A handover method of a node and related device

Abstract

Embodiments of the present application provide a node switching method and related equipment, a source donor node sends a switching request message to a target donor node, the switching request message comprising context information of an IAB node and context information of at least one terminal device, the source donor node receives a switching response message sent by the target donor node, the switching response message comprising an identifier of an accepted terminal device among the at least one terminal device and / or an identifier of a rejected terminal device among the at least one terminal device. In this way, among the terminal devices connected to the IAB node, the terminal devices accepted by the target donor node can switch to the target donor node, so that the IAB node and the accepted terminal devices switch to the target donor node together, ensuring normal transmission of data of the accepted terminal devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication, and in particular to a node switching method and related equipment. BACKGROUND

[0002] The protocol standard of the fifth generation cellular mobile communication system formulated by the third generation partnership project (3GPP) standard organization supports larger transmission bandwidth, more transceiver antenna arrays, higher transmission rate and more flexible and smaller granularity scheduling mechanism compared with the long term evolution (LTE) system. The above characteristics of the NR system provide more application range.

[0003] In the existing NR system, in the integrated access and backhaul (IAB) scenario, a terminal device and an IAB donor node perform data interaction. There is at least one IAB node between the terminal device and the IAB donor node, and the terminal device establishes a communication connection with the IAB donor node through the at least one IAB node, wherein the IAB node further includes an IAB-distributed unit (IAB-DU) and an IAB-mobile terminal (IAB-MT).

[0004] When the IAB node switches the IAB donor node, the existing switching technology can realize that the IAB-MT in the IAB node switches from a source donor node to a target donor node, and does not involve the processing of the IAB-DU in the IAB node and the child nodes (for example: terminal devices or other IAB nodes) of the IAB node, so that the child nodes of the IAB node will not work normally after the IAB node switches. SUMMARY

[0005] The present application provides a node switching method and related equipment. The source donor node triggers the IAB node and its child nodes (for example: other IAB nodes or terminals) to switch to the target donor node together, so as to ensure the normal transmission of the data of the terminal device after the IAB node switches.

[0006] A first aspect of the present application provides a node switching method, in which: a source host node sends a switching request message to a target host node, the switching request message including context information of an integrated access backhaul IAB node and context information of at least one terminal device, the switching request message being used to request that the IAB node and at least one terminal device be switched to the target host node, wherein the terminal device is directly connected to the IAB node, or the terminal device is connected to the IAB node through at least one other IAB node; the source host node receives a switching response message sent by the target host node, the switching response message including an identifier of an accepted terminal device among the at least one terminal device, and / or an identifier of a rejected terminal device among the at least one terminal device.

[0007] In this application, the terminal devices connected to the IAB node and accepted by the target host node are switched to the target host node, so that the IAB node and the accepted terminal devices are switched to the target host node together, ensuring normal transmission of data of the accepted terminal devices.

[0008] In a possible implementation of the first aspect, if the terminal device is directly connected to the IAB node, the method further includes: the source host node receives a measurement result sent by the IAB node, the measurement result including a result of the IAB node measuring the signal quality of the serving cell and a result of the IAB node measuring the signal quality of the neighboring cell; the source host node determines to switch the IAB node and at least one terminal device to the target host node based on the measurement result.

[0009] In this possible implementation, if the source host node confirms that the signal quality of the service cell is better than that of the neighboring cell, the source host node does not need to send a switching request message to the target host node. If the IAB node is not working in carrier aggregation (CA) mode, there is a service cell. If the signal quality of a neighboring cell is higher than the signal quality of the service cell, the source host node determines to switch the IAB node and at least one terminal device to the target host node based on the measurement result. If the IAB node works in CA mode, the service cell includes a main cell and at least one secondary cell. If the signal quality of a neighboring cell is higher than the signal quality of the main cell, the source host node determines to switch the IAB node and at least one terminal device to the target host node based on the measurement result. This possible implementation ensures that the IAB node and at least one terminal device are switched again when the signal quality of the neighboring cell is better than the signal quality of the current cell, thereby improving the communication quality of the IAB node and at least one terminal device.

[0010] In a possible implementation of the first aspect, if the terminal device is connected to the IAB node through at least one other IAB node, the handover request message also includes context information of the other IAB node, and the handover response message also includes an identifier of the accepted other IAB node among the at least one other IAB node, and / or an identifier of the rejected other IAB node among the at least one other IAB node.

[0011] In this possible implementation, the handover response message received by the source host node includes the identifier of at least one other IAB node that is accepted among the other IAB nodes, and / or the identifier of at least one other IAB node that is rejected among the other IAB nodes. This implementation enables the target host node to select other IAB nodes to accept based on its own network load and other conditions, which is conducive to fully utilizing the resources of the target host node and avoiding handover failures caused by insufficient resources of the target host node.

[0012] In a possible implementation of the first aspect, the method further includes:

[0013] The source host node receives the measurement results sent by the IAB node, the measurement results including the result of the IAB node measuring the signal quality of the serving cell and the result of the IAB node measuring the signal quality of the neighboring cell; the source host node determines, based on the measurement results, to switch the IAB node, at least one other IAB node, and at least one terminal device to the target host node.

[0014] In this possible implementation, if the source host node confirms that the signal quality of the serving cell is better than that of the neighboring cell, the source host node does not need to send a handover request message to the target host node. If the IAB node is not operating in CA mode, there is a serving cell. If the signal quality of a neighboring cell is higher than the signal quality of the serving cell, the source host node can determine to hand over the IAB node, at least one other IAB node, and at least one terminal device to the target host node based on the measurement result. If the IAB node is operating in CA mode, the serving cell includes a primary cell and at least one secondary cell. If the signal quality of a neighboring cell is higher than the signal quality of the primary cell, the source host node can determine to hand over the IAB node, at least one other IAB node, and at least one terminal device to the target host node based on the measurement result. This possible implementation ensures that the IAB node, at least one other IAB node, and at least one terminal device are handed over only when the signal quality of the neighboring cell is better than the signal quality of the current cell, thereby improving the communication quality of the IAB node, at least one other IAB node, and at least one terminal device.

[0015] In a possible implementation manner of the first aspect, the IAB node comprises an integrated access backhaul mobile terminal (IAB-MT) and an integrated access backhaul distributed unit (IAB-DU), and the context information of the IAB node comprises context information of the IAB-MT and context information of the IAB-DU; the context information of the IAB-MT comprises configuration information of a backhaul radio link control channel (BH RLC CH) between the IAB-MT and a parent node of the IAB node; and the context information of the IAB-DU comprises an identifier of the IAB-DU and / or a cell identifier of the IAB-DU.

[0016] In the possible implementation manner, the source donor node delivers the context information of the IAB node to the target donor node, so that the target donor node prepares switching resources for the IAB node according to the context information, and the possible implementation manner improves the success rate of switching the IAB node to the target donor node.

[0017] In a possible implementation manner of the first aspect, the context information of the IAB-DU further comprises activation indication information of a cell of the IAB-DU, and the activation indication information is used to indicate whether the cell of the IAB-DU has been activated, and the possible implementation manner ensures that the cell that has been activated can still maintain normal communication after the IAB node is switched to the target donor node.

[0018] In the possible implementation manner, the target donor node knows which cells of the IAB-DU have been activated by the source donor node, and these cells still need to be activated by the target donor node after the IAB node is switched to the target donor node. The possible implementation manner ensures that the cell that has been activated can still maintain normal communication after the IAB node is switched to the target donor node.

[0019] In a possible implementation manner of the first aspect, the context information of the IAB node further comprises a backhaul adaptation protocol (BAP) address allocated by the source donor node for the IAB node.

[0020] In the possible implementation manner, the target donor node knows the BAP address allocated by the source donor node for the IAB node, so that the BAP address newly allocated by the target donor node for the IAB node is different from the BAP address allocated by the source donor node for the IAB node.

[0021] In a possible implementation of the first aspect, the context information of the terminal device includes an identifier of the terminal device, and the identifier of the terminal device includes a physical cell identifier (PCI) of a cell accessed by the terminal device and a cell-radio network temporary identifier (C-RNTI) of the terminal device in the accessed cell.

[0022] In this possible implementation, since the PCI of the IAB-DU cell remains unchanged before and after the IAB node switching, the target host node identifies the terminal device according to the terminal device's identifier. This possible implementation improves the accuracy of the target host node in identifying the terminal device.

[0023] In a possible implementation manner of the first aspect, the context information of the IAB node further includes identifiers of child nodes of the IAB node, which are used to indicate a topological relationship between the IAB node and the child nodes of the IAB node.

[0024] In this possible implementation, the target host node can learn the topological relationship between the nodes to be switched to.

[0025] In a possible implementation of the first aspect, the context information of the IAB node further includes network topology list information. If the terminal device is directly connected to the IAB node, the network topology list information indicates a topological relationship between the IAB node and the terminal device; if the terminal device is connected to the IAB node through at least one other IAB node, the network topology list information indicates a topological relationship between the IAB node and the other IAB nodes, and between the other IAB nodes and the terminal device.

[0026] In this possible implementation, the target host node learns the topological relationship between the nodes to be switched to.

[0027] In a possible implementation manner of the first aspect, the other IAB nodes include other IAB-MTs and other IAB-DUs, and the context information of the other IAB nodes includes context information of the other IAB-MTs and context information of the other IAB-DUs; the context information of the other IAB-MTs includes configuration information of a BH RLC CH between the other IAB-MTs and parent nodes of the other IAB nodes; and the context information of the other IAB-DUs includes identifiers of the other IAB-DUs and / or cell identifiers of the other IAB-DUs.

[0028] In this possible implementation, the source host node transmits the context information of other IAB nodes to the target host node, so that the target host node prepares to switch resources for other IAB nodes based on the context information. This possible implementation improves the success rate of other IAB nodes following the IAB node to switch to the target host node.

[0029] In a possible implementation manner of the first aspect, the context information of the other IAB-DU further includes activation indication information of the cell of the other IAB-DU, where the activation indication information of the cell of the other IAB-DU is used to indicate whether the cell of the other IAB-DU has been activated.

[0030] In this possible implementation, the target host node learns which cells of other IAB-DUs have been activated by the source host node, and these cells still need to be activated by the target host node after the other IAB nodes switch to the target host node. This possible implementation ensures that the cells that have been activated after the other IAB nodes switch to the target host node can still maintain normal communication.

[0031] In a possible implementation manner of the first aspect, the context information of the other IAB node further includes a BAP address allocated by the source host node to the other IAB node.

[0032] In this possible implementation, the target host node learns the BAP addresses allocated by the source host node to other IAB nodes, so that the BAP addresses newly allocated by the target host node to other IAB nodes are different from the BAP addresses allocated by the source host node to other IAB nodes.

[0033] In a possible implementation of the first aspect, the context information of the other IAB node further includes an identifier of a parent node of the other IAB node and / or an identifier of a child node of the other IAB node, which is used to indicate a topological relationship between the other IAB node and the parent node of the other IAB node and / or between the other IAB node and the child node of the other IAB node.

[0034] In this possible implementation, the target host node can learn the topological relationship between the nodes to be switched to.

[0035] In a possible implementation of the first aspect, the source host node includes a source Donor-CU, the target host node includes a target Donor-CU, and the method further includes: the source Donor-CU obtains a first radio resource control RRC message generated by the target Donor-CU from the switching response message, the first RRC message includes the cell configuration information after the first IAB node switches to the target host node, the first IAB node includes the IAB node and other IAB nodes accepted among other IAB nodes; the source Donor-CU sends the first RRC message to the first IAB node.

[0036] The transmission method of the cell configuration information provided by this possible implementation has little impact on existing standards, thereby improving the feasibility of the solution.

[0037] In a possible implementation of the first aspect, the source host node includes a source Donor-CU, the target host node includes a target Donor-CU, and the method further includes: the source Donor-CU obtains a first F1 application layer protocol (F1 application protocol, F1AP) message generated by the target Donor-CU from the switching response message, the first F1AP message including the cell configuration information after the first IAB node switches to the target host node, the first IAB node including the IAB node and other IAB nodes accepted; the source Donor-CU encapsulates the first F1AP message in a second F1AP message and sends it to the first IAB node.

[0038] The cell configuration information transmission method provided by this possible implementation is to transmit the updated cell configuration information through the existing F1AP message between the source Donor-CU and the first IAB node, which makes little change to the standard protocol process and improves the feasibility of the solution.

[0039] In a possible implementation of the first aspect, the source host node includes a source Donor-CU, the target host node includes a target Donor-CU, and the method further includes: the source Donor-CU obtains, from the switching response message, the cell configuration information of the first IAB node after switching to the target host node, the first IAB node including the IAB node and other IAB nodes that are accepted; the source Donor-CU encapsulates the cell configuration information in an F1AP message and sends it to the first IAB node.

[0040] The cell configuration information transmission method provided by this possible implementation is to transmit the updated cell configuration information through the existing F1AP message between the source Donor-CU and the first IAB node, which makes little change to the standard protocol process and improves the feasibility of the solution.

[0041] A second aspect of the present application provides a node switching method, which includes: a target host node receives a switching request message sent by a source host node, the switching request message including context information of an integrated access backhaul IAB node and context information of at least one terminal device, the switching request message being used to request that the IAB node and at least one terminal device be switched to the target host node, wherein the terminal device is directly connected to the IAB node, or the terminal device is connected to the IAB node through at least one other IAB node; the target host node sends a switching response message to the source host node, the switching response message including an identifier of an accepted terminal device among the at least one terminal device, and / or an identifier of a rejected terminal device among the at least one terminal device.

[0042] In a possible implementation of the second aspect, the target host node includes a target Donor-CU, and the method further includes: the target Donor-CU sends a context establishment request message to the first IAB node, the context establishment request message carries the identifier of the terminal device, the identifier of the terminal device includes the cell identifier of the terminal device accessing the first IAB node and the identifier C-RNTI of the terminal device in the access cell; if the terminal device is directly connected to the IAB node, the first IAB node is the IAB node; if the terminal device is connected to the IAB node through at least one other IAB node, the first IAB node is the at least one other IAB node.

[0043] In this possible implementation, the IAB host node (donor-CU) sends a terminal device context establishment request message to the parent node of the IAB node (the IAB-DU part of the parent node), so that the parent node of the IAB node allocates air interface resources to the IAB node, establishes a BH RLC CH between the IAB node and its parent node, and establishes a corresponding GTP tunnel between the parent node of the IAB node and the IAB host node to transmit the return data of the IAB node.

[0044] In a possible implementation of the second aspect, the IAB node includes an access and backhaul integrated mobile terminal IAB-MT and an access and backhaul integrated distributed unit IAB-DU, and the context information of the IAB node includes context information of the IAB-MT and context information of the IAB-DU; the context information of the IAB-MT includes configuration information of a backhaul radio link control channel BH RLC CH between the IAB-MT and a parent node of the IAB node; the context information of the IAB-DU includes an IAB-DU identifier and / or an IAB-DU cell identifier.

[0045] In this possible implementation, the source host node transmits the context information of other IAB nodes to the target host node, so that the target host node prepares to switch resources for other IAB nodes based on the context information. This possible implementation improves the success rate of other IAB nodes following the IAB node to switch to the target host node.

[0046] In a possible implementation manner of the second aspect, the context information of the IAB-DU further includes activation indication information of a cell of the IAB-DU, where the activation indication information is used to indicate whether the cell of the IAB-DU has been activated.

[0047] In this possible implementation, the target donor node learns which cells of the IAB-DU have been activated by the source donor node. These cells must still be activated by the target donor node after the IAB node switches to the target donor node. This possible implementation ensures that cells that have been activated after other IAB nodes switch to the target donor node can still maintain normal communication.

[0048] In a possible implementation manner of the second aspect, the context information of the IAB node further includes a Backhaul Adaptation Protocol (BAP) address allocated by the source host node to the IAB node.

[0049] In this possible implementation, the target host node learns the BAP address allocated by the source host node to the IAB node, so that the BAP address newly allocated by the target host node to other IAB nodes is different from the BAP address allocated by the source host node to other IAB nodes.

[0050] In a possible implementation of the second aspect, the context information of the terminal device includes an identifier of the terminal device, and the identifier of the terminal device includes a physical cell identifier PCI of a cell accessed by the terminal device and an identifier C-RNTI of the terminal device in the accessed cell.

[0051] In this possible implementation, since the PCI of the IAB-DU cell remains unchanged before and after the IAB node switching, the target host node identifies the terminal device according to the terminal device's identifier. This possible implementation improves the accuracy of the target host node in identifying the terminal device.

[0052] In a possible implementation manner of the second aspect, the context information of the IAB node further includes an identifier of a child node of the IAB node, which is used to indicate a topological relationship between the IAB node and the child node of the IAB node.

[0053] In this possible implementation, the target host node is able to learn the topological relationship between the nodes to be switched to. In a possible implementation of the second aspect, the context information of the IAB node also includes network topology list information; if the terminal device is directly connected to the IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the terminal device; if the terminal device is connected to the IAB node through at least one other IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the other IAB nodes, and between the other IAB nodes and the terminal device.

[0054] In this possible implementation, the target host node learns the topological relationship between the nodes to be switched to.

[0055] In a possible implementation manner of the second aspect, if the other IAB nodes include other IAB-MTs and other IAB-DUs, the context information of the other IAB nodes includes the context information of the other IAB-MTs and the context information of the other IAB-DUs; the context information of the other IAB-MTs includes the configuration information of the BH RLC CH between the other IAB-MTs and the parent nodes of the other IAB nodes; the context information of the other IAB-DUs includes the identifiers of the other IAB-DUs and / or the cell identifiers of the other IAB-DUs.

[0056] In this possible implementation, the source host node transmits the context information of other IAB nodes to the target host node, so that the target host node prepares to switch resources for other IAB nodes based on the context information. This possible implementation improves the success rate of other IAB nodes following the IAB node to switch to the target host node.

[0057] In a possible implementation manner of the second aspect, the context information of the other IAB-DU further includes activation indication information of a cell of the other IAB-DU, and the activation indication information of the cell of the other IAB-DU is used to indicate whether the cell of the other IAB-DU has been activated.

[0058] In the possible implementation manner, the target donor node knows which cells of the other IAB-DU have been activated by the source donor node, and the cells still need to be activated by the target donor node after the other IAB node switches to the target donor node. The possible implementation manner ensures that the activated cells can still maintain normal communication after the other IAB node switches to the target donor node.

[0059] In a possible implementation manner of the second aspect, the context information of the other IAB node further includes a BAP address allocated by the source donor node for the other IAB node.

[0060] In the possible implementation manner, the target donor node knows the BAP address allocated by the source donor node for the other IAB node, so that the BAP address newly allocated by the target donor node for the other IAB node is different from the BAP address allocated by the source donor node for the other IAB node.

[0061] In a possible implementation manner of the second aspect, the context information of the other IAB node further includes an identifier of a parent node of the other IAB node and / or an identifier of a child node of the other IAB node, and is used to indicate a topological relationship between the other IAB node and the parent node of the other IAB node and / or between the other IAB node and the child node of the other IAB node.

[0062] In the possible implementation manner, the target donor node can know the topological relationship between the IAB node to be switched and the other IAB node.

[0063] In a possible implementation manner of the second aspect, the target donor node includes a target Donor-CU, and the target donor node sends the switching response message to the source donor node, including that the target Donor-CU sends the switching response message to the source donor node, and the switching response message includes a first RRC message, and the first RRC message includes cell configuration information of the first IAB node after the first IAB node switches to the target donor node, and the first IAB node includes the IAB node and the accepted other IAB node of the other IAB nodes.

[0064] The transmission manner of the cell configuration information provided in the possible implementation manner has little influence on the existing standard, and improves the realizability of the scheme.

[0065] In a possible implementation manner of the second aspect, the target host node comprises a target Donor-CU; and the target host node sends the handover response message to the source host node, comprising: the target Donor-CU sends the handover response message to the source host node, and the handover response message comprises cell configuration information of the first IAB node after switching to the target host node, the first IAB node comprising the IAB node or the accepted other IAB node.

[0066] The transmission manner of the cell configuration information provided in the possible implementation manner is to transmit the updated cell configuration information through the existing F1AP message between the source Donor-CU and the first IAB node, and the standard protocol flow is less changed, and the realizability of the scheme is improved.

[0067] In a possible implementation manner of the second aspect, the target host node comprises a target Donor-CU; and the target host node sends the handover response message to the source host node, comprising: the target Donor-CU sends the handover response message to the source host node, and the handover response message comprises cell configuration information of the first IAB node after switching to the target host node, the first IAB node comprising the IAB node or the accepted other IAB node.

[0068] The transmission manner of the cell configuration information provided in the possible implementation manner is to transmit the updated cell configuration information through the existing F1AP message between the source Donor-CU and the first IAB node, and the standard protocol flow is less changed, and the realizability of the scheme is improved.

[0069] In a possible implementation manner of the second aspect, the target host node comprises a target Donor-CU, and the method further comprises: the target donor-CU sends first indication information to the other IAB node, the first indication information being used to indicate that the IAB node switching is completed.

[0070] In the possible implementation manner, the target donor-CU sends the first indication information to the other IAB node, and the other IAB node can perceive that the IAB node switching is completed through the first indication information, that is, the other IAB node can perceive that the link between the IAB node and the target host node is opened, so the IAB-DU of the other IAB node can determine the time of triggering the application layer processing.

[0071] In a possible implementation of the second aspect, before the target donor-CU sends the first indication information to the other IAB node, the method further includes: the target donor-CU sends second indication information to the other IAB node, where the second indication information is used to indicate that the IAB node is switching or preparing to switch.

[0072] In this possible implementation, the target donor-CU sends a second indication message to other IAB nodes. Other IAB nodes can perceive through the second indication message that the IAB node is switching or preparing to switch, that is, other IAB nodes can perceive that the link between the IAB node and the target host node is not connected, so the IAB-DUs of other IAB nodes can decide not to trigger application layer processing through the second indication message.

[0073] A third aspect of the present application provides a node switching method, wherein: an IAB node switches from a source host node to a target host node; the IAB node sends first indication information to a child node of the IAB node, the first indication information being used to indicate that the IAB node switching is complete. The child node of the IAB node is a terminal device or another IAB node.

[0074] In this application, the IAB node sends a first indication message to other IAB nodes, and other IAB nodes can perceive the completion of the IAB node switching through the first indication message, that is, other IAB nodes can perceive that the link between the IAB node and the target host node is opened, so the IAB-DU of other IAB nodes can determine the time to trigger the application layer processing.

[0075] In a possible implementation of the third aspect, before the IAB node sends the first indication information to its child node, the method further includes: the IAB node sending second indication information to its child node, where the second indication information is used to indicate that the IAB node is switching or preparing to switch.

[0076] In this possible implementation, the IAB node sends second indication information to other IAB nodes. Other IAB nodes can perceive through the second indication information that the IAB node is switching or preparing to switch, that is, other IAB nodes can perceive that the link between the IAB node and the target host node is not connected, so the IAB-DU of other IAB nodes can decide not to trigger application layer processing through the second indication information.

[0077] A fourth aspect of the present application provides an IAB host node, the IAB host node including at least a sending unit, a receiving unit, and a processing unit;

[0078] a sending unit, configured to execute a sending action of the source host node in the node switching method provided in the aforementioned first aspect or any possible implementation manner of the first aspect;

[0079] a receiving unit, configured to perform a receiving action of the source host node in the node switching method provided in the aforementioned first aspect or any possible implementation manner of the first aspect;

[0080] A processing unit is configured to execute a processing action of a source host node in the node switching method provided in the aforementioned first aspect or any possible implementation manner of the first aspect.

[0081] A fifth aspect of the present application provides an IAB host node, the IAB host node including at least a sending unit, a receiving unit, and a processing unit;

[0082] A sending unit, configured to execute a sending action of a target host node in the node switching method provided in the aforementioned second aspect or any possible implementation manner of the second aspect;

[0083] A receiving unit, configured to perform a receiving action of a target host node in the node switching method provided in the aforementioned second aspect or any possible implementation manner of the second aspect;

[0084] A processing unit is configured to execute a processing action of a target host node in the node switching method provided in the aforementioned second aspect or any possible implementation of the second aspect.

[0085] A sixth aspect of the present application provides an IAB node, the IAB node including at least a sending unit, a receiving unit, and a processing unit;

[0086] a sending unit, configured to execute a sending action of the IAB node in the node switching method provided in the third aspect or any possible implementation manner of the third aspect;

[0087] a receiving unit, configured to perform a receiving action of the IAB node in the node switching method provided in the third aspect or any possible implementation manner of the third aspect;

[0088] A processing unit is configured to execute the processing action of the IAB node in the node switching method provided in the aforementioned third aspect or any possible implementation manner of the third aspect.

[0089] In a seventh aspect, the present application provides a communication device, comprising: a processor, the processor being coupled to a memory, the memory being used to store computer programs or instructions, the processor being used to execute the computer programs or instructions in the memory, if the communication device is a source host node or a chip of a source host node, the communication device executes the method in the above-mentioned first aspect or any possible implementation of the first aspect, if the communication device is a target host node or a chip of a target host node, the communication device executes the method in the above-mentioned second aspect or any possible implementation of the second aspect, if the communication device is an IAB node or a chip of an IAB node, the communication device executes the method in the above-mentioned third aspect or any possible implementation of the third aspect.

[0090] The eighth aspect of the present application provides a computer-readable storage medium, characterized in that the computer-readable storage medium is used to store a computer program. When the computer program is run on a computer, the computer is caused to execute the method in the above-mentioned first aspect or any possible implementation of the first aspect, or the computer is caused to execute the method in the above-mentioned second aspect or any possible implementation of the second aspect, or the computer is caused to execute the method in the above-mentioned third aspect or any possible implementation of the third aspect.

[0091] In the ninth aspect of the present application, a chip is provided, comprising a processor and a communication interface, wherein the processor is used to read instructions to execute the method in the above-mentioned first aspect or any possible implementation of the first aspect, or to execute the method in the above-mentioned second aspect or any possible implementation of the second aspect, or to execute the method in the above-mentioned third aspect or any possible implementation of the third aspect.

[0092] In a tenth aspect, the present application provides a network device, comprising a processor, the processor being connected to a memory, the memory being used to store a computer program, the processor being used to execute the computer program stored in the memory, so that the network device performs the method in the above-mentioned first aspect or any possible implementation of the first aspect, or performs the method in the above-mentioned second aspect or any possible implementation of the second aspect, or performs the method in the above-mentioned third aspect or any possible implementation of the third aspect.

[0093] In the eleventh aspect of the present application, a communication system is provided, comprising the source host node described in the first aspect or any possible implementation of the first aspect, the target host node described in the second aspect or any possible implementation of the second aspect, and the IAB node described in the third aspect or any possible implementation of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 Schematic diagram of the separation architecture of gNB-CU and gNB-DU in existing communication systems;

[0095] Figure 2 This is a schematic diagram of the control plane protocol stack in an existing communication system where the gNB adopts a CU-DU separation architecture.

[0096] Figure 3 This is a diagram of the user plane protocol stack in an existing communication system where the gNB adopts a CU-DU separation architecture;

[0097] Figure 4 A schematic diagram of a two-hop data backhaul scenario in an existing communication system;

[0098] Figure 5 Schematic diagram of the control plane protocol stack for two-hop data backhaul;

[0099] Figure 6 Schematic diagram of the user plane protocol stack for two-hop data backhaul;

[0100] Figure 7 Schematic diagram of an application scenario of the node switching system provided in this application;

[0101] Figure 8 A schematic diagram of an embodiment of a node switching system provided by this application;

[0102] Figure 9 A schematic diagram of another embodiment of a node switching system provided by the present application;

[0103] Figure 10 A schematic diagram of an embodiment of a node switching method provided by this application;

[0104] Figure 11 A schematic diagram of another embodiment of the node switching method provided by the present application;

[0105] Figure 12 A schematic diagram of another embodiment of the node switching method provided by the present application;

[0106] Figure 13 A schematic diagram of another embodiment of the node switching method provided by the present application;

[0107] Figure 14 A schematic diagram of another embodiment of the node switching method provided by the present application;

[0108] Figure 15 A schematic diagram of another embodiment of the node switching method provided by the present application;

[0109] Figure 16 A schematic diagram of the structure of the IAB host node provided by this application;

[0110] Figure 17 Another structural diagram of the IAB host node provided by this application;

[0111] Figure 18 A schematic diagram of the structure of the IAB node provided in this application;

[0112] Figure 19 A schematic diagram of the structure of the communication device provided in this application. DETAILED DESCRIPTION

[0113] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art are within the scope of protection of the present invention.

[0114] The terms "first," "second," "third," "fourth," and so forth (if any) in the description and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequential sequence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that shown or described herein.

[0115] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner to facilitate understanding.

[0116] “And / or” in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. Moreover, in the description of this application, unless otherwise specified, “multiple” means two or more than two. “At least one of the following items” or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0117] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, fifth generation (5G) system, namely new radio (NR) and future mobile communication systems.

[0118] Some of the terms used in the embodiments of the present application are explained below to facilitate understanding by those skilled in the art.

[0119] gNB: A node that provides NR user and control plane transmission for terminal devices and consists of one or more cells. A gNB connects to the 5G Core (5GC) via the Next Generation (NG) interface and to other gNBs via the Xn interface. Control plane signaling between two gNBs is transmitted via the Xn-control (Xn-C) interface, and user plane data between two gNBs is transmitted via the Xn-user (Xn-U) interface. The interface between a gNB and a terminal device is called the Uu interface.

[0120] gNB-Central Unit (gNB-CU): A logical node that includes the Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) layers of a gNB, or the RRC and / or PDCP layers of an en-gNB, and controls one or more gNB-Distributed Units (gNB-DUs).

[0121] gNB-DU: A logical node that includes the Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) layers of a gNB or en-gNB. A gNB-DU supports one or more cells, but a cell can belong to only one gNB-DU. Furthermore, a gNB-DU can only be connected to one gNB-CU.

[0122] Figure 1Schematic diagram of the separation architecture of gNB-CU and gNB-DU in existing communication systems.

[0123] like Figure 1 As shown in the figure, in existing communication scenarios, the gNB can adopt a CU-DU split architecture. The gNB consists of one gNB-CU and one or more gNB-DUs. The gNB-CU and gNB-DU are connected via the F1 interface, and the gNB-CU and the 5G core network are connected via the NG interface. Furthermore, terminal devices access the gNB-CU through the gNB-DU. The PHY layer, MAC layer, and RLC layer functions that are equivalent to the terminal device are located on the gNB-DU, while the PDCP layer, SDAP layer, and RRC layer functions that are equivalent to the terminal device are located on the gNB-CU.

[0124] Figure 2 This figure shows the control plane protocol stack diagram for gNB in ​​the existing communication system using a CU-DU separation architecture.

[0125] like Figure 2 As shown, for the control plane, in the UL direction, the gNB-DU encapsulates the RRC message generated by the terminal device in the F1AP message of the F1 interface and sends it to the gNB-CU. In the DL direction, the gNB-CU encapsulates the RRC message in the F1AP message and sends it to the gNB-DU. The gNB-DU extracts the RRC message from the F1AP message, maps it to the Signaling Radio Bearer (SRB) corresponding to the Uu interface, and sends it to the terminal device. Optionally, the SRB can be SRB0, SRB1, or SRB2, and the specific details are not limited here.

[0126] Figure 3 This figure shows the user plane protocol stack in the existing communication system where the gNB adopts the CU-DU separation architecture.

[0127] like Figure 3 As shown in the figure, for the user plane, in the UL direction, the gNB-DU maps data packets sent by the terminal device received from the Data Radio Bearer (DRB) of the Uu interface to the corresponding GPRS Tunneling Protocol (GTP) tunnel and sends them to the gNB-CU. In the DL direction, the gNB-CU maps the terminal device data packets to the corresponding GTP tunnel and sends them to the gNB-DU. The gNB-DU extracts the terminal device data packets from the GTP tunnel and maps them to the corresponding DRB of the Uu interface and sends them to the terminal device.

[0128] In existing communication technologies, the concepts of an IAB node (IAB node) and an IAB donor node (IAB donor) are introduced. The IAB donor can be a gNB or an upgraded gNB.

[0129] Figure 4 A two-hop data backhaul scenario in an existing communication system is shown.

[0130] Taking a two-hop data backhaul (BH) scenario as an example, as shown in Figure 4 The IAB network adopts a CU-DU separation architecture, that is, an IAB donor is composed of an integrated access and backhaul donor central unit (IAB donor-CU) and an integrated access and backhaul donor distributed unit (IAB donor-DU), and an IAB node is composed of an integrated access and backhaul node mobile terminal (IAB-MT) and an integrated access and backhaul node distributed unit (IAB-DU). The IAB-MT can also be referred to as an IAB-UE.

[0131] For the IAB donor, the donor-DU is similar to the gNB-DU in function, and the donor-CU is similar to the gNB-CU in function.

[0132] For the IAB node, the IAB-DU is similar to the gNB-DU in function, and is used to provide access services for child nodes of the IAB node. The child nodes of the IAB node can be terminal devices or other IAB nodes. The IAB-MT has the function of a terminal device, and is used to provide data backhaul for child nodes of the IAB node.

[0133] The IAB node can be further divided into an access IAB node and an intermediate IAB node. The IAB node accessed by a terminal device is referred to as an access IAB node, and an IAB node on a path between the access IAB node and the IAB donor is referred to as an intermediate IAB node.

[0134] As shown in Figure 4As shown, the terminal device accesses IAB node2. The terminal device is called the child node of IAB node2, and IABnode2 is called the access IAB node or parent node of the terminal device. The specific details are not limited here. The link between the terminal device and IAB node2 is called the access link. IAB node2 is connected to the IAB donor through IAB node1. The previous hop node of IAB node2 is IAB node1, that is, the parent node of IAB node2 is IAB node1, and the child node of IAB node1 is IABnode2. IAB node1 is called the intermediate IAB node. The previous hop node of IAB node1 is the IAB donor, that is, the parent node of IAB node1 is IAB donor, and the child node of IAB donor is IAB node1. The link between IAB node1 and IAB node2, and the link between IAB node1 and IAB donor are both called backhaul links. The PHY, MAC, and RLC layers, which correspond to the terminal device, are located on the access IAB node, also known as the IAB2-DU. The PDCP, SDAP, and RRC layers, which correspond to the terminal device, are located on the IAB donor-CU. All IAB nodes use an L2 data forwarding architecture. The specific control plane protocol stack and user plane protocol stack are described separately below.

[0135] Figure 5 Schematic diagram of the control plane protocol stack for two-hop data backhaul.

[0136] like Figure 5 As shown in the control plane protocol stack, an F1 control plane (F1-Control, F1-C) interface is established between the IAB2-DU and the donor-CU-CP. Specifically, if the donor CU adopts a control plane-user plane (CP-UP) separation architecture, an F1-C interface is established between the IAB2-DU and the donor CU-CP. The terminal device's RRC message is encapsulated in an F1AP message and transmitted over the F1-C interface.

[0137] Figure 6 Schematic diagram of the user plane protocol stack for two-hop data backhaul.

[0138] like Figure 6As shown in the user plane protocol stack, an F1 user plane (F1-user, F1-U) interface is established between the IAB2-DU and the donor CU-UP. Specifically, if the donor CU adopts a CP-UP separation architecture, an F1-U interface is established between the IAB2-DU and the donor CU-UP, and a per-UE bearer GTP tunnel is established on this F1-U interface. In other words, each UE DRB established on the interface between the UE and the IAB2-DU corresponds to a separate GTP tunnel on the interface between the IAB2-DU and the donor CU-UP.

[0139] The 3rd Generation Partnership Project (3GPP) standards organization developed the protocol standard for the fifth-generation cellular mobile communication system. Compared with the long-term evolution (LTE) system, the New Radio (NR) system supports a larger transmission bandwidth, more transmit and receive antenna arrays, a higher transmission rate, and a more flexible and fine-grained scheduling mechanism. These features of the NR system provide a wider range of applications.

[0140] In existing NR systems, in Integrated Access and Backhaul (IAB) scenarios, data is exchanged between terminal devices and IAB host nodes. There is at least one IAB node between the terminal device and the IAB host node, and the terminal device establishes a communication connection with the IAB host node through the at least one IAB node.

[0141] When an IAB node switches an IAB host node, the existing switching technology can only switch the IAB-MT in the IAB node from the source host node to the target host node, but does not involve the processing of the IAB-DU in the IAB node and the child nodes of the IAB node (for example, terminal devices or other IAB nodes), resulting in the child nodes of the IAB node not being able to work normally after the IAB node is switched.

[0142] In response to the above problems, the present application provides a node switching method and related equipment, in which a source host node sends a switching request message to a target host node, the switching request message including the context information of the IAB node and the context information of at least one terminal device, and the source host node receives a switching response message sent by the target host node, the switching response message including the identifier of the accepted terminal device among the at least one terminal device, and / or the identifier of the rejected terminal device among the at least one terminal device. In this way, the terminal devices connected to the IAB node that are accepted by the target host node are switched to the target host node, while the terminal devices rejected by the target host node will have the source host node reselect a switching target node for them, so that the IAB node and the accepted terminal devices are switched to the target host node together, ensuring the normal transmission of data of the accepted terminal devices, and enabling the rejected terminal devices to switch to the target node that allows them to switch, thereby also ensuring the normal transmission of data of the rejected terminal devices.

[0143] Figure 7 Schematic diagram of the application scenario of the node switching system provided in this application.

[0144] See also Figure 7 In the embodiment of the present application, the source host node 101, the target host node 102, the IAB node 103, and the terminal device 104 constitute a node switching system. The embodiment of the present application is described using a single-hop backhaul link as an example, but the solution of the embodiment of the application is also applicable to two-hop and multi-hop backhaul link scenarios, and the specific details are not limited here.

[0145] Before the IAB node 103 performs node switching, the terminal device 104 accesses the IAB node 103 and is connected to the source host node 101 through the IAB node 103. After the IAB node 103 performs node switching, it switches from the source host node 101 to the target host node 102, and the terminal device 104 is connected to the target host node 102 through the IAB node 103.

[0146] In the embodiments of the present application, the source host node is short for the source IAB host node, and the target host node is short for the target IAB host node. Optionally, the source host node and the target host node may be gNBs, or other devices, which are not specifically limited here.

[0147] The terminal device in the embodiments of the present application can be a device that provides voice and / or data connectivity to a user, a handheld device with wireless connection function, or other processing equipment connected to a wireless modem. The terminal device can be a mobile terminal, such as a mobile phone (or "cellular" phone) and a computer with a mobile terminal, for example, a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device that exchanges language and / or data with a network device. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), and other devices. The terminal device may also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, an access point, a remote terminal, an access terminal, a user agent, a user device, or user equipment, a user station, a remote station, a user terminal (TE), a terminal, a wireless communication device, and a user agent or user equipment. In addition, the terminal device may also be a chip system for implementing UE functions. Specific limitations are not made here.

[0148] In the switching system provided in the embodiment of the present application, only the topological relationship between one terminal device and one IAB node is used as an example for description. The switching system may also include more terminal devices and more IAB nodes, which are not specifically limited here.

[0149] Figure 8 A schematic diagram of an embodiment of a node switching system provided in this application.

[0150] See also Figure 8 In the switching system provided in this application, optionally, the terminal device can be directly connected to the IAB node. The terminal device can also be connected to the IAB node through other IAB nodes such as IAB node A and IAB node B, which are not limited here.

[0151] Figure 9 A schematic diagram of an embodiment of a node switching system provided in this application.

[0152] See also Figure 9 In the handover system provided herein, a direct connection between a terminal device and an IAB node is used as an example for illustration. Alternatively, the IAB node may be directly connected to the source host node or the target host node. Alternatively, the IAB node may be connected to the source host node via at least one IAB node such as IAB node A, or may be connected to the target host node via at least one IAB node such as IAB node B. The specific details are not limited herein.

[0153] In the switching system provided by the present application, the IAB node described in the following embodiments may be the IAB node that triggers the switching, and the IAB node that triggers the switching may be referred to as the migrating IAB node, and other IAB nodes are the next-hop child nodes or multi-hop grandchild nodes or grandchild nodes of the IAB node (switching IAB node), which are not specifically limited here. Optionally, the terminal device may be directly connected to the switching IAB node. Alternatively, the terminal device may also be connected to the switching IAB node through other IAB nodes such as IAB node A and IAB node B. Optionally, before the switching, the switching IAB node may be directly connected to the source host node, or the switching IAB node may also be connected to the source host node through at least one IAB node such as IAB node C. After the switching, the switching IAB node may be directly connected to the target host node, or the switching IAB node may also be connected to the target host node through at least one IAB node such as IAB node D, that is, Figure 8 Figure 9 The solutions shown in can be combined with each other, and the specific details are not limited here.

[0154] based on Figures 7 to 9 The node switching system described herein describes the node switching method provided in this application.

[0155] Figure 10 A schematic diagram of an embodiment of a node switching method provided in this application.

[0156] See also Figure 10 An embodiment of the node switching method provided in this application includes steps 201 to 202.

[0157] 201. The source host node sends a handover request message to the target host node. Similarly, the target host node receives the handover request message sent by the source host node.

[0158] In an embodiment of the present application, the handover request message is used to request that the IAB node and at least one terminal device be handed over to the target host node. The handover request message includes context information of the IAB node and context information of at least one terminal device.

[0159] Optionally, as a possible implementation, the source host node sends a handover request message to the target host node. If the terminal device is directly connected to the IAB node, the handover request message includes context information of the IAB node and context information of at least one terminal device; if the terminal device is connected to the IAB node through at least one other IAB node, the handover request message also includes context information of the other IAB node.

[0160] Optionally, as another possible implementation method, the source host node sends multiple handover request messages to the target host node, and each handover request message includes the context information of a node. If the terminal device is directly connected to the IAB node, that is, the context information of the IAB node is carried in a separate handover request message, the context information of a terminal device is carried in a separate handover request message, and the context information of different terminal devices is carried in different handover request messages; if the terminal device is connected to the IAB node through at least one other IAB node, then in addition to the context information of the IAB node and at least one terminal device being carried in a separate handover request message, the context of one other IAB node is also carried in a separate handover request message, and the context of different other IAB nodes is carried in different handover request messages.

[0161] After receiving the switching request message, the target host node decides whether to accept the switching of the IAB node and at least one terminal device together based on its own network load conditions, etc. If the terminal device is directly connected to the IAB node, the target host node decides whether to accept the switching of the IAB node, at least one other IAB node, and at least one terminal device together. If the terminal device is connected to the IAB node through at least one other IAB node, the target host node decides whether to accept the switching of the IAB node, at least one other IAB node, and at least one terminal device together.

[0162] 202. The source host node receives the handover response message sent by the target host node. Similarly, the target host node sends a handover response message to the source host node.

[0163] In an embodiment of the present application, the switching response message includes an identifier of an accepted terminal device among at least one terminal device, and / or an identifier of a rejected terminal device among at least one terminal device.

[0164] Optionally, as a possible implementation, if the source host node sends a handover request message to the target host node, the target host node sends a handover response message to the source host node. If the terminal device is directly connected to the IAB node, the handover response message includes the identifier of the at least one terminal device that is accepted and / or the identifier of the at least one terminal device that is rejected; if the terminal device is connected to the IAB node through at least one other IAB node, the handover response message also includes the identifier of the at least one other IAB node that is accepted and / or the identifier of the at least one other IAB node that is rejected.

[0165] Optionally, as another possible implementation, if the source host node sends multiple switching request messages to the target host node, the target host node sends multiple switching response messages to the source host node, and each switching response message corresponds to one node. If the terminal device is directly connected to the IAB node, that is: the IAB node corresponds to a separate switching response message, one terminal device corresponds to a separate switching response message, and different terminal devices correspond to different switching response messages. Among them, the switching response message corresponding to the accepted terminal device includes the identifier of the accepted terminal device, and the switching response message corresponding to the rejected terminal device is a switching rejection message or a switching preparation failure message or a switching failure message, which includes the identifier of the rejected terminal device. Optionally, the message also includes the reason for the rejection; if the terminal device is connected to the IAB node through at least one other IAB node, that is: in addition to the IAB node and at least one terminal device each corresponding to a separate switching response message, one other IAB node also corresponds to a separate switching response message, and different other IAB nodes correspond to different switching response messages. Among them, the handover response message corresponding to the other accepted IAB nodes includes the identifier of the other accepted IAB nodes, and the handover response message corresponding to the other rejected IAB nodes is a handover rejection message or a handover preparation failure message or a handover failure message, which includes the identifier of the other rejected IAB nodes. Optionally, the message also includes the reason for rejection, and the reason for rejection may be due to insufficient resources of the target host node, and the network load of the target host node cannot bear all other IAB nodes requesting to switch or all terminal devices requesting to switch. The reason for rejection may also be that the node identifier (for example: UE XnAPID) sent by the source host node is unavailable, and the target host cannot recognize the node identifier sent by the source host node. The reason for rejection may also be other reasons, which are not limited here.

[0166] In the embodiment of the present application, in addition to the above steps 201 to 202, before the source host node sends a handover request message to the target host node, the source host node also receives the measurement result sent by the IAB node. This step will be described in detail in the following embodiments.

[0167] Scenario 1: If the terminal device is directly connected to the IAB node.

[0168] The source host node receives the measurement result sent by the IAB node.

[0169] The measurement result includes a result A of the IAB node measuring the signal quality of the serving cell managed by the source host node and a result B of the IAB node measuring the signal quality of the neighboring cell managed by the target host node. Optionally, the measurement result includes a reference signal received power (RSRP) and / or a reference signal received quality (RSRQ), which is not specifically limited here.

[0170] The source host node determines to switch the IAB node and at least one terminal device to the target host node according to the measurement result.

[0171] If the source host node confirms that result A is better than result B, it can be determined that the signal quality of the serving cell is better than that of the neighboring cell, and the source host node does not need to send a handover request message to the target host node. If the IAB node is not operating in CA mode, there is a serving cell. If the signal quality B of a neighboring cell is higher than the signal quality A of the serving cell, the source host node determines to hand over the IAB node and at least one terminal device to the target host node based on the measurement result. If the IAB node is operating in CA mode, the serving cell includes a primary cell and at least one secondary cell. If the signal quality B of a neighboring cell is higher than the signal quality A of the primary cell, the source host node determines to hand over the IAB node and at least one terminal device to the target host node based on the measurement result.

[0172] Optionally, the source host node groups the IAB node and at least one terminal device as a group and switches all members of the group to the target host node. If the source host node sends multiple switching request messages to the target host node, the source host node also needs to send an indication message to the target host node. The indication message is used to indicate the number of members in the group so that the target host node can determine the number of switching request messages to be received, that is, one switching request message for each member.

[0173] Scenario 2: If the terminal device is connected to the IAB node through at least one other IAB node.

[0174] The source host node receives the measurement result sent by the IAB node.

[0175] The measurement result includes A, a measurement result of the IAB node measuring the signal quality of the serving cell managed by the source host node, and B, a measurement result of the IAB node measuring the signal quality of the neighboring cell managed by the target host node. Optionally, the measurement result includes RSRP and / or RSRQ, which is not specifically limited here.

[0176] The source host node determines, based on the measurement result, to switch the IAB node, at least one other IAB node, and at least one terminal device to the target host node.

[0177] If the source host node confirms that result A is better than result B, it can be seen that the signal quality of the serving cell is better than that of the neighboring cell, and the source host node does not need to send a handover request message to the target host node. If the IAB node is not operating in CA mode, there is a serving cell. If the signal quality B of a neighboring cell is higher than the signal quality A of the serving cell, the source host node can determine to hand over the IAB node, at least one other IAB node, and at least one terminal device to the target host node based on the measurement result; if the IAB node is operating in CA mode, the serving cell includes a primary cell and at least one secondary cell. If the signal quality B of a neighboring cell is higher than the signal quality A of the primary cell, the source host node can determine to hand over the IAB node, at least one other IAB node, and at least one terminal device to the target host node based on the measurement result.

[0178] Optionally, the source host node groups the IAB node, at least one other IAB node, and at least one terminal device as a group, and switches all members of the group to the target host node. If the source host node sends multiple switching request messages to the target host node, the source host node also sends an indication message to the target host node, where the indication message indicates the number of members in the group so that the target host node can determine the number of switching request messages to be received, i.e., one switching request message for each member.

[0179] In the embodiment of the present application, the context information of the IAB node and the context information of other IAB nodes include a variety of different parameters, which will be specifically described in the following embodiments.

[0180] In an embodiment of the present application, the IAB node includes an IAB-MT and an IAB-DU, the context information of the IAB node includes the context information of the IAB-MT and the context information of the IAB-DU, the context information of the IAB-MT includes the configuration information of the backhaul radio link control channel (BHRLC CH) between the IAB-MT and the parent node of the IAB node, and the context information of the IAB-DU includes the identifier of the IAB-DU and / or the cell identifier of the IAB-DU. Optionally, the context information of the IAB-DU may also include activation indication information of the cell of the IAB-DU, and the activation indication information is used to indicate whether the cell of the IAB-DU has been activated, wherein each cell of the IAB-DU corresponds to a separate activation indication information. Optionally, the context information of the IAB node also includes a backhaul adaptation protocol (BAP) address assigned by the source host node to the IAB node.

[0181] In an embodiment of the present application, the context information of the terminal device includes an identifier of the terminal device, and the identifier of the terminal device includes a physical cell identifier (PCI) of a cell accessed by the terminal device and an identifier (C-RNTI) of the terminal device within the accessed cell. Specifically, the cell accessed by the terminal device belongs to a source host node, that is, the base station identifier included in the cell identifier of the cell is consistent with the base station identifier of the source host node.

[0182] In an embodiment of the present application, other IAB nodes include other IAB-MTs and other IAB-DUs, and the context information of other IAB nodes includes the context information of other IAB-MTs and the context information of other IAB-DUs. The context information of other IAB-MTs includes the configuration information of the BH RLC CH between the other IAB-MTs and the parent nodes of the other IAB nodes. The context information of other IAB-DUs includes the identifiers of other IAB-DUs and / or the cell identifiers of other IAB-DUs. Optionally, the context information of other IAB-DUs also includes activation indication information of the cells of other IAB-DUs, and the activation indication information of the cells of other IAB-DUs is used to indicate whether the cells of other IAB-DUs have been activated, wherein each cell of other IAB-DUs corresponds to a separate activation indication information. Optionally, the context information of other IAB nodes also includes the BAP address assigned by the source host node to the other IAB nodes.

[0183] In the embodiment of the present application, the context information of the IAB node and the context information of other IAB nodes also include the topological relationship between the IAB node, other IAB nodes and terminal devices. The specific implementation method will be described in the following embodiments.

[0184] Scenario 1: If the terminal device is directly connected to the IAB node.

[0185] Method 1: The context information of the IAB node also includes the identifier of the IAB node's child node (or next-hop node), which is used to indicate the topological relationship between the IAB node and the IAB node's child node (or next-hop node). Since the terminal device is directly connected to the IAB node, the IAB node's child node (or next-hop node) is the terminal device, and the identifier of the IAB node's child node (or next-hop node) is the terminal device's identifier. For example, the terminal device's identifier can be the user equipment Xn application protocol identity (UE XnAPID), which is not limited here.

[0186] Optionally, the context information of the terminal device may also include an identifier of the terminal device's parent node (or previous hop node), which is used to indicate the topological relationship between the terminal device and the terminal device's parent node (or previous hop node). Since the terminal device is directly connected to the IAB node, the terminal device's parent node (or previous hop node) is the IAB node, and the identifier of the terminal device's parent node (or previous hop node) is the identifier of the IAB node. For example, the identifier of the IAB node can be the UE XnAP ID or the BAP address of the IAB node, and the specific details are not limited here.

[0187] Method 2: The context information of the IAB node can also include network topology list information. Since the terminal device is directly connected to the IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the terminal device. For example: if the terminal device is connected to the IAB node, the network topology list information includes the identifier of the IAB node and the identifier of the child node (or next-hop node) of the IAB node (i.e., the identifier of the terminal device), or the network topology list information includes the identifier of the terminal device and the identifier of the parent node (or previous-hop node) of the terminal device (i.e., the identifier of the IAB node). Among them, the identifier of the terminal device can be the UE XnAP ID, and the identifier of the IAB node can also be the UE XnAP ID or the BAP address, which is not limited here.

[0188] Optionally, the network topology list information may not be carried in the context information of the IAB node, but may be directly carried in the handover request message sent by the source host node to the target host node, which is not limited here.

[0189] In the embodiment of the present application, based on the handover request message sent by the source host node, the target host node can obtain the topological relationship between the IAB node and the terminal device. In addition to the implementation methods mentioned in Methods 1 and 2 in the above embodiments, the target host node can also obtain the topological relationship between the IAB node and the terminal device through other methods, which are not limited here.

[0190] Scenario 2: If the terminal device is connected to the IAB node through at least one other IAB node.

[0191] Method 1: The context information of the IAB node also includes the identifier of the child node (or next-hop node) of the IAB node, which is used to indicate the topological relationship between the IAB node and the child node (or next-hop node) of the IAB node. Since the terminal device is connected to the IAB node through at least one other IAB node, the child node (or next-hop node) of the IAB node is the other IAB node, and the identifier of the child node (or next-hop node) of the IAB node is the identifier of the other IAB node. For example, the identifier of the other IAB node can be the UE XnAP ID or the BAP address of the other IAB node, and the specific details are not limited here.

[0192] Optionally, the context information of other IAB nodes also includes the identifier of the parent node (or previous hop node) of the other IAB node, and / or the identifier of the child node (or next hop node) of the other IAB node, which is used to indicate the topological relationship between the other IAB node and the parent node (or previous hop node) of the other IAB node, and / or the other IAB node and the child node (or next hop node) of the other IAB node. Since the terminal device is connected to the IAB node through at least one other IAB node, for example, the terminal device is connected to the IAB node through IAB node A, the other IAB node is IAB node A, the parent node (or previous hop node) of the other IAB node is the IAB node, and the identifier of the parent node (or previous hop node) of the other IAB node is the identifier of the IAB node. The child node (or next hop node) of the other IAB node is the terminal device, and the identifier of the child node (or next hop node) of the other IAB node is the identifier of the terminal device. The identifier of the terminal device may be a UE XnAP ID, and the identifier of the IAB node may be a UE XnAP ID or a BAP address, which are not specifically limited here.

[0193] Optionally, the context information of the terminal device also includes the identifier of the parent node (or previous hop node) of the terminal device, which is used to indicate the topological relationship between the terminal device and the parent node (or previous hop node) of the terminal device. Since the terminal device is connected to the IAB node through at least one other IAB node, the parent node (or previous hop node) of the terminal device is the other IAB node, and the identifier of the parent node (or previous hop node) of the terminal device is the identifier of the other IAB node. For example, the identifier of the other IAB node can be the UE XnAP ID or the BAP address of the other IAB node, which is not limited here.

[0194] Method 2: The context information of the IAB node also includes network topology list information. Since the terminal device is connected to the IAB node through at least one other IAB node, the network topology list information is used to indicate the topological relationship between the IAB node, other IAB nodes, and the terminal device. For example: if the terminal device is connected to the IAB node through IAB node A, the network topology list information includes two sets of lists. The first set of lists includes the identifier of the IAB node and the identifier of the child node (or next-hop node) of the IAB node. If the child node of the IAB node is IAB node A, the identifier of the child node (or next-hop node) of the IAB node is the identifier of IAB node A. The second set of lists includes the identifier of IAB node A and the identifier of the child node (or next-hop node) of IAB node A. If the child node (or next-hop node) of IAB node A is the terminal device, the identifier of the child node (or next-hop node) of IAB node A is the identifier of the terminal device. Alternatively, the network topology list information includes two groups of lists, the first group of lists including the identifier of the terminal device and the identifier of the parent node (or previous hop node) of the terminal device, wherein the parent node of the terminal device is IAB node A, then the identifier of the parent node (or previous hop node) of the terminal device is the identifier of IAB node A; the second group of lists including the identifier of IAB node A and the identifier of the parent node (or previous hop node) of IAB node A, wherein the parent node (or previous hop node) of IAB node A is an IAB node, then the identifier of the parent node (or previous hop node) of IAB node A is the identifier of the IAB node. Among them, the identifier of the terminal device can be UE XnAP ID, the identifier of the IAB node can also be UE XnAP ID or BAP address, and the identifier of other IAB nodes (for example: IAB node A) can also be UE XnAP ID or BAP address, which is not limited here.

[0195] Optionally, the network topology list information may not be carried in the context information of the IAB node, but may be directly carried in the handover request message sent by the source host node to the target host node, which is not limited here.

[0196] In the embodiments of the present application, the target donor node obtains the topology relationship among the IAB node, the other IAB node and the terminal device according to the handover request message sent by the source donor node. In addition to the implementation manners mentioned in the first mode and the second mode in the above embodiments, the target donor node can also obtain the topology relationship among the IAB node, the other IAB node and the terminal device through other manners, which are not limited here.

[0197] Figure 11 An embodiment of the node handover method provided in the present application is shown in the figure.

[0198] Please refer to Figure 11 For example, the terminal device is connected to the IAB node through the IAB node B and the IAB node A.

[0199] Optionally, in a possible implementation manner, the context information of the IAB node includes the identifier of the child node of the IAB node (i.e., the identifier of the IAB node A), the context information of the IAB node A includes the identifier of the child node of the IAB node A (i.e., the identifier of the IAB node B), and the context information of the IAB node B includes the identifier of the child node of the IAB node B (i.e., the identifier of the terminal device). In this way, the target donor node can obtain the topology relationship among the IAB node, the IAB node A, the IAB node B and the terminal device according to the context information carried in the handover request message sent by the source donor node to the target donor node.

[0200] Optionally, in another possible implementation manner, the context information of the IAB node A includes the identifier of the parent node of the IAB node A (i.e., the identifier of the IAB node), the context information of the IAB node B includes the identifier of the parent node of the IAB node B (i.e., the identifier of the IAB node A), and the context information of the terminal device includes the identifier of the parent node of the terminal device (i.e., the identifier of the IAB node B). In this way, the target donor node can obtain the topology relationship among the IAB node, the IAB node A, the IAB node B and the terminal device according to the context information carried in the handover request message sent by the source donor node to the target donor node.

[0201] Optionally, in another possible implementation, the context information of the IAB node includes the child node identifier of the IAB node (i.e., the identifier of IAB node A), the context information of IAB node A includes the parent node identifier of IAB node A (i.e., the identifier of IAB node) and the child node identifier of IAB node A (i.e., the identifier of IAB node B), the context of IAB node B includes the parent node identifier of IAB node B (i.e., the identifier of IAB node A) and the child node identifier of IAB node B (i.e., the identifier of the terminal device), and the context information of the terminal device includes the parent node identifier of the terminal device (i.e., the identifier of IAB node B). In this way, the target host node obtains the topological relationship between the IAB node, IAB node A, IAB node B, and the terminal device based on the context information carried in the handover request message sent by the source host node to the target host node.

[0202] Optionally, other implementations may be used to describe the network topology relationship between the IAB node, other IAB nodes, and the terminal device through node identifiers in the context information of the IAB node and other IAB nodes, which are not specifically limited here.

[0203] Optionally, in addition to being carried in the context information, the topology information may also be carried in a handover request message sent by the source host node to the target host node, that is, the handover request message sent by the source host node to the target host node may also include network topology list information, and the network topology list information is used to indicate the topological relationship between the IAB node, IAB node A, IAB node B, and the terminal device. That is, the network topology list information includes three groups of lists, the first group of lists includes the identifier of the IAB node and the identifier of the child node of the IAB node (that is, the identifier of IAB node A), the second group of lists includes the identifier of IAB node A and the identifier of the child node of IAB node A (that is, the identifier of IAB node B), and the third group of lists includes the identifier of IAB node B and the identifier of the child node of IAB node B (that is, the identifier of the terminal device). Alternatively, the first group list includes the identifier of IAB node A and the parent node identifier of IAB node A (i.e., the identifier of the IAB node), the second group list includes the identifier of IAB node B and the parent node identifier of IAB node B (i.e., the identifier of IAB node A), and the third group list includes the identifier of the terminal device and the parent node identifier of the terminal device (i.e., the identifier of IAB node B).

[0204] In an embodiment of the present application, the identifier of the terminal device can be a UE XnAP ID, the identifier of the IAB node can also be a UE XnAP ID or a BAP address, the identifier of the IAB node A can be a UE XnAP ID or a BAP address, and the identifier of the IAB node B can be a UE XnAP ID or a BAP address. The specific details are not limited here.

[0205] In the embodiment of the present application, based on the handover request message sent by the source host node, the target host node can obtain the topological relationship between the IAB node, other IAB nodes, and the terminal device. In addition to the implementation methods mentioned in the above embodiment, the target host node can also obtain the topological relationship between the IAB node, other IAB nodes, and the terminal device through other methods, which are not limited here.

[0206] In an embodiment of the present application, if the terminal device is directly connected to the IAB node, the source host node can carry the context information of the IAB node and the context information of the terminal device in one switching request message and send it to the target host node, or the context information of the IAB node and the context information of the terminal device can be carried in different switching request messages and sent to the target host node respectively. The specific details are not limited here.

[0207] By the same token, if the terminal device accesses the IAB node through at least one other IAB node, the source host node can carry the context information of the IAB node, the context information of other IAB nodes, and the context information of the terminal device in one switching request message and send it to the target host node. Alternatively, the context information of the IAB node, the context information of other IAB nodes, and the context information of the terminal device can be carried in different switching request messages and sent to the target host node respectively. The specific details are not limited here.

[0208] In the embodiment of the present application, in addition to steps 201 and 202 above, the cell configuration information changes after the first IAB node switches to the target host node. The first IAB node includes the IAB node and other IAB nodes that are accepted. There are various implementation methods for the IAB node to receive the updated cell configuration information from the target host node via the source host node. The specific implementation methods will be described in detail in the following embodiments.

[0209] Figure 12 This is a schematic diagram of an embodiment of the source host node sending configuration information in the node switching method provided by this application.

[0210] See also Figure 12 In a possible implementation, the source host node includes a source Donor-CU, the target host node includes a target Donor-CU, and the first IAB node includes a first IAB-MT and a first IAB-DU.

[0211] The target Donor-CU sends a handover response message to the source donor node.

[0212] In an embodiment of the present application, after the target Donor-CU receives the handover request message, the target Donor-CU will update the cell configuration of the first IAB node. For example, optionally, the target Donor-CU can update the cell global identifier (cell group identifier, CGI) of the IAB-DU. Optionally, the target Donor-CU can also update the cell identity (Cell Identity) of the IAB-DU. The specific details are not limited here. The updated cell configuration is carried in the handover response message, and the handover response message is sent to the source Donor-CU. Specifically, the handover response message includes a first RRC message generated by the target Donor-CU, and the first RRC message includes the cell configuration information after the first IAB node switches to the target host node. The first IAB node includes the IAB node and other IAB nodes accepted among other IAB nodes.

[0213] The source Donor-CU obtains the first radio resource control RRC message from the handover response message.

[0214] The source Donor-CU sends the first RRC message to the first IAB-MT through the source Donor-DU.

[0215] In an embodiment of the present application, the target Donor-CU carries the updated cell configuration information of the first IAB-DU in the first RRC message (RRC Reconfiguration) generated by the target Donor-CU, and then encapsulates the first RRC message in a handover response message (Handover Request Acknowledge) and sends it to the source Donor-CU. After the source Donor-CU extracts the first RRC message from the handover response message, it sends the first RRC message to the first IAB-MT through the source Donor-DU. The first IAB-MT extracts the updated cell configuration of the first IAB-DU from the first RRC message, and sends the received updated cell configuration of the first IAB-DU to the first IAB-DU through the internal interface, so that the first IAB-DU updates the cell configuration.

[0216] In this embodiment of the present application, after the source donor node sends a handover request message to the target donor node, the cell configuration of the first IAB-DU is updated. For example, the base station identifier included in the first IAB-DU cell identifier CGI or Cell Identity is consistent with the base station identifier to which the donor-CU belongs. During the handover process, the first IAB-DU obtains new configuration information from the target donor-CU.

[0217] Figure 13This is a schematic diagram of an embodiment of the source host node sending configuration information in the node switching method provided by this application.

[0218] See also Figure 13 In a possible implementation, the source host node includes a source Donor-CU, the target host node includes a target Donor-CU, and the first IAB node includes a first IAB-MT and a first IAB-DU.

[0219] The target Donor-CU sends a handover response message to the source donor node.

[0220] In an embodiment of the present application, the switching response message includes a first F1AP message, the first F1AP message includes the cell configuration information after the first IAB node switches to the target host node, and the first IAB node includes the IAB node and other IAB nodes accepted among other IAB nodes.

[0221] The source Donor-CU obtains the first application layer protocol F1AP message from the handover response message.

[0222] The source Donor-CU encapsulates the first F1AP message into a second F1AP message and sends it to the first IAB-DU.

[0223] In the embodiment of the present application, after the source Donor-CU encapsulates the first F1AP message in the second F1AP message, the source Donor-CU sends the second F1AP message to the first IAB-DU, so that the first IAB-DU updates the cell configuration.

[0224] In an embodiment of the present application, the target Donor-CU illustratively carries the updated cell configuration information of the first IAB-DU in a first F1AP message generated by the target Donor-CU. Optionally, the first F1AP message can be a newly defined F1AP message, or an existing F1AP message, such as a gNB Configuration Update message (gNB-CUConfigurationUpdate), which is not limited herein. The target Donor-CU then carries the F1AP message in a Handover Request Acknowledge message and sends it to the source Donor-CU. The source Donor-CU extracts the first F1AP message from the Handover Request Acknowledge message and carries the first F1AP message in a second F1AP message, which is sent to the first IAB-DU via the source Donor-DU. The first IAB-DU extracts the first F1AP message generated by the target Donor-CU from the second F1AP message, allowing the first IAB-DU to update the cell configuration.

[0225] In this embodiment, after the source donor node sends a handover request message to the target donor node, the cell configuration of the first IAB-DU is updated. For example, the cell identifier CGI or the base station identifier included in the cell identity of the first IAB-DU is consistent with the base station identifier of the donor-CU. During the handover process, the first IAB-DU obtains the new configuration information from the target donor-CU.

[0226] In this application Figure 13 The embodiments provided have an impact on the existing IAB protocol stack. Figure 13 The protocol stack architecture corresponding to the provided embodiment is as follows Figure 14 As shown, the F1AP message carries the F1AP message.

[0227] Figure 14 This is a schematic diagram of the protocol stack architecture for the source host node to send configuration information in the node switching method provided in this application. Figure 15 This is a schematic diagram of an embodiment of the source host node sending configuration information in the node switching method provided by this application.

[0228] See also Figure 15 In a possible implementation, the source host node includes a source Donor-CU, the target host node includes a target Donor-CU, and the first IAB node includes a first IAB-MT and a first IAB-DU.

[0229] The target Donor-CU sends a handover response message to the source donor node.

[0230] In the embodiment of the present application, the handover response message includes the cell configuration information after the first IAB node is handed over to the target host node, and the first IAB node includes the IAB node and other IAB nodes that are accepted among the other IAB nodes.

[0231] The source Donor-CU obtains the cell configuration information after the first IAB node is switched to the target donor node from the handover response message.

[0232] The source Donor-CU encapsulates the cell configuration information after the first IAB node is switched to the target donor node into an F1AP message and sends it to the first IAB-DU.

[0233] In the embodiments of the present application, the target Donor-CU carries the updated cell configuration information of the first IAB-DU in the Handover Request Acknowledge message and sends it to the source Donor-CU. The source Donor-CU extracts the updated cell configuration information of the first IAB-DU from the Handover Request Acknowledge message, and carries the updated cell configuration information of the first IAB-DU in the F1AP message generated by the source Donor-CU and sends it to the first IAB-DU, so that the first IAB-DU updates the cell configuration. Optionally, the F1AP message generated by the source Donor-CU can be a newly defined message, or it can also be an existing F1AP message, for example: gNB-CU Configuration Update message, which is not limited here.

[0234] In the embodiments of the present application, after the source host node sends the handover request message to the target host node, the cell configuration of the first IAB-DU is updated, for example, the base station identifier contained in the cell identifier CGI or Cell Identity of the first IAB-DU is consistent with the base station identifier of the Donor-CU. During the handover process, the first IAB-DU obtains new configuration information from the target Donor-CU.

[0235] The above Figures 12 to 15 The embodiments illustrated in the above

[0236] The above Figures 12 to 15 The embodiments illustrated in the above steps 201 and 202 can be implemented independently without being based on the embodiments illustrated in the above steps 201 and 202, which are not limited here.

[0237] In the embodiments of the present application, in addition to the above steps 201 to 202, the target host node also sends a context setup request message to the IAB node, which will be described in detail in the following embodiments.

[0238] In the embodiments of the present application, the source host node includes a source Donor-CU, and the target host node includes a target Donor-CU.

[0239] Scenario 1: If the terminal device is directly connected to the IAB node.

[0240] The target Donor-CU sends a context setup request message to the IAB node.

[0241] In an embodiment of the present application, the context establishment request message carries the identifier of the terminal device, and the identifier of the terminal device includes the cell identifier of the terminal device accessing the IAB node and the identifier C-RNTI of the terminal device in the access cell. Optionally, the cell identifier of the terminal device accessing the IAB node can be PCI, or CGI, or other identifiers, which are not limited here.

[0242] In the embodiment of the present application, a context of a child node of the IAB node is established between the IAB node and the target Donor-CU. In this embodiment, the child node of the IAB node is a terminal device, that is, a context of the terminal device is established between the IAB node and the target Donor-CU.

[0243] Specifically, before and after the IAB node is switched, the cell identifier PCI of the IAB-DU of the IAB node remains unchanged, and the identifier C-RNTI of the terminal device under the IAB-DU cell remains unchanged. Once the IAB-MT of the IAB node successfully accesses the target Donor-CU, the target Donor-CU sends a context establishment request message (UE Context SetupRequest) to the IAB-DU of the IAB node. The message carries the identifier of the terminal device under the IAB-DU cell of the IAB node. Optionally, the identifier can be a combination of PCI and C-RNTI, or a combination of CGI and C-RNTI, which is not limited here. Among them, CGI can be the cell identifier of the IAB-DU of the IAB node under the source host node, or it can be the cell identifier of the IAB-DU of the IAB node under the target host node. According to the identifier of the terminal device under the IAB-DU cell of the IAB node, the IAB-DU of the IAB node can know for which terminal device the UE Context Setup Request message is used to request to establish a context.

[0244] Scenario 2: If the terminal device is connected to the IAB node through at least one other IAB node.

[0245] The target Donor-CU sends a context setup request message to the second IAB node, the second IAB node being an access node or a parent node of the terminal device, i.e., one of the at least one other IAB node accessed by the terminal device, and the context setup request message carrying an identifier of the terminal device, the identifier of the terminal device being a cell identifier of a cell of the second IAB node accessed by the terminal device and a C-RNTI of the terminal device in the cell. Optionally, the cell identifier of the second IAB node accessed by the terminal device can be a PCI, or can be a CGI, or can be another identifier, which is not limited here.

[0246] In the embodiment of the application, the context of the child node of the second IAB node is established between the second IAB node and the target Donor-CU. In the embodiment, the child node of the second IAB node is the terminal device, i.e., the context of the terminal device is established between the second IAB node and the target Donor-CU.

[0247] Specifically, before and after the handover of the second IAB node, the cell PCI of the IAB-DU of the second IAB node remains unchanged, and the C-RNTI of the terminal device under the IAB-DU cell of the second IAB node remains unchanged. Once the IAB-MT of the second IAB node successfully accesses the target Donor-CU, the target Donor-CU sends a context setup request message (UE Context Setup Request) to the IAB-DU of the second IAB node, and the message carries the identifier of the terminal device under the IAB-DU cell of the second IAB node. Optionally, the identifier can be a PCI and a C-RNTI, or can be a CGI and a C-RNTI, which is not limited here. The CGI can be a cell identifier of the IAB-DU of the second IAB node under the source host node, or can be a cell identifier of the IAB-DU of the second IAB node under the target host node. According to the identifier of the terminal device under the IAB-DU cell of the second IAB node, the IAB-DU of the second IAB node can know which terminal device the UE Context Setup Request message is used to request to establish a context for.

[0248] The above-mentioned different embodiments of the context setup request message sent by the target host node to the IAB node can be implemented based on the embodiments described in steps 201 and 202, or can be independently implemented without being based on the embodiments described in steps 201 and 202, which is not limited here.

[0249] In the embodiment of the present application, in addition to steps 201 to 202 above, if the terminal device is connected to the IAB node via at least one other IAB node, the target host node or the IAB node further sends first indication information and / or second indication information to the other IAB node, where the first indication information is used to indicate that the IAB node handover is complete, and the second indication information is used to indicate that the IAB node is in the process of handover or is preparing to handover.

[0250] This step will be described in detail in the following examples.

[0251] In the prior art, after an IAB node switches to a target host node, other IAB nodes are unable to detect the completion of the IAB node switch, that is, they are unable to detect that the link between the IAB node and the target host node has been established. Therefore, the IAB-DUs of the other IAB nodes cannot determine when to trigger application layer processing. Optionally, the application layer processing can be that the IAB-DUs of the other IAB nodes trigger the establishment of a stream control transmission protocol (SCTP) association with the target host node (e.g., the target Donor-CU), or the IAB-DUs of the other IAB nodes trigger a request to the operation administration and maintenance (OAM) server for a new configuration, or other processing methods are also possible, which are not limited here.

[0252] For example, when the IAB node has not completed the handover, the link between the IAB node and the target host node is disconnected. Since the IAB node has not completed the handover, it means that the IAB node has not successfully switched to the target host node. Then, the air interface link between the IAB node and the target host node has not been established. Moreover, the bearer mapping and routing on the link between the IAB node and the target host node are not configured, so data cannot be transmitted. Therefore, it can be considered that the link is disconnected. If the IAB-DU of other IAB nodes triggers application layer processing at this time and triggers an SCTP association establishment request to the target host node (for example, Donor-CU), the IAB-DU of other IAB nodes will not be able to receive a response to the SCTP association request sent by the target host node, resulting in the bottom layer link being considered disconnected, causing the SCTP association establishment process to fail.

[0253] To address the above issues, in this implementation, the target host node or IAB node may send first indication information and / or second indication information to other IAB nodes. The first indication information is used to indicate that the IAB node has completed handover, i.e., has switched to the target host node. The second indication information is used to indicate that the IAB node is in the process of handover or is preparing to handover. The other IAB nodes may be child nodes, grandchild nodes, or grand-grandchild nodes of the IAB node.

[0254] Mode 1: The target host node sends the first indication information and / or the second indication information to other IAB nodes.

[0255] In the embodiment of the present application, the target host node includes the target Donor-CU, the IAB nodes include IAB-MT1 and IAB-DU1, and the other IAB nodes include IAB-MT2 and IAB-DU2.

[0256] 1. The target donor-CU sends the second indication information to other IAB nodes.

[0257] In an embodiment of the present application, after the target Donor-CU receives the switching request message sent by the source Donor-CU, it learns that the IAB node and other IAB nodes will be switched to the target Donor-CU together. Then, the RRC reconfiguration message (or switching command message) sent by the target Donor-CU to other IAB nodes carries second indication information for indicating that the IAB node is preparing to switch or is switching.

[0258] 2. The target donor-CU sends the first indication information to other IAB nodes.

[0259] In an embodiment of the present application, if the IAB node has been switched to the target host node, that is, IAB-MT1 has been switched to the target Donor-CU, the target Donor-CU sends a first indication message to IAB-MT2. The first indication message is used to indicate that the IAB node switching is completed, that is, it has been switched to the target host node.

[0260] Exemplarily, after the IAB node successfully switches to the target host node, or after IAB-MT1 receives the BAP configuration information of the target Donor-CU (for example, routing configuration information and / or bearer mapping configuration information of the BAP layer, etc.), the target Donor-CU sends a first indication information to IAB-MT2, and the first indication information is carried in an RRC message.

[0261] Mode 2: The IAB node sends the first indication information and / or the second indication information to other IAB nodes.

[0262] In the embodiment of the present application, the target host node includes the target Donor-CU, the IAB nodes include IAB-MT1 and IAB-DU1, and the other IAB nodes include IAB-MT2 and IAB-DU2.

[0263] 1. The IAB node sends second indication information to other IAB nodes.

[0264] In the embodiment of the present application, after IAB-MT1 receives the handover command message sent by the target Donor-CU, IAB-DU1 sends second indication information to IAB-MT2, where the indication information is used to indicate that IAB-MT1 is in the process of handover or IAB-MT1 is preparing for handover.

[0265] In the embodiment of the present application, optionally, IAB-DU1 may carry the second indication information in a MAC CE and send it to IAB-MT2, or may carry the second indication information in a BAP control PDU and send it to IAB-MT2, which is not limited here.

[0266] 2. The IAB node sends first indication information to other IAB nodes.

[0267] Exemplarily, after IAB-MT1 successfully switches to the target Donor-CU, or after IAB-MT1 receives BAP configuration information of the target host node (eg, target Donor-CU), IAB-DU1 sends first indication information to IAB-MT2.

[0268] In an embodiment of the present application, optionally, the BAP configuration information may include routing configuration information of the BAP layer, or include bearer mapping configuration information. The BAP configuration information may also include other configuration information, which is not specifically limited here.

[0269] In the embodiment of the present application, optionally, IAB-DU1 may carry the first indication information in a MAC CE and send it to IAB-MT2, or may carry the first indication information in a BAP control PDU and send it to IAB-MT2, which is not limited here.

[0270] The multiple different embodiments of the target host node or IAB node sending the first indication information and / or the second indication information to other IAB nodes can be implemented based on the embodiments described in steps 201 and 202, or can be implemented independently without being based on the embodiments described in steps 201 and 202. The specific embodiments are not limited here.

[0271] The above embodiment provides a different implementation of a node switching method. The following provides an IAB host node 30, such as Figure 16As shown, the IAB host node 30 is used to execute the steps executed by the source host node in the above embodiment. The execution steps and corresponding beneficial effects are specifically understood with reference to the above corresponding embodiments and are not described in detail here. The IAB host node 30 includes:

[0272] A sending unit 301, a receiving unit 302, and a processing unit 303;

[0273] The sending unit 301 is configured to execute the sending action of the source host node in the node switching method provided in any possible implementation manner of the aforementioned embodiment;

[0274] A receiving unit 302 is configured to execute a receiving action of a source host node in the node switching method provided in any possible implementation manner of the aforementioned embodiment;

[0275] The processing unit 303 is configured to execute the processing action of the source host node in the node switching method provided in any possible implementation manner in the aforementioned embodiment.

[0276] like Figure 16 As shown, the IAB host node 30 includes a processing unit and a transceiver unit. The transceiver unit may include a transmitting unit 301 and a receiving unit 302. For example, the transceiver unit may be a transceiver, which may include an antenna and a radio frequency circuit, etc. The processing unit 303 may be a processor (or a processing circuit), such as a baseband processor, which may include one or more central processing units (CPUs). When the IAB host node 30 is a component with network device functions, the transceiver unit may be a radio frequency unit, and the processing unit may be a processor (or a processing circuit), such as a baseband processor. When the IAB host node 30 is a chip system, the transceiver unit may be the input and output interface of the chip (such as a baseband chip), and the processing unit 303 may be the processor (or a processing circuit) of the chip system, which may include one or more central processing units. It should be understood that the processing unit in the embodiments of the present application may be implemented by a processor or processor-related circuit components (or processing circuits), and the transceiver unit may be implemented by a transceiver or transceiver-related circuit components.

[0277] In addition, the transceiver unit can be a functional module that can perform both sending and receiving operations. For example, the transceiver unit can be used to perform Figure 2 The embodiment shown to Figure 15In any of the embodiments shown, all sending operations and receiving operations performed by the source host node, for example, when performing a sending operation, the transceiver unit can be considered as a sending module, and when performing a receiving operation, the transceiver unit can be considered as a receiving module; or, the transceiver unit can also be two functional modules, and the transceiver unit can be regarded as a general term for the two functional modules, which are the sending unit 301 and the receiving unit 302, respectively. The sending unit 301 is used to complete the sending operation, for example, the sending module can be used to perform Figure 2 The embodiment shown to Figure 15 In any of the embodiments shown, all sending operations performed by the source host node or the target host node, the receiving module is used to complete the receiving operation, for example, the receiving unit can be used to perform Figure 2 The embodiment shown to Figure 15 All receive operations performed by a source host node or a target host node in any of the illustrated embodiments.

[0278] It should be noted that the information interaction, execution process, and other contents between the modules of the above-mentioned IAB host node 30 are based on the same concept as the method embodiment of the present application, and the technical effects they bring are the same as those of the method embodiment of the present application. For specific contents, please refer to the description of the method embodiment shown above in the present application, and will not be repeated here.

[0279] The above embodiment provides a different implementation of an IAB host node 30. The following provides an IAB host node 40, such as Figure 17 As shown, the IAB host node 40 is used to execute the steps executed by the target host node in the above embodiment. The execution steps and corresponding beneficial effects are specifically understood with reference to the above corresponding embodiments and are not described in detail here. The IAB host node 40 includes:

[0280] Receiving unit 401, sending unit 402 and processing unit 403;

[0281] The receiving unit 401 is configured to execute a receiving action of a target host node in the node switching method provided in any possible implementation manner of the aforementioned embodiment;

[0282] The sending unit 402 is configured to execute the sending action of the target host node in the node switching method provided in any possible implementation manner of the aforementioned embodiment;

[0283] The processing unit 403 is configured to execute the processing action of the target host node in the node switching method provided in any possible implementation manner in the aforementioned embodiment.

[0284] like Figure 17As shown, the IAB host node 40 includes a processing unit and a transceiver unit. The transceiver unit may include a transmitting unit 402 and a receiving unit 401. For example, the transceiver unit may be a transceiver, which may include an antenna and a radio frequency circuit, etc. The processing unit may be a processor (or a processing circuit), such as a baseband processor, which may include one or more central processing units (CPUs). When the IAB host node 40 is a component with network device functions, the transceiver unit may be a radio frequency unit, and the processing unit may be a processor (or a processing circuit), such as a baseband processor. When the IAB host node 40 is a chip system, the transceiver unit may be the input and output interface of the chip (such as a baseband chip), and the processing unit may be the processor (or a processing circuit) of the chip system, which may include one or more central processing units. It should be understood that the processing unit in the embodiments of the present application may be implemented by a processor or processor-related circuit components (or processing circuits), and the transceiver unit may be implemented by a transceiver or transceiver-related circuit components.

[0285] In addition, the transceiver unit can be a functional module that can perform both sending and receiving operations. For example, the transceiver unit can be used to perform Figure 2 The embodiment shown to Figure 15 In any of the embodiments shown, all sending operations and receiving operations performed by the target host node, for example, when performing a sending operation, the transceiver unit can be considered as a sending module, and when performing a receiving operation, the transceiver unit can be considered as a receiving module; or, the transceiver unit can also be two functional modules, and the transceiver unit can be regarded as a general term for the two functional modules, which are the sending unit 402 and the receiving unit 401, respectively. The sending unit 402 is used to complete the sending operation, for example, the sending module can be used to perform Figure 2 The embodiment shown to Figure 15 In any of the embodiments shown, all sending operations performed by the target host node, the receiving module is used to complete the receiving operation, for example, the receiving unit can be used to perform Figure 2 The embodiment shown to Figure 15 All receive operations performed by the target host node in any of the illustrated embodiments.

[0286] It should be noted that the information interaction, execution process, and other contents between the modules of the above-mentioned IAB host node 40 are based on the same concept as the method embodiment of the present application, and the technical effects brought about are the same as those of the method embodiment of the present application. For specific contents, please refer to the description of the method embodiment shown above in the present application, and will not be repeated here.

[0287] The above embodiment provides a different implementation of an IAB host node 40. The following provides an IAB node 50, such as Figure 18 As shown, the IAB node 50 is used to execute the steps executed by the IAB node in the above embodiment. The execution steps and corresponding beneficial effects are specifically understood with reference to the above corresponding embodiments and will not be described in detail here. The IAB node 50 includes:

[0288] Processing unit 501, sending unit 502;

[0289] The processing unit 501 is configured to execute the processing action of the IAB node in the node switching method provided in any possible implementation manner of the aforementioned embodiments.

[0290] The sending unit 502 is configured to execute the sending action of the IAB node in the node switching method provided in any possible implementation manner of the aforementioned embodiment.

[0291] like Figure 18 As shown, the IAB node 50 includes a processing unit and a transceiver unit, and the transceiver unit may include a transmitting unit 502. For example, the transceiver unit may be a transceiver, which may include an antenna and a radio frequency circuit, etc. The processing unit 501 may be a processor (or a processing circuit), such as a baseband processor, which may include one or more central processing units (CPUs). When the IAB node 50 is a component with network device functions, the transceiver unit may be a radio frequency unit, and the processing unit may be a processor (or a processing circuit), such as a baseband processor. When the IAB node 50 is a chip system, the transceiver unit may be the input and output interface of the chip (such as a baseband chip), and the processing unit may be the processor (or a processing circuit) of the chip system, which may include one or more central processing units. It should be understood that the processing unit 501 in the embodiments of the present application may be implemented by a processor or processor-related circuit components (or processing circuits), and the transceiver unit may be implemented by a transceiver or transceiver-related circuit components.

[0292] In addition, the transceiver unit can be a functional module that can perform both sending and receiving operations. For example, the transceiver unit can be used to perform Figure 2 The embodiment shown to Figure 15In any of the embodiments shown, all sending operations and receiving operations performed by the IAB node, for example, when performing a sending operation, the transceiver unit can be considered as a sending module, and when performing a receiving operation, the transceiver unit can be considered as a receiving module; or, the transceiver unit can also be two functional modules, and the transceiver unit can be considered as a general term for the two functional modules, which are the sending unit 502 and the receiving unit, respectively. The sending unit 502 is used to complete the sending operation, for example, the sending module can be used to perform Figure 2 The embodiment shown to Figure 15 All sending operations are performed by the IAB node in any of the illustrated embodiments.

[0293] It should be noted that the information interaction, execution process, etc. between the modules of the above-mentioned IAB node 50 are based on the same concept as the method embodiment of the present application, and the technical effects they bring are the same as those of the method embodiment of the present invention. For specific contents, please refer to the description of the method embodiment shown above in the present application, and will not be repeated here.

[0294] Please refer to Figure 19 , a schematic diagram of a communication device 60 provided in an embodiment of the present application, is used to implement the operations of the source host node, target host node, and IAB node in the above embodiments. The communication device includes: a processor 601 and a communication interface 602. Optionally, the communication device also includes a memory 603. The communication interface 602 is used to implement communication with other devices.

[0295] In the above embodiments, the method executed by the network device or terminal device can be implemented by the processor 601 calling a program stored in a memory (which can be the memory 603 in the network device or terminal device, or an external memory). That is, the apparatus for the source host node, the target host node, and the IAB node may include a processor 601, and the processor 601 executes the method executed by the source host node, the target host node, and the IAB node in the above method embodiments by calling the program in the memory. The processor here can be an integrated circuit with signal processing capabilities, such as a CPU. The apparatus for the source host node, the target host node, and the IAB node can be implemented by configuring one or more integrated circuits to implement the above methods. For example: one or more ASICs, or one or more microprocessors DSPs, or one or more FPGAs, etc., or a combination of at least two of these integrated circuit forms. Alternatively, the above implementations can be combined.

[0296] For example, Figure 16 、 Figure 17 as well as Figure 18 The function / implementation process of the processing module in Figure 19The processor 601 in the communication device 60 shown calls the computer executable instructions stored in the memory 603 to implement, Figure 16 、 Figure 17 as well as Figure 18 The function / implementation process of the transceiver unit in Figure 19 It is implemented by the communication interface 602 in the communication device 60 shown in FIG.

[0297] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0298] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0299] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0300] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0301] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), disk or optical disk, and other media that can store program code.

[0302] It should be noted that the description in this application is applicable to all embodiments, and in order to avoid repetition, it is not described in detail in each embodiment. It should be understood that the "embodiment" mentioned throughout the specification means the specific features, structures or characteristics related to the embodiment, and these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present invention, the size of the sequence number of each process above does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

Claims

1. A node switching method, characterized in that: include: The target host node receives a handover request message sent by the source host node, where the handover request message includes context information of the integrated access backhaul IAB node and context information of at least one terminal device, and the handover request message is used to request that the IAB node and the at least one terminal device be handed over to the target host node, wherein the terminal device is directly connected to the IAB node, or the terminal device is connected to the IAB node through at least one other IAB node; The target host node sends a handover response message to the source host node, where the handover response message includes an identifier of an accepted terminal device among the at least one terminal device and / or an identifier of a rejected terminal device among the at least one terminal device; The target donor node includes a target Donor-CU, and the target Donor-CU sends a context establishment request message to the first IAB node. The context establishment request message carries an identifier of the terminal device, and the identifier of the terminal device includes an identifier of a cell through which the terminal device accesses the first IAB node and a C-RNTI identifier of the terminal device in the access cell. If the terminal device is directly connected to the IAB node, the first IAB node is the IAB node; If the terminal device is connected to the IAB node through at least one other IAB node, the first IAB node is the at least one other IAB node.

2. The node switching method according to claim 1, wherein: The context information of the IAB node also includes a Backhaul Adaptation Protocol (BAP) address allocated by the source host node to the IAB node.

3. The node switching method according to any one of claims 1 to 2, characterized in that: The context information of the IAB node further includes identifiers of child nodes of the IAB node, which are used to indicate a topological relationship between the IAB node and the child nodes of the IAB node.

4. The node switching method according to any one of claims 1 to 2, characterized in that: The context information of the IAB node also includes network topology list information; If the terminal device is directly connected to the IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the terminal device; If the terminal device is connected to the IAB node through at least one other IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the other IAB nodes, and between the other IAB nodes and the terminal device.

5. The node switching method according to any one of claims 1 to 2, characterized in that: The terminal device is connected to the IAB node through at least one other IAB node, the handover request message includes context information of the other IAB nodes, and the context information of the other IAB nodes includes the BAP address allocated by the source host node to the other IAB nodes.

6. The node switching method according to claim 5, characterized in that: The context information of the other IAB node also includes an identifier of a parent node of the other IAB node and / or an identifier of a child node of the other IAB node, which is used to indicate a topological relationship between the other IAB node and the parent node of the other IAB node and / or between the other IAB node and the child node of the other IAB node.

7. The node switching method according to any one of claims 1 to 2, characterized in that: The target host node includes a target Donor-CU. If the terminal device is connected to the IAB node via at least one other IAB node, the method further includes: The target donor-CU sends first indication information to the other IAB node, where the first indication information is used to indicate that the IAB node switching is completed.

8. The node switching method according to any one of claims 1 to 2, characterized in that: The target host node includes a target Donor-CU. If the terminal device is connected to the IAB node via at least one other IAB node, the method further includes: The target donor-CU sends second indication information to the other IAB node, where the second indication information is used to indicate that the IAB node is being switched or is preparing to be switched.

9. A node switching method, characterized in that: include: The source host node sends a handover request message to the target host node, where the handover request message includes context information of the integrated access and backhaul IAB node and context information of at least one terminal device, and the handover request message is used to request that the IAB node and at least one terminal device be handed over to the target host node, wherein the terminal device is directly connected to the IAB node, or the terminal device is connected to the IAB node through at least one other IAB node; The source host node receives a handover response message sent by the target host node, where the handover response message includes an identifier of an accepted terminal device among the at least one terminal device and / or an identifier of a rejected terminal device among the at least one terminal device; the target host node includes a target Donor-CU, and the target Donor-CU is used to send a context establishment request message to the first IAB node, where the context establishment request message carries an identifier of the terminal device, and the identifier of the terminal device includes an identifier of a cell through which the terminal device accesses the first IAB node and an identifier C-RNTI of the terminal device in the access cell; if the terminal device is directly connected to the IAB node, the first IAB node is the IAB node; If the terminal device is connected to the IAB node through at least one other IAB node, the first IAB node is the at least one other IAB node.

10. The node switching method according to claim 9, characterized in that: If the terminal device is connected to the IAB node through at least one other IAB node, the handover request message also includes context information of the other IAB node, and the handover response message also includes an identifier of the accepted other IAB node among the at least one other IAB node, and / or an identifier of the rejected other IAB node among the at least one other IAB node.

11. The node switching method according to claim 9 or 10, characterized in that: The context information of the IAB node further includes identifiers of child nodes of the IAB node, which are used to indicate a topological relationship between the IAB node and the child nodes of the IAB node.

12. The node switching method according to claim 9 or 10, characterized in that: The context information of the IAB node also includes network topology list information; If the terminal device is directly connected to the IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the terminal device; If the terminal device is connected to the IAB node through at least one other IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the other IAB nodes, and between the other IAB nodes and the terminal device.

13. The node switching method according to claim 10, characterized in that: The context information of the other IAB node also includes an identifier of a parent node of the other IAB node and / or an identifier of a child node of the other IAB node, which is used to indicate a topological relationship between the other IAB node and the parent node of the other IAB node and / or between the other IAB node and the child node of the other IAB node.

14. An IAB host node, characterized in that: include: a receiving unit, configured to receive a handover request message sent by a source host node, the handover request message including context information of an integrated access and backhaul IAB node and context information of at least one terminal device, the handover request message being used to request handover of the IAB node and at least one terminal device to a target host node, wherein the terminal device is directly connected to the IAB node, or the terminal device is connected to the IAB node through at least one other IAB node; a sending unit, configured to send a handover response message to the source host node, wherein the handover response message includes an identifier of an accepted terminal device among the at least one terminal device and / or an identifier of a rejected terminal device among the at least one terminal device; The target host node includes the target Donor-CU, The target Donor-CU sends a context establishment request message to the first IAB node, where the context establishment request message carries an identifier of the terminal device, where the identifier of the terminal device includes an identifier of a cell where the terminal device accesses the first IAB node and a C-RNTI identifier of the terminal device in the access cell; If the terminal device is directly connected to the IAB node, the first IAB node is the IAB node; If the terminal device is connected to the IAB node through at least one other IAB node, the first IAB node is the at least one other IAB node.

15. The IAB host node according to claim 14, wherein: The context information of the IAB node also includes a Backhaul Adaptation Protocol (BAP) address allocated by the source host node to the IAB node.

16. The IAB host node according to any one of claims 14 to 15, characterized in that: The context information of the IAB node further includes identifiers of child nodes of the IAB node, which are used to indicate a topological relationship between the IAB node and the child nodes of the IAB node.

17. The IAB host node according to any one of claims 14 to 15, characterized in that: The context information of the IAB node also includes network topology list information; If the terminal device is directly connected to the IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the terminal device; If the terminal device is connected to the IAB node through at least one other IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the other IAB nodes, and between the other IAB nodes and the terminal device.

18. The IAB host node according to any one of claims 14 to 15, characterized in that: The terminal device is connected to the IAB node through at least one other IAB node, the handover request message includes context information of the other IAB nodes, and the context information of the other IAB nodes includes the BAP address allocated by the source host node to the other IAB nodes.

19. The IAB host node according to claim 18, wherein: The context information of the other IAB node also includes an identifier of a parent node of the other IAB node and / or an identifier of a child node of the other IAB node, which is used to indicate a topological relationship between the other IAB node and the parent node of the other IAB node and / or between the other IAB node and the child node of the other IAB node.

20. The IAB host node according to any one of claims 14 to 15, wherein: The target host node includes a target Donor-CU, if the terminal device is connected to the IAB node through at least one other IAB node; The target donor-CU sends first indication information to the other IAB node, where the first indication information is used to indicate that the IAB node switching is completed.

21. The IAB host node according to any one of claims 14 to 15, wherein: The target host node includes a target Donor-CU. If the terminal device is connected to the IAB node via at least one other IAB node, The target donor-CU sends second indication information to the other IAB node, where the second indication information is used to indicate that the IAB node is being switched or is preparing to be switched.

22. An IAB host node, characterized in that: include: a sending unit, configured to send a handover request message to a target host node, the handover request message including context information of the integrated access and backhaul IAB node and context information of at least one terminal device, the handover request message being used to request handover of the IAB node and at least one terminal device to the target host node, wherein the terminal device is directly connected to the IAB node, or the terminal device is connected to the IAB node through at least one other IAB node; A receiving unit, configured to receive a switching response message sent by the target host node, the switching response message including an identifier of an accepted terminal device among the at least one terminal device, and / or an identifier of a rejected terminal device among the at least one terminal device; the target host node includes a target Donor-CU, the target Donor-CU is configured to send a context establishment request message to the first IAB node, the context establishment request message carries the identifier of the terminal device, the identifier of the terminal device includes the cell identifier of the terminal device accessing the first IAB node and the identifier C-RNTI of the terminal device in the access cell; if the terminal device is directly connected to the IAB node, the first IAB node is the IAB node; if the terminal device is connected to the IAB node through at least one other IAB node, the first IAB node is the at least one other IAB node.

23. The IAB host node according to claim 22, wherein: If the terminal device is connected to the IAB node through at least one other IAB node, the handover request message also includes context information of the other IAB node, and the handover response message also includes an identifier of the accepted other IAB node among the at least one other IAB node, and / or an identifier of the rejected other IAB node among the at least one other IAB node.

24. The IAB host node according to claim 22 or 23, wherein: The context information of the IAB node further includes identifiers of child nodes of the IAB node, which are used to indicate a topological relationship between the IAB node and the child nodes of the IAB node.

25. The IAB host node according to claim 22 or 23, characterized in that: The context information of the IAB node also includes network topology list information; If the terminal device is directly connected to the IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the terminal device; If the terminal device is connected to the IAB node through at least one other IAB node, the network topology list information is used to indicate the topological relationship between the IAB node and the other IAB nodes, and between the other IAB nodes and the terminal device.

26. The IAB host node according to claim 23, wherein: The context information of the other IAB node also includes an identifier of a parent node of the other IAB node and / or an identifier of a child node of the other IAB node, which is used to indicate a topological relationship between the other IAB node and the parent node of the other IAB node and / or between the other IAB node and the child node of the other IAB node.

27. A communication device, characterized in that: include: A processor, the processor being coupled to a memory, the memory being used to store a computer program or instructions, the processor being used to execute the computer program or instructions in the memory, so that the computer performs the method according to any one of claims 1 to 8, or the computer performs the method according to any one of claims 9 to 13.

28. A communication system comprising the IAB host node according to any one of claims 14 to 21 and the IAB host node according to any one of claims 22 to 26.

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