CN117835337A

CN117835337A - Communication method and related equipment

Info

Publication number: CN117835337A
Application number: CN202211183378.0A
Authority: CN
Inventors: 朱世超; 史玉龙; 朱元萍; 孙飞
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-09-27
Filing date: 2022-09-27
Publication date: 2024-04-05
Also published as: WO2024066947A1

Abstract

The application provides a communication method and related equipment, which are used for saving the overhead for triggering the cell switching process and improving the execution speed of cell switching so as to improve the success rate of cell switching. In the method, a terminal device receives a first message, wherein the first message comprises switching configuration information of N cells, and N is a positive integer, and the switching configuration information is used for a cell switching process triggered based on a second message; the terminal device performs cell handover based on the handover configuration information after receiving the second message.

Description

Communication method and related equipment

Technical Field

The present disclosure relates to the field of wireless communications technologies, and in particular, to a communication method and related devices.

Background

In the communication system, after the terminal equipment accesses a certain cell, the cell accessed by the terminal equipment can be switched by a cell switching mode. The cell to which the terminal device accesses may be referred to as a source cell before the cell handover is performed, and the cell to which the terminal device accesses may be referred to as a target cell after the cell handover is performed.

At present, in the implementation process of cell switching, after detecting signal quality deterioration with a terminal device, a source cell can issue a switching message carrying configuration information of a target cell, so that the terminal device can access the target cell based on the configuration information of the target cell after receiving the message.

However, in the above implementation, the network device needs to trigger sending the handover message to the terminal device only when the signal quality is detected to be degraded, which may cause slow transmission of the handover message due to the poor signal quality, affect the speed of cell handover, and even cause cell handover failure.

Disclosure of Invention

The application provides a communication method and related equipment, which are used for saving the overhead for triggering the cell switching process and improving the execution speed of cell switching so as to improve the success rate of cell switching.

The first aspect of the present application provides a communication method, where the method is performed by a terminal device, or where the method is performed by a part of a component (e.g. a processor, a chip or a system on a chip, etc.) in the terminal device, or where the method may also be implemented by a logic module or software that is capable of implementing all or part of the functions of the terminal device. In the first aspect and its possible implementation manner, the communication method is described as an example executed by the terminal device. In the method, a terminal device receives a first message, wherein the first message comprises switching configuration information of N cells, and N is a positive integer, and the switching configuration information is used for a cell switching process triggered based on a second message; the terminal device performs cell handover based on the handover configuration information after receiving the second message.

Based on the above technical solution, the terminal device receives a first message including handover configuration information of N cells, where the handover configuration information is used for a cell handover procedure triggered based on a second message, and after receiving the second message, the terminal device performs cell handover based on the handover configuration information. Compared with the implementation mode that the configuration information of the target cell is carried in the handover message triggering the cell handover, the terminal equipment can acquire the handover configuration information used for the cell handover process triggered based on the second message in advance, and can trigger the cell handover to be performed based on the handover configuration information after receiving the second message. Therefore, under the condition that the terminal equipment is required to be scheduled to execute the cell switching, the second message which is issued to the terminal equipment and used for triggering the execution of the cell switching does not need to carry the switching configuration information of the target cell, the cost of the triggering process can be saved, the execution speed of the cell switching is improved, and the success rate of the cell switching is improved.

In addition, compared to the implementation manner in which the terminal device locally triggers the cell switch based on the measurement event of the signal quality degradation, the above technical solution for triggering and executing the cell switch through the second message can support more cell switch scenarios, that is, in the case where the signal quality between the terminal device and the source cell is not degraded (for example, in the case where the access backhaul integrated (integrated access and backhaul, IAB) node where the source cell is located has a cross Centralized Unit (CU) to migrate and enable the target cell corresponding to the target CU, or in the case where the IAB node where the source cell is located needs to schedule the terminal device to connect to another cell in the IAB node, or in the case where the IAB node where the source cell is located determines that the source cell is to be turned off or deactivated, etc.), the cell switch can still be executed through the second message triggering, so that in the case where the signal quality is not degraded, the above technical solution can obtain the overhead of saving the triggering process and the gain of the execution speed of the cell switch, and also avoid the situation that the cell switch cannot be executed due to the local triggering of the terminal device.

In a possible implementation manner of the first aspect, the second message includes first information, where the first information is carried in any one of the following: a short message (short message) field in downlink control information (download control information, DCI) of a physical downlink control channel (physical download control channel, PDCCH) scrambled by a paging radio network temporary identity (paging radio network temporary identifier, P-RNTI); information in Paging Occasions (POs); or, any one of the N cells broadcasts information.

Based on the above technical solution, the second message may be implemented by any one of the above, in other words, the source cell or the N cells may trigger the terminal device to perform cell handover by any one of the above ways, so as to improve flexibility of implementation of the solution.

It can be appreciated that, in the case that the first information is carried in the short message field, the second message may be a DCI message; in the case that the first information is carried in the PO, the second message may be a message that the PO indicates that the system information is updated; in the case where the first information is carried in any broadcast information of the N cells, the second message may be a message broadcast by any one of the N cells.

In a possible implementation manner of the first aspect, the first message further includes at least one of the following: the first indication information indicates that the switching configuration information is used for a cell switching process triggered based on the second message; or, second indication information indicating that the second message is monitored over all of the POs.

Optionally, all POs indicated by the second indication information refer to all POs in a Paging Frame (PF) that the terminal device can perceive, or all POs indicated by the second indication information refer to any POs in the PF that the terminal device can perceive.

Based on the above technical solution, the first message including the handover configuration information of the N cells may further include at least one indication information, and the indication information is displayed to indicate that the handover configuration information is used for a cell handover process triggered based on the second message, and/or indicate that the second message is monitored on all POs, so that the terminal device explicitly performs cell handover based on the indication information carried by the display.

In a possible implementation manner of the first aspect, the second message is a broadcast message.

Based on the above technical solution, the handover configuration information carried by the first message is used for triggering a cell handover process based on the second message, that is, the second message is used for triggering the terminal device to execute the cell handover process, so that the implementation mode of the message (that is, the broadcast message) sent by the second message in a broadcast manner can trigger the plurality of terminal devices to execute cell handover based on the scheduling of the broadcast message, so as to save the overhead. And, the sending speed of the second message can be improved, so that the speed of triggering and executing the cell switching by a plurality of terminal devices based on the broadcast message is improved.

In a possible implementation manner of the first aspect, N has a value of 1.

Based on the above technical solution, when the value of N is 1, the implementation manner that the first message includes the handover configuration information of a certain cell can save the overhead of the first message, and also can reduce the overhead of the terminal device for monitoring signals of a plurality of cells in the process of executing cell handover.

In a possible implementation manner of the first aspect, the handover configuration information is conditional handover (conditional handover, CHO) configuration information.

Optionally, when the handover configuration information included in the first message is CHO configuration information, a trigger condition corresponding to the CHO configuration information is triggered based on the second message. In addition, the CHO configuration information is the name of the handover configuration information in the current standard/protocol for triggering the cell handover based on the triggering condition, and in future standards/protocols, the CHO configuration information may be other names, which is not limited herein.

The second aspect of the present application provides a communication method, where the method is performed by a terminal device, or where the method is performed by a part of a component (e.g. a processor, a chip or a system on a chip, etc.) in the terminal device, or where the method may also be implemented by a logic module or software that is capable of implementing all or part of the functions of the terminal device. In the second aspect and its possible implementation manner, the communication method is described as an example executed by the terminal device. In the method, the terminal equipment receives a first message, wherein the first message comprises switching configuration information of N cells, and N is a positive integer; and after determining (within a preset duration) that the second message is not received or determining that the indication information indicating the cell handover procedure cancellation corresponding to the handover configuration information is received, the terminal equipment ignores or deletes the handover configuration information, wherein the second message is used for triggering the cell handover procedure corresponding to the handover configuration information.

Based on the above technical solution, after receiving a first message including a handover configuration of N cells, the terminal device ignores or deletes the handover configuration information after determining that a second message (the second message is used to trigger a cell handover procedure corresponding to the handover configuration information) is not received or determining that indication information indicating cancellation of the cell handover procedure corresponding to the handover configuration information is received. Compared to the implementation manner that the terminal device triggers the cell handover when receiving the handover message carrying the configuration information of the target cell, the terminal device may acquire the handover configuration information for the cell handover procedure triggered based on the second message in advance, and may determine to ignore or delete the handover configuration information based on the scheduling of the network device (e.g. the network device does not issue the second message, or the network device sends the indication information to cancel the cell handover, etc.), i.e. the terminal device may determine not to perform the cell handover based on the scheduling of the network device, so as to avoid the cell handover failure.

In a possible implementation manner of the second aspect, the handover configuration information is used for a cell handover procedure triggered based on the second message, or the handover configuration information is CHO configuration information triggered based on a measurement event.

Based on the technical scheme, the configuration information of the N cells carried by the first message can be realized in the plurality of modes, so that the flexibility of scheme realization is improved.

A third aspect of the present application provides a communication method, which is performed by the source CU, or by a part of the components (e.g. a processor, a chip or a system-on-chip, etc.) in the source CU, or which may be implemented by a logic module or software that is capable of implementing all or part of the functions of the source CU. In the third aspect and its possible implementation manner, the communication method is described as being executed by the source CU as an example. In the method, a source CU determines a first message, wherein the first message comprises switching configuration information of N cells, N is a positive integer, and the switching configuration information is used for a cell switching process triggered based on a second message; wherein the N cells are located in a target centralized unit (DU); the source CU sends the first message to the terminal device via the IAB node.

Based on the above technical solution, the first message sent by the source CU to the terminal device through the IAB node includes handover configuration information of N cells, and the handover configuration information is used for a cell handover procedure triggered based on the second message. Compared with the implementation mode that the configuration information of the target cell is carried in the switching message for triggering and executing the cell switching, the terminal equipment can acquire the switching configuration information used for the cell switching process triggered based on the second message in advance, and can trigger and execute the cell switching based on the switching configuration information after receiving the second message, so that the success rate of the cell switching is improved.

In a possible implementation manner of the third aspect, the target DU is located in the IAB node.

Based on the above technical solution, the IAB node connected to the terminal device includes a source DU where a source cell is located, and when a target DU where the target cell is located in the IAB node where the source DU is located, the solution can be applied to a scenario where the terminal device performs cell switching between different DUs in the same IAB node (or a scenario where the IAB node performs migration across CUs and enables the target cell corresponding to the target CU).

Alternatively, in the case that the target DU is located in the IAB node, the terminal device and the IAB node may be a direct link (i.e. there are no other IAB nodes between them), or the terminal device and the IAB node may also be a non-direct link (i.e. there may be other IAB nodes between them), which is not limited herein.

Alternatively, the target DU may be located in other IAB nodes as well.

In a possible implementation manner of the third aspect, the method further includes: after determining that the target DU and the target CU have established F1 connection, the source CU sends a switching request message of the terminal to the target CU; the source CU receives a handover response message from the target CU, the handover response message including the handover configuration information.

Based on the above technical solution, after determining that the target DU and the target CU have established the F1 connection, the source CU determines that the cell under the target DU can be used as a potential target cell, and for this purpose, the source CU may acquire the handover configuration information with the target CU through an interaction manner of the handover request message and the handover response message, so that the source CU sends a first message including the handover configuration information to the terminal device.

In a possible implementation manner of the third aspect, the method further includes: the source CU sends the second message to the terminal device.

Based on the above technical solution, the source CU may further send the second message to the terminal device, so that the terminal device triggers to execute cell handover based on the second message. Compared with the implementation mode that the configuration information of the target cell is carried in the handover message triggering the cell handover, the terminal equipment can acquire the handover configuration information used for the cell handover process triggered based on the second message in advance, and can trigger the cell handover to be performed based on the handover configuration information after receiving the second message. Therefore, under the condition that the terminal equipment is required to be scheduled to execute the cell switching, the second message which is issued to the terminal equipment and used for triggering the execution of the cell switching does not need to carry the switching configuration information of the target cell, the cost of the triggering process can be saved, the execution speed of the cell switching is improved, and the success rate of the cell switching is improved.

In addition, compared to the implementation manner in which the terminal device locally triggers the cell switch based on the measurement event of the signal quality degradation, the above technical solution for performing the cell switch by triggering through the second message can support more cell switch scenarios, that is, in the case where the signal quality between the terminal device and the source cell is not degraded (for example, in the case where the IAB node where the source cell is located migrates across CUs and enables the target cell corresponding to the target CU, or in the case where the IAB node where the source cell is located needs to schedule the terminal device to connect to another cell in the IAB node, or in the case where the IAB node where the source cell is located determines that the source cell is to be turned off or deactivated, etc.), the cell switch can still be performed by triggering through the second message, so that in the case where the signal quality is not degraded, the above technical solution can obtain the gain that saves the overhead of the triggering process and increases the execution speed of the cell switch, the situation that the terminal device cannot perform the cell switch due to the local triggering of the cell switch, can be avoided.

In a possible implementation manner of the third aspect, the source CU sends the second message to the terminal device when at least one of the following is satisfied, including: the source CU determines that the target DU and the target CU have established F1 connection; the source CU determines that the mobile terminal (mobile termination, MT) in the IAB node is to be handed over to the target CU; or, the source CU receives an indication from the target CU to allow the terminal device to perform a cell handover based on the handover configuration information.

Based on the above technical solution, when at least one of the above items is satisfied, the source CU determines that the terminal device is currently capable of performing cell handover and successfully switches to N cells under the target DU, and for this purpose, the source CU may send a second message to the terminal device, so that the terminal device triggers to perform cell handover based on the received second message.

In a possible implementation manner of the third aspect, the source CU sends the first message when any one of the following is satisfied, including: after sending a first switching request message to the target CU, the source CU receives a first switching response message from the target CU, wherein the first switching response message comprises switching configuration information of N cells; after the source CU sends a second switching request message to the target CU, receiving a second switching response message from the target CU, wherein the second switching request message comprises N cell identifiers and N cells are inactive cells; or, after receiving the first configuration information from the target DU and transmitting the first configuration information to the target CU, the source CU receives handover configuration information of N cells from the target CU, where the handover configuration information of the N cells includes the first configuration information and the second configuration information.

Based on the above technical solution, when at least one item is satisfied, the source CU determines that the cell under the target DU will be a potential target cell, and for this reason, the source CU may send a first message including handover configuration information of N cells to the terminal device, so that the handover configuration information of N cells is issued before the handover condition is satisfied, so that in a case where it is determined that the terminal device needs to be scheduled to switch to the N cells and issue a scheduling message, signaling consumption of the scheduling message can be saved, so as to improve a cell handover success rate.

In a possible implementation manner of the third aspect, the first configuration information includes radio link control (radio link control, RLC) layer configuration information and/or medium access control (media access control, MAC) layer configuration information, and the second configuration information includes packet data convergence protocol (packet data convergence protocol, PDCP) layer configuration information and/or service data adaptation protocol (service data adaptation protocol, SDAP) layer configuration information.

Based on the above technical solution, in the case that the F1 connection has not been established between the target DU and the target CU, the target DU may send the first configuration information (including RLC and/or MAC layer configuration information) to the target CU through the source CU, so that the target CU determines handover configuration information (including RLC and/or MAC configuration information and PDCP and/or SDAP configuration information) of N cells under the target DU based on the first configuration information, and the target CU may send the handover configuration information of the N cells to the terminal device through the source CU in a first message.

Alternatively, the handover configuration information of the N cells sent by the target CU to the source CU may be carried in a handover response message (e.g., the first handover response message or the second handover response message, etc. as described above), or other message.

In a possible implementation manner of the third aspect, the determining, by the source CU, that the target DU and the target CU have established an F1 connection includes: the source CU determines that the target DU has established an F1 connection with the target CU based on third indication information from the target CU, the third indication information indicating that the terminal device performs cell handover based on the handover configuration information.

Based on the above technical solution, the source CU may determine, through the third indication information sent by the target CU, that the target DU and the target CU have established an F1 connection, and further determine that the terminal device may successfully perform cell handover to the target DU based on the handover configuration information.

Alternatively, the third indication information may be implemented in other manners, for example, the third indication information indicates that the terminal device is allowed to perform cell handover based on the handover configuration information; as another example, the third indication information indicates (allows) the source CU to send handover configuration information of N cells to the terminal device; as another example, the third indication information indicates that N cells in the target DU have been activated.

In a possible implementation manner of the third aspect, the second message includes first information, where the first information is carried in any one of the following: a short message field in DCI of the P-RNTI scrambled PDCCH; information in the PO; or, any one of the N cells broadcasts information.

In a possible implementation manner of the third aspect, the first message further includes at least one of the following: the first indication information indicates that the switching configuration information is used for a cell switching process triggered based on the second message; or, second indication information indicating that the second message is monitored over all of the POs.

In a possible implementation manner of the third aspect, the second message is a broadcast message.

In a possible implementation manner of the third aspect, N has a value of 1.

In a possible implementation manner of the third aspect, the handover configuration information is conditional handover (conditional handover, CHO) configuration information.

In a possible implementation manner of the third aspect, the method further includes: and the source CU sends indication information for indicating the cell switching process cancellation corresponding to the switching configuration information to the terminal equipment.

Optionally, the source CU may also implicitly indicate that the cell handover procedure corresponding to the handover configuration information is cancelled by other means, e.g. the source CU does not send the second message (within a preset time period).

Based on the above technical solution, the terminal device may acquire in advance the handover configuration information for the cell handover procedure triggered based on the second message, and may determine to ignore or delete the handover configuration information based on the scheduling of the source CU (e.g., the source CU does not issue the second message, or the source CU sends the indication information to cancel the cell handover, etc.), i.e., the terminal device may determine not to perform the cell handover based on the scheduling of the network device, so as to avoid the cell handover failure.

A fourth aspect of the present application provides a communication method, where the method is performed by the target CU, or where the method is performed by a part of the components (e.g., a processor, a chip, or a chip system, etc.) in the target CU, or where the method may also be implemented by a logic module or software that is capable of implementing all or part of the functions of the target CU. In the fourth aspect and its possible implementation manner, the description is given by taking the example that the communication method is executed by the target CU. In the method, after determining that an F1 connection has been established with a target DU, the target CU determines third indication information indicating that the terminal device is allowed to perform cell handover based on the handover configuration information, the target DU including N cells, N being a positive integer; the switching configuration information is used for a cell switching process triggered based on the second message; the target CU sends the third indication information to the source CU.

Based on the above technical solution, after determining that the F1 connection is established with the target CU, the target CU may determine that the terminal device can be handed over to N cells included in the target DU based on the cell handover procedure, for this purpose, the target CU sends third indication information to the source CU indicating that the terminal device is allowed to perform cell handover based on the handover configuration information, so that the source CU determines that the terminal device can be triggered to perform cell handover based on the third indication information. The switching configuration information is used for triggering a cell switching process based on the second message, so that the terminal equipment can trigger to execute cell switching based on the switching configuration information after receiving the second message, and the success rate of cell switching is improved. Compared with the implementation mode that the switching information for triggering and executing the cell switching carries the configuration information of the target cell, when the source CU determines that the terminal equipment needs to be scheduled to execute the cell switching based on the third indication information from the target CU, the second information for triggering and executing the cell switching, which is issued to the terminal equipment, does not need to carry the switching configuration information of the target cell, so that the cost of the triggering process can be saved, the executing speed of the cell switching can be improved, and the success rate of the cell switching can be improved.

In a possible implementation manner of the fourth aspect, the sending, by the target CU, the third indication information to the source CU includes: the target CU sends the third indication information to the source CU after determining that the target DU has configured the context of the terminal device.

Based on the above technical solution, after determining that the target DU has configured the context of the terminal device, the target CU may determine that the terminal device is able to access the network through N cells included in the target DU, and for this purpose, the target CU may send the third indication information to the source CU, so that the source CU schedules the terminal device to perform cell handover based on the third indication information from the target CU.

In a possible implementation manner of the fourth aspect, before the target CU sends the third indication information to the source CU, the method further includes: the target CU receives a second switching request message from the source centralized unit CU, wherein the second switching request message comprises the identifications of N cells, and the N cells are inactive cells; wherein N cells are located in the target DU; the target CU sends a second handover response message to the source CU, the second handover response message including handover configuration information of the N cells.

Based on the above technical solution, before the target CU sends the third indication information to the source CU, interaction between the target CU and the source CU may be performed by using the second handover request message and the second handover response message, so that after the target CU determines corresponding handover configuration information based on the N cells that are not activated, the handover configuration information is sent to the terminal device by using the source CU, so that the terminal device can execute a cell handover process corresponding to the handover configuration information based on the trigger of the second message.

In a possible implementation manner of the fourth aspect, before the target CU sends the third indication information to the source CU, the method further includes: after receiving the first configuration information from the source centralized unit CU, the target CU sends handover configuration information of N cells to the source CU, where the handover configuration information of N cells includes the first configuration information and the second configuration information.

Optionally, the first configuration information includes RLC layer configuration information and/or MAC layer configuration information, and the second configuration information includes PDCP layer configuration information and/or SDAP layer configuration information.

Based on the above technical solution, in the case that the F1 connection has not been established between the target DU and the target CU, the target DU may send the first configuration information (including RLC and/or MAC layer configuration information) to the target CU through the source CU, so that the target CU determines handover configuration information (including RLC and/or MAC configuration information and PDCP and/or SDAP configuration information) of N cells under the target DU based on the first configuration information, and the target CU may send the handover configuration information of the N cells to the terminal device through the source CU in a first message manner, so that the terminal device may execute a cell handover procedure corresponding to the handover configuration information based on triggering of the second message.

A fifth aspect of the present application provides a communication method, where the method is performed by the first CU, or where the method is performed by a part of the components (e.g. a processor, a chip or a system-on-chip, etc.) in the first CU, or where the method may also be implemented by a logic module or software that is capable of implementing all or part of the functions of the first CU. In a fifth aspect and its possible implementation manner, the communication method is described by taking the first CU as an example. In the method, the first CU determines third configuration information including third configuration information of the first DU; wherein the first DU is located at an IAB node, the IAB node further comprising a second DU and an MT; the first CU sends the third configuration information to the IAB node.

Based on the above-mentioned technical solution, in a case where the first CU has a communication connection with the IAB node (for example, in a case where the first CU has a radio resource control (radio resource control, RRC) connection with an MT in the IAB node and/or in a case where the first CU has an F1 connection with a second DU in the IAB node), the first CU may send third configuration information of the first DU (i.e., other DUs than the second DU) to the IAB node, so that the first DU can communicate based on the third configuration information. The MT in the IAB node can acquire the third configuration information and communicate based on the third configuration information without receiving the configuration information from the first CU through the RRC connection again. Therefore, in a case where the MT in the IAB node cannot acquire the configuration information from the first CU in time (for example, in a case where the MT and the first DU are respectively connected to different CUs to perform communication, for example, in a case where the MT and the first DU are both switched to the same CU but the switching timing of the MT is later than that of the first DU, etc.), the first DU can be enabled to perform communication based on the third configuration information, so as to avoid the situation that the first DU cannot perform communication due to the lack of the third configuration information.

In a possible implementation manner of the fifth aspect, the third configuration information is carried in an F1 application protocol (F1 application protocol, F1 AP) message, or the third configuration information is carried in an RRC message.

Based on the above technical solution, the first CU may send the third configuration information to the IAB node in a plurality of ways. The third configuration information may be transmitted through an F1 connection between the second DU and the first CU in the IAB node, that is, the third configuration information may be carried in an F1 AP message on the F1 connection. Alternatively, the third configuration information may be transmitted over an RRC connection between the MT and the first CU in the IAB node, i.e. the third configuration information may be carried on an RRC message on the RRC connection.

In a possible implementation manner of the fifth aspect, the third configuration information includes at least one of the following: -a new wireless cell global identity (new radio cell global identifier, NCGI) for determining the CU identity of the NCGI, or-a first key for the first DU to establish encrypted communication of the F1 connection with other CUs, or-a physical cell identity (physical cell identifier, PCI) of the cells in the first DU.

Optionally, the third configuration information sent by the first CU to the IAB node may include configuration information of the first DU and other communication nodes (such as a CU or other IAB node or terminal device, etc.), where the configuration information may include the NCGI described above, a CU identifier used to determine the NCGI, a PCI, or other configuration information, which is not limited herein.

In a possible implementation manner of the fifth aspect, after the first CU sends the third configuration information to the IAB node, the method further includes: the first CU receives fourth indication information for indicating that the third configuration information of the first DU is valid, or for indicating that the first CU transmits a handover command to a terminal device to which the second DU is connected, or for indicating that the first DU has transmitted a third message determined based on the third configuration information.

Based on the above technical solution, in the case that the first DU is capable of communicating based on the third configuration information, the first DU may further send indication information to the first CU, so that the first CU determines that the first DU has validated the third configuration information, and subsequently the first CU may schedule the first DU and/or a terminal device connected to the first DU based on the third configuration information.

A sixth aspect of the present application provides a communication method, where the method is performed by an IAB node, or where the method is performed by some components (e.g., a processor, a chip, or a system-on-chip, etc.) in the IAB node, or where the method may also be implemented by a logic module or software that is capable of implementing all or part of the IAB node functionality. In a sixth aspect and its possible implementation manner, the communication method is described as being executed by an IAB node as an example. In the method, the IAB node receives third configuration information, the third configuration information comprising third configuration information of the first DU; the IAB node sends a third message, wherein the third message is obtained based on the third configuration information.

Based on the above technical solution, in a case where the first CU has a communication connection with the IAB node (for example, in a case where the first CU has an RRC connection with an MT in the IAB node and/or where the first CU has an F1 connection with a second DU in the IAB node), the IAB node receives third configuration information of the first DU (i.e., other DUs than the second DU) from the first CU, so that the first DU can send a third message obtained based on the third configuration information. The MT in the IAB node can acquire the third configuration information and communicate based on the third configuration information without receiving the configuration information from the first CU through the RRC connection again. Therefore, in a case where the MT in the IAB node cannot acquire the configuration information from the first CU in time (for example, in a case where the MT and the first DU are respectively connected to different CUs to perform communication, for example, in a case where the MT and the first DU are both switched to the same CU but the switching timing of the MT is later than that of the first DU, etc.), the first DU can be enabled to perform communication based on the third configuration information, so as to avoid the situation that the first DU cannot perform communication due to the lack of the third configuration information.

In a possible implementation manner of the sixth aspect, the third configuration information is carried in an F1 AP message, or the third configuration information is carried in an RRC message.

In a possible implementation manner of the sixth aspect, the third configuration information includes at least one of the following: the new wireless cell global identity NCGI, a CU identity for determining the NCGI, a first key for the first DU to establish encrypted communications for the F1 connection with other CUs, or a physical cell identity PCI for the cell in the first DU.

Optionally, the third configuration information sent by the first CU to the IAB node may include configuration information of the first DU and other communication nodes (e.g., the CU or other IAB nodes or terminal devices, etc.), where the configuration information may include the NCGI described above, a CU identifier used to determine the NCGI, a PCI, or other configuration information, which is not limited herein.

In a possible implementation manner of the sixth aspect, the first DU sends the third message when at least one of the following is satisfied, including: the MT of the IAB node determines that the execution condition of cell switching is satisfied, and a target cell corresponding to the cell switching is positioned on the other CU; the first DU of the IAB node determining to establish an F1 connection with the other CU; or, the IAB node detects that the PCI of any cell under the first DU collides with other PCI.

Based on the above technical solution, in case the first DU determines that the above at least one item is satisfied, the first DU may determine that communication may be performed based on the third configuration information, and for this purpose, the first DU may transmit a third message derived based on the third configuration information.

In a possible implementation manner of the sixth aspect, after the first DU sends the third message, the method further includes: the first DU sends fourth indication information to the first CU, where the fourth indication information is used to indicate that the third configuration information of the first DU is valid, or is used to instruct the first CU to send a handover command to a terminal device connected to the first DU.

In a possible implementation manner of the sixth aspect, the third message includes a synchronization signal/physical broadcast channel block (synchronization signal/physical broadcast channel PBCH block, SS/PBCH block) (may be abbreviated as SS/PBCH block or SSB) sent by the first DU to the terminal device, or an F1 connection establishment request message sent by the first DU to the other CU.

Optionally, the third message may include other messages of the first DU and a subordinate communication node (e.g., a terminal device or other IAB node) in addition to the SSB described above.

Optionally, the third message may include other messages of the first DU and the upper level communication node (e.g., CU or other IAB node) in addition to the above-mentioned F1 connection establishment request message, which is not limited herein.

A seventh aspect of the present application provides a communication apparatus, where the apparatus is a terminal device, or where the apparatus is a part of a component (such as a processor, a chip, or a chip system, etc.) in the terminal device, or where the apparatus may also be a logic module or software capable of implementing all or part of the functions of the terminal device. In a seventh aspect and its possible implementation manner, the communication apparatus is described as an example of execution for a terminal device. The device comprises a receiving and transmitting unit and a processing unit; the receiving and transmitting unit is used for receiving a first message, wherein the first message comprises switching configuration information of N cells, N is a positive integer, and the switching configuration information is used for triggering a cell switching process based on a second message; the processing unit is configured to perform cell handover based on the handover configuration information after the transceiver unit receives the second message.

In a possible implementation manner of the seventh aspect, the second message includes first information, where the first information is carried in any one of the following:

a short message field in downlink control information DCI of a physical downlink control channel PDCCH scrambled by a paging radio network temporary identifier P-RNTI;

information in paging opportunity PO; or alternatively, the first and second heat exchangers may be,

any of the N cells broadcasts information.

In a possible implementation manner of the seventh aspect, the first message further includes at least one of the following:

the first indication information indicates that the switching configuration information is used for a cell switching process triggered based on the second message; or alternatively, the first and second heat exchangers may be,

and second indication information indicating that the second message is monitored over all of the POs.

In a possible implementation manner of the seventh aspect, the second message is a broadcast message.

In a possible implementation manner of the seventh aspect, N has a value of 1.

In a possible implementation manner of the seventh aspect, the handover configuration information is conditional handover CHO configuration information.

In the seventh aspect of the embodiments of the present application, the constituent modules of the communication device may also be configured to execute the steps executed in each possible implementation manner of the first aspect, and achieve corresponding technical effects, and all details may refer to the first aspect, which is not described herein.

An eighth aspect of the present application provides a communication apparatus, where the apparatus is a terminal device, or the apparatus is a part of a component (such as a processor, a chip, or a chip system, etc.) in the terminal device, or the apparatus may also be a logic module or software capable of implementing all or part of the functions of the terminal device. In the eighth aspect and its possible implementation manner, the description is given taking the communication apparatus as an example of execution of the terminal device. The device comprises a receiving and transmitting unit and a processing unit; the receiving and transmitting unit is used for receiving a first message, wherein the first message comprises switching configuration information of N cells, and N is a positive integer; the processing unit is configured to ignore or delete the handover configuration information after determining that the second message is not received (the second message is used to trigger a cell handover procedure corresponding to the handover configuration information) or determining that indication information indicating cancellation of the cell handover procedure corresponding to the handover configuration information is received.

In a possible implementation manner of the eighth aspect, the handover configuration information is used for a cell handover procedure triggered based on the second message.

In a possible implementation manner of the eighth aspect, the handover configuration information is conditional handover CHO configuration information triggered based on a measurement event.

In the eighth aspect of the embodiments of the present application, the constituent modules of the communication device may also be configured to execute the steps executed in each possible implementation manner of the second aspect, and achieve corresponding technical effects, and all details may refer to the second aspect, which is not described herein.

A ninth aspect of the present application provides a communication method, where the apparatus is a source CU, or the apparatus is a part of a component (such as a processor, a chip, or a chip system, etc.) in the source CU, or the apparatus may also be a logic module or software capable of implementing all or part of the functions of the source CU. In the ninth aspect and its possible implementation manner, the description is given taking the communication device as a source CU execution example. The device comprises a receiving and transmitting unit and a processing unit; the processing unit is used for determining a first message, the first message comprises switching configuration information of N cells, N is a positive integer, and the switching configuration information is used for triggering a cell switching process based on a second message; wherein, N cells are located in the target DU; the transceiver unit is configured to send the first message to the terminal device through the access backhaul integrated IAB node.

In a possible implementation manner of the ninth aspect, the target DU is located in the IAB node.

In a possible implementation manner of the ninth aspect, the transceiver unit is further configured to send a handover request message of the terminal to the target CU after the processing unit determines that the target DU has established an F1 connection with the target centralized unit CU; the transceiver unit is further configured to receive a handover response message from the target CU, where the handover response message includes the handover configuration information.

In a possible implementation manner of the ninth aspect, the transceiver unit is further configured to send the second message to the terminal device.

In a possible implementation manner of the ninth aspect, the sending and receiving unit sends the second message to the terminal device when at least one of the following is satisfied, including:

the processing unit determines that the target DU and the target CU have established an F1 connection;

the processing unit determining that a mobile terminal MT in the IAB node is to be handed over to the target CU; or alternatively, the first and second heat exchangers may be,

the processing unit determines that receiving the indication from the target CU allows the terminal device to perform a cell handover based on the handover configuration information.

In a possible implementation manner of the ninth aspect, the sending and receiving unit sends the first message when any one of the following is satisfied, including:

the processing unit determines that after the transceiver unit sends a first switching request message to the target CU, the first switching response message from the target CU is received, wherein the first switching response message comprises switching configuration information of N cells;

The processing unit determines that the transceiver unit sends a second handover request message to the target CU, and then receives a second handover response message from the target CU, where the second handover request message includes identifiers of N cells and the N cells are inactive cells; or alternatively, the first and second heat exchangers may be,

the processing unit determines that the transceiving unit receives the first configuration information from the target DU and transmits the first configuration information to the target CU, and then receives handover configuration information of N cells from the target CU, where the handover configuration information of the N cells includes the first configuration information and the second configuration information.

In a possible implementation manner of the ninth aspect, the first configuration information includes radio link control RLC layer configuration information and/or medium access control MAC layer configuration information, and the second configuration information includes packet data convergence protocol PDCP layer configuration information and/or service data adaptation protocol SDAP layer configuration information.

In a possible implementation manner of the ninth aspect, the determining unit is specifically configured to determine that the target DU has established an F1 connection with the target centralized unit CU based on third indication information from the target CU, where the third indication information indicates that the terminal device performs cell handover based on the handover configuration information.

In a possible implementation manner of the ninth aspect, the second message includes first information, where the first information is carried in any one of the following:

any of the N cells broadcasts information.

In a possible implementation manner of the ninth aspect, the first message further includes at least one of the following:

In a possible implementation manner of the ninth aspect, the second message is a broadcast message.

In a possible implementation manner of the ninth aspect, N has a value of 1.

In a possible implementation manner of the ninth aspect, the method further includes:

and sending indication information for indicating the cell switching process cancellation corresponding to the switching configuration information.

In the ninth aspect of the embodiment of the present application, the constituent modules of the communication device may also be configured to execute the steps executed in each possible implementation manner of the third aspect, and achieve corresponding technical effects, and all details may refer to the third aspect, which is not described herein.

A tenth aspect of the present application provides a communication method, where the apparatus is a target CU, or the apparatus is a part of a component (such as a processor, a chip, or a chip system, etc.) in the target CU, or the apparatus may also be a logic module or software capable of implementing all or part of the functions of the target CU. In a tenth aspect and its possible implementation manner, the description is given with the communication device as an example of execution of the target CU. The device comprises a receiving and transmitting unit and a processing unit; the processing unit is used for determining third indication information after determining that F1 connection is established with a target distributed unit DU, wherein the third indication information indicates the terminal equipment to execute cell switching based on the switching configuration information, and the target DU comprises N cells, and N is a positive integer; the switching configuration information is used for a cell switching process triggered based on the second message; the transceiver unit is configured to send the third indication information to the source CU.

In a possible implementation manner of the tenth aspect, the transceiving unit is specifically configured to send the third indication information to the source CU after the processing unit determines that the target DU has configured the context of the terminal device.

In a possible implementation manner of the tenth aspect, the transceiver unit is further configured to receive a second handover request message from the source centralized unit CU, where the second handover request message includes an identity of N cells and the N cells are inactive cells; wherein N cells are located in the target DU; the transceiver unit is further configured to send a second handover response message to the source CU, where the second handover response message includes handover configuration information of the N cells.

In a possible implementation manner of the tenth aspect, the transceiver unit is further configured to send, after receiving the first configuration information from the source centralized unit CU, handover configuration information of N cells to the source CU, where the handover configuration information of N cells includes the first configuration information and the second configuration information.

In a possible implementation manner of the tenth aspect, the first configuration information includes radio link control RLC layer configuration information and/or medium access control MAC layer configuration information, and the second configuration information includes packet data convergence protocol PDCP layer configuration information and/or service data adaptation protocol SDAP layer configuration information.

In the tenth aspect of the embodiment of the present application, the constituent modules of the communication device may also be configured to execute the steps executed in each possible implementation manner of the fourth aspect, and achieve corresponding technical effects, and all details may refer to the fourth aspect, which is not described herein again.

An eleventh aspect of the present application provides a communication device, where the device is a source CU, or where the device is a part of a component (such as a processor, a chip, or a system on a chip) in the source CU, or where the device may also be a logic module or software capable of implementing all or part of the functions of the source CU. In an eleventh aspect and its possible implementation manner, the communication apparatus is described as an example of the source CU execution. The device comprises a receiving and transmitting unit and a processing unit; the processing unit is configured to determine third configuration information, where the third configuration information includes third configuration information of the first centralized unit DU; the first DU is positioned at an access backhaul integrated IAB node, and the IAB node further comprises a second DU and a mobile terminal MT; the transceiver unit is configured to send the third configuration information to the IAB node.

In a possible implementation manner of the eleventh aspect, the third configuration information is carried in an F1 AP message, or the third configuration information is carried in an RRC message.

In a possible implementation manner of the eleventh aspect, the third configuration information includes at least one of the following: the new wireless cell global identity NCGI, a CU identity for determining the NCGI, or a first key for the first DU to establish encrypted communications for the F1 connection with other CUs, or a physical cell identity PCI for the cell in the first DU.

In a possible implementation manner of the eleventh aspect, the transceiver unit is further configured to receive fourth indication information, where the fourth indication information is used to indicate that the third configuration information of the first DU is valid, or is used to indicate that the first CU sends a handover command to a terminal device connected to the second DU.

In the eleventh aspect of the embodiment of the present application, the constituent modules of the communication device may also be configured to execute the steps executed in each possible implementation manner of the fifth aspect, and achieve corresponding technical effects, and all details may refer to the fifth aspect, which is not described herein.

A twelfth aspect of the present application provides a communication method, where the apparatus is an IAB node, or the apparatus is a part of a component (such as a processor, a chip, or a system on a chip) in the IAB node, or the apparatus may also be a logic module or software capable of implementing all or part of the IAB node function. In a twelfth aspect and its possible implementation manner, the communication apparatus is described as an example of being executed by an IAB node. The device comprises a receiving and transmitting unit and a processing unit; the apparatus includes a processing unit and a transceiving unit for receiving third configuration information including third configuration information of the first DU; the processing unit is used for determining a third message, and the third message is obtained based on the third configuration information; the transceiver unit is also configured to transmit a third message.

In a possible implementation manner of the twelfth aspect, the third configuration information is carried in an F1 AP message, or the third configuration information is carried in an RRC message.

In a possible implementation manner of the twelfth aspect, the third configuration information includes at least one of the following: the new wireless cell global identity NCGI, a CU identity for determining the NCGI, a first key for the first DU to establish encrypted communications for the F1 connection with other CUs, or a physical cell identity PCI for the cell in the first DU.

In a possible implementation manner of the twelfth aspect, the sending and receiving unit sends the third message when at least one of the following is satisfied, including:

the processing unit determines that the cell switching execution condition is met, and a target cell corresponding to the cell switching is positioned on the other CU;

the processing unit determining to establish an F1 connection with the other CU; or alternatively, the first and second heat exchangers may be,

the processing unit determines that the PCI of any cell under the first DU is detected to collide with other PCI.

In a possible implementation manner of the twelfth aspect, the transceiver unit is further configured to send fourth indication information to the first CU, where the fourth indication information is used to indicate that the third configuration information of the first DU is valid, or is used to indicate that the first CU sends a handover command to a terminal device connected to the first DU.

In a possible implementation manner of the twelfth aspect, the third message includes an SSB sent by the first DU to the terminal device, or an F1 connection establishment request message sent by the first DU to the other CU.

In the twelfth aspect of the embodiments of the present application, the constituent modules of the communication device may also be configured to execute the steps executed in each possible implementation manner of the sixth aspect, and achieve corresponding technical effects, and all details may refer to the sixth aspect, which is not described herein again.

A thirteenth aspect of the present embodiments provides a communication device comprising at least one processor coupled to a memory; the memory is used for storing programs or instructions; wherein the at least one processor is configured to execute the program or instructions to cause the apparatus to implement the method according to any one of the foregoing first to sixth aspects and any one of their possible implementation manners.

A fourteenth aspect of the embodiments of the present application provides a communication device, including at least one logic circuit and an input-output interface; the logic circuit is configured to perform a method as described in any one of the foregoing first to sixth aspects and any one of its possible implementation forms.

A fifteenth aspect of the embodiments of the present application provides a computer readable storage medium storing instructions which, when executed by a processor, perform a method as described in any one of the above first to sixth aspects and any one of its possible implementation manners.

A sixteenth aspect of the embodiments of the present application provides a computer program product (or computer program) comprising computer program code which, when run by a processor, causes the processor to carry out the method according to any one of the first to sixth aspects and any one of its possible implementation manners.

A seventeenth aspect of the embodiments of the present application provides a chip system comprising at least one processor for supporting a communication device to implement the functions involved in any one of the above-mentioned first to sixth aspects and any one of their possible implementations.

In one possible design, the system-on-chip may further include a memory to hold the necessary program instructions and data for the first communication device. The chip system can be composed of chips, and can also comprise chips and other discrete devices. Optionally, the chip system further comprises an interface circuit providing program instructions and/or data to the at least one processor.

An eighteenth aspect of the embodiments of the present application provides a communication system including at least two of the communication device of the fourth aspect, the communication device of the fifth aspect, and the communication device of the sixth aspect.

Alternatively, the communication system comprises a source CU and a terminal device, optionally the communication system further comprises a target CU. Wherein the terminal device is configured to perform the method of the first aspect or the second aspect and any possible implementation manner thereof, the source CU is configured to perform the method of the third aspect and any possible implementation manner thereof, and the target CU is configured to perform the method of the fourth aspect and any possible implementation manner thereof.

Alternatively, the communication system includes a first CU and an IAB node. Wherein the first CU is configured to perform the method of the fifth aspect and any possible implementation manner thereof, and the IAB node is configured to perform the method of the sixth aspect and any possible implementation manner thereof.

It should be understood that the technical effects caused by any one of the seventh to eighteenth aspects may be referred to the technical effects caused by the different designs in the first to sixth aspects, and are not described herein.

From the above technical scheme, the scheme provided by the application has the following beneficial effects:

in some embodiments, a terminal device receives a first message including handover configuration information for a cell handover procedure triggered based on a second message, after which the terminal device performs a cell handover based on the handover configuration information after receiving the second message. Compared with the implementation mode that the configuration information of the target cell is carried in the handover message triggering the cell handover, the terminal equipment can acquire the handover configuration information used for the cell handover process triggered based on the second message in advance, and can trigger the cell handover to be performed based on the handover configuration information after receiving the second message. Therefore, under the condition that the terminal equipment is required to be scheduled to execute the cell switching, the second message which is issued to the terminal equipment and used for triggering the execution of the cell switching does not need to carry the switching configuration information of the target cell, the cost of the triggering process can be saved, the execution speed of the cell switching is improved, and the success rate of the cell switching is improved.

In some embodiments, the first CU may send third configuration information of the first DU (i.e., other DUs than the second DU) to the IAB node in case the first CU has a communication connection with the IAB node (e.g., in case the first CU has a radio resource control (radio resource control, RRC) connection with an MT in the IAB node and/or in case the first CU has an F1 connection with a second DU in the IAB node), such that the first DU is capable of communicating based on the third configuration information. The MT in the IAB node can acquire the third configuration information and communicate based on the third configuration information without receiving the configuration information from the first CU through the RRC connection again. Therefore, in a case where the MT in the IAB node cannot acquire the configuration information from the first CU in time (for example, in a case where the MT and the first DU are respectively connected to different CUs to perform communication, for example, in a case where the MT and the first DU are both switched to the same CU but the switching timing of the MT is later than that of the first DU, etc.), the first DU can be enabled to perform communication based on the third configuration information, so as to avoid the situation that the first DU cannot perform communication due to the lack of the third configuration information.

Drawings

FIG. 1a is a schematic diagram of a communication system provided herein;

FIG. 1b is another schematic diagram of a communication system provided herein;

FIG. 2a is a schematic diagram of IAB node migration across CUs;

FIG. 2b is another schematic diagram of IAB node migration across CUs;

FIG. 3 is another schematic diagram of the communication system provided herein;

FIG. 4 is a schematic diagram of a communication method provided herein;

FIG. 5 is another schematic diagram of the communication method provided herein;

FIG. 6 is another schematic diagram of a communication method provided herein;

FIG. 7 is another schematic diagram of the communication method provided herein;

FIG. 8 is another schematic diagram of a communication method provided herein;

FIG. 9 is another schematic diagram of the communication method provided herein;

FIG. 10 is another schematic diagram of the communication method provided herein;

FIG. 11 is another schematic diagram of the communication method provided herein;

FIG. 12 is a schematic diagram of a communication device provided herein;

FIG. 13 is another schematic diagram of a communication device provided herein;

FIG. 14 is another schematic diagram of a communication device provided herein;

fig. 15 is another schematic diagram of the communication device provided in the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

First, some terms in the embodiments of the present application are explained for easy understanding by those skilled in the art.

(1) Terminal equipment: may be a wireless terminal device capable of receiving network device scheduling and indication information, which may be a device providing voice and/or data connectivity to a user, or a handheld device having wireless connection capabilities, or other processing device connected to a wireless modem.

The terminal device may communicate with one or more core networks or the internet via a radio access network (radio access network, RAN), and may be a mobile terminal device, such as a mobile phone (or "cellular" phone), a computer and a data card, e.g. a portable, pocket, hand-held, computer-built-in or vehicle-mounted mobile device, which exchanges voice and/or data with the radio access network. Such as personal communication services (personal communication service, PCS) phones, cordless phones, session Initiation Protocol (SIP) phones, wireless local loop (wireless local loop, WLL) stations, personal digital assistants (personal digital assistant, PDAs), tablet computers (Pad), computers with wireless transceiver capabilities, and the like. The wireless terminal device may also be referred to as a system, subscriber unit (subscriber unit), subscriber station (subscriber station), mobile Station (MS), remote station (AP), access Point (AP), remote terminal device (remote), access terminal device (access terminal), user terminal device (user terminal), user agent (user agent), user station (subscriber station, SS), user equipment (customer premises equipment, CPE), terminal (terminal), user Equipment (UE), mobile Terminal (MT), etc.

By way of example, and not limitation, in embodiments of the present application, the terminal device may also be a wearable device. The wearable device can also be called as a wearable intelligent device or an intelligent wearable device, and is a generic name for intelligently designing daily wear and developing wearable devices, such as glasses, gloves, watches, clothes, shoes, and the like, by applying wearable technology. The wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also can realize a powerful function through software support, data interaction and cloud interaction. The generalized wearable intelligent device includes full functionality, large size, and may not rely on the smart phone to implement complete or partial functionality, such as: smart watches or smart glasses, etc., and focus on only certain types of application functions, and need to be used in cooperation with other devices, such as smart phones, e.g., various smart bracelets, smart helmets, smart jewelry, etc.

The terminals may also be unmanned, robotic, terminals in device-to-device (D2D), terminals in vehicle alien (vehicle to everything, V2X), virtual Reality (VR) terminal devices, augmented reality (augmented reality, AR) terminal devices, wireless terminals in industrial control (industrial control), wireless terminals in unmanned (self driving), wireless terminals in telemedicine (remote media), wireless terminals in smart grid (smart grid), wireless terminals in transportation security (transportation safety), wireless terminals in smart city (smart home), wireless terminals in smart home (smart home), etc.

In addition, the terminal device may be a terminal device in a communication system which evolves after the fifth generation (5th generation,5G) communication system (for example, a sixth generation (6th generation,6G) communication system, etc.), a terminal device in a public land mobile network (public land mobile network, PLMN) which evolves in the future, or the like. By way of example, the 6G network may further extend the morphology and functionality of 5G communication terminals, 6G terminals including, but not limited to, vehicles, cellular network terminals (converged satellite terminal functionality), drones, internet of things (internet of things, ioT) devices.

(2) Network equipment: may be a device in a wireless network, e.g., a network device may be a RAN node (or device) that accesses a terminal device to the wireless network, which may also be referred to as a base station. Currently, some examples of RAN equipment are: base station gNB (gNodeB), transmission and reception point (transmission reception point, TRP), evolved Node B (eNB), radio network controller (radio network controller, RNC), node B (Node B, NB), home base station (e.g., home evolved Node B, or home Node B, HNB), base Band Unit (BBU) in a 5G communication system. In addition, in one network structure, the network device may include a Centralized Unit (CU) node, or a Distributed Unit (DU) node, or a RAN device including a CU node and a DU node.

The network device may be other means of providing wireless communication functionality for the terminal device. The embodiment of the application does not limit the specific technology and the specific device form adopted by the network device. For convenience of description, embodiments of the present application are not limited.

In the embodiment of the present application, the means for implementing the function of the network device may be the network device, or may be a means capable of supporting the network device to implement the function, for example, a chip system, and the apparatus may be installed in the network device. In the technical solution provided in the embodiments of the present application, the device for implementing the function of the network device is exemplified by the network device, and the technical solution provided in the embodiments of the present application is described.

(3) Configuration and pre-configuration: in this application, configuration and pre-configuration are used simultaneously. Wherein, the configuration refers to that the network device/server sends configuration information of some parameters or values of the parameters to the terminal through messages or signaling, so that the terminal determines the parameters of communication or resources during transmission according to the values or information. The pre-configuration is similar to the configuration, and the pre-configuration can be parameter information or parameter values which are negotiated by the network equipment/server and the terminal equipment in advance, can be parameter information or parameter values adopted by the base station/network equipment or the terminal equipment specified by a standard protocol, and can also be parameter information or parameter values which are pre-stored in the base station/server or the terminal equipment. The present application is not limited in this regard.

Further, these values and parameters may be changed or updated.

(4) Paging (paging) the effect of a paging sent by a network device to a terminal device mainly comprises on the one hand paging (e.g. for terminal devices in RRC IDLE state (rrc_idle) and RRC INACTIVE state (rrc_inactive)) and on the other hand system message updating (e.g. for terminal devices in RRC CONNECTED state (rrc_connected)).

In general, the content (Paging message) of the Paging message is sent to the terminal device through a physical downlink traffic channel (physical downlink service channel, PDSCH) resource location, and the PDSCH resource is indicated by scrambling the PDCCH through a P-RNTI (where the P-RNTI is a fixed value). That is, to obtain the Paging message, the terminal device periodically wakes up to monitor the PDCCH channel scrambled by the P-RNTI, then parses the DCI to further obtain the time-frequency position of the PDSCH channel, and parses the content of the Paging message at the position of the corresponding PDSCH channel. The fields of the DCI include fields such as a short message indication (short message indicator), a short message, and the like.

Optionally, for the short message field in DCI, if the network device sends paging to the terminal device only for paging, the field is reserved (or otherwise not active, and the terminal device will ignore the field), and the short message is mainly used to indicate system information update except paging. After receiving the system message update indication of the short message field in the DCI, the terminal device receives a new system message in the next modification period (modification period).

In addition, the frequency domain resources occupied by the Paging message are specified by the P-RNTI scrambled PDCCH. In the time domain, the terminal device tries to receive the Paging message at the PO of a specific frame (called PF) in its Paging cycle, so the network device needs to send the Paging message out of the air interface at this time, so that the terminal device may receive the Paging message at this time. The PF is a radio frame that may contain one or more POs. A PO is a set of PDCCH monitoring occasions, possibly containing multiple slots (or frames, subframes, symbols, etc.), on which there may be a PDCCH scrambled with a P-RNTI and indicating a Paging message. When discontinuous reception (discontinuous reception, DRX) is used, the terminal device needs to detect 1 PO per DRX cycle (DRX cycle), that is, 1 PO per Paging cycle is available for sending Paging for each terminal device. Wherein DRX cycle is the same concept as Paging cycle.

Alternatively, the PFs and POs for paging are determined in the following manner.

The system frame number of the PF (denoted as (sfn+pf_offset) mod T) is determined by:

(SFN+PF_offset)mod T＝(T div N)*(UE_ID mod N)；

the index of the PO (denoted as i_s) is determined by:

i_s＝floor(UE_ID/N)mod Ns；

The significance of each parameter is shown in table 1 below:

TABLE 1

From the above, it can be seen that: the system message update may be indicated by a short message field in the DCI for indicating the frequency domain location of the paging message. In addition, the PF and PO of each terminal device are related to its own ue_id. In general, in order to save power, the terminal device detects PDCCH on its own PF and PO related to the ue_id, receives DCI, and further receives paging message, and especially when DRX is configured, the terminal device receives only one PO in one DRX cycle. The PO network device of each terminal device is aware that when the network device wants to page a certain terminal device, a Paging message is sent in the PO time domain resources of its corresponding PO, and if the network device wants to broadcast a system message update to all terminal devices, a Paging message is sent in the PO time domain resources of all terminal devices.

(5) Access backhaul integration (integrated access and backhaul, IAB) technology.

The IAB technology can adopt a wireless transmission scheme through an Access Link (Access Link) and a Backhaul Link (Backhaul Link), so that the optical fiber deployment can be reduced; and moreover, the method can meet the improvement of network capacity, wider coverage requirements, ultra-high reliability, ultra-low time delay and the like.

In an IAB network, a relay node, or an IAB node (IAB-node), may provide a radio access service for a terminal device, and service data of the terminal device is transmitted by the IAB-node via a radio backhaul link to an IAB host (IAB-node). The IAB-node consists of an MT part and a DU part, wherein when the IAB-node faces to a parent node, the IAB-node can be used as a terminal device, namely the role of the MT; when an IAB-node is towards its child node (which may be another IAB-node, or a generic terminal device), it is considered a network device, i.e. takes on the role of a DU. An IAB-donor is an access network element with the function of a complete base station (e.g. a gNB) comprising CUs and DUs, which is connected to a core network serving terminal devices (e.g. to a 5G core network).

The IAB network will be described with reference to the implementation examples shown in fig. 1a to 1 b.

As shown in fig. 1a, a schematic diagram of a wireless relay scenario is shown.

In the IAB network shown in fig. 1a, the terminal devices include UE1 and UE2, and the IAB nodes include IAB Node1 (IAB Node 1) to IAB Node 5 (IAB Node 5), and IAB host (donor) nodes. One or more IAB-nodes may be included on one transmission path between any UE and the IAB-node. Each IAB-node needs to maintain a wireless backhaul link towards the parent node and also needs to maintain a wireless link with the child node. If the sub-node of the IAB-node is a terminal device (e.g. UE1 or UE2 in fig. 1 a), then a radio access link is between the IAB-node and the sub-node (i.e. UE). If the child node of the IAB-node is another IAB-node, a wireless backhaul link is between the IAB-node and the child node (i.e., the other IAB-node). Illustratively, in FIG. 1a, in path "UE1→IAB-node4→IAB-node3→IAB-node1→IAB-node" UE1 accesses IAB-node4 through a wireless access link, IAB-node4 is connected to IAB-node3 through a wireless backhaul link, IAB-node3 is connected to IAB-node1 through a wireless backhaul link, and IAB-node1 is connected to IAB-node r through a wireless backhaul link.

As shown in fig. 1b, a schematic diagram of a wireless relay scenario implemented through independent (SA) networking is shown.

As shown in fig. 1b, the communication node comprises a 5G core network (5G core,5 gc), a 5G access network device (denoted as gNodeB in the figure), an IAB-node, and one or more IAB-nodes. In fig. 1b, an IAB-node DU (hereinafter simply referred to as IAB-DU) is logically connected to an IAB-donor CU (hereinafter simply referred to as CU) through an F1 interface, and in fact, the connection of the IAB-DU to the CU is implemented through an NR Uu interface between the IAB-node MT and the parent node DU of each hop, but since the final IAB-DU can communicate with the CU, it can be considered that the F1 interface logically exists.

Optionally, the F1 interface supports a user plane protocol (F1-user plane) and a control plane protocol (F1-C), wherein the user plane protocol includes one or more of the following protocol layers: general wireless packet service protocol user plane (general packet radio service tunneling protocol user plane, GTP-U), user datagram protocol (user datagram protocol, UDP), internet protocol (internet protocol, IP) and other protocol layers. The control plane protocol includes one or more of the following: f1 application protocol (F1 application protocol, F1 AP), stream control transmission protocol (stream control transport protocol, SCTP), IP, etc. Through F1-C, interface management, IAB-DU management, and UE context-dependent configuration can be performed between IAB-donor and IAB-node. And through F1-U, the functions of user plane data transmission, downlink transmission state feedback and the like can be executed between the IAB-donor and the IAB-node.

(6) Migration across CUs. In an IAB network, for any IAB node between a terminal device and an IAB-node, migration across CUs is supported.

Among them, in the handover scenario of migration across CUs, an IAB node where migration occurs may be referred to as a boundary node (boundary node), and the migration across CUs is divided into two scenarios of partial migration (Partial migration) and full migration (full migration) with whether or not an F1 connection needs to be established with a target CU as a distinction.

The following will be presented by way of the scenarios shown in fig. 2a to 2b, respectively.

As shown in fig. 2a, which is an example of an implementation of the handover procedure for partial migration, the border node is IAB-node2.

Before the handover, the communication link between the terminal device and the source CU (CU 1 in the figure) passes through the IAB-node4 (including the IAB-MT4 and the IAB-DU4 in the figure), the IAB-node2 (including the IAB-MT2 and the IAB-DU2 in the figure), the IAB-node1 (including the IAB-MT1 and the IAB-DU1 in the figure), and the Donor-DU1, respectively.

After the handover, the communication link between the terminal device and the source CU (CU 1 in the figure) passes through IAB-node4 (including IAB-MT4 and IAB-DU4 in the figure), IAB-node2 (including IAB-MT2 and IAB-DU2 in the figure), IAB-node3 (including IAB-MT3 and IAB-DU3 in the figure) and Donor-DU1, respectively.

In the implementation example shown in fig. 2a, before Partial migration, there is an RRC connection between IAB-MT2 and CU1, there is an F1 interface between IAB-DU2 and CU1, and IAB-node2 and IAB-node communicate via a source path (via IAB-node1 consisting of IAB-MT1 and IAB-DU 1). At Partial migration, IAB-MT2 has cell handover across CU and RRC connection with CU2 is established, but to avoid Introducing the re-establishment procedure of the F1 interface, IAB-DU2 still keeps the F1 interface with CU1 and does not establish the F1 interface with CU2, so the communication path between CU1 and IAB-DU2 becomes cross-topology:in FIG. 2a, CU1 and CU2 are referred to as a terminating CU (F1-terminating CU) on the F1 interface and a non-terminating CU (non-F1-terminating CU) on the F1 interface, respectively. It should be noted that the data is not transmitted via CU2 during this path, and CU1 and Donor-DU2 are in direct communication via the IP network.

As shown in fig. 2b, which is an example of an implementation of the handover procedure for all migration, the border node is IAB-node3.

Before the handover, the communication link between the terminal device and the source CU (CU 1 in the figure) passes through IAB-node3 (including IAB-MT3, IAB-DU3a and IAB-DU3b in the figure), IAB-DU3a and IAB-MT3, IAB-node1 (including IAB-MT1 and IAB-DU1 in the figure) and Donor-DU1, respectively.

After the handover, the communication link between the terminal device and the source CU (CU 1 in the figure) passes through IAB-node3 (including IAB-MT3, IAB-DU3a and IAB-DU3b in the figure), IAB-DU3b and IAB-MT3, IAB-node2 (including IAB-MT2 and IAB-DU2 in the figure) and Donor-DU1, respectively. The switched path may be referred to as a target path (target path).

In the scenario example of the overall migration shown in fig. 2b, the F1 interface between the IAB-DU3 and CU1 needs to be migrated to CU2, since the protocol does not support the simultaneous existence of the F1 interface between one DU and two CUs, in order to implement this handover procedure, by expanding the IAB-DU3 into two logical DUs, i.e. IAB-DU3a and IAB-DU3b, the IAB-DU3a always maintains the F1 interface with CU1, whereas the IAB-DU3b is used to establish a new F1 interface with CU2, DU3a and DU3b can be regarded as two DUs, each with an F1 interface, the terminal device needs to make a handover from the cell under the IAB-DU3a to the cell under the IAB-DU3 b. All migration includes the following three implementations.

Gradually from Top to bottom (grade Top-down), in this implementation, similar to partial migration, first, MT3 is switched according to the procedure of partial migration, and cross topologies F1-C and F1-U between DU3a and CU1 are established, CU2, while helping to establish cross topologies F1-C and F1-U between DU3a and CU1, also establishes F1-C and F1-U between DU3b and CU2, and then the terminal device is switched under DU3b, and the terminal device can directly communicate with CU2 on the target path.

In the implementation manner, firstly, by establishing cross topology F1-C and F1-U between DU3b and CU2, terminal equipment can be switched under DU3b, data transmission between DU3b and CU2 through IAB-Node1 and control plane and user plane of Donor-DU1 is established, after the terminal equipment is successfully switched, a switching command is sent to MT or the switching command of MT is validated, and then F1-C/F1-U is established on the target path, so that the flow of the terminal equipment can be migrated to the target path.

The implementation is similar to the Gradual from-up, and firstly, by establishing a cross topology F1-C between DU3b and CU2 (only establishing the cross topology F1-C, allowing terminal equipment to be cut under DU3b when being used for CU2 to make a switching decision, but not establishing the cross topology F1-U, and not performing cross topology data transmission), the terminal equipment can allow the terminal equipment to be switched under DU3b, and immediately after sending a switching command to all the terminal equipment, sending the switching command to MT or validating the switching command of MT, and then directly establishing F1-C/F1-U on a target path, so that the flow of the terminal equipment can be migrated to the target path.

As can be seen from the above implementation example, in Partial migration, MT has occurred across CUs, but DU still maintains F1 connection with source CU; in full migration, however, the DU needs to establish an F1 connection with the target CU.

Alternatively, in the migration scenario facing the IAB node taking load balancing as a starting point, partial migration may be adopted, by switching MT, so that the F1 interface changes a path to transmit, but the anchor point of the F1 interface is not changed.

Optionally, in the migration scenario facing the movement caused by the IAB node movement, when the IAB node movement range is large, it is not appropriate to still maintain the F1 connection with the source CU, and the anchor point of the F1 connection needs to be changed to the target CU, so the full migration will likely be an essential feature of the mobile IAB.

(7) The terms "system" and "network" in embodiments of the present application may be used interchangeably. "plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: cases where A alone, both A and B together, and B alone, where A and B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one of A, B, and C" includes A, B, C, AB, AC, BC, or ABC. And, unless otherwise specified, references to "first," "second," etc. in the embodiments herein are for distinguishing between multiple objects and not for defining the order, timing, priority, or importance of the multiple objects.

Throughout this application, unless specifically stated otherwise, identical or similar parts between the various embodiments may be referred to each other. In the present application, terms and/or descriptions of the various embodiments and the various methods/designs/implementations of the various embodiments are consistent and may be mutually referenced if not specifically stated and logically conflicting, and the technical features of the various embodiments and the various methods/designs/implementations of the various embodiments may be combined to form new embodiments, methods, or implementations according to their inherent logical relationships. The embodiments of the present application described below do not limit the scope of the present application.

Fig. 3 is a schematic architecture diagram of a communication system 1000 to which embodiments of the present application apply.

As shown in fig. 3, the communication system comprises a radio access network 100 and a core network 200, and optionally the communication system 1000 may further comprise the internet 300. The radio access network 100 may include at least one radio access network device (also referred to as a network device as described above, e.g. 110a and 110b in fig. 3) and may also include at least one terminal (also referred to as a terminal device as described above, e.g. 120a-120j in fig. 3). The radio access network device may be a macro base station (e.g., 110a in fig. 3), a micro base station, an indoor station (e.g., 110b in fig. 3), a relay node, a donor node, or the like. It will be appreciated that all or part of the functionality of the radio access network device in the present application may also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform, such as a cloud platform. The embodiment of the application does not limit the specific technology and the specific equipment form adopted by the wireless access network equipment.

For convenience of description, description will be made taking a base station as a radio access network device and a terminal device as a terminal as an example. It will be appreciated that the base station may be an IAB node in the case where the communication system comprises an IAB network.

In this application, the base station and the terminal may be fixed in position or movable. The base stations and terminals may be deployed on land, including indoor or outdoor, hand-held or vehicle-mounted, on water, and on aerial aircraft, balloons, and satellites. The application scenes of the base station and the terminal are not limited in the embodiment of the application.

The roles of base station and terminal may be relative, e.g., helicopter or drone 120i in fig. 3 may be configured as a mobile base station, terminal 120i being the base station for those terminals 120j that access radio access network 100 through 120 i. But for base station 110a 120i is a terminal, i.e., communication between 110a and 120i is via a wireless air interface protocol. Of course, communication between 110a and 120i may be performed via an interface protocol between base stations, and in this case, 120i is also a base station with respect to 110 a. Thus, both the base station and the terminal may be collectively referred to as a communication device, 110a and 110b in fig. 3 may be referred to as a communication device having a base station function, and 120a-120j in fig. 3 may be referred to as a communication device having a terminal function.

Communication can be performed between the base station and the terminal, between the base station and the base station, and between the terminal and the terminal through the licensed spectrum, communication can be performed through the unlicensed spectrum, and communication can also be performed through the licensed spectrum and the unlicensed spectrum at the same time. Communication can be performed through a frequency spectrum of 6 gigahertz (GHz) or less, communication can be performed through a frequency spectrum of 6GHz or more, and communication can be performed using a frequency spectrum of 6GHz or less and a frequency spectrum of 6GHz or more simultaneously. The embodiments of the present application do not limit the spectrum resources used for wireless communications.

In the embodiments of the present application, the functions of the base station may be performed by a module (such as a chip) in the base station, or may be performed by a control subsystem including the functions of the base station. The control subsystem comprising the base station function can be a control center in the application scene of the terminal such as a smart grid, industrial control, intelligent transportation, smart city and the like. The functions of the terminal may be performed by a module (e.g., a chip or a modem) in the terminal, or by a device including the functions of the terminal.

In this application, the base station transmits a downlink signal (or downlink information) to the terminal, and the downlink signal (or downlink information) is carried on a downlink channel. The terminal transmits an uplink signal (or uplink information) to the base station, and the uplink signal (or uplink information) is carried on an uplink channel.

It is to be appreciated that the present application can be applied to long term evolution (long term evolution, LTE) systems, new Radio (NR) systems, or communication systems that evolve after 5G (e.g., 6G, etc.). The communication system comprises network equipment and terminal equipment.

In the communication system, after the terminal equipment accesses a certain cell, the cell accessed by the terminal equipment can be switched by a cell switching mode. The cell to which the terminal device accesses may be referred to as a source cell before the cell handover is performed, and the cell to which the terminal device accesses may be referred to as a target cell after the cell handover is performed. In the implementation process of cell switching, after detecting signal quality deterioration with the terminal equipment, the source cell can issue a switching message carrying configuration information of the target cell, so that the terminal equipment can access the target cell based on the configuration information of the target cell after receiving the message.

In one possible implementation manner, the network device may send CHO configuration information triggered based on a measurement event to the terminal device before the signal quality is degraded, so that after the terminal device determines that the signal quality is degraded based on the measurement event locally, the terminal device performs cell handover based on the CHO configuration information, which can accelerate the handover speed of the terminal device, and avoid handover failure possibly caused by handover preparation after the signal quality is degraded in the conventional handover procedure to a certain extent. However, in this implementation, the triggering manner of the cell handover is still located in a scenario where the signal quality between the terminal device and the source cell is degraded, but in a case where the signal quality between the terminal device and the source cell is not degraded (for example, in a case where the IAB node where the source cell is located in the scenario shown in fig. 2b migrates across CUs and enables a newly configured cell in the IAB-DU3b corresponding to the target CU, or in a case where the IAB node where the source cell is located needs to schedule the terminal device to connect to another cell in the IAB node, or in a case where the IAB node where the source cell is located determines that the source cell is to be turned off or deactivated, etc.), CHO configuration information triggered based on the measurement event will not be effective, and still the effect of improving the cell handover speed to improve the cell handover success rate is not achieved.

In summary, how to increase the execution speed of cell switching so as to increase the success rate of cell switching is a technical problem to be solved.

In order to solve the above problems, the communication method and the related device provided by the present application are used for saving the overhead of triggering the cell switching process, and improving the execution speed of the cell switching so as to improve the success rate of the cell switching. Further description will be provided below with reference to the accompanying drawings.

Referring to fig. 4, a schematic diagram of an implementation of a communication method provided in the present application is provided, and the method includes the following steps.

S401, the source CU determines a first message.

In this embodiment, the source CU determines in step S401 a first message, where the first message includes handover configuration information of N cells, where N is a positive integer, and the handover configuration information is used for a cell handover procedure triggered based on the second message.

S402, the source CU sends a first message to the terminal equipment.

In this embodiment, the source CU sends a first message to the terminal device through the IAB node in step S402, and the terminal device receives the first message in step S402.

In one possible implementation, the target DU is located at the IAB node. Specifically, the IAB node to which the terminal device is connected includes a source DU where a source cell is located, and when a target DU where the target cell is located in the IAB node where the source DU is located, the scheme can be applied to a scenario where the terminal device performs cell switching between different DUs in the same IAB node (or a scenario where the IAB node performs migration across CUs and enables the target cell corresponding to the target CU).

Alternatively, the target DU may be located in other IAB nodes as well.

In a possible implementation manner, the first message sent by the source CU in step S402 further includes at least one of the following: the first indication information indicates that the switching configuration information is used for a cell switching process triggered based on the second message; or, second indication information indicating that the second message is monitored over all of the POs. Specifically, the first message including the handover configuration information of the N cells may further include at least one indication information, and instruct, by displaying the indication information, that the handover configuration information is used for a cell handover process triggered based on the second message, and/or instruct to monitor the second message on all POs, so that the terminal device explicitly performs cell handover based on the indication information carried by the display.

Optionally, the second message is a broadcast message. Specifically, the handover configuration information carried by the first message is used for triggering a cell handover process based on the second message, that is, the second message is used for triggering the terminal device to execute the cell handover process, so that the implementation mode of the message (that is, the broadcast message) sent by the second message in a broadcast mode can trigger a plurality of terminal devices to execute cell handover based on the scheduling of the broadcast message, thereby saving the cost. And, the sending speed of the second message can be improved, so that the speed of triggering and executing the cell switching by a plurality of terminal devices based on the broadcast message is improved.

Optionally, N has a value of 1. Specifically, when the value of N is 1, the implementation manner that the first message includes the switching configuration information of a certain cell can save the overhead of the first message, and simultaneously can reduce the overhead of the terminal equipment for monitoring signals of a plurality of cells in the process of executing cell switching.

In one possible implementation, the handover configuration information included in the first message sent by the source CU in step S402 is conditional handover (conditional handover, CHO) configuration information. Optionally, when the handover configuration information included in the first message is CHO configuration information, a trigger condition corresponding to the CHO configuration information is triggered based on the second message. In addition, the CHO configuration information is the name of the handover configuration information in the current standard/protocol for triggering the cell handover based on the triggering condition, and in future standards/protocols, the CHO configuration information may be other names, which is not limited herein.

In one possible implementation, before step S401, the method further includes: after determining that the target DU and the target CU have established F1 connection, the source CU sends a switching request message of the terminal to the target CU; the source CU receives a handover response message from the target CU, the handover response message including the handover configuration information. Specifically, after determining that the target DU and the target CU have established the F1 connection, the source CU determines that a cell under the target DU can be used as a potential target cell, and for this purpose, the source CU may acquire the handover configuration information with the target CU through an interaction manner of a handover request message and a handover response message, so that the source CU sends a first message including the handover configuration information to the terminal device.

Optionally, the source CU determining that the target DU has established an F1 connection with the target CU includes: the source CU determines that the target DU has established an F1 connection with the target CU based on third indication information from the target CU, the third indication information indicating that the terminal device performs cell handover based on the handover configuration information. Specifically, the source CU may determine that the target DU and the target CU have established the F1 connection through the third indication information sent by the target CU, and further determine that the terminal device can successfully perform cell handover to the target DU based on the handover configuration information.

In one possible implementation, the source CU sends the first message in step S402 when any of the following is satisfied, including:

after the source CU sends a first handover request message to the target CU, receiving a first handover response message from the target CU, where the first handover response message includes handover configuration information of N cells (for convenience of reference hereinafter, this mode is denoted as mode a);

after the source CU sends a second handover request message to the target CU, receiving a second handover response message from the target CU, where the second handover request message includes identities of N cells and the N cells are inactive cells (for convenience of reference hereinafter, this mode is denoted as mode B); or alternatively, the first and second heat exchangers may be,

after receiving the first configuration information from the target DU and transmitting the first configuration information to the target CU, the source CU receives handover configuration information of N cells from the target CU, where the handover configuration information of the N cells includes the first configuration information and the second configuration information (for convenience of reference hereinafter, this mode is denoted as mode C).

In the above manner a, when the source CU determines that the target DU and the target CU have established the F1 connection, interaction between the source CU and the target CU may be enabled by the first handover request message and the first handover response message, so that the source CU may obtain handover configuration information of N cells under the target DU. Accordingly, after the source CU acquires the configuration information of the N cells, the source CU may send a first message including the configuration information of the N cells to the terminal device in step S402.

It is to be understood that, in the mode a, the time when the F1 connection between the target CU and the target DU is completed is before the time when the source CU issues the configuration information to the terminal device in step S402, and the scheme may be applied to full close and full bottom-up flows of full migration. At this point, the target DU is ready and the N cells under the target DU may be configured in the first message as potential target cells for the terminal device.

In the above manner B, in the case that the source CU determines that the target DU may need to be handed over to the target CU, the source CU may determine N cells under the target CU as potential target cells of the terminal device. For this purpose, the source CU may send a first message containing configuration information of the N cells to the terminal device in step S402 after the source CU and the target CU may interact with each other by a second handover request message and a second handover response message to inform the target CU that the target DU will be likely to be handed over to the target CU.

It may be appreciated that in the manner B, the time when the F1 connection between the target CU and the target DU is completed is located after the time when the source CU issues the configuration information to the terminal device in step S402, and the scheme may be applied to the full-scale top-down flow of full-scale. For example, in the data top-down, the F1 connection between the target DU and the target CU is established almost at the last, if the gain of configuring the configuration information of N cells in advance is to be taken, a first message including the configuration information of N cells needs to be issued in advance, and at the time of sending the first message in step S402, N cells in the target DU are not yet activated, and a real handover preparation procedure cannot be currently performed.

In the above manner C, in a case where the source CU determines that the target DU is likely to need to be handed over to the target CU, the source CU may acquire first configuration information from the target DU and send the first configuration information to the target CU to inform the target CU that the target DU is likely to be handed over to the target CU, so that the target CU determines and sends configuration information of N cells to the source CU based on the first configuration information. Accordingly, after the source CU acquires the configuration information of the N cells, the source CU may send a first message including the configuration information of the N cells to the terminal device in step S402.

Optionally, in mode C, the first configuration information includes radio link control (radio link control, RLC) layer configuration information and/or medium access control (media access control, MAC) layer configuration information, and the second configuration information includes packet data convergence protocol (packet data convergence protocol, PDCP) layer configuration information and/or service data adaptation protocol (service data adaptation protocol, SDAP) layer configuration information. Specifically, in the case that the F1 connection has not been established between the target DU and the target CU, the target DU may send the first configuration information (including RLC and/or MAC layer configuration information) to the target CU through the source CU, so that the target CU determines handover configuration information (including RLC and/or MAC configuration information, and PDCP and/or SDAP configuration information) of N cells under the target DU based on the first configuration information, and the target CU may send the handover configuration information of the N cells to the terminal device through the source CU in a first message.

It will be appreciated that, similarly to the manner B, the time when the F1 connection between the target CU and the target DU is completed is located after the time when the source CU issues the configuration information to the terminal device in step S402, and the scheme may be applied to the full-scale top-down flow of full migration.

In the conventional handover scheme, in an RRC reconfiguration message (carrying a CHO handover command) sent by a source CU to a terminal device, RLC layer configuration, MAC layer configuration, PDCP layer configuration, and SDAP layer configuration after a target cell is carried (for example, a cell group configuration (cellgroup configuration) cell in the RRC reconfiguration message carries RLC layer configuration and MAC layer configuration of the target cell), and a radio bearer configuration (radio bearer configuration) cell in the RRC reconfiguration message includes PDCP layer configuration and SDAP layer configuration after the terminal device arrives at the target cell. That is, the terminal device needs to know the configuration of the plurality of protocol stacks after the handover to the target cell. However, RLC layer and MAC layer configurations need to be generated by the target DU, and PDCP layer and SDAP layer of higher layers need to be generated by the target CU, and when no F1 connection is established between the target DU and the target CU, a technical scheme provided by way C is needed to enable the terminal device to acquire RLC layer and MAC layer configurations and PDCP layer and SDAP layer configurations.

In mode C, through establishing an F1 connection between the target DU and the source CU, after the first configuration information of N cells in the target DU is sent to the source CU, the first configuration information is sent to the target CU via the source CU, after adding the second configuration information at the target CU, the complete configuration information of N cells is sent to the source CU (for example, the configuration information of N cells is carried in a radio resource control Container (RRC Container)), and then the source CU sends a first message including the configuration information of N cells to the terminal device in step S402.

Specifically, when at least one of the above manner a, manner B and manner C is satisfied, the source CU determines that the cell under the target DU will be a potential target cell, for this reason, the source CU may send a first message including handover configuration information of N cells to the terminal device, so that the handover configuration information of N cells is issued before the handover condition is satisfied, so that in a case where it is determined that it is necessary to schedule the terminal device to switch to the N cells and issue a scheduling message, signaling consumption of the scheduling message can be saved, so as to improve the cell handover success rate.

S403, the source CU sends a second message to the terminal equipment.

In this embodiment, the source CU sends a second message to the terminal device in step S403, and the terminal device receives the second message in step S403.

In a possible implementation manner, the second message sent by the source CU in step S403 includes first information, where the first information is carried in any one of the following: a short message (short message) field in downlink control information (download control information, DCI) of a physical downlink control channel (physical download control channel, PDCCH) scrambled by a paging radio network temporary identity (paging radio network temporary identifier, P-RNTI); information in Paging Occasions (POs); or, any one of the N cells broadcasts information. Specifically, the second message may be implemented by any one of the foregoing, in other words, the source cell or the N cells may trigger the terminal device to perform cell handover by any one of the foregoing manners, so as to improve flexibility of implementation of the scheme.

In a possible implementation manner, the source CU sends the second message to the terminal device in step S403 when at least one of the following is satisfied, including: the source CU determines that the target DU and the target CU have established F1 connection; the source CU determines that the mobile terminal (mobile termination, MT) in the IAB node is to be handed over to the target CU; or, the source CU receives an indication from the target CU to allow the terminal device to perform a cell handover based on the handover configuration information. Specifically, when at least one of the above is satisfied, the source CU determines that the terminal device is currently capable of performing cell handover and successfully switches to N cells under the target DU, and for this purpose, the source CU may send a second message to the terminal device, so that the terminal device triggers to perform cell handover based on the received second message.

S404, the terminal equipment executes cell switching.

In this embodiment, after receiving the second message in step S403, the terminal device triggers the cell handover procedure of step S404, that is, triggers the terminal device to perform cell handover based on the handover configuration information received in step S402.

Based on the technical solution shown in fig. 4, the terminal device receives in step S402 a first message including handover configuration information of N cells, the handover configuration information being used for a cell handover procedure triggered based on a second message, after which the terminal device performs in step S404 a cell handover based on the handover configuration information after receiving the second message in step S403. Compared with the implementation mode that the configuration information of the target cell is carried in the handover message triggering the cell handover, the terminal equipment can acquire the handover configuration information used for the cell handover process triggered based on the second message in advance, and can trigger the cell handover to be performed based on the handover configuration information after receiving the second message. Therefore, under the condition that the terminal equipment is required to be scheduled to execute the cell switching, the second message which is issued to the terminal equipment and used for triggering the execution of the cell switching does not need to carry the switching configuration information of the target cell, the cost of the triggering process can be saved, the execution speed of the cell switching is improved, and the success rate of the cell switching is improved.

In one possible implementation, in the implementation shown in fig. 4 above, the process of the source CU sending the first message in step S402 and/or the process of the source CU sending the second message in step S403 may need to rely on the indication of the target CU. The following will explain in detail the implementation based on fig. 5.

Referring to fig. 5, a schematic diagram of an implementation of a communication method provided in the present application is provided, and the method includes the following steps.

S501, the target CU determines third indication information.

In this embodiment, the target CU determines in step S501 third indication information, where the third indication information is used to indicate that the terminal device is allowed to perform cell handover based on the handover configuration information, and the target DU includes N cells, where N is a positive integer.

S502, the target CU sends third indication information to the source CU.

In this embodiment, after the target CU determines the third indication information in step S501, the target CU transmits the third indication information to the source CU in step S502.

In one possible implementation, the sending of the third indication information to the source CU by the target CU in step S502 includes: the target CU sends the third indication information to the source CU after determining that the target DU has configured the context of the terminal device. Specifically, after determining that the target DU has configured the context of the terminal device, the target CU may determine that the terminal device is able to access the network through N cells contained in the target DU, and for this purpose the target CU may send the third indication information to the source CU, so that the source CU schedules the terminal device to perform cell handover based on the third indication information from the target CU.

In a possible implementation manner, before the target CU sends the third indication information to the source CU in step S502, the method further includes: the target CU receives a second switching request message from the source centralized unit CU, wherein the second switching request message comprises the identifications of N cells, and the N cells are inactive cells; wherein N cells are located in the target DU; the target CU sends a second handover response message to the source CU, the second handover response message including handover configuration information of the N cells. Specifically, before the target CU sends the third indication information to the source CU, interaction between the target CU and the source CU may be enabled by the second handover request message and the second handover response message, so that after the target CU determines corresponding handover configuration information based on N cells that are not activated, the handover configuration information is sent to the terminal device by the source CU, so that the terminal device can execute a cell handover process corresponding to the handover configuration information based on triggering of the second message.

In one possible implementation, before the target CU sends the third indication information to the source CU, the method further includes: after receiving the first configuration information from the source centralized unit CU, the target CU sends handover configuration information of N cells to the source CU, where the handover configuration information of N cells includes the first configuration information and the second configuration information. Specifically, in the case that the F1 connection has not been established between the target DU and the target CU, the target DU may send the first configuration information (including RLC and/or MAC layer configuration information) to the target CU through the source CU, so that the target CU determines handover configuration information (including RLC and/or MAC configuration information and PDCP and/or SDAP configuration information) of N cells under the target DU based on the first configuration information, and the target CU may send the handover configuration information of the N cells to the terminal device through the source CU in a first message manner, so that the terminal device may subsequently perform a cell handover procedure corresponding to the handover configuration information based on triggering of the second message.

It should be noted that, the implementation manner may refer to the implementation processes of the foregoing manners a to C in the embodiment of fig. 4, and the corresponding technical effects are achieved, which is not described herein.

In addition, the embodiment shown in fig. 5 is an alternative implementation procedure of the embodiment shown in fig. 4, where the source CU receives the third indication information in step S502 and may trigger the execution of step S504 as a trigger condition of the source CU, that is, the execution sequence of step S502 precedes step S504. Alternatively, the source CU may trigger the execution of step S505 as the trigger condition of the source CU when receiving the third indication information in step S502, i.e. the execution sequence of step S502 precedes step S505.

S503, the source CU determines a first message.

In this embodiment, the source CU determines in step S503 a first message, where the first message includes handover configuration information of N cells, where N is a positive integer, and the handover configuration information is used for a cell handover procedure triggered based on the second message.

S504, the source CU sends a first message to the terminal equipment.

In this embodiment, the source CU sends a first message to the terminal device in step S504, and the terminal device receives the first message in step S504.

S505, the source CU sends a second message to the terminal equipment.

In this embodiment, the source CU sends a second message to the terminal device in step S505, and the terminal device receives the second message in step S505.

S506, the terminal equipment executes cell switching.

In this embodiment, after the terminal device receives the second message in step S505, the terminal device triggers the cell handover procedure of step S506, that is, triggers the terminal device to perform cell handover based on the handover configuration information received in step S505.

It should be noted that, the implementation process of step S503 to step S506 may refer to the implementation process of step S401 to step S404, and the corresponding technical effects are achieved, which is not described herein.

Based on the technical solution shown in fig. 5, after determining that the F1 connection is established with the target CU, the target CU may determine that the terminal device can be handed over to N cells included in the target DU based on the cell handover procedure, and for this purpose, the target CU sends third indication information to the source CU, which indicates that the terminal device is allowed to perform cell handover based on the handover configuration information, so that the source CU determines that the terminal device can be triggered to perform cell handover based on the third indication information. The switching configuration information is used for triggering a cell switching process based on the second message, so that the terminal equipment can trigger to execute cell switching based on the switching configuration information after receiving the second message, and the success rate of cell switching is improved. Compared with the implementation mode that the switching information for triggering and executing the cell switching carries the configuration information of the target cell, when the source CU determines that the terminal equipment needs to be scheduled to execute the cell switching based on the third indication information from the target CU, the second information for triggering and executing the cell switching, which is issued to the terminal equipment, does not need to carry the switching configuration information of the target cell, so that the cost of the triggering process can be saved, the executing speed of the cell switching can be improved, and the success rate of the cell switching can be improved.

Referring to fig. 6, a schematic diagram of an implementation of a communication method provided in the present application includes the following steps.

S601, the source CU determines a first message.

In this embodiment, the source CU determines in step S503 a first message including handover configuration information of N cells, where N is a positive integer.

S602, the source CU sends a first message to the terminal equipment.

S603, the terminal device ignores or deletes the switching configuration information.

In this embodiment, when the terminal device receives the indication information indicating that the cell handover procedure corresponding to the handover configuration information is canceled or determines that the second message is not received, the terminal device determines to ignore or delete the handover configuration information received in step S602.

Specifically, the source CU sends indication information indicating cancellation of the cell handover procedure corresponding to the handover configuration information to the terminal device. The terminal device may acquire the handover configuration information for the cell handover procedure triggered based on the second message in advance, and may determine to ignore or delete the handover configuration information based on the schedule of the source CU (e.g., the source CU does not issue the second message, or the source CU sends the indication information to cancel the cell handover, etc.), that is, the terminal device may determine not to perform the cell handover based on the schedule of the network device, so as to avoid the cell handover failure.

It should be noted that, the handover configuration information is used for a cell handover procedure triggered based on the second message, or the handover configuration information is CHO configuration information triggered based on a measurement event. In the case where the handover configuration information is used in the cell handover procedure triggered based on the second message, the implementation procedure of step S601 and step S602 may refer to the implementation procedures of step S401 to step S402 shown in fig. 4 and implement corresponding technical effects, which are not described herein.

Based on the technical solution shown in fig. 6, the terminal device receives a first message including a handover configuration of N cells in step S602, and ignores or deletes the handover configuration information after determining that a second message is not received (the second message is used to trigger a cell handover procedure corresponding to the handover configuration information) or determining that indication information indicating cancellation of the cell handover procedure corresponding to the handover configuration information is received in step S603. Compared to the implementation manner that the terminal device triggers the cell handover when receiving the handover message carrying the configuration information of the target cell, the terminal device may acquire the handover configuration information for the cell handover procedure triggered based on the second message in advance, and may determine to ignore or delete the handover configuration information based on the scheduling of the network device (e.g. the network device does not issue the second message, or the network device sends the indication information to cancel the cell handover, etc.), i.e. the terminal device may determine not to perform the cell handover based on the scheduling of the network device, so as to avoid the cell handover failure.

As can be seen from the implementation manners shown in fig. 4 to fig. 6, the above technical solution can be applied to a scenario in which the source DU connected to the terminal device is migrated across CUs at the IAB node where the source DU is located. For the source CU, there may be various relations between the time when the N cells under the target DU are activated (or the target DU has acquired the UE context configuration of the terminal device) and the time when the terminal device acquires the handover configuration information of the N cells.

For example, the time of occurrence of the former may be before the time of occurrence of the latter (as in the aforementioned manner a), which will be exemplarily described in the scene shown in fig. 2b in connection with the example shown in fig. 7.

As another example, the time when the former occurs may be located after the time when the latter occurs (as in the foregoing manner B and manner C), which will be exemplarily described below in the scene shown in fig. 2B in conjunction with the examples shown in fig. 8 and 9.

It should be understood that in the embodiments of fig. 7 to 9 described below, the terminal device is denoted as UE, the source CU is denoted as CU1, the target CU is denoted as CU2, the source DU is denoted as DU3a, and the target DU is denoted as DU3b for example.

Referring to fig. 7, a schematic diagram of an implementation of a communication method provided in the present application is provided, and the method includes the following steps.

The CU2 sends an F1 connection response message to the IAB node, and accordingly, the IAB node receives the F1 connection response message from the CU2 in this step.

In step 1, after the establishment of the F1-C interface between the DU3b and the CU2, the CU2 issues an F1 SETUP RESPONSE message to the DU3 b.

CU2 sends a third indication to CU1, and accordingly, CU1 receives the third indication from CU2 in this step.

In step 2, CU2 informs CU1 that DU3b is ready, and may send a handover request (not limited to CHO handover request here) for the UE.

The UE sends a measurement report to CU1, and accordingly, CU1 receives the measurement report from the UE in this step.

In step 3, CU1 receives a measurement report of the UE. This step is optional because DU3b and DU3a are logical DUs under the same physical DU, and there may be a correspondence between cells under DU3b and cells under DU3a, in which case the target cell of the UE may be directly designated without measurement.

Optionally, step 3 is an optional step.

CU1 sends a handover request message to CU2, and accordingly, CU2 receives the handover request message from CU1 in this step.

CU2 admission control.

CU2 sends a handover response message to CU1, and accordingly, CU1 receives the handover response message from CU2 in this step.

Steps 4 to 6 are CHO handover preparation procedures for UE between CU1 and CU 2.

CU1 sends a first message to the UE, which in turn receives the first message from CU 1.

In step 7, CU1 sends a first message to the UE, which may be an RRC message (which may be carried in a CHO handover command message). Optionally, the RRC message carries at least one of the following information:

1) Informing the UE that the CHO is triggered in a broadcasting mode; and/or

2) If the corresponding relation exists between the DU3b and the cell under the DU3a, the unique target cell of each UE under the DU3b is directly specified.

1) contains two layers of information, firstly, the UE is informed that the CHO is triggered to be executed, and the method is different from the traditional CHO based on self judgment; second, the UE is informed that the CHO will trigger in a broadcast manner, rather than a unicast trigger. The two layers of information may not appear at the same time, and layering is required to be shown when writing rights.

Ue listening.

After receiving the RRC message of step 7, the UE listens to the PDCCH on all the PFs and POs that may occur. In other words, step 7 also optionally has the effect of instructing the UE to monitor PDCCH on all the PFs and POs that may be present.

The IAB node sends a measurement report to CU1 and accordingly CU1 receives the measurement report from the IAB node in this step.

CU1 determines whether MT handoff needs to be performed.

In steps 9 to 10, CU1 determines that MT3 has reached the handover condition based on the measurement report of MT 3.

Optionally, the steps 9 to 10 are optional steps.

CU1 sends an indication to UE to cancel the handover, and accordingly, the UE receives an indication to cancel the handover from CU1 in this step.

In step 11, if the MT3 has not reached the handover condition all the time, it is considered that full handover may not be performed at this time, and the network may send indication information (for example, the indication information is carried in an RRC message) to the UE, informing that CHO is cancelled this time, and the UE deletes the configuration in the CHO handover command before.

CU1 controls IAB node to send second message, and the first information in the second message is carried in short message field. Accordingly, the UE receives a second message from CU1 through the IAB node in this step.

In step 12, CU1 broadcasts DCI scrambled with P-RNTI to UE through DU3a, and instructs group CHO to perform in the short message field.

The CU1 controls the IAB node to send a short message field, which is used to indicate the time domain position of the PO. Correspondingly, the UE receives, through the IAB node, a short message field carried in the DCI from CU1 in this step.

The cu1 controls the IAB node to send a second message, the first information in the second message being carried on the PO. Accordingly, the UE receives a second message from CU1 through the IAB node in this step.

CU1 broadcasts DCI scrambled with P-RNTI to the UE through DU3a in step 13, indicates system information update in short message field, and then CU1 indicates group CHO execution in updated system message in step 14.

It can be understood that the broadcasting scheme enables all UEs under the DU3a to receive, and may indicate the execution of the group CHO by using the reserved bit of the short message field, or indicate the execution of the group CHO in the new system message after triggering the UEs to receive the system message update by paging.

In addition, in steps 9 to 10, the MT3 may have reached the handover condition, but the execution sequence of the MT3 handover and steps 12 to 14 is not limited, and although the UE handover needs to be performed before the MT3 handover according to the flows of full adjacent and full bottom-up, the implementation scenario is not limited to the three flows of full adjacent/full bottom-up/full top-down, and it may also occur that "DU3b establishes a cross-topology F1 interface with CU2—mt3 handover—du3a establishes a cross-topology F1 interface with CU1, and DU3b migrates from the cross-topology to the co-topology with the F1 interface of CU2," at this time, MT3 may be first switched, and then instruct the UE to execute CHO. In short, steps 11 to 12 may be performed before MT3 handover or after MT3 handover, as long as the F1 connection between DU3a and CU1 and the F1 connection between DU3b and CU2 exist.

It will be appreciated that in steps 12-14, the network side triggers CHO execution in broadcast form, since CHO may be less productive if CHO execution is then indicated in unicast form. The source of the CHO gain is to configure the UE in advance, the UE judges that the UE needs to be directly executed when switching, and the network side issues indication information of CHO execution to a plurality of UEs at one time in a broadcast mode to obtain more gain in consideration of the fact that the UE can not judge by itself.

Cell handover is performed between ue and IAB node.

The UE initiates random access to the target cell under DU3 b. If step 7, 2) exists, the UE directly accesses the appointed target cell, otherwise, the UE selects the target cell to access according to the measurement result of the cell under DU3 b.

As can be seen from the embodiment shown in fig. 7, this embodiment gives a case where the F1-C interface of the DU3b is issued prior to CHO configuration of the UE (a full connected and a full bottom-up procedure applicable to full migration), at this time, the DU3b is ready, and the cell under the DU3b can be configured as a potential target cell of the UE in the CHO handover command. The network side sends broadcast information to the UE to trigger the CHO to execute, so that the execution time of the full migration flow is reduced. In addition, the embodiment solves the problem that the UE cannot judge the execution of CHO by itself because the UE and the vehicle-mounted IAB node do not have relative motion in the vehicle-mounted mobile IAB scene, and enables the execution of the UE CHO during the migration of the vehicle-mounted mobile IAB.

Referring to fig. 8, a schematic diagram of an implementation of a communication method provided in the present application is provided, and the method includes the following steps.

In step 1, CU1 sends a handover REQUEST (HO REQUEST) message for UE CHO to CU2, wherein the target cell identity under DU3b corresponds to the target cell that has not been activated. Since DU3b and DU3a belong to one entity DU, the identity of the cell to be activated under DU3b may be preconfigured, and IAB-node3 may inform CU1 about this (signaling other patent informing CU1 of the cell identity to be activated under DU3b is protected), CU1 may carry the identity of the target cell that is not yet activated in the HO REQUEST and inform CU2 that the target cell is not activated.

CU2 admission control.

In step 2, CU2 performs admission control, but since the F1 interface with DU3b is not yet established, UE context configuration is not performed to DU3 b.

CU1 sends a first message to the UE via the IAB node, and accordingly, the UE receives the first message from CU1 in this step.

In step 4, the process is substantially the same as step 7 in the embodiment shown in fig. 7. Optionally, if the first message sent in step 4 carries the target cell identifier, the target cell corresponding to the target cell identifier is not yet activated.

MT in iab node performs handover.

DU in IAB node establishes F1 connection with CU 2.

In step 6, an F1 interface is established between DU3b and CU2 under the topology of CU 2. After the F1 interface of the DU3b is established, the CU2 configures the UE context to the DU3b according to the UE context obtained in step 1.

In step 7, after the CU2 has configured the UE context to the DU3b, a third indication is sent to inform the CU1 that CHO of the UE may be performed.

CU1 controls IAB node to send short message field, which is used to indicate the time domain position of PO. Correspondingly, the UE receives, through the IAB node, a short message field carried in the DCI from CU1 in this step.

The CU1 controls the IAB node to send a second message, wherein the first information in the second message is loaded on the PO. Accordingly, the UE receives a second message from CU1 through the IAB node in this step.

The implementation shown in step 8 to step 10 may refer to the implementation shown in step 12 to step 14 in the implementation shown in fig. 7.

It should be appreciated that the implementation shown in fig. 8 can also support the implementation of canceling the handover configuration shown in step 11 in the implementation shown in fig. 7, and reference may be made to the foregoing embodiments for implementation.

The ue detects any broadcast message of the N cells. Accordingly, the N cells transmit broadcast messages in this step.

In step 11, the UE detects a signal under DU3b and triggers CHO execution. In this embodiment, since the activation time of the DU3b is late and the CHO handover command of the UE is issued earlier than the activation of the DU3b, it is possible to allow CHO handover to be performed once the UE detects the signal under the DU3 b.

Cell handover is performed between ue and IAB node.

The implementation shown in step 12 may refer to the implementation shown in step 15 in the implementation shown in fig. 7.

In this embodiment, the case is given that the CHO configuration of the UE issues the F1-C interface establishment prior to the DU3b (the full-down procedure is applicable to full migration), in which the F1-C interface of the DU3b is almost established only last, if the CHO gain is to be obtained, the CHO handover command of the UE needs to be issued before the MT3 handover, and at this time, the target cell under the DU3b is not yet activated and cannot perform the real handover preparation procedure. The network side sends broadcast information to the UE to trigger the CHO to execute, or triggers the CHO to execute after the UE detects the signal of the DU3b, so that the execution time of the full migration flow is reduced. In addition, the embodiment solves the problem that the UE cannot judge the execution of CHO by itself because the UE and the vehicle-mounted IAB node do not have relative motion in the vehicle-mounted mobile IAB scene, and enables the execution of the UE CHO during the migration of the vehicle-mounted mobile IAB.

Referring to fig. 9, a schematic diagram of an implementation of a communication method provided in the present application is provided, and the method includes the following steps.

An F1 connection is established between the iab node and CU1.

In step 1, an F1 interface is established between DU3b and CU1, but in an F1 SETUP RESPONSE message sent by CU1 to DU3 b.

Alternatively, any cell under DU3b is not activated. The cells under DU3b do not need to be activated at this time, because the F1 interface established by DU3b with CU1 is only for receiving the underlying configuration information of the per UE from CU1, and is not really ready to accept the UE to switch to under DU3b, and if the following step adopts step 11 in the embodiment shown in fig. 8, the N cells under DU3b should not be activated at this time.

CU1 requests first configuration information from IAB node, and accordingly, IAB node receives the request from CU1 in this step.

In step 2, CU1 configures UE context to DU3b through F1AP, and sends UE CONTEXT SETUP REQUEST message.

The IAB node sends the first configuration information to the CU1, and accordingly, the CU1 receives the first configuration information from the IAB node in this step.

In step 3, DU3b generates the UE's underlying configuration information (i.e., first configuration information) and sends it to CU1 via a UE CONTEXT SETUP RESPONSE message.

CU1 sends the first configuration information to CU2, and accordingly, CU2 receives the first configuration information from CU1 in this step.

In step 4, CU1 transmits the bottom layer configuration information of DU3b to CU2. Since CU2 is a CU whose DU3b is to ultimately establish the F1 interface, higher layer configuration information (i.e., second configuration information) of the UE under DU3b needs to be generated by CU2.

CU2 sends handover configuration information for N cells to CU1, and accordingly, CU1 receives handover configuration information for N cells from CU2 in this step.

In step 5, CU2 combines the lower layer configuration information and the higher layer configuration information of DU3b received in step 4, and sends them to CU1 through RRC Container.

CU1 sends a first message to the UE, which in turn receives the first message from CU1.

In step 6, CU1 sends an RRC reconfiguration message (CHO handover command) to the UE, carrying the complete protocol stack configuration information of the UE under the target cell.

F1 connection release between DU3b and CU1 in the iab node.

MT in iab node performs handover.

In step 8 MT3 switches to the target cell under CU2.

DU3b in IAB node establishes F1 connection with CU2.

In step 9, DU3b re-establishes the F1 interface with CU2 and activates the cell.

Thereafter, the UE, the IAB node, the CU1 and the CU2 perform steps 7 to 12 shown in fig. 8.

In the conventional HANDOVER preparation procedure, the source CU sends a HANDOVER REQUEST to the target CU, then the target CU sends UE CONTEXT SETUP REQUEST to the target DU, the target DU returns UE CONTEXT SETUP RESPONSE (carrying the under layer configuration) to the target CU, the target CU will combine the under layer configuration reported by the DU with its own generated higher layer configuration, and then returns HANDOVER REQUEST ACKNOWLEDGE the combined under layer configuration to the source CU through the RRC Container, and then the source CU issues an RRC reconfiguration message (HANDOVER command) to the UE, so as to transparently transmit the information in the RRC Container. In this embodiment, since the DU3b cannot directly establish the F1 interface with the CU2, it is proposed that the CU1 is used as a transfer station, so that the DU3b reports the configuration of the bottom layer to the CU1, and then the CU1 reports the configuration of the bottom layer to the CU2. In the embodiment shown in fig. 9, before MT3 is switched, an F1 interface needs to be established between DU3b and CU1, and the purpose of communication between DU3b and CU2 is achieved through an F1 interface between DU3b and CU1, and an interface (such as an XN interface) between CU1 and CU2.

In this embodiment, before MT3 handover, an F1 interface is established between DU3b and CU1, and through the F1 interface between DU3b and CU1 and the interface (e.g. XN interface) between CU1 and CU2, CU1 can obtain the complete protocol stack configuration of UE under DU3b, and further can send CHO handover command to UE. Moreover, the present embodiment solves the problem that the complete protocol stack under the DU3b cannot be configured for the UE when the DU3b does not establish the F1 interface with the CU2, so that the UE CHO can be executed on the premise that the IAB node full reduction is executed in a data top-down manner.

In an IAB network, configuration information for a DU in an IAB node to communicate needs to be obtained from a host node by an MT in the IAB node. However, in the case where the MT in the IAB node does not acquire the third configuration information in time (for example, in the case where the MT and the first DU are connected to different CUs for communication, for example, in the case where the MT and the first DU are both switched to the same CU but the switching timing of the MT is later than that of the first DU, etc.), there is a possibility that the DU in the IAB node cannot normally communicate. Figures 10 and 11 and related embodiments provided by the present application will be presented below to address this problem.

Referring to fig. 10, a schematic diagram of an implementation of a communication method provided in the present application is provided, and the method includes the following steps.

S1001, the first CU determines third configuration information.

In this embodiment, the first CU determines third configuration information in step S1001, where the third configuration information includes third configuration information of the first DU; wherein the first DU is located at an IAB node, the IAB node further comprising a second DU and an MT.

S1002. the first CU sends third configuration information to the IAB node.

In this embodiment, after the first CU determines the third configuration information in step S1001, the first CU sends the third configuration information to the IAB node in step S1002, and correspondingly, the IAB node receives the third configuration information in step S1002.

In one possible implementation, the third configuration information sent by the first CU in step S1002 is carried on an F1 application protocol (F1 application protocol, F1 AP) message, or the third configuration information sent by the first CU in step S1002 is carried on an RRC message. Specifically, the first CU may issue the third configuration information to the IAB node in a variety of ways. The third configuration information may be transmitted through an F1 connection between the second DU and the first CU in the IAB node, that is, the third configuration information may be carried in an F1 AP message on the F1 connection. Alternatively, the third configuration information may be transmitted over an RRC connection between the MT and the first CU in the IAB node, i.e. the third configuration information may be carried on an RRC message on the RRC connection.

In one possible implementation, the third configuration information sent by the first CU in step S1002 includes at least one of: -new wireless cell global identity (new radio cell global identifier, NCGI) for determining the CU identity of the NCGI, or a first key for the first DU to establish encrypted communication of the F1 connection with other CUs, or-physical cell identity (physical cell identifier, PCI) of the cells in the first DU.

Optionally, the third configuration information sent by the first CU in step S1002 may include configuration information of the first DU and other communication nodes (e.g., CU or other IAB node or terminal device, etc.), where the configuration information may include the NCGI described above, a CU identifier used to determine the NCGI, a PCI, or other configuration information, which is not limited herein.

In a possible implementation manner, after the first CU sends the third configuration information to the IAB node in step S1002, the method further includes: the first CU receives fourth indication information for indicating that the third configuration information of the first DU is valid, or for indicating that the first CU transmits a handover command to a terminal device to which the second DU is connected, or for indicating that the first DU has transmitted a third message determined based on the third configuration information. Specifically, in the case that the first DU is capable of communicating based on the third configuration information, the first DU may further send indication information to the first CU, so that the first CU definitely determines that the first DU has validated the third configuration information, and subsequently the first CU may schedule the first DU and/or a terminal device connected to the first DU based on the third configuration information.

In a possible implementation, the third message includes a synchronization signal/physical broadcast channel block (synchronization signal/physical broadcast channel PBCH block, SS/PBCH block) (may be simply referred to as SS/PBCH block or SSB) sent by the first DU to the terminal device, or an F1 connection establishment request message sent by the first DU to the other CU.

By way of example, the information that may be included in the third configuration information will be described below by way of some implementation examples.

In an implementation example where the third configuration information comprises an NCGI or a CU identification of an NCGI. The NCGI is used for uniquely identifying a cell in the global scope, and can be received by the UE in a system message block 1 (System Information Block, SIB 1) message broadcasted by the DU, the NCGI is formed by splicing a gNB ID of the F1 anchor CU and a cell ID of a cell under the DU, and the cell ID of the DU3b is preconfigured to IAB-node3, so that when the F1 anchor CU of the DU3b is determined, the NCGI after the activation of the cell under the DU3b can be determined. In partial migration, since the IAB-DU is not changed by the F1 anchor CU, the NCGI is unchanged, and after full migration is introduced, the problem of NCGI change of the cell under the DU3b needs to be considered, and this embodiment expands the problem to the CHO scenario of the MT or the scenario of decoupling the DU from MT migration.

In an implementation example where the third configuration information includes PCI. PCI means physical cell identification, which is used to distinguish physical resources (such as SSB resources) of different cells, for example 1008 PCI are available in NR, which is far smaller than the number of NR cells worldwide, so PCI needs to be multiplexed to some extent. In order to avoid neighbor cell interference, the PCIs of the neighbor cells need to be different. During network planning, the IAB cell and other cells are not originally adjacent, so the same PCI may be used, but the cells become adjacent cells due to movement, and there is a conflict at this time, and the cells under the IAB need to change the PCI, and the changing mode is to start a new DU (DU 3 b), use the new PCI, and then switch the UE from DU3a to DU3 b.

In an implementation example where the third configuration information includes the first key. When the IAB-DU communicates with the donor-CU on the F1 interface, the data of the F1 interface needs to be encrypted safely, and the security key (K _iab ) Is computationally generated from a security algorithm, which requires 3 input parameters: IAB-DU IP address, donor-CU Key (K) _gNB ) (the Key of the donor-CU or the secure Key is the first Key).

Based on the solution shown in fig. 10, in a case where the first CU has a communication connection with the IAB node (for example, in a case where the first CU has a radio resource control (radio resource control, RRC) connection with an MT in the IAB node and/or in a case where the first CU has an F1 connection with a second DU in the IAB node), the first CU may send third configuration information of the first DU (i.e., other DUs than the second DU) to the IAB node, so that the first DU can communicate based on the third configuration information. The MT in the IAB node can acquire the third configuration information and communicate based on the third configuration information without receiving the configuration information from the first CU through the RRC connection again. Therefore, in a case where the MT in the IAB node cannot acquire the configuration information from the first CU in time (for example, in a case where the MT and the first DU are respectively connected to different CUs to perform communication, for example, in a case where the MT and the first DU are both switched to the same CU but the switching timing of the MT is later than that of the first DU, etc.), the first DU can be enabled to perform communication based on the third configuration information, so as to avoid the situation that the first DU cannot perform communication due to the lack of the third configuration information.

As an implementation example of the technical solution shown in fig. 10, an implementation shown in fig. 11 will be described below. In the embodiment shown in fig. 11, consider a scenario in which MT in the IAB node is configured with CHO, or a scenario in which MT in the IAB node is decoupled from migration of DUs. The core idea of this embodiment is to forward the information (e.g. PCI, NCGI, kgNB) required by the first DU under the second CU in advance, and when the IAB-MT or the IAB-DU determines the second CU, or when the IAB-node detects a PCI collision, the IAB-DU determines to use the corresponding information under the second CU. For a scene triggered based on a PCI collision, the first CU and the second CU may be the same.

Referring to fig. 11, a schematic diagram of an implementation of a communication method provided in the present application is provided, and the method includes the following steps.

1. The first CU sends third configuration information to the IAB node, and accordingly, the IAB node receives the third configuration information from the first in this step.

In step 1, the information (e.g., NCGI, kgNB, PCI) required for the (at least one) first DU under the plurality of potential second CUs is pre-informed to the IAB node in the RRC message of the MT in the IAB node or the F1AP message of the second DU. The RRC message may be a CHO handover command for MT 3. In general, PCI information is not required to be from another CU, as long as the PCI is one that does not collide with a neighboring cell.

The specific implementation process of the third configuration information may refer to the description of the embodiment shown in fig. 10, which is not described herein.

The IAB node determines a trigger event for triggering the validation of the third configuration information.

In this embodiment, in the case that the trigger event is determined to occur, the first DU in the IAB node determines to validate the third configuration information, that is, the first DU in the IAB node performs step 3 and/or step 4.

Optionally, in step 2, the triggering event may include at least one of:

when the MT in the IAB node meets the switching condition and needs to be switched to the second CU, the first DU in the IAB node determines the CU establishing the F1 interface as the second CU, or the cell PCI of the first DU detected in the IAB node collides with the PCI of the nearby cell.

It should be appreciated that in a communication system, the PCIs of the neighbors need to be different in order to avoid neighbor interference. When the network planning is performed, the IAB cell and other cells are not originally adjacent, so the same PCI may be used, but the cells become adjacent cells due to movement, and then have collision, and the cells under the IAB need to change the PCI at this time, and the change mode is to start a new DU (such as a first DU), use the new PCI, and switch the UE from the second DU to the first DU. Thus detecting a PCI collision may also be used as an effective condition for configuration under the first DU.

Optionally, the detection in the IAB node that the cell PCI of the first DU collides with the neighboring cell PCI may include any implementation procedure, for example: the MT in the IAB node detects the PCI of the adjacent cell through the measurement of the adjacent cell, and discovers that the PCI is the same as the PCI of the cell under the second DU; or it may be that the second DU in the IAB node learns of the PCI collision by implementing it (e.g. the current PCI is available in a pre-configured geographical area, the second DU finds itself to move to an area where the current PCI is not available based on the locating device).

The IAB node sends a third message to the terminal equipment, and the terminal equipment receives the third message from the IAB node in the step correspondingly.

It should be understood that in case the third configuration information comprises configuration information for communication with the terminal device, the IAB node may send a third message to the terminal device in step 3 based on the configuration information.

The IAB node sends a third message to the second CU, and accordingly, CU2 receives the third message from the IAB node in this step.

It should be appreciated that in case the third configuration information comprises configuration information for communication with the CU, the IAB node may send a third message to the second CU in step 3 based on the configuration information.

The IAB node sends an indication to the first CU, and the first CU receives the indication from the IAB node in this step, accordingly.

Step 5 is an optional step. When the IAB node determines that the third configuration information is valid, the IAB node sends indication information (which may be an RRC message bearer of the MT or an F1AP message bearer of the second DU or an F1AP message bearer of the first DU) to the first CU, where the manner of F1AP of the DU3b is only applicable to the same scenario where the DU3b and the F1 anchor CU of the DU3a are the same, i.e. the above-mentioned PCI change scenario), to indicate that the configuration of the DU3b is valid, or to indicate that the UE may switch to the first DU.

In this embodiment, the third configuration information (e.g., NCGI, kgNB, PCI) required by the first DU is issued in advance, and when the MT in the IAB node or the second DU in the IAB node determines to connect with other CUs, or when the IAB node detects a PCI collision, the first DU of the IAB node determines to use the corresponding information under the target CU. So as to enable the scenario when the MT is decoupled from the MT through CHO handover or migration of DUs, the present embodiment can enable the first DU to obtain the required configuration information (e.g., NCGI, kgNB, PCI) correctly in both scenarios.

The present application is described above from a method perspective, and further examples provided herein are described below.

Referring to fig. 12, a schematic diagram of an implementation of a communication device provided in the present application, the communication device 1200 includes a processing unit 1201 and a transceiver unit 1202. The communication apparatus 1200 may implement the functions of the communication apparatus (including the terminal device, the source CU, the target CU, the first CU, the IAB node, etc.) in the foregoing method embodiment, and thus may also implement the beneficial effects of the foregoing method embodiment. In this embodiment of the present application, the communication apparatus 1200 may be a terminal device (or a source CU, a target CU, a first CU, an IAB node, etc.), or may be an integrated circuit or an element, such as a chip, inside the terminal device (or the source CU, the target CU, the first CU, the IAB node, etc.). The following embodiments will take the communication apparatus 1200 as an example of a terminal device (or a source CU, a target CU, a first CU, an IAB node, or the like).

In a possible implementation manner, when the apparatus 1200 is configured to perform the method performed by the terminal device in the foregoing embodiment, the apparatus includes a processing unit 1201 and a transceiver unit 1202; the transceiver unit 1202 is configured to receive a first message, where the first message includes handover configuration information of N cells, N is a positive integer, and the handover configuration information is used for a cell handover procedure triggered based on a second message; the processing unit 1201 is configured to perform a cell handover based on the handover configuration information after the transceiving unit 1202 receives the second message.

In one possible implementation, the second message includes first information carried by any one of: a short message field in downlink control information DCI of a physical downlink control channel PDCCH scrambled by a paging radio network temporary identifier P-RNTI; information in paging opportunity PO; or, any one of the N cells broadcasts information.

In one possible implementation, the first message further includes at least one of: the first indication information indicates that the switching configuration information is used for a cell switching process triggered based on the second message; or, second indication information indicating that the second message is monitored over all of the POs.

In one possible implementation, the second message is a broadcast message.

In one possible implementation, N has a value of 1.

In one possible implementation, the handover configuration information is conditional handover CHO configuration information.

In a possible implementation manner, when the apparatus 1200 is configured to perform the method performed by the terminal device in the foregoing embodiment, the apparatus includes a processing unit 1201 and a transceiver unit 1202; the transceiver 1202 is configured to receive a first message, where the first message includes handover configuration information of N cells, and N is a positive integer; the processing unit 1201 is configured to ignore or delete the handover configuration information after determining that the second message is not received (the second message is used to trigger the cell handover procedure corresponding to the handover configuration information) or determining that indication information indicating cancellation of the cell handover procedure corresponding to the handover configuration information is received.

In one possible implementation, the handover configuration information is used for a cell handover procedure triggered based on the second message.

In one possible implementation, the handover configuration information is conditional handover CHO configuration information triggered based on measurement events.

In a possible implementation manner, when the apparatus 1200 is used to perform the method performed by the source CU in the foregoing embodiment, the apparatus includes a processing unit 1201 and a transceiver unit 1202; the processing unit 1201 is configured to determine a first message, where the first message includes handover configuration information of N cells, where N is a positive integer, and the handover configuration information is used for a cell handover procedure triggered based on a second message; wherein, N cells are located in the target DU; the transceiver unit 1202 is configured to send the first message to a terminal device through an access backhaul integrated IAB node.

In one possible implementation, the target DU is located at the IAB node.

In a possible implementation manner, the transceiver unit 1202 is further configured to send a handover request message of the terminal to the target CU after the processing unit 1201 determines that the target DU has established an F1 connection with the target centralized unit CU; the transceiver unit 1202 is further configured to receive a handover response message from the target CU, where the handover response message includes the handover configuration information.

In a possible implementation, the transceiving unit 1202 is further configured to send the second message to the terminal device.

In one possible implementation, the transceiver unit 1202 sends the second message to the terminal device when at least one of the following is satisfied, including: the processing unit 1201 determines that the target DU and the target CU have established an F1 connection; the processing unit 1201 determines that the mobile terminal MT in the IAB node is to be handed over to the target CU; or, the processing unit 1201 determines that receiving the indication from the target CU allows the terminal device to perform cell handover based on the handover configuration information.

In one possible implementation, the transceiver unit 1202 sends the first message when any of the following is satisfied, including: the processing unit 1201 determines that, after the transceiver unit 1202 sends a first handover request message to the target CU, receives a first handover response message from the target CU, the first handover response message including handover configuration information of N cells; after determining that the transceiver unit 1202 sends the second handover request message to the target CU, the processing unit 1201 receives a second handover response message from the target CU, where the second handover request message includes identities of N cells and the N cells are inactive cells; or, the processing unit 1201 determines that the transceiving unit 1202 receives the handover configuration information of N cells from the target CU after receiving the first configuration information from the target DU and transmitting the first configuration information to the target CU, and the handover configuration information of the N cells includes the first configuration information and the second configuration information.

In one possible implementation, the first configuration information includes radio link control RLC layer configuration information and/or medium access control MAC layer configuration information, and the second configuration information includes packet data convergence protocol PDCP layer configuration information and/or service data adaptation protocol SDAP layer configuration information.

In a possible implementation, the determining unit is specifically configured to determine that the target DU has established an F1 connection with the target centralized unit CU based on third indication information from the target CU, the third indication information indicating that the terminal device performs cell handover based on the handover configuration information.

In one possible implementation, the second message is a broadcast message.

In one possible implementation, N has a value of 1.

In one possible implementation, the method further includes: and sending indication information for indicating the cell switching process cancellation corresponding to the switching configuration information.

In a possible implementation manner, when the apparatus 1200 is used to perform the method performed by the target CU in the foregoing embodiment, the apparatus includes a processing unit 1201 and a transceiver unit 1202; the processing unit 1201 is configured to determine, after determining that an F1 connection has been established with a target distributed unit DU, third indication information, where the third indication information indicates that the terminal device performs cell handover based on the handover configuration information, and the target DU includes N cells, where N is a positive integer; the switching configuration information is used for a cell switching process triggered based on the second message; the transceiving unit 1202 is configured to send the third indication information to the source CU.

In a possible implementation, the transceiving unit 1202 is specifically configured to send the third indication information to the source CU after the processing unit 1201 determines that the target DU has configured the context of the terminal device.

In a possible implementation manner, the transceiver unit 1202 is further configured to receive a second handover request message from the source centralized unit CU, where the second handover request message includes an identity of N cells and the N cells are inactive cells; wherein N cells are located in the target DU; the transceiver unit 1202 is further configured to send a second handover response message to the source CU, where the second handover response message includes handover configuration information of the N cells.

In a possible implementation manner, the transceiver unit 1202 is further configured to send, after receiving the first configuration information from the source centralized unit CU, handover configuration information of N cells to the source CU, where the handover configuration information of N cells includes the first configuration information and the second configuration information.

In a possible implementation manner, when the apparatus 1200 is configured to perform the method performed by the first CU in the foregoing embodiment, the apparatus includes a processing unit 1201 and a transceiver unit 1202; the processing unit 1201 is configured to determine third configuration information, where the third configuration information includes third configuration information of the first centralized unit DU; the first DU is positioned at an access backhaul integrated IAB node, and the IAB node further comprises a second DU and a mobile terminal MT; the transceiver unit 1202 is configured to send the third configuration information to the IAB node.

In one possible implementation, the third configuration information is carried in an F1 AP message, or the third configuration information is carried in an RRC message.

In one possible implementation, the third configuration information includes at least one of: the new wireless cell global identity NCGI, a CU identity for determining the NCGI, or a first key for the first DU to establish encrypted communications for the F1 connection with other CUs, or a physical cell identity PCI for the cell in the first DU.

In a possible implementation manner, the transceiver unit 1202 is further configured to receive fourth indication information, where the fourth indication information is used to indicate that the third configuration information of the first DU is valid, or to instruct the first CU to send a handover command to the terminal device connected to the second DU.

In a possible implementation manner, when the apparatus 1200 is configured to perform the method performed by the IAB node in the foregoing embodiment, the apparatus includes a processing unit 1201 and a transceiver unit 1202; the transceiver unit 1202 is configured to receive third configuration information, where the third configuration information includes third configuration information of the first DU; the processing unit 1201 is configured to determine a third message, where the third message is obtained based on the third configuration information; the transceiving unit 1202 is further configured to send a third message.

In one possible implementation, the third configuration information includes at least one of: the new wireless cell global identity NCGI, a CU identity for determining the NCGI, a first key for the first DU to establish encrypted communications for the F1 connection with other CUs, or a physical cell identity PCI for the cell in the first DU.

In one possible implementation, the transceiver unit 1202 sends the third message when at least one of the following is satisfied, including: the processing unit 1201 determines that the cell handover execution condition is satisfied, and that the target cell corresponding to the cell handover is located on the other CU; the processing unit 1201 determines to establish an F1 connection with the other CU; or, the processing unit 1201 determines that the PCI of any cell under the first DU is detected to collide with other PCIs.

In a possible implementation manner, the transceiver unit 1202 is further configured to send fourth indication information to the first CU, where the fourth indication information is used to indicate that the third configuration information of the first DU is valid, or is used to indicate that the first CU sends a handover command to a terminal device connected to the first DU.

In one possible implementation, the third message includes an SSB sent by the first DU to the terminal device, or an F1 connection establishment request message sent by the first DU to the other CU.

It should be noted that, for details of the information execution process of the unit of the communication apparatus 1200, reference may be made to the description in the foregoing method embodiment of the present application, and details are not repeated here.

Referring to fig. 13, for another schematic structural diagram of a communication device 1300 provided in the present application, the communication device 1300 includes at least an input/output interface 1302. The communication device 1300 may be a chip or an integrated circuit.

Optionally, the communication device further comprises logic 1301.

The transceiver unit 1202 shown in fig. 12 may be a communication interface, which may be the input/output interface 1302 in fig. 13, and the input/output interface 1302 may include an input interface and an output interface. Alternatively, the communication interface may be a transceiver circuit, which may include an input interface circuit and an output interface circuit.

Optionally, in the case where the communication apparatus 1300 is a terminal device (or a component in the terminal device) in the foregoing embodiment, the input/output interface 1302 is configured to receive a first message, where the first message includes handover configuration information of N cells, where N is a positive integer, and the handover configuration information is used for a cell handover procedure triggered based on a second message; the logic circuit 1301 is configured to perform a cell handover based on the handover configuration information after the input output interface 1302 receives the second message.

Optionally, in the case where the communication apparatus 1300 is a terminal device (or a component in the terminal device) in the foregoing embodiment, the input/output interface 1302 is configured to receive a first message, where the first message includes handover configuration information of N cells, and N is a positive integer; the logic circuit 1301 is configured to ignore or delete the handover configuration information after determining that the second message is not received (the second message is used to trigger the cell handover procedure corresponding to the handover configuration information) or determining that indication information indicating cancellation of the cell handover procedure corresponding to the handover configuration information is received.

Optionally, in the case that the communication apparatus 1300 is the source CU (or a component in the source CU) in the foregoing embodiment, the logic circuit 1301 is configured to determine a first message, where the first message includes handover configuration information of N cells, where N is a positive integer, and the handover configuration information is used for a cell handover procedure triggered based on the second message; wherein, N cells are located in the target DU; the input/output interface 1302 is configured to send the first message to the terminal device through the access backhaul integrated IAB node.

Alternatively, in the case that the communication apparatus 1300 is the target CU (or a component in the target CU) in the foregoing embodiment, the logic circuit 1301 is configured to determine, after determining that the F1 connection has been established with the target distributed unit DU, the target DU includes N cells, where N is a positive integer, third indication information indicating that the terminal device performs cell handover based on the handover configuration information; the switching configuration information is used for a cell switching process triggered based on the second message; the input/output interface 1302 is configured to send the third indication information to the source CU.

Optionally, in the case that the communication apparatus 1300 is the first CU (or a component in the first CU) in the foregoing embodiment, the logic circuit 1301 is configured to determine third configuration information, where the third configuration information includes third configuration information of the first centralized unit DU; the first DU is positioned at an access backhaul integrated IAB node, and the IAB node further comprises a second DU and a mobile terminal MT; the input-output interface 1302 is configured to send the third configuration information to the IAB node.

Optionally, in the case that the communication apparatus 1300 is an IAB node (or a component in an IAB node) in the foregoing embodiment, the input-output interface 1302 is configured to receive third configuration information, where the third configuration information includes third configuration information of the first DU; the logic circuit 1301 is configured to determine a third message, where the third message is obtained based on the third configuration information; the input-output interface 1302 is also used to send a third message.

The logic circuit 1301 and the input/output interface 1302 may also perform other steps performed by the network device in any embodiment and achieve corresponding beneficial effects, which are not described herein.

In one possible implementation, the processing unit 1201 illustrated in fig. 12 may be the logic circuit 1301 in fig. 13.

Alternatively, the logic 1301 may be a processing apparatus, and the functions of the processing apparatus may be implemented partially or entirely in software. Wherein the functions of the processing device may be partially or entirely implemented by software.

Optionally, the processing means may comprise a memory for storing a computer program and a processor for reading and executing the computer program stored in the memory for performing the corresponding processes and/or steps in any of the method embodiments.

Alternatively, the processing means may comprise only a processor. The memory for storing the computer program is located outside the processing means and the processor is connected to the memory via circuitry/electrical wiring for reading and executing the computer program stored in the memory. Wherein the memory and the processor may be integrated or may be physically independent of each other.

Alternatively, the processing means may be one or more chips, or one or more integrated circuits. For example, the processing device may be one or more field-programmable gate arrays (FPGAs), application-specific integrated chips (application specific integrated circuit, ASICs), system-on-chips (socs), central processing units (central processor unit, CPUs), network processors (network processor, NPs), digital signal processing circuits (digital signal processor, DSPs), microcontrollers (micro controller unit, MCUs), programmable controllers (programmable logic device, PLDs) or other integrated chips, or any combination of the above chips or processors, or the like.

Referring to fig. 14, a communication apparatus 1400 according to the above embodiment provided in the present application may be specifically a communication apparatus as a terminal device in the above embodiment.

Wherein, a schematic diagram of one possible logical structure of the communication device 1400, the communication device 1400 may include, but is not limited to, at least one processor 1401 and a communication port 1402.

Further optionally, the device may further comprise at least one of a memory 1403, a bus 1404, the at least one processor 1401 being for controlling the actions of the communication device 1400 in the embodiments of the present application.

Further, the processor 1401 may be a central processor unit, a general purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Which may implement or perform the various exemplary logic blocks, modules, and circuits described in connection with this disclosure. The processor may also be a combination that performs the function of a computation, e.g., a combination comprising one or more microprocessors, a combination of a digital signal processor and a microprocessor, and so forth. It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.

It should be noted that, the communication apparatus 1400 shown in fig. 14 may be specifically used to implement the steps implemented by the terminal device in the foregoing method embodiment, and implement the technical effects corresponding to the terminal device, and the specific implementation manner of the communication apparatus shown in fig. 14 may refer to the descriptions in the foregoing method embodiment, which are not repeated herein.

Referring to fig. 15, a schematic structural diagram of a communication apparatus 1500 according to the foregoing embodiment provided in the embodiments of the present application, where the communication apparatus 1500 may specifically be a communication apparatus as a network device (for example, a source CU, a target CU, a first CU, an IAB node, etc.) in the foregoing embodiment. The structure of the communication device may refer to the structure shown in fig. 15.

The communications device 1500 includes at least one processor 1511 and at least one network interface 1514. Further optionally, the communication device further comprises at least one memory 1512, at least one transceiver 1513, and one or more antennas 1515. The processor 1511, the memory 1512, the transceiver 1513, and the network interface 1514 are connected, for example, by a bus, and in the embodiment of the present application, the connection may include various interfaces, transmission lines, buses, or the like, which is not limited in this embodiment. An antenna 1515 is coupled to the transceiver 1513. The network interface 1514 is used to enable the communication apparatus to communicate with other communication devices via a communication link. For example, the network interface 1514 may include a network interface between the communication apparatus and the core network device, such as an S1 interface, and the network interface may include a network interface between the communication apparatus and other communication apparatuses (such as other network devices or core network devices), such as an X2 or Xn interface.

The processor 1511 is mainly configured to process communication protocols and communication data, and to control the entire communication apparatus, execute software programs, and process data of the software programs, for example, to support the communication apparatus to perform the actions described in the embodiments. The communication device may include a baseband processor, which is mainly used for processing the communication protocol and the communication data, and a central processor, which is mainly used for controlling the whole terminal device, executing the software program, and processing the data of the software program. The processor 1511 in fig. 15 may integrate the functions of a baseband processor and a central processor, and those skilled in the art will appreciate that the baseband processor and the central processor may also be separate processors, interconnected by bus technology, etc. Those skilled in the art will appreciate that the terminal device may include multiple baseband processors to accommodate different network formats, and that the terminal device may include multiple central processors to enhance its processing capabilities, and that the various components of the terminal device may be connected by various buses. The baseband processor may also be referred to as a baseband processing circuit or baseband processing chip. The central processing unit may also be expressed as a central processing circuit or a central processing chip. The function of processing the communication protocol and the communication data may be built in the processor, or may be stored in a memory in the form of a software program, which is executed by the processor to realize the baseband processing function.

The memory is mainly used for storing software programs and data. Memory 1512 may be separate and coupled to processor 1511. Alternatively, the memory 1512 may be integrated with the processor 1511, such as within a chip. The memory 1512 is capable of storing program codes for implementing the technical solutions of the embodiments of the present application, and the processor 1511 controls the execution of the program codes, and various executed computer program codes may be regarded as drivers of the processor 1511.

Fig. 15 shows only one memory and one processor. In an actual terminal device, there may be multiple processors and multiple memories. The memory may also be referred to as a storage medium or storage device, etc. The memory may be a memory element on the same chip as the processor, i.e., an on-chip memory element, or a separate memory element, as embodiments of the present application are not limited in this regard.

The transceiver 1513 may be used to support the reception or transmission of radio frequency signals between the communication device and the terminal, and the transceiver 1513 may be coupled to an antenna 1515. The transceiver 1513 includes a transmitter Tx and a receiver Rx. Specifically, one or more antennas 1515 may receive the rf signal, and a receiver Rx of the transceiver 1513 is configured to receive the rf signal from the antenna, convert the rf signal into a digital baseband signal or a digital intermediate frequency signal, and provide the digital baseband signal or the digital intermediate frequency signal to the processor 1511, so that the processor 1511 performs further processing, such as demodulation processing and decoding processing, on the digital baseband signal or the digital intermediate frequency signal. The transmitter Tx in the transceiver 1513 is also configured to receive a modulated digital baseband signal or digital intermediate frequency signal from the processor 1511, convert the modulated digital baseband signal or digital intermediate frequency signal to a radio frequency signal, and transmit the radio frequency signal through the one or more antennas 1515. In particular, the receiver Rx may selectively perform one or more steps of down-mixing and analog-to-digital conversion on the radio frequency signal to obtain a digital baseband signal or a digital intermediate frequency signal, where the order of the down-mixing and analog-to-digital conversion is adjustable. The transmitter Tx may selectively perform one or more stages of up-mixing processing and digital-to-analog conversion processing on the modulated digital baseband signal or the digital intermediate frequency signal to obtain a radio frequency signal, and the sequence of the up-mixing processing and the digital-to-analog conversion processing may be adjustable. The digital baseband signal and the digital intermediate frequency signal may be collectively referred to as a digital signal.

The transceiver 1513 may also be referred to as a transceiver unit, transceiver device, etc. Alternatively, the device for implementing the receiving function in the transceiver unit may be regarded as a receiving unit, and the device for implementing the transmitting function in the transceiver unit may be regarded as a transmitting unit, that is, the transceiver unit includes a receiving unit and a transmitting unit, where the receiving unit may also be referred to as a receiver, an input port, a receiving circuit, etc., and the transmitting unit may be referred to as a transmitter, or a transmitting circuit, etc.

It should be noted that, the communication apparatus 1500 shown in fig. 15 may be specifically used to implement the steps implemented by the network device in the foregoing method embodiment, and implement the technical effects corresponding to the network device, and the specific implementation manner of the communication apparatus 1500 shown in fig. 15 may refer to the descriptions in the foregoing method embodiment, which are not repeated herein.

Embodiments of the present application also provide a computer-readable storage medium storing one or more computer-executable instructions that, when executed by a processor, perform a method as described in the possible implementation of the terminal device in the previous embodiments.

Embodiments also provide a computer-readable storage medium storing one or more computer-executable instructions that, when executed by a processor, perform a method as described in the foregoing embodiments as a possible implementation of a network device (e.g., a source CU, a target CU, a first CU, an IAB node, etc.).

Embodiments of the present application also provide a computer program product (or computer program) storing one or more computers, which when executed by the processor performs a method as described above as a possible implementation of the terminal device.

Embodiments also provide a computer program product storing one or more computers that, when executed by the processor, perform a method of a possible implementation of the above-described network device (e.g., source CU, target CU, first CU, IAB node, etc.).

The embodiment of the application also provides a chip system, which comprises at least one processor and is used for supporting the communication device to realize the functions involved in the possible realization mode of the communication device. Optionally, the chip system further comprises an interface circuit providing program instructions and/or data to the at least one processor. In one possible design, the system-on-chip may further include a memory to hold the necessary program instructions and data for the communication device. The chip system may be formed by a chip, or may include a chip and other discrete devices, where the communication device may specifically be a terminal device in the foregoing method embodiment.

The embodiment of the application also provides a chip system, which comprises at least one processor and is used for supporting the communication device to realize the functions involved in the possible realization mode of the communication device. Optionally, the chip system further comprises an interface circuit providing program instructions and/or data to the at least one processor. In one possible design, the system on a chip may further include a memory to hold the necessary program instructions and data for the communication device. The chip system may be formed by a chip, or may include a chip and other discrete devices, where the communication apparatus may specifically be a network device (for example, a source CU, a target CU, a first CU, an IAB node, etc.) in the foregoing method embodiment.

The embodiment of the application also provides a communication system, which comprises the terminal device and the network device (including at least one of a source CU, a target CU, a first CU, an IAB node and the like) in any of the above embodiments.

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

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

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units. The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, including several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Claims

1. A method of communication, comprising:

receiving a first message, wherein the first message comprises switching configuration information of N cells, N is a positive integer, and the switching configuration information is used for triggering a cell switching process based on a second message;

after receiving the second message, performing a cell handover based on the handover configuration information.

2. The method of claim 1, wherein the second message comprises first information carried by any one of:

any one of the N cells broadcasts information.

3. The method according to claim 1 or 2, wherein the first message further comprises at least one of:

and second indication information indicating that the second message is monitored on all POs.

4. A method according to claim 3, wherein the second message is a broadcast message.

5. The method according to any one of claims 1 to 4, wherein N has a value of 1.

6. The method according to any of claims 1 to 5, wherein the handover configuration information is conditional handover CHO configuration information.

7. A method of communication, comprising:

determining a first message, wherein the first message comprises switching configuration information of N cells, N is a positive integer, and the switching configuration information is used for triggering a cell switching process based on a second message; wherein, N cells are located in the target DU;

and sending the first message to the terminal equipment through the access backhaul integrated IAB node.

8. The method of claim 7, wherein the target DU is located at the IAB node.

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

after determining that the target DU and the target centralized unit CU have established an F1 connection, sending a handover request message of the terminal to the target CU;

and receiving a switching response message from the target CU, wherein the switching response message comprises the switching configuration information.

10. The method according to any one of claims 7 to 9, further comprising:

And sending the second message to the terminal equipment.

11. The method of claim 10, wherein sending the second message to the terminal device when at least one of:

determining that the target DU and the target CU have established F1 connection;

determining that a mobile terminal MT in the IAB node is to be handed over to the target CU; or alternatively, the first and second heat exchangers may be,

receiving an indication from the target CU allows the terminal device to perform a cell handover based on the handover configuration information.

12. The method according to any one of claims 7 to 11, wherein sending the first message when any one of the following is satisfied comprises:

after sending a first switching request message to the target CU, receiving a first switching response message from the target CU, wherein the first switching response message comprises switching configuration information of the N cells;

after sending a second handover request message to the target CU, receiving a second handover response message from the target CU, the second handover request message including identities of the N cells and the N cells being inactive cells; or alternatively, the first and second heat exchangers may be,

after receiving the first configuration information from the target DU and sending the first configuration information to the target CU, receiving handover configuration information of the N cells from the target CU, where the handover configuration information of the N cells includes the first configuration information and the second configuration information.

13. The method according to claim 12, wherein the first configuration information comprises radio link control, RLC, layer configuration information and/or medium access control, MAC, layer configuration information and the second configuration information comprises packet data convergence protocol, PDCP, layer configuration information and/or service data adaptation protocol, SDAP, layer configuration information.

14. The method according to any one of claims 9 to 13, wherein the determining that the target DU has established an F1 connection with a target CU comprises:

and determining that the target DU and the target CU have established F1 connection based on third indication information from the target CU, wherein the third indication information indicates the terminal equipment to execute cell switching based on the switching configuration information.

15. The method according to any of claims 7 to 14, wherein the second message comprises first information carried on any of:

any one of the N cells broadcasts information.

16. The method according to any one of claims 7 to 15, wherein the first message further comprises at least one of:

17. The method of claim 16, wherein the second message is a broadcast message.

18. The method according to any one of claims 7 to 17, wherein N has a value of 1.

19. The method according to any one of claims 7 to 18, further comprising:

and sending indication information for indicating the cell switching process cancellation corresponding to the switching configuration information to the terminal equipment.

20. A method of communication, comprising:

after determining that an F1 connection has been established with a target distributed unit DU, determining third indication information, the third indication information indicating that the terminal device performs cell handover based on the handover configuration information, the target DU including the N cells, N being a positive integer; the switching configuration information is used for a cell switching process triggered based on the second message;

and sending the third indication information to the source CU.

21. The method of claim 20, wherein the sending the third indication information to the source CU comprises:

After determining that the target DU has configured the context of the terminal device, the third indication information is sent to the source CU.

22. The method according to claim 20 or 21, wherein before sending the third indication information to the source CU, the method further comprises:

receiving a second handover request message from a source centralized unit CU, the second handover request message comprising identities of N cells and the N cells being inactive cells; wherein the N cells are located in the target DU;

and sending a second switching response message to the source CU, wherein the second switching response message comprises switching configuration information of the N cells.

23. The method according to claim 20 or 21, wherein before sending the third indication information to the source CU, the method further comprises:

after receiving the first configuration information from the source centralized unit CU, transmitting handover configuration information of the N cells to the source CU, where the handover configuration information of the N cells includes the first configuration information and the second configuration information.

24. The method according to claim 23, wherein the first configuration information comprises radio link control, RLC, layer configuration information and/or medium access control, MAC, layer configuration information and the second configuration information comprises packet data convergence protocol, PDCP, layer configuration information and/or service data adaptation protocol, SDAP, layer configuration information.

25. A communication device, comprising a processing unit and a transceiver unit;

wherein the processing unit and the transceiver unit are adapted to perform the method of any of claims 1 to 24.

26. A communication device comprising at least one processor, the at least one processor coupled to a memory;

the memory is used for storing programs or instructions;

the at least one processor is configured to execute the program or instructions to cause a communication device to implement the method of any one of claims 1 to 24.

27. A communication system, characterized in that the system comprises at least two of the communication means performing the method of any of claims 1 to 6, the communication means performing the method of any of claims 7 to 19 and the communication means performing the method of any of claims 20 to 24.

28. A computer readable storage medium storing instructions which, when executed by a computer, implement the method of any one of claims 1 to 24.

29. A computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any of claims 1 to 24.