gNB ID length, and broadcasts the mobileIAB-Support information element, then the neighboring cell supports the first operating mode, and mobile IAB node 1 can determine the gNB ID of the IAB donor to which the neighboring cell belongs based on the NCGI and the gNB ID length.

[0243] Step 606B may be performed when mobile IAB node 1 determines to switch its operating mode from the second operating mode to the first operating mode.

[0244] 607B, mobile IAB node 1 sends a measurement report to the MN. Correspondingly, the MN receives the measurement report from mobile IAB node 1.

[0245] The measurement report includes a measurement report of a candidate neighboring cell, and the candidate neighboring cell supports the first working mode.

[0246] Alternatively, the mobile IAB node 1 sends identification information of at least one candidate IAB donor to the MN.

[0247] 608B, the MN determines the SN based on the measurement report. Alternatively, the MN determines the SN based on the identification information of at least one candidate IAB donor.

[0248] The measurement report includes the candidate neighbor's cell ID and the measurement result. Based on the candidate neighbor's cell ID, the mobile node can determine the candidate neighbor's IAB donor and, consequently, the network subscriber. If there is only one candidate neighbor, the mobile node determines the IAB donor based on the neighbor's cell ID as the network subscriber.

[0249] Optionally, when the number of candidate IAB donors is one, the MN can use the candidate IAB donor as the SN without performing a determination action.

[0250] In mode C, MN determines SN based on Xn interaction.

[0251] 606C, the MN obtains the working modes supported by the neighboring cells and / or candidate IAB donors.

[0252] Based on Xn interaction, MN obtains the working mode supported by neighboring cells and / or candidate IAB donors.

[0253] 607C, the MN determines the SN based on the working modes supported by the neighboring cells and / or the candidate IAB donors.

[0254] The implementation process of step 606C and step 607C can refer to the specific description of method 1 in the embodiment shown in Figure 4, and will not be repeated here.

[0255] Optionally, the MN determines the SN based on the operating modes supported by the neighboring cell and / or candidate IAB donor and first indication information. The first indication information comes from mobile IAB node 1 and instructs the MN to determine the SN that supports the first operating mode. The first indication information may be carried in an RRC message. Alternatively, the first indication information comes from the AMF and may be carried in an NGAP message.

[0256] Optionally, the MN determines the SN based on the operating modes supported by the neighboring cells and / or candidate IAB donors and the neighboring cell measurement reports. The neighboring cell measurement reports include measurement reports of all neighboring cells of the serving cell, not just measurement reports of candidate neighboring cells supporting the first operating mode.

[0257] The above methods A to C are for illustrative purposes only and do not constitute a limitation on the embodiments of the present application.

[0258] After the SN is determined, step 609 and subsequent steps are executed.

[0259] 609, MN and SN execute the secondary node adding process.

[0260] The MN sends an SN Addition Request message to the SN. After receiving the SN Addition Request message, the SN sends an SN Addition Request Acknowledge message to the MN. The SN Addition Request Acknowledge message may include an RRC configuration message generated by the SN, which includes the SN's air interface configuration information.

[0261] 610. The MN and mobile IAB node 1 perform an RRC reconfiguration process.

[0262] The MN and mobile IAB node 1 perform an RRC reconfiguration procedure to enable mobile IAB node 1 to access the SN based on the SN's air interface configuration information. The MN may send the SN's air interface configuration information to mobile IAB node 1 via an RRC reconfiguration message. In response to the RRC reconfiguration message, mobile IAB node 1 returns an RRC reconfiguration complete message to the MN, which includes a response to the SN's RRC configuration.

[0263] 611. The MN sends a secondary node reconfiguration completion message to the SN. Correspondingly, the SN receives the secondary node reconfiguration completion message from the MN.

[0264] The SN Reconfiguration Complete message is used to notify the SN that the mobile IAB node 1 has successfully completed the reconfiguration process, including the response to the RRC configuration of the SN.

[0265] 612. Mobile IAB node 1 sends a working mode conversion request message to the AMF. Accordingly, the AMF receives the working mode conversion request message from mobile IAB node 1. The working mode conversion request message is used to request conversion to the first working mode.

[0266] If the MN supports the first operating mode, mobile IAB node 1 resends an RRC message or NAS message to the MN, which carries the mobile IAB-Node Indication information element. The MN then uses an NGAP message to indicate to the AMF that it is requesting to switch to the first operating mode. Alternatively, after the MN determines to add the SN, it indicates the Mobile IAB Node Indication information element to the AMF via an NGAP message. The NGAP message can be, for example, an uplink NAS transport message.

[0267] If the MN only supports the second working mode, mobile IAB node 1 can directly send an uplink NAS message to the AMF. The message carries the mobileIAB-NodeIndication information element, and the MN then sends the message to the AMF through an NGAP message.

[0268] 613. The AMF determines to authorize mobile IAB node 1 to operate in the first mode.

[0269] 614. The AMF sends the second indication information to the MN. Correspondingly, the MN receives the second indication information from the AMF.

[0270] The second indication information indicates that the mobile IAB node 1 is authorized to operate in the first working mode. The second indication information may be carried in an NGAP message.

[0271] At this time, the MN saves two authorization states of mobile IAB node 1, namely, authorized to the second working mode when joining the network, and authorized to the first working mode after adding the SN. Optionally, the second indication information further indicates deauthorization of the second working mode.

[0272] Optionally, the AMF may indicate to the SN that mobile IAB node 1 is authorized to operate in the first working mode.

[0273] 615, the MN sends the second indication information to the mobile IAB node 1. Correspondingly, the mobile IAB node 1 receives the second indication information from the MN.

[0274] When the MN receives the second indication information, it may send the second indication information to the mobile IAB node 1 through an RRC message.

[0275] 616. The MN migrates the traffic of the mobile IAB node 1 when it operates in the first operating mode from the MN to the SN.

[0276] Optionally, during this process, the MN sends fourth indication information to the SN, indicating that mobile IAB node 1 is authorized to operate in the first working mode. For example, the fourth indication information may be carried in an IAB Transport Migration Management Request message or an IAB Transport Migration Modification Request message.

[0277] 617, mobile IAB node 1 establishes an F1 connection with SN.

[0278] Optionally, mobile IAB node 1 sends an F1 Setup Request message to the SN to trigger establishment of an F1 connection.

[0279] Optionally, after establishing the F1 connection, the AMF may indicate to the SN that mobile IAB node 1 is authorized to operate in the first mode.

[0280] Optionally, in step 618 , mobile IAB node 1 releases the F1 connection with the MN.

[0281] Optionally, the mobile IAB node 1 sends a release connection request message to the MN to request the release of the F1 connection between the MN and the mobile IAB node 1. Optionally, the MN sends a release connection request message to the mobile IAB node 1 to request the release of the F1 connection between the MN and the mobile IAB node 1.

[0282] The mobile IAB node 1 may release the F1 connection with the MN after the mobile IAB node 1 establishes the F1 connection with the SN.

[0283] Optionally, mobile IAB node 1 releases the RRC connection with the MN.

[0284] In the embodiment shown in Figure 6 , flexible deployment of mobile IAB node 1 is supported in dual-connectivity scenarios, helping to improve the performance utilization of mobile IAB node 1 and, in turn, improving the communication performance of the IAB network. In the embodiment shown in Figure 6 , the IAB traffic migration management process enables transitions in the operating mode of mobile IAB node 1 without service interruption, thereby improving service continuity for UEs.

[0285] The present application provides a communication device that can be used to implement the functions of the above-mentioned mobile IAB node 1, IAB donor 1 or AMF. The communication device can be mobile IAB node 1, IAB donor 1 or AMF. The communication device includes a unit that corresponds one-to-one to the method / operation / step / action performed by mobile IAB node 1, IAB donor 1 or AMF in the above-mentioned method embodiment. The unit can be a hardware circuit, or software, or a combination of a hardware circuit and software. Please refer to Figure 7, which shows a structural diagram of a communication device 700 in an embodiment of the present application. The communication device 700 may include an interface unit 701 and a processing unit 702. Specifically, the processing unit 702 is used to process signaling and / or data, and the signaling and / or data may be data received by the interface unit 701, and the processed signaling and / or data may also be sent by the interface unit 701;

[0286] In one embodiment, when the communication device 700 is a mobile IAB node 1, wherein:

[0287] The interface unit 701 is configured to receive broadcast information from a neighboring cell, where the broadcast information indicates whether the neighboring cell supports a first operating mode, where the first operating mode indicates that mobile IAB node 1 operates as a mobile IAB node.

[0288] The processing unit 702 is configured to determine a candidate neighboring cell based on the broadcast information of the neighboring cell, where the candidate neighboring cell supports the first working mode;

[0289] Interface unit 701 is further configured to send a measurement report to IAB donor 1, where the measurement report is a measurement report of a candidate neighboring cell, and the measurement report is used by IAB donor 1 to determine IAB donor 2 that supports the first working mode; or, to send identification information of at least one candidate IAB donor to IAB donor 1, where at least one candidate IAB donor supports the first working mode, and the identification information of at least one candidate IAB donor is used by IAB donor 1 to determine IAB donor 2 that supports the first working mode; wherein a connection has been established between mobile IAB node 1 and IAB donor 1.

[0290] In this embodiment, for the specific implementation of the interface unit 701 and the processing unit 702, reference may be made to the specific implementation steps of the mobile IAB node 1 in FIG. 4 , FIG. 5 or FIG. 6 , which will not be repeated here.

[0291] In another embodiment, when the communication device shown in FIG. 7 is an IAB donor 1, wherein:

[0292] The processing unit 702 is configured to determine the IAB donor 2, where the IAB donor 2 supports a first operating mode, and the first operating mode instructs the mobile IAB node 1 to operate as a mobile IAB node.

[0293] The interface unit 701 is configured to send a request message to the IAB donor 2, where the request message is used to request that the mobile IAB node 1 be switched or redirected to the IAB donor 2, or the request message is used to request that the IAB donor 2 be added as a secondary node.

[0294] In this embodiment, the specific implementation of the interface unit 701 and the processing unit 702 can be found in the specific implementation steps of the IAB donor 1 in FIG. 4 , FIG. 5 or FIG. 6 , which will not be repeated here.

[0295] In yet another embodiment, when the communication device shown in FIG7 is an AMF, the AMF serves mobile IAB node 1, wherein:

[0296] The interface unit 701 is configured to obtain an operating mode supported by at least one IAB donor, where the operating mode is a first operating mode and / or a second operating mode, where the first operating mode indicates that the mobile IAB node 1 operates as a mobile IAB node, and the second operating mode indicates that the mobile IAB node 1 operates as an IAB node.

[0297] A processing unit 702 is configured to determine at least one candidate IAB donor based on the working mode supported by at least one IAB donor, wherein the at least one candidate IAB donor supports a first working mode;

[0298] The interface unit 701 is further configured to send identification information of at least one candidate IAB donor to the IAB donor 1. The mobile IAB node 1 has established a connection with the IAB donor 1. The identification information of the at least one IAB donor is used by the IAB donor 1 to determine the IAB donor 2. The IAB donor 2 supports the first working mode.

[0299] or,

[0300] The interface unit 701 is configured to receive a first handover request from the IAB donor 1, where the first handover request includes identification information of the IAB donor 4 and is used to request handover of the mobile IAB node 1 to the IAB donor 4.

[0301] a processing unit 702 configured to, in response to IAB donor 4 not supporting the first operating mode and / or in response to mobile IAB node 1 being authorized to operate in the second operating mode, determine IAB donor 2 based on an operating mode supported by at least one IAB donor, where the operating mode supported by the at least one IAB donor is the first operating mode and / or the second operating mode, where the first operating mode indicates that mobile IAB node 1 operates as a mobile IAB node, and the second operating mode indicates that mobile IAB node 1 operates as an IAB node;

[0302] The interface unit 701 is further configured to send a second switching request to the IAB donor 2 , where the second switching request is used to request that the mobile IAB node 1 be switched to the IAB donor 2 .

[0303] In this embodiment, for the specific implementation of the above-mentioned interface unit 701 and processing unit 702, please refer to the specific implementation steps of AMF in Figure 4, Figure 5 or Figure 6, which will not be repeated here.

[0304] FIG8 shows a communication device 800 provided in an embodiment of the present application, configured to implement the aforementioned functions of mobile IAB node 1, IAB donor 1, or AMF. The device can be a communication device or a device used in a communication device, such as mobile IAB node 1, IAB donor 1, or AMF. The device used in a communication device can be a system-on-chip (SoC) or chip within the communication device. The SoC can consist of a chip alone or include a chip and other discrete components.

[0305] The communication device 800 includes at least one processor 810, which is used to implement the processing functions of the device (such as mobile IAB node 1, IAB donor 1 or AMF) in the method provided in the embodiment of the present application. The communication device 800 may also include a communication interface 820, which is used to implement the transceiver operations of the device (such as mobile IAB node 1, IAB donor 1 or AMF) in the method provided in the embodiment of the present application. In the embodiment of the present application, the communication interface can be a transceiver, circuit, bus, module or other type of communication interface, which is used to communicate with other devices through a transmission medium. For example, the communication interface 820 is used for the device in the communication device 800 to communicate with other devices. The processor 810 uses the communication interface 820 to send and receive data, and is used to implement the method described in the above method embodiment.

[0306] The communication device 800 may also include at least one memory 830 for storing program instructions and / or data. The memory 830 is coupled to the processor 810. The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units, or modules, which may be electrical, mechanical, or other forms, and is used for information exchange between the devices, units, or modules. The processor 810 may operate in conjunction with the memory 830. The processor 810 may execute program instructions stored in the memory 830. At least one of the at least one memory may be included in the processor.

[0307] The specific connection medium between the communication interface 820, processor 810, and memory 830 is not limited in the embodiments of the present application. In Figure 8, the embodiment of the present application shows that the memory 830, processor 810, and communication interface 820 are connected via a bus. The bus is represented by a bold line in Figure 8. The connection method between other components is only for schematic illustration and is not limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one bold line is used in Figure 8, but this does not mean that there is only one bus or one type of bus.

[0308] When the communication device 800 is specifically a device for a device (e.g., mobile IAB node 1, IAB donor 1, or AMF), for example, when the communication device 800 is specifically a chip or a chip system, the communication interface 820 may output or receive a baseband signal. When the communication device 800 is specifically a device (e.g., mobile IAB node 1, IAB donor 1, or AMF), the communication interface 820 may output or receive a radio frequency signal. In the embodiment of the present application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array, or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0309] When the above-mentioned communication device 800 is a module applied to a base station, the base station module implements the functions of the base station in the above-mentioned method embodiment. The base station module receives information from other modules in the base station (such as a radio frequency module or an antenna), and the information is sent by the terminal to the base station; or, the base station module sends information to other modules in the base station (such as a radio frequency module or an antenna), and the information is sent by the base station to the terminal. The base station module here can be a baseband chip of a base station, or a CU, DU or other module, or a device under the O-RAN architecture, such as an open CU, open DU and other devices.

[0310] It should be noted that the communication interface 820 may be used to execute the functions of the interface unit 701 , and the processor 810 may be used to execute the functions of the processing unit 702 , which will not be described in detail here.

[0311] When the communication device is a chip applied to mobile IAB node 1, the chip implements the functions of mobile IAB node 1 in the above method embodiment, and the chip receives information from other devices; or the chip sends information to other devices.

[0312] When the communication device is a chip applied to the IAB donor 1, the chip implements the functions of the IAB donor 1 in the above method embodiment. The chip receives information from other devices; or the chip sends information to other devices.

[0313] When the communication device is a chip for AMF, the chip implements the AMF functions in the above method embodiments. The chip receives information from other devices (such as mobile IAB nodes or IAB donors); or the chip sends information to other devices.

[0314] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0315] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, compact discs (CD-ROMs), or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC. In addition, the ASIC can be located in an access network device or a terminal. Of course, the processor and storage medium can also exist as discrete components in a terminal or access network device.

[0316] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instruction is loaded and executed on a computer, the process or function described in the embodiment of the present application is executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer program or instruction can be stored in a computer-readable storage medium or transmitted via the computer-readable storage medium. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; it can also be an optical medium, such as a digital video disk (DVD); it can also be a semiconductor medium, such as a solid state drive (SSD).

[0317] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0318] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

[0319] An embodiment of the present application further provides a computer-readable storage medium having computer-executable instructions stored therein. When the computer-executable instructions are executed, the method performed by mobile IAB node 1, IAB donor 1, or AMF in the above method embodiment is implemented.

[0320] An embodiment of the present application further provides a computer program product, which includes a computer program. When the computer program is executed, the method performed by mobile IAB node 1, IAB donor 1 or AMF in the above method embodiment is implemented.

[0321] The embodiment of the present application further provides a communication system, which includes a mobile IAB node 1, an IAB donor 1, or an AMF, wherein each device is configured to execute the method executed by each device in the above method embodiment.

[0322] It should be noted that for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

[0323] The descriptions of the various embodiments provided in this application can refer to each other. The descriptions of each embodiment have their own focus. For parts not described in detail in a particular embodiment, please refer to the relevant descriptions of other embodiments. For the convenience and brevity of description, for example, the functions and execution steps of the various devices and equipment provided in the embodiments of this application can refer to the relevant descriptions of the method embodiments of this application. The various method embodiments and the various device embodiments can also refer to, be combined with, or quote each other.

[0324] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A communication method, characterized in that: The method is applied to a first host node, and includes: Determining a second host node, where the second host node supports a first operating mode; the first operating mode instructs the first mobile relay node to operate as a mobile relay node; A request message is sent to the second host node, where the request message is used to request that the first mobile relay node be switched or redirected to the second host node; or, the request message is used to request that the second host node be added as a secondary node.

2. The method according to claim 1, wherein When the first mobile relay node is connected to the first host node, the first mobile relay node is authorized to be in a second working mode, and the second working mode indicates that the first mobile relay node works as a relay node.

3. The method according to claim 1 or 2, wherein: The method further comprises: First indication information is received, where the first indication information instructs the first host node to determine the second host node.

4. The method according to claim 3, wherein The first indication information comes from a core network device or from the first mobile relay node, and the core network device serves the first mobile relay node.

5. The method according to any one of claims 1 to 4, characterized in that The determining of the second host node includes: Obtaining a working mode supported by a neighboring cell and / or a candidate host node, where the working mode is the first working mode and / or the second working mode, and the second working mode indicates that the first mobile relay node operates as a relay node; The second host node is determined based on the working mode supported by the neighboring cell and / or the candidate host node.

6. The method according to any one of claims 1 to 5, wherein: The determining of the second host node includes: receiving a measurement report from the first mobile relay node; Based on the measurement report, the second donor node is determined.

7. The method according to claim 6, wherein The measurement report is a measurement report of a candidate neighboring cell, and the candidate neighboring cell supports the first working mode.

8. The method according to any one of claims 1 to 5, wherein: The determining of the second host node includes: Receiving identification information of at least one candidate host node, where the at least one candidate host node supports the first working mode; The second host node is determined from the at least one candidate host node.

9. The method according to claim 8, wherein The identification information of the at least one candidate host node comes from a core network device or from the first mobile relay node, and the core network device serves the first mobile relay node.

10. The method according to any one of claims 1 to 9, wherein: The method further comprises: Second indication information is received from a core network device, where the second indication information indicates that the first mobile relay node is authorized to operate in the first working mode, and the core network device serves the first mobile relay node.

11. The method according to claim 10, wherein The second indication information further indicates deauthorization of a second working mode, where the second working mode indicates that the first mobile relay node operates as a relay node.

12. The method according to any one of claims 1 to 11, wherein: The method further comprises: Third indication information is sent to the core network device, where the third indication information indicates that the working mode expected by the first mobile relay node is the first working mode, and the core network device serves the first mobile relay node.

13. The method according to any one of claims 1 to 12, wherein: The method further comprises: Migrating traffic of the first mobile relay node when operating in the first operating mode from the first host node to the second host node.

14. The method according to any one of claims 1 to 13, wherein: The method further comprises: Send fourth indication information to the second host node, where the fourth indication information indicates that the first mobile relay node is authorized to be in the first working mode.

15. A communication method, characterized in that: The method is applied to a first mobile relay node, and includes: receiving broadcast information from a neighboring cell, where the broadcast information indicates whether the neighboring cell supports a first operating mode, where the first operating mode indicates that the first mobile relay node operates as a mobile relay node; Determine, based on the broadcast information of the neighboring cell, a candidate neighboring cell, where the candidate neighboring cell supports the first operating mode; Sending a measurement report to the first host node, where the measurement report is a measurement report of the candidate neighboring area, and the measurement report is used by the first host node to determine the second host node; or sending identification information of at least one candidate host node to the first host node, where the at least one candidate host node supports the first working mode; the identification information of the at least one candidate host node is used to determine the second host node by the first host node; The second host node supports the first working mode, and the first mobile relay node has established a connection with the first host node.

16. The method according to claim 15, wherein When the first mobile relay node is connected to the first host node, the first mobile relay node is authorized to be in a second working mode, and the second working mode indicates that the first mobile relay node works as a relay node.

17. The method according to claim 15 or 16, wherein: The sending the measurement report to the first donor node includes: In response to determining that the operating mode is the first operating mode, sending the measurement report to the first donor node; The sending the identification information of the at least one candidate host node to the first host node includes: In response to determining that the working mode is the first working mode, identification information of the at least one candidate host node is sent to the first host node.

18. The method according to any one of claims 15 to 17, wherein: The method comprises: Send fifth indication information, where the fifth indication information indicates that the working mode expected by the first mobile relay node is the first working mode.

19. The method according to any one of claims 15 to 18, wherein: The method comprises: Establish a radio resource control RRC connection and / or an F1 connection with the second donor node.

20. A communication method, characterized in that: The method is applied to a core network device, where the core network device serves a first mobile relay node. The method includes: Obtaining an operating mode supported by at least one donor node, where the operating mode is a first operating mode and / or a second operating mode, the first operating mode indicating that the first mobile relay node operates as a mobile relay node, and the second operating mode indicating that the first mobile relay node operates as a relay node; Determine at least one candidate host node based on the working mode supported by the at least one host node, wherein the at least one candidate host node supports the first working mode; The identification information of the at least one candidate host node is sent to the first host node, the first mobile relay node has established a connection with the first host node, and the identification information of the at least one candidate host node is used by the first host node to determine the second host node, and the second host node supports the first working mode.

21. The method according to claim 20, wherein The sending the identification information of the at least one candidate host node to the first host node includes: In response to determining that the working mode of the first mobile relay node is the first working mode, identification information of the at least one candidate host node is sent to the first host node.

22. The method according to claim 20 or 21, wherein: The method further comprises: Second indication information is sent to the first host node, where the second indication information indicates that the first mobile relay node is authorized to be in the first working mode.

23. The method according to claim 22, wherein The second indication information further indicates deauthorizing the second working mode.

24. The method according to any one of claims 20 to 23, wherein: The determining at least one candidate host node based on the working mode supported by the at least one host node includes: In response to the first host node not supporting the first working mode, determining the at least one candidate host node based on the working modes supported by the at least one host node; and / or, In response to the first mobile relay node being authorized for the second working mode, the at least one candidate donor node is determined based on the working mode supported by the at least one donor node.

25. The method of claim 24, wherein: The method further comprises: Receive third indication information from the first host node, where the third indication information indicates that the desired working mode of the first mobile relay node is the first working mode.

26. A communication device, characterized in that: Comprising a module for performing the method of any one of claims 1 to 15, or a module for performing the method of any one of claims 16 to 19, or a module for performing the method of any one of claims 20 to 25.

27. A communication device, characterized in that: The method comprises a processor configured to implement the method according to any one of claims 1 to 15, the method according to any one of claims 16 to 19, or the method according to any one of claims 20 to 25 through logic circuits and / or by executing computer programs or instructions.

28. The communication device according to claim 27, wherein: Also includes: A memory is used to store the computer program or instructions.

29. A communication device, characterized in that: The method comprises a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor is used to implement the method according to any one of claims 1 to 15, or implement the method according to any one of claims 16 to 19, or implement the method according to any one of claims 20 to 25 through a logic circuit or executing code instructions.

30. A computer-readable storage medium, characterized in that The storage medium stores a computer program or instruction. When the computer program or instruction is executed by the communication device, it implements the method according to any one of claims 1 to 15, or implements the method according to any one of claims 16 to 19, or implements the method according to any one of claims 20 to 25.

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