CN114125957A

CN114125957A - Communication method, device and computer readable storage medium

Info

Publication number: CN114125957A
Application number: CN202010901420.2A
Authority: CN
Inventors: 王�锋; 胡丹; 张旭; 曲秉玉
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2022-03-01
Also published as: WO2022042136A1

Abstract

The application provides a communication method, a communication device and a computer readable storage medium. Wherein, the method comprises the following steps: determining that a carrier for uplink transmission of the terminal equipment in the first cell is a first carrier after the terminal equipment is switched from the second cell to the first cell; the first carrier and the second carrier belong to the same frequency band, and the second carrier is a carrier of the terminal device in a second cell. By the technical scheme, random access is not needed, and the terminal equipment can realize uplink transmission in the first cell. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

Description

Communication method, device and computer readable storage medium

Technical Field

The present application relates to the field of wireless communication technologies, and in particular, to a communication method, an apparatus, and a computer-readable storage medium.

Background

In a wireless communication system, when a User Equipment (UE) is in a traffic connection state and maintains a traffic service, the UE moves from one cell to another cell, and handover is required to ensure continuity of UE communication.

In a new radio access technology (NR), during handover, the UE needs to perform random access to a target cell to obtain a Timing Advance (TA) value after the UE is handed over to the target cell, so as to complete uplink synchronization of the UE in the target cell. However, a problem of delay and interruption may occur during a handover of the UE to the target cell requiring random access, so that efficiency of communication is reduced.

Disclosure of Invention

The application provides a communication method, a communication device and a computer readable storage medium, which can improve the communication efficiency.

In a first aspect, the present application provides a communication method, which may be applied to a terminal device and may also be applied to a module (e.g., a chip) in the terminal device, and the following description takes the application to the terminal device as an example. The communication method may include: determining that a carrier for uplink transmission of the terminal equipment in the first cell is a first carrier after the terminal equipment is switched from the second cell to the first cell; the first carrier and the second carrier belong to the same frequency band, and the second carrier is a carrier of the terminal device in a second cell.

In the solution provided in this application, before the terminal device is switched, the terminal device communicates with the second network device in the second cell, the second network device may send downlink transmission to the terminal device, the terminal device may send uplink transmission to the fourth network device on the second carrier, and the fourth network device refers to a network device that can receive the uplink transmission sent by the terminal device on the second carrier. The fourth network device sends the uplink data to the second network device, for example, the fourth network device may send the uplink data to the second network device through the backhaul. If the second network device is a fourth network device, that is, the second carrier and the second cell are co-sited, or the second carrier and the second network device are co-sited, the terminal device may directly send the uplink transmission to the second network device on the second carrier. After the terminal device is switched, the terminal device communicates with the first network device in the first cell, the first network device may send downlink transmission to the terminal device, the terminal device may send uplink transmission to the fifth network device in the first carrier, and the fifth network device is a network device that can receive the uplink transmission sent by the terminal device in the first carrier. The fifth network device sends the uplink data to the first network device, for example, the fifth network device may send the uplink data to the first network device through the backhaul. If the first network device is the fifth network device, that is, the first carrier and the first cell are co-sited, or the first carrier and the first network device are co-sited, the terminal device may directly send the uplink transmission to the first network device on the first carrier.

The handover mentioned in the embodiment of the present application may be a cell handover. The first cell may be a target cell (target cell) and the second cell may be a source cell (source cell). The first network device may be a target network device, and the second network device may be a source (original) network device, that is, the first network device is a network device corresponding to a first cell, and the second network device is a network device corresponding to a second cell.

It should be understood that a certain network device is a network device corresponding to a certain cell, it may be understood that a certain network device is a network device to which a certain cell belongs, it may also be understood that a certain network device serves a certain cell, and it may also be understood that a certain cell of a certain network device. For example, information of a cell may be acquired from a network device, where the information may be scheduling information, and the scheduling information may be used for uplink transmission from the terminal device to the network device or downlink transmission from the network device to the terminal device.

The first carrier is a carrier of a first cell, and the second carrier is a carrier of a second cell, which can be understood as that the first carrier is a carrier corresponding to the first cell, and the second carrier is a carrier corresponding to the second cell; it can also be understood that the first carrier is a carrier configured by a first cell, and the second carrier is a carrier configured by a second cell.

The first carrier and the second carrier may belong to the same frequency band, and uplink transmissions sent by the terminal device on the first carrier and the second carrier are received by the same network device. In one possible approach, the first carrier and the second carrier are the same carrier.

The first carrier and the second carrier are the same carrier, and it can be understood that uplink transmissions sent by the terminal device on the first carrier and the second carrier are received by the same network device, and at least one of the following conditions is satisfied: the carrier frequencies of the first carrier and the second carrier are the same; the frequency reference points of the first carrier and the second carrier are the same; the frequency positions of the first carrier wave and the second carrier wave are the same; the carrier bandwidths of the first carrier and the second carrier are the same.

After the terminal device is switched from the second cell to the first cell, the carrier in the first cell, where the terminal device performs uplink transmission, is the first carrier, and it may be understood that after the terminal device is switched, the first cell communicates with the first network device, the first network device may send downlink transmission to the terminal device, the terminal device may send uplink transmission to the fourth network device on the first carrier, and the fourth network device sends uplink transmission data to the first network device, for example, the fourth network device may send uplink transmission data to the first network device through a backhaul. If the first network device is the fourth network device, the terminal device may directly send uplink transmission to the first network device on the first carrier, where the first carrier and the second carrier belong to the same frequency band, and the uplink transmission sent by the terminal device on the first carrier and the second carrier is received by the same network device. The second carrier is a carrier of the terminal device in the second cell.

After the terminal device is switched from the second cell to the first cell, the carrier in the first cell where the terminal device performs uplink transmission is the first carrier, which may also be understood as that before the terminal device is switched until after the terminal device is switched, the uplink transmission may be sent to the fourth network device on the first carrier in the same frequency band as the second carrier in the second cell and the first cell; it can also be understood that, before the terminal device switches to the second network device, the terminal device may send uplink transmission to the fourth network device in the second cell and the first cell on the first carrier at the same frequency position as the second carrier; it can also be understood that, before the terminal device switches to the second network device, the uplink transmission may be continuously sent to the fourth network device in the second cell and the first cell on the same carrier, that is, the second carrier. For example, a Supplementary Uplink (SUL) carrier of the terminal device in the first cell and a SUL carrier of the second cell belong to the same frequency band, the terminal device sends uplink transmission to the fourth network device in the SUL carriers in the two cells, respectively, and the fourth network device is a network device capable of receiving the uplink transmission sent by the terminal device in the SUL carrier. For another example, the SUL carrier of the terminal device in the first cell and the NUL carrier of the second cell belong to the same frequency band, the terminal device respectively sends uplink transmission to the fourth network device in the NUL (or SUL) carrier in the two cells, and the fourth network device is a network device capable of receiving the uplink transmission sent by the terminal device in the NUL (or SUL) carrier. For another example, the NUL carrier of the terminal device in the first cell and the SUL carrier of the second cell belong to the same frequency band, the terminal device respectively sends uplink transmission to the fourth network device in the SUL (or NUL) carrier in the two cells, and the fourth network device is a network device capable of receiving the uplink transmission sent by the terminal device in the SUL (or NUL) carrier. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

In one possible implementation, the communication method further includes: and determining a first TA value according to the transmission timing (transmission timing) of the terminal equipment on the second carrier, the downlink timing (downlink timing) of the first cell and the Timing Advance (TA) offset value of the first cell, wherein the first TA value is the TA value of the terminal equipment on the first carrier.

It should be understood that, if the uplink carrier only has the first carrier after the terminal device is switched to the first cell, then determining the TA value of the terminal device in the first carrier may also be understood as determining the TA value of the terminal device in the first cell; if the uplink carrier has the first carrier and also has other carriers after the terminal device is switched to the first cell, determining the TA value of the terminal device in the first carrier under the condition that the TA values of the first carrier and the other carriers are the same, which can also be understood as determining the TA value of the terminal device in the first cell.

After the terminal device determines that the carrier on which the terminal device performs uplink transmission in the first cell is the first carrier after the terminal device is handed over from the second cell to the first cell, the terminal device may determine the first TA value according to the transmission timing of the second carrier, the downlink timing of the first cell, and the TA offset value of the first cell. The first carrier and the second carrier may be uplink carriers, and the transmission timing of the terminal device in the second carrier may be understood as uplink timing of the terminal device in the second carrier. The first TA value is the TA value of the terminal equipment in the first carrier. Therefore, the TA value of the first carrier can be determined without random access, and the uplink synchronization of the terminal equipment in the first carrier of the first cell is realized. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

In one possible implementation, the same carrier as the second carrier exists in the active carriers of the first cell.

The first cell may include a first carrier and a second carrier, where the first carrier is the same as the second carrier in the active carriers of the first cell. At least one carrier identical to the second carrier exists in the effective carriers of the first cell.

One of the effective carriers of the first cell is the same carrier as the second carrier, and it can be understood that uplink transmission sent by the terminal device on one of the effective carriers of the first cell and the second carrier is received by the same network device, and at least one of the following conditions is satisfied: the carrier frequencies of the first carrier and the second carrier are the same; one carrier in the effective carriers of the first cell is the same as the frequency reference point of the second carrier; one carrier in the effective carriers of the first cell is identical to the frequency position of the second carrier; one carrier in the effective carriers of the first cell and the carrier bandwidth of the second carrier are the same.

The effective carrier may be understood as a carrier that covers a cell, or a carrier that covers the cell and can be configured, or a carrier that can be configured in the cell, or a carrier that belongs to the cell, or a carrier that is configured for use by a terminal device, or a carrier that is configured for the cell, or a carrier that is shared (configured) by at least one cell, or a carrier that is available for the terminal device to acquire configuration information from a system message of the cell, or a carrier that is available for the terminal device to acquire configuration information from a dedicated signaling of the cell, and the effective carrier may be one or more carriers, which is not limited in this application. Data or control information scheduled by the terminal device in the cell may be sent on the active carrier.

In the solution provided in the present application, if there is a carrier that is the same as the second carrier in the effective carrier of the first cell, it can be ensured that the carrier in the first cell where the terminal device performs uplink transmission is the first carrier after the terminal device is switched from the second cell to the first cell. Thus, the switching can be realized without random access, and the communication efficiency can be improved. If the same carrier as the second carrier does not exist in the effective carrier of the first cell, random access is also performed in the switching process of the terminal equipment, which may cause problems of time delay and interruption.

In one possible implementation, the communication method further includes: and under the condition that the carrier of the terminal equipment in the second cell is a third carrier and the same carrier as the third carrier does not exist in the effective carrier of the first cell, the terminal equipment is switched to the second carrier in the second cell.

In the solution provided in the present application, if the carrier of the terminal device in the second cell is the third carrier, and the same carrier as the third carrier does not exist in the active carrier of the first cell, the terminal device may switch from the third carrier to the second carrier in the second cell first. Therefore, the carrier same as the second carrier can be ensured to exist in the effective carrier of the first cell, and the uplink transmission can be ensured to be carried out on the first carrier of the first cell after the terminal equipment is switched. Thus, the switching can be realized without random access, and the communication efficiency can be improved.

In one possible implementation, the communication method further includes: receiving first indication information sent by a second network device, where the first indication information is used to indicate that a carrier for the terminal device to perform uplink transmission in the first cell is the first carrier, and the second network device is a network device corresponding to the second cell.

In the solution provided in the present application, the second network device may send the first indication information to the terminal device, indicate the carrier that the terminal device performs uplink transmission in the first cell to be the first carrier, and determine that the carrier that performs uplink transmission in the first cell is the first carrier, where the carrier may be issued to the terminal device by the second network device and is not determined by the terminal device. Therefore, the resource consumption of the terminal device can be reduced.

In one possible implementation, the communication method may further include: receiving first information sent by a second network device, where the first information includes a TA offset value of the first cell.

In the scheme provided by the application, the first information may be used for the terminal device to calculate a TA value in the first carrier, so as to implement uplink synchronization of the terminal device in the first carrier of the first cell.

In one possible implementation manner, the first information further includes: at least one of a time slot offset value between the first cell and the second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell; the determining, according to the transmission timing of the terminal device on the second carrier, the downlink timing of the first cell, and the TA offset value of the first cell, a first TA value includes: and determining a first TA value according to the sending timing of the terminal equipment in the second carrier, the downlink timing of the first cell and the first information.

In the solution provided in this application, after the terminal device is switched from the second cell to the first cell, the carrier in the first cell for uplink transmission by the terminal device is the first carrier, that is, before and after the switching, the carrier in the same frequency band is used for uplink transmission sent by the terminal device in the second cell and the first cell, and the uplink transmission sent by the terminal device in the first carrier and the second carrier is received by the same network device, so the sending timing for sending the uplink transmission by the terminal device should be kept unchanged. When the first cell performs uplink transmission, the terminal device needs to refer to the downlink timing of the first cell, and does not need to refer to the downlink timing of the second cell any more, so that the terminal device needs to perform corresponding adjustment on the TA value of the first carrier. Specifically, the first information may be sent by the second network device to the terminal device, the transmission timing of the second carrier is determined by the terminal device, and the downlink timing of the first cell may be obtained by the terminal device by detecting Synchronization Signal Block (SSB) information or other reference signals of the first cell. Therefore, the terminal device may determine the first TA value according to the first information, the transmission timing in the second carrier, and the downlink timing of the first cell, thereby implementing uplink synchronization of the terminal device in the first carrier of the first cell.

In one possible implementation, the first TA value may satisfy the following formula:

or

Or

Or

Or

Wherein N is_TAIs the first TA value, T_ttTiming of transmission of the terminal device on the second carrier, T being downlink timing of the first cell, N_TA-offsetIs TA offset value, T, of the first cell_C＝1/(Δf_max·N_f)，Δf_max＝480·10³Hz and N_f＝4096，T_slot-offsetIs a slot offset value, T, between the first cell and the second cell_sfn-offsetIs a system frame number offset value, the T, between the first cell and the second cell_Fb-offsetIs a frame boundary offset value between the first cell and the second cell.

In the solution provided in the present application, the first TA value may be determined according to any one of the formulas, so as to implement uplink synchronization of the terminal device on the first carrier of the first cell.

In one possible implementation, the communication method may further include: receiving second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an Identity (ID) of the first cell.

In the solution provided by the present application, the terminal device receives second indication information sent by the second network device, and the terminal device may determine which cell the first cell to be handed over to is according to the ID of the first cell included in the second indication information.

In one possible implementation, the communication method may further include: receiving a measurement configuration sent by the second network equipment; reporting a measurement result of a fifth cell to the second network equipment according to the measurement configuration; the third cell is at least one cell in the fifth cells.

In the solution provided in the present application, the second network device obtains a measurement result of a fifth cell from the terminal device by issuing measurement configuration to the terminal device, where the fifth cell may include the second cell and an adjacent cell of the second cell. The second network device may determine whether the terminal device needs to be switched according to the measurement result of the fifth cell, and may determine the first cell according to the measurement result of the third cell and the information of the third cell and issue the second indication information to the terminal device when the terminal device needs to be switched.

In one possible implementation, the communication method may further include: determining N fourth cells according to the measurement result of the third cell and the information of the third cell, wherein N is an integer greater than or equal to 1, and at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell; sending indication information of the N fourth cells to the second network equipment; receiving second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell, and the first cell is one of the N fourth cells.

In the solution provided in the present application, the terminal device may determine N fourth cells according to the measurement result of the third cell and the information of the third cell, and the fourth cells may be candidate cells. And then reporting the indication information of the N fourth cells to the second network equipment, determining a first cell from the N fourth cells by the second network equipment, and then sending second indication information to the terminal equipment by the second network equipment. Because the effective carrier of the third cell and the effective carrier of the second cell have at least one same carrier, the N fourth cells are determined according to the measurement result of the third cell and the information of the third cell, and it can be ensured that the effective carrier of each cell in the N fourth cells has a carrier that is the same as the effective carrier of the second cell, and then the second network device determines a first cell from the N fourth cells, and it can be ensured that after the terminal device is switched from the second cell to the first cell, the carrier in the first cell where the terminal device performs uplink transmission is the first carrier, so that the terminal device does not need random access in the switching process, the uplink synchronization of the terminal device on the first carrier of the first cell is realized, and the communication efficiency can be improved.

In a possible implementation manner, the determining N fourth cells according to the measurement result of the third cell and the information of the third cell includes: determining the priority corresponding to each cell in the third cell according to the information of the third cell; and determining the N fourth cells according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In the solution provided in the present application, the information of the third cell may include an ID of each cell in the third cell and effective carrier information of each cell, the information of different effective carriers may correspond to different priorities, that is, the information of different effective carriers of each cell corresponds to different priorities, and the terminal device determines N fourth cells according to the priority corresponding to each cell in the third cell and the measurement result. The correspondence between the information of the active carrier and the priority may be predefined by a protocol or determined by the second network device.

In one possible implementation, the communication method may further include: receiving a measurement configuration sent by the second network equipment; and determining a measurement result of the fifth cell according to the measurement configuration.

In the solution provided in the present application, the second network device may issue measurement configuration to the terminal device, and after the terminal device obtains the measurement result of the fifth cell according to the measurement configuration, the terminal device does not need to report the measurement result of the fifth cell to the second network device, so that the terminal device determines N fourth cells.

In one possible implementation, the communication method may further include: and receiving information of the third cell sent by the second network device, where the third cell is at least one cell in the fifth cells.

In the solution provided in the present application, the terminal device may receive information of the third cell sent by the second network device. The third cell is at least one cell in the fifth cells, so the terminal device can obtain the measurement result of the third cell from the measurement result of the fifth cell, and then determine N fourth cells according to the measurement result of the third cell and the information of the third cell.

In one possible implementation, the communication method may further include: and sending second information on the first carrier, where the second information is used to confirm handover to the first network device, and the first network device is a network device corresponding to the first cell.

In the solution provided in the present application, the terminal device sends uplink transmission to the fifth network device on the first carrier, and the fifth network device sends the uplink transmission data to the first network device. The uplink transmission may be second information, and the second information may be used to confirm the handover to the first network device, and the confirming the handover may be confirming that the terminal device is handed over from the second cell to the first cell. Therefore, the terminal device can determine the first TA value without random access, and can implement uplink synchronization of the terminal device on the first carrier of the first cell according to the first TA value, thereby improving the communication efficiency.

In one possible implementation, the communication method may further include: receiving third indication information sent by the second network device, where the third indication information is used to indicate whether a second TA value is the same as the first TA value, the second TA value is a TA value of the terminal device in a fourth carrier, and the fourth carrier is a carrier, different from the first carrier, of the terminal device in the first cell.

In the solution provided in this application, the terminal device may determine the second TA value according to the third indication information from the second network device, and the fourth carrier may be an uplink carrier that is different from the first carrier in the first cell. For example, the fourth carrier may be a Normal Uplink (NUL) carrier. If the third indication information indicates that the second TA value is the same as the first TA value, the second TA value can be determined without random access, so that uplink synchronization of the terminal device on the fourth carrier of the first cell is realized, and the communication efficiency can be improved.

In one possible implementation, the communication method may further include: and sending second information on the fourth carrier, wherein the second information is used for confirming the switching to the first network equipment.

In the solution provided in this application, the terminal device may send uplink transmission to a sixth network device on a fourth carrier, where the sixth network device is a network device that can receive the uplink transmission sent by the terminal device on the fourth carrier, and the sixth network device sends the uplink transmission data to the first network device, and if the first network device is the sixth network device, the terminal device may directly send the uplink transmission to the first network device on the fourth carrier. The uplink transmission may be second information, and the second information may be used to confirm the handover to the first network device. Therefore, the terminal device can determine the second TA value without random access, and can implement uplink synchronization of the terminal device on the fourth carrier of the first cell according to the second TA value, thereby improving the communication efficiency.

In a second aspect, the present application provides a communication method, which may be applied to a second network device, and may also be applied to a module (e.g., a chip) in the second network device, and the following description will be given by taking the application to the second network device as an example. The method comprises the following steps: and sending first indication information to the terminal equipment, wherein the first indication information is used for indicating that a carrier for performing uplink transmission in the first cell by the terminal equipment is a first carrier, the first carrier and the second carrier belong to the same frequency band, and the uplink transmission sent by the terminal equipment on the first carrier and the second carrier is received by the same network equipment. The second carrier is a carrier of the terminal device in a second cell.

In the solution provided in the present application, the second network device may indicate, by sending the first indication information to the terminal device, that the carrier where the terminal device performs uplink transmission in the first cell is the first carrier.

The carrier for performing uplink transmission in the first cell is a first carrier, and it can be understood that after the terminal device is switched, the terminal device communicates with the first network device in the first cell, the first network device may send downlink transmission to the terminal device, the terminal device may send uplink transmission to the fourth network device on the first carrier, and the fourth network device sends uplink transmission data to the first network device, for example, the fourth network device may send uplink transmission data to the first network device through a backhaul. If the first network device is the fourth network device, the terminal device may directly send uplink transmission to the first network device on the first carrier, where the first carrier and the second carrier belong to the same frequency band, and the uplink transmission sent by the terminal device on the first carrier and the second carrier is received by the same network device. The second carrier is a carrier of the terminal device in the second cell.

The carrier for performing uplink transmission in the first cell is a first carrier, and it may also be understood that, before the terminal device switches to the second cell, the terminal device may send uplink transmission to the fourth network device on the first carrier in the same frequency band as the second carrier in the second cell and the first cell; it can also be understood that, before the terminal device switches to the second network device, the terminal device may send uplink transmission to the fourth network device in the second cell and the first cell on the first carrier having the same frequency as the second carrier; it can also be understood that, before the terminal device switches to the second network device, the uplink transmission may be continuously sent to the fourth network device in the second cell and the first cell on the same carrier, that is, the second carrier. For example, a Supplementary Uplink (SUL) carrier of the terminal device in the first cell and a SUL carrier of the second cell belong to the same frequency band, the terminal device sends uplink transmission to the fourth network device in the SUL carriers in the two cells, respectively, and the fourth network device is a network device capable of receiving the uplink transmission sent by the terminal device in the SUL carrier. For another example, the SUL carrier of the terminal device in the first cell and the NUL carrier of the second cell belong to the same frequency band, the terminal device respectively sends uplink transmission to the fourth network device in the NUL (or SUL) carrier in the two cells, and the fourth network device is a network device capable of receiving the uplink transmission sent by the terminal device in the NUL (or SUL) carrier. For another example, the NUL carrier of the terminal device in the first cell and the SUL carrier of the second cell belong to the same frequency band, the terminal device respectively sends uplink transmission to the fourth network device in the SUL (or NUL) carrier in the two cells, and the fourth network device is a network device capable of receiving the uplink transmission sent by the terminal device in the SUL (or NUL) carrier. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

After the terminal device determines that the carrier on which the terminal device performs uplink transmission in the first cell is the first carrier after the terminal device is switched from the second cell to the first cell, a first TA value may be determined according to the transmission timing of the second carrier, the downlink timing of the first cell, and the TA offset value of the first cell, where the first TA value is the TA value of the terminal device on the first carrier. Therefore, the TA value of the first carrier can be determined without random access, and the uplink synchronization of the terminal equipment in the first carrier of the first cell is realized. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

It should be understood that the second aspect is executed by the second network device, the specific content of the second aspect corresponds to the content of the first aspect, the corresponding features of the second aspect and the achieved beneficial effects can be referred to the description of the first aspect, and the detailed description is appropriately omitted here to avoid repetition.

In one possible implementation, the communication method may further include: and sending first information to the terminal equipment, wherein the first information comprises a TA offset value of the first cell.

In one possible implementation manner, the first information further includes: at least one of a time slot offset value between the first cell and the second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell.

In one possible implementation, the communication method may further include: determining the first cell according to the measurement result of the third cell and the information of the third cell, wherein at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell; and sending second indication information to the terminal equipment, wherein the second indication information is used for indicating the first cell, and the second indication information comprises the ID of the first cell.

In the solution provided in the present application, the information of the third cell is known by the second terminal device, and since the third cell is at least one cell in the fifth cell, the measurement result of the third cell can be obtained from the measurement result of the fifth cell reported by the terminal device. The second network device may determine the first cell according to the measurement result of the third cell and the information of the third cell, and then issue the second indication information to the terminal device. Because the effective carrier of the third cell and the effective carrier of the second cell have at least one same carrier, the first cell is determined according to the measurement result of the third cell and the information of the third cell, and the carrier for uplink transmission of the terminal equipment in the first cell can be ensured to be the first carrier after the terminal equipment is switched from the second cell to the first cell, so that the terminal equipment does not need random access in the switching process, the uplink synchronization of the terminal equipment on the first carrier of the first cell is realized, and the communication efficiency can be improved.

The effective carrier of the third cell and the effective carrier of the second cell have the same carrier, which may be understood as one of the effective carriers of the second cell existing in the effective carrier of the third cell, or may be understood as one of the effective carriers of the second cell and one of the effective carriers of the third cell being the same carrier. There may be at least one of the carriers of the third cell having the same active carrier as the active carrier of the second cell.

One of the effective carriers of the second cell and one of the effective carriers of the third cell are the same carrier, and it can be understood that uplink transmission sent by the terminal device on one of the effective carriers of the second cell and one of the effective carriers of the third cell is received by the same network device, and at least one of the following conditions is satisfied: one of the effective carriers of the second cell has the same carrier frequency as one of the effective carriers of the third cell; one of the effective carriers of the second cell is the same as a frequency reference point of one of the effective carriers of the third cell; one of the effective carriers of the second cell has the same frequency position as one of the effective carriers of the third cell; the carrier bandwidths of the first carrier and the second carrier are the same.

In one possible implementation manner, the determining the first cell according to the measurement result of the third cell and the information of the third cell includes: determining the priority corresponding to each cell in the third cell according to the information of the third cell; and determining the first cell according to the priority corresponding to each cell in the third cell and the measurement result of the third region.

In the solution provided in the present application, the information of the third cell may include an ID of each cell in the third cell and effective carrier information of each cell, the information of different effective carriers may correspond to different priorities, that is, the information of different effective carriers of each cell corresponds to different priorities, and the second network device may determine the first cell according to the priority corresponding to each cell in the third cell and the measurement result. The correspondence between the information of the active carrier and the priority may be predefined by a protocol or determined by the second network device.

In one possible implementation, the communication method may further include: and sending the measurement configuration to the terminal equipment.

In one possible implementation, the communication method may further include: receiving a measurement result of a fifth cell sent by the terminal equipment; the third cell is at least one cell in the fifth cells.

In one possible implementation, the communication method may further include: receiving indication information of N fourth cells sent by the terminal equipment, wherein N is an integer greater than or equal to 1, the N fourth cells are determined by the terminal equipment according to a measurement result of a third cell and information of the third cell, and at least one same carrier exists between an effective carrier of the third cell and an effective carrier of the second cell; determining the first cell according to the N fourth cells, wherein the first cell is one of the N fourth cells; and sending second indication information to the terminal equipment, wherein the second indication information is used for indicating the first cell, and the second indication information comprises the ID of the first cell.

In the solution provided in the present application, after determining N fourth cells according to the measurement result of the third cell and the information of the third cell, the terminal device reports the indication information of the N fourth cells to the second network device, where at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell. The second network device may determine a first cell from the N fourth cells, and then issue the second indication information to the terminal device, and the terminal device may determine which cell the first cell to be handed over to is according to the ID of the first cell included in the second indication information.

In one possible implementation, the communication method may further include: and sending information of the third cell to the terminal equipment, wherein the third cell is at least one cell in the fifth cells.

In one possible implementation, the communication method may further include: and sending third indication information to the terminal device, where the third indication information is used to indicate whether a second TA value is the same as the first TA value, the second TA value is a TA value of the terminal device in a fourth carrier, and the fourth carrier is a carrier different from the first carrier of the terminal device in the first cell.

In one possible implementation, the communication method may further include: and sending request information to first network equipment, wherein the request information is used for requesting the terminal equipment to access the first network equipment, and the first network equipment is network equipment corresponding to the first cell.

In the solution provided by the present application, after determining the first cell, the second network device may send request information to the first network device, requesting the terminal device to access the first network device, where the first network device is a network device corresponding to the first cell. And under the condition that the first network equipment allows access, the second network equipment sends second indication information to the terminal equipment.

In a third aspect, the present application provides a communication method, which may be applied to a first network device, and may also be applied to a module (e.g., a chip) in the first network device, and the following description will be given by taking the application to the first network device as an example. The method comprises the following steps: and receiving request information sent by a second network device, wherein the request information is used for requesting the terminal device to access the first network device, and the second network device is a network device corresponding to a second cell.

In the solution provided by the present application, after determining the first cell, the second network device may send request information to the first network device, requesting the terminal device to access the first network device. Under the condition that the first network equipment allows access, the second network equipment issues second indication information to the terminal equipment; in the case where the first network device does not allow access, the second network device may re-determine the first cell.

In a fourth aspect, the present application provides a communication method, which may be applied to a terminal device and may also be applied to a module (e.g., a chip) in the terminal device, and the following description takes the application to the terminal device as an example. The method comprises the following steps: and receiving third information sent by a second network device, wherein the third information comprises first indication information and the ID of the first cell, and the first indication information is used for indicating the terminal device to continue sending uplink transmission to a fourth network device.

In the solution provided in the present application, the terminal device may determine which cell the first cell to be handed over to is through the ID of the first cell included in the third information. It may also be determined, through the first indication information included in the third information, that the uplink transmission continues to be sent to the fourth network device in the first cell, specifically:

before the terminal device is switched, the terminal device communicates with the second network device in the second cell, the second network device may send downlink transmission to the terminal device, the terminal device may send uplink transmission to the fourth network device, and the fourth network device is a network device that can receive the uplink transmission sent by the terminal device in the second cell. The fourth network device sends the uplink data to the second network device, for example, the fourth network device may send the uplink data to the second network device through the backhaul. If the second network device is a fourth network device, that is, the fourth network device and the second network device are co-sited, the terminal device may send the uplink transmission directly to the second network device. After the terminal device is switched, the terminal device communicates with the first network device in the first cell, the first network device may send downlink transmission to the terminal device, and the terminal device may send uplink transmission to the fifth network device, where the fifth network device is a network device that can receive the uplink transmission sent by the terminal device in the first cell. The fifth network device sends the uplink data to the first network device, for example, the fifth network device may send the uplink data to the first network device through the backhaul. If the first network device is the fifth network device, that is, the fifth network device and the first network device are co-located, the terminal device may directly send the uplink transmission to the first network device.

The uplink transmission is continuously sent to the fourth network device, which may be understood as that the uplink transmission may be sent to the same network device, that is, the fourth network device, in the second cell and the first cell before the terminal device is switched until after the terminal device is switched. Specifically, the method comprises the following steps: after the terminal device is switched, the terminal device communicates with the first network device in the first cell, the first network device may send downlink transmission to the terminal device, the terminal device may continue to send uplink transmission to the fourth network device, and the fourth network device sends the uplink transmission data to the first network device, for example, the fourth network device may send the uplink transmission data to the first network device through a backhaul. If the first network device is the fourth network device, the terminal device may send the uplink transmission directly to the first network device. Therefore, the terminal equipment can send uplink transmission in the first cell without random access. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

In one possible implementation, the communication method may further include: determining a first TA value according to a first transmission timing, a downlink timing of the first cell, and a TA offset value of the first cell, where the first TA value is used to continue to transmit uplink transmission to the fourth network device.

In the solution provided in the present application, the first transmission timing may be a transmission timing at which the terminal device transmits uplink transmission in the second cell, and therefore, the first transmission timing may also be referred to as a first uplink timing. Therefore, the first TA value is determined by the first sending timing, and the first TA value can be determined without random access, so that uplink synchronization of the terminal equipment in the first cell is realized, and the communication efficiency can be improved.

It should be understood that the detailed description of the fourth aspect corresponds to the description of the first aspect, and the corresponding features and advantages of the fourth aspect can be referred to the description of the first aspect, and the detailed description is omitted here as appropriate to avoid redundancy.

In one possible implementation manner, the first information further includes: at least one of a time slot offset value between the first cell and a second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell.

In one possible implementation, the determining a first TA value according to the first transmission timing, the downlink timing of the first cell, and the TA offset value of the first cell includes: determining a first TA value based on a first transmit timing, a downlink timing of the first cell, and the first information.

or

Or

Or

Or

Wherein N is_TAIs the first TA value, T_ttFor the first transmission timing, T is the downlink timing of the first cell, N_TA-offsetIs TA offset value, T, of the first cell_C＝1/(Δf_max·N_f)，Δf_max＝480·10³Hz and N_f＝4096，T_slot-offsetIs the firstTime slot offset value, T, between a cell and the second cell_sfn-offsetIs a system frame number offset value, the T, between the first cell and the second cell_Fb-offsetIs a frame boundary offset value between the first cell and the second cell.

In one possible implementation, the communication method may further include: and receiving second indication information sent by the second network device, where the second indication information is used for indicating the first cell, and the second indication information includes an ID of the first cell.

In one possible implementation, the communication method may further include: determining N fourth cells according to the measurement result of the third cell and the information of the third cell, wherein N is an integer greater than or equal to 1, and at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell; sending indication information of the N fourth cells to second network equipment; and receiving second indication information sent by the second network device, where the second indication information is used for indicating the first cell, and the second indication information includes an ID of the first cell.

In one possible implementation, the communication method may further include: sending uplink transmission information to the first network device when the fourth network device is the first network device, wherein the uplink transmission information comprises second information, and the second information is used for confirming switching to the first network device; or sending uplink transmission information to the second network device when the fourth network device is the second network device, where the uplink transmission information includes second information, and the second information is used to confirm handover to the first network device.

In the solution provided in the present application, before the terminal device is switched, until after the terminal device is switched, uplink transmission may be sent to the same network device, that is, a fourth network device, in the second cell and the first cell. If the fourth network device is the second network device, the terminal device may directly send the uplink transmission to the second network device; if the fourth network device is the first network device, the terminal device may directly send the uplink transmission to the first network device, where the uplink transmission may include second information, and the second information is used to confirm the handover to the first network device, and the confirmation of the handover may refer to the terminal device being handed over from the second cell to the first cell. Therefore, uplink synchronization of the terminal equipment in the first cell can be realized without random access. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

In a fifth aspect, the present application provides a communication method, which may be applied to a second network device, and may also be applied to a module (e.g., a chip) in the second network device, and the following description will be given by taking the application to the second network device as an example. The method comprises the following steps: and sending third information to the terminal equipment, wherein the third information comprises first indication information and the ID of the first cell, and the first indication information is used for indicating the terminal equipment to continue sending uplink transmission to fourth network equipment.

In the solution provided in the present application, the terminal device may determine which cell the first cell to be handed over to is through the ID of the first cell included in the third information. It may also be determined, by the first indication information included in the third information, that the uplink transmission continues to be sent to the fourth network device in the first cell. In this way, the terminal device can achieve uplink synchronization of the first carrier of the first cell without random access. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

It should be understood that the main subject of the fifth aspect is the second network device, the specific contents of the fifth aspect correspond to the contents of the fourth aspect, the corresponding features of the fifth aspect and the achieved beneficial effects can refer to the description of the fourth aspect, and the detailed description is appropriately omitted here to avoid repetition.

In one possible implementation, the communication method may further include: and sending request information to first network equipment, wherein the request information is used for requesting the terminal equipment to access the first network equipment.

In one possible implementation, the communication method may further include: and receiving uplink transmission information sent by the terminal device when the fourth network device is the second network device, wherein the uplink transmission information includes second information, and the second information is used for confirming the handover to the first network device.

In the solution provided in the present application, before the terminal device is switched, until after the terminal device is switched, uplink transmission may be sent to the same network device, that is, a fourth network device, in the second cell and the first cell. If the fourth network device is a second network device, the terminal device may send the uplink transmission directly to the second network device. Therefore, uplink synchronization of the terminal equipment in the first cell can be realized without random access. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

In a sixth aspect, the present application provides a communication method, which may be applied to a first network device, and may also be applied to a module (e.g., a chip) in the first network device, and the following description will be given by taking the application to the first network device as an example. The method comprises the following steps: and receiving uplink transmission information sent by the terminal equipment under the condition that the fourth network equipment is the first network equipment, wherein the uplink transmission information comprises second information, and the second information is used for confirming switching to the first network equipment.

In the solution provided in the present application, before the terminal device is switched, until after the terminal device is switched, uplink transmission may be sent to the same network device, that is, a fourth network device, in the second cell and the first cell. If the fourth network device is the first network device, the terminal device may send the uplink transmission directly to the first network device. Therefore, uplink synchronization of the terminal equipment in the first cell can be realized without random access. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell in need of random access, and can improve the communication efficiency

In one possible implementation, the communication method may further include: and receiving request information sent by second network equipment, wherein the request information is used for requesting the terminal equipment to access the first network equipment.

In the solution provided by the present application, after determining the first cell, the second network device may send request information to the first network device, requesting the terminal device to access the first network device. And under the condition that the first network equipment allows access, the second network equipment issues second indication information to the terminal equipment.

In a seventh aspect, a communication method is provided, which may be applied to a terminal device and may also be applied to a module (e.g., a chip) in the terminal device, and the following description takes the application to the terminal device as an example. The method comprises the following steps: determining N fourth cells according to the information of a third cell and the measurement result of a fifth cell, wherein N is an integer greater than or equal to 1, and at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell; sending indication information of the N fourth cells to a second network device, wherein the second network device is a network device corresponding to the second cell; receiving second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell, and the first cell is one of the N fourth cells.

In the solution provided in the present application, the terminal device may obtain a measurement result of the fifth cell according to the measurement configuration, determine N fourth cells according to the measurement result of the fifth cell and information of the third cell from the second network terminal device, send the N fourth cells to the second network device, and determine a first cell from the N fourth cells by the second network device. Compared with the determination of the N fourth cells only according to the measurement result of the third cell and the information of the third cell, although the carrier with the same effective carrier of each cell in the third cell and the effective carrier of the second cell can be preferentially selected as the first cell, if the measurement result of each cell is not good, the first cell determined from the third cell is not in accordance with the condition of terminal equipment handover. Therefore, it may be considered that N fourth cells reported to the second network device are re-determined according to the measurement result of the sixth cell. The sixth cell may be another cell in the fifth cell except the third cell, and the sixth cell may include a cell in which the effective carrier does not intersect with the effective carrier of the second cell, but intersects with the effective carrier of another cell except the second cell, or may include a cell in which the effective carrier does not intersect with the effective carrier of the second cell and the effective carrier of another cell except the second cell. Even if the effective carrier of the sixth cell does not have the carrier same as the effective carrier of the second cell, the measurement results of the N fourth cells determined according to the sixth cell are good and accord with the conditions of the first cell, and even if random access is required, normal switching of the terminal equipment is also ensured.

In a possible implementation manner, the determining N fourth cells according to the information of the third cell and the measurement result of the fifth cell includes: under the condition that the third cell exists in the fifth cell, determining the corresponding priority of each cell in the third cell according to the information of the third cell; and determining the N fourth cells according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In the solution provided in this application, the terminal device may determine a measurement result of the fifth cell according to the measurement configuration sent by the second network device, and may also receive information of a third cell sent by the second network device, first determine whether the fifth cell has the third cell, and if the fifth cell has the third cell, may determine N fourth cells according to the information of the third cell and the measurement result of the third cell, specifically: the information of the third cell may include an ID of each cell in the third cell and effective carrier information of each cell, the information of different effective carriers may correspond to different priorities, that is, the information of different effective carriers of each cell corresponds to different priorities, and the terminal device determines N fourth cells according to the priority and the measurement result corresponding to each cell in the third cell. The correspondence between the information of the active carrier and the priority may be predefined by a protocol or determined by the second network device.

If the measurement results of the N fourth cells determined according to the information of the third cell and the measurement result of the third cell are not good, the N fourth cells may be re-determined according to the measurement result of the sixth cell.

In a possible implementation manner, the determining N fourth cells according to the information of the third cell and the measurement result of the fifth cell includes: determining the N fourth cells according to the measurement result of the fifth cell when a third cell does not exist in the fifth cell.

In the solution provided in the present application, the terminal device first determines whether a third cell exists in the fifth cell, and if the third cell does not exist in the fifth cell, N fourth cells may be determined according to a measurement result of the fifth cell, so as to ensure normal handover of the terminal device.

In one possible implementation, the communication method may further include: receiving measurement configuration sent by a second network device, wherein the second network device is a network device corresponding to the second cell; determining a measurement result of the fifth cell according to the measurement configuration.

In one possible implementation, the communication method may further include: and receiving the information of the third cell sent by the second network equipment.

In the solution provided in the present application, the terminal device may receive information of the third cell sent by the second network device.

In one possible implementation, the communication method may further include: receiving measurement configuration sent by a second network device, wherein the second network device is a network device corresponding to the second cell; and reporting the measurement result of the fifth cell to the second network equipment according to the measurement configuration.

In the solution provided by the present application, the second network device obtains the measurement result of the fifth cell from the terminal device by issuing the measurement configuration to the terminal device. After the second network device obtains the measurement result of the fifth cell, the first cell may be determined.

In an eighth aspect, the present application provides a communication method, which may be applied to a second network device, and may also be applied to a module (e.g., a chip) in the second network device, and the following description will be given by taking the application to the second network device as an example. The method comprises the following steps: and determining the first cell according to the information of the third cell and the measurement result of the fifth cell, wherein at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell.

In the solution provided in the present application, the second network device may issue measurement configuration to the terminal device, receive a measurement result of the fifth cell determined according to the measurement configuration and reported by the terminal device, and determine the first cell according to the measurement result of the fifth cell and information of the third cell. Although the carrier having the same effective carrier of each cell in the third cell as the effective carrier of the second cell may be preferentially selected as the first cell, if the measurement result of each cell is not good, the first cell determined from the third cell does not meet the condition for handover of the terminal device, as compared with the determination of the first cell only from the measurement result of the third cell and the information of the third cell. Therefore, it may be considered to re-determine the first cell from the measurement result of the sixth cell. The sixth cell may be another cell in the fifth cell except the third cell, and the sixth cell may include a cell in which the effective carrier does not intersect with the effective carrier of the second cell, but intersects with the effective carrier of another cell except the second cell, or may include a cell in which the effective carrier does not intersect with the effective carrier of the second cell and the effective carrier of another cell except the second cell. Even if the effective carrier of the sixth cell does not have the carrier same as the effective carrier of the second cell, the measurement result of the first cell determined according to the sixth cell is good, and even if random access is required, normal switching of the terminal equipment is ensured.

It should be understood that the main subject of the eighth aspect is the second network device, the specific contents of the eighth aspect correspond to the contents of the seventh aspect, the corresponding features of the eighth aspect and the advantages achieved by the eighth aspect may refer to the description of the seventh aspect, and the detailed description is appropriately omitted here to avoid repetition.

In one possible implementation, the determining the first cell according to the information of the third cell and the measurement result of the fifth cell includes: under the condition that the third cell exists in the fifth cell, determining the corresponding priority of each cell in the third cell according to the information of the third cell; and determining the first cell according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In the solution provided in this application, the second network device may receive a measurement result of the fifth cell sent by the terminal device, first determine whether the fifth cell has the third cell, and if the fifth cell has the third cell, determine the first cell according to information of the third cell and the measurement result of the third cell, specifically: the information of the third cell may include an ID of each cell in the third cell and effective carrier information of each cell, the information of different effective carriers may correspond to different priorities, that is, the information of different effective carriers of each cell corresponds to different priorities, and the second network device determines the first cell according to the priority and the measurement result corresponding to each cell in the third cell. The correspondence between the information of the active carrier and the priority may be predefined by a protocol or determined by the second network device.

If the measurement result of the first cell determined from the information of the third cell and the measurement result of the third cell is not good, the first cell may be re-determined from the measurement result of the sixth cell.

In one possible implementation, the determining the first cell according to the information of the third cell and the measurement result of the fifth cell includes: determining the first cell according to a measurement result of the fifth cell in a case where the third cell does not exist in the fifth cell.

In the solution provided in the present application, the second network device first determines whether a third cell exists in the fifth cell, and if the third cell does not exist in the fifth cell, the first cell may be determined according to a measurement result of the fifth cell, so as to ensure that the terminal device performs normal handover.

In one possible implementation, the communication method may further include: sending a measurement configuration to the terminal device; and receiving the measurement result of the fifth cell sent by the terminal equipment.

In one possible implementation, the communication method may further include: receiving indication information of N fourth cells sent by a terminal device, wherein N is an integer greater than or equal to 1, the N fourth cells are determined by the terminal device according to information of a third cell and a measurement result of a fifth cell, and at least one same carrier exists between an effective carrier of the third cell and an effective carrier of the second cell; and determining a first cell according to the N fourth cells, wherein the first cell is one of the N fourth cells.

In one possible implementation, the communication method may further include: and sending the information of the third cell to the terminal equipment.

In a ninth aspect, a communication apparatus is provided, which may be a terminal device or a module (e.g., a chip) in the terminal device. The communication apparatus may include:

a processing unit, configured to determine that a carrier in the first cell, where the terminal device performs uplink transmission after the terminal device is switched from the second cell to the first cell, is a first carrier; the first carrier and the second carrier belong to the same frequency band, and the second carrier is a carrier of the terminal device in a second cell.

In a possible implementation manner, the processing unit is further configured to determine a first TA value according to a transmission timing of the terminal device on the second carrier, a downlink timing of the first cell, and a TA offset value of the first cell, where the first TA value is a TA value of the terminal device on the first carrier.

In a possible implementation manner, when the carrier of the terminal device in the second cell is a third carrier and the same carrier as the third carrier does not exist in the active carrier of the first cell, the terminal device switches to the second carrier in the second cell.

In one possible implementation, the communication apparatus may further include:

a transceiver unit, configured to receive first indication information sent by a second network device, where the first indication information is used to indicate that a carrier used by the terminal device to perform uplink transmission in the first cell is the first carrier, and the second network device is a network device corresponding to the second cell.

In a possible implementation manner, the transceiver unit is further configured to receive first information sent by a second network device, where the first information includes a TA offset value of the first cell.

In one possible implementation manner, the first information further includes: at least one of a time slot offset value between the first cell and the second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell;

The determining, by the processing unit, a first TA value according to the transmission timing of the terminal device on the second carrier, the downlink timing of the first cell, and the TA offset value of the first cell includes: and determining a first TA value according to the sending timing of the terminal equipment in the second carrier, the downlink timing of the first cell and the first information.

or

Or

Or

Or

In a possible implementation manner, the transceiver unit is further configured to receive second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell.

In a possible implementation manner, the transceiver unit is further configured to receive a measurement configuration sent by the second network device; reporting a measurement result of a fifth cell to the second network equipment according to the measurement configuration; the third cell is at least one cell in the fifth cells.

In a possible implementation manner, the processing unit is further configured to determine N fourth cells according to a measurement result of a third cell and information of the third cell, where N is an integer greater than or equal to 1, and at least one same carrier exists between an effective carrier of the third cell and an effective carrier of the second cell;

the transceiver unit is further configured to send the indication information of the N fourth cells to the second network device; receiving second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell, and the first cell is one of the N fourth cells.

In one possible implementation manner, the determining, by the processing unit, N fourth cells according to the measurement result of the third cell and the information of the third cell includes: determining the priority corresponding to each cell in the third cell according to the information of the third cell; and determining the N fourth cells according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In a possible implementation manner, the transceiver unit is further configured to receive a measurement configuration sent by the second network device;

the processing unit is further configured to determine a measurement result of a fifth cell according to the measurement configuration.

In a possible implementation manner, the transceiver unit is further configured to receive information of the third cell sent by the second network device, where the third cell is at least one cell in the fifth cells.

In a possible implementation manner, the transceiver unit is further configured to send second information on the first carrier, where the second information is used to confirm handover to the first network device, and the first network device is a network device corresponding to the first cell.

In a possible implementation manner, the transceiver unit is further configured to receive third indication information sent by the second network device, where the third indication information is used to indicate whether a second TA value is the same as the first TA value, the second TA value is a TA value of the terminal device in a fourth carrier, and the fourth carrier is a carrier, different from the first carrier, of the terminal device in the first cell.

In a possible implementation manner, the transceiver unit is further configured to send second information on the fourth carrier, where the second information is used to confirm handover to the first network device.

In a tenth aspect, a communication apparatus is provided, which may be a second network device and may also be a module (e.g., a chip) in the second network device. The communication apparatus may include:

the receiving and sending unit is configured to send first indication information to a terminal device, where the first indication information is used to indicate that a carrier for the terminal device to perform uplink transmission in the first cell is a first carrier, where the first carrier and a second carrier belong to a same frequency band, and the second carrier is a carrier of a second cell.

In a possible implementation manner, the transceiver unit is further configured to send first information to the terminal device, where the first information includes a TA offset value of the first cell.

a processing unit, configured to determine a first cell according to a measurement result of a third cell and information of the third cell, where at least one same carrier exists between an active carrier of the third cell and an active carrier of the second cell;

the transceiver unit is further configured to send second indication information to the terminal device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell.

In one possible implementation manner, the determining, by the processing unit, the first cell according to the measurement result of the third cell and the information of the third cell includes: determining the priority corresponding to each cell in the third cell according to the information of the third cell; and determining the first cell according to the priority corresponding to each cell in the third cell and the measurement result of the third region.

In a possible implementation manner, the transceiver unit is further configured to send a measurement configuration to the terminal device;

in a possible implementation manner, the transceiver unit is further configured to receive a measurement result of a fifth cell sent by the terminal device; the third cell is at least one cell in the fifth cells.

In a possible implementation manner, the transceiver unit is further configured to receive indication information of N fourth cells sent by the terminal device, where N is an integer greater than or equal to 1, where the N fourth cells are determined by the terminal device according to a measurement result of a third cell and information of the third cell, and at least one same carrier exists between an effective carrier of the third cell and an effective carrier of the second cell;

the processing unit is further configured to determine the first cell according to the N fourth cells, where the first cell is one of the N fourth cells;

In a possible implementation manner, the transceiver unit is further configured to send the measurement configuration to the terminal device.

In a possible implementation manner, the transceiver unit is further configured to send information of the third cell to the terminal device, where the third cell is at least one cell in the fifth cell.

In a possible implementation manner, the transceiver unit is further configured to send third indication information to the terminal device, where the third indication information is used to indicate whether a second TA value is the same as the first TA value, the second TA value is a TA value of the terminal device in a fourth carrier, and the fourth carrier is a carrier, different from the first carrier, of the terminal device in the first cell.

In a possible implementation manner, the transceiver unit is further configured to send request information to a first network device, where the request information is used to request the terminal device to access the first network device, and the first network device is a network device corresponding to the first cell.

In an eleventh aspect, a communication apparatus is provided, where the communication apparatus may be a first network device and may also be a module (e.g., a chip) in the first network device. The communication apparatus may include:

and the receiving and sending unit is used for receiving request information sent by second network equipment, wherein the request information is used for requesting the terminal equipment to access the first network equipment, and the second network equipment is network equipment corresponding to a second cell.

In a twelfth aspect, a communication apparatus is provided, where the communication apparatus may be a terminal device, and may also be a module (e.g., a chip) in the terminal device. The communication apparatus may include: a transceiver unit, configured to receive third information sent by a second network device, where the third information includes first indication information and an ID of a first cell, and the first indication information is used to indicate the terminal device to continue sending uplink transmission to a fourth network device.

In one possible implementation, the communication apparatus may further include: a processing unit, configured to determine a first TA value according to a first sending timing, a downlink timing of the first cell, and a TA offset value of the first cell, where the first TA value is used to continue sending uplink transmission to the fourth network device.

In one possible implementation manner, the determining, by the processing unit, a first TA value according to the first transmission timing, the downlink timing of the first cell, and the TA offset value of the first cell includes: determining a first TA value based on a first transmit timing, a downlink timing of the first cell, and the first information.

or

Or

Or

Or

Wherein N is_TAIs the first TA value, T_ttFor the first transmission timing, T is the downlink timing of the first cell, N_TA-offsetIs TA offset value, T, of the first cell_C＝1/(Δf_max·N_f)，Δf_max＝480·10³Hz and N_f＝4096，T_slot-offsetIs a slot offset value, T, between the first cell and the second cell_sfn-offsetIs a system frame number offset value, the T, between the first cell and the second cell_Fb-offsetIs a frame boundary offset value between the first cell and the second cell.

The transceiver unit is further configured to send the indication information of the N fourth cells to a second network device; receiving second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell, and the first cell is one of the N fourth cells.

In a possible implementation manner, the transceiver unit is further configured to receive a measurement configuration sent by the second network device; and determining a measurement result of the fifth cell according to the measurement configuration.

In a possible implementation manner, the transceiver unit is further configured to send, to the first network device, uplink transmission information when the fourth network device is the first network device, where the uplink transmission information includes second information, and the second information is used to confirm handover to the first network device; or sending uplink transmission information to the second network device when the fourth network device is the second network device, where the uplink transmission information includes second information, and the second information is used to confirm handover to the first network device.

In a thirteenth aspect, a communication apparatus is provided, which may be a second network device and may also be a module (e.g., a chip) in the second network device. The communication apparatus may include: a transceiving unit, configured to send third information to a terminal device, where the third information includes first indication information and an ID of a first cell, and the first indication information is used to indicate the terminal device to continue sending uplink transmission to a fourth network device.

In one possible implementation, the communication apparatus may further include: a processing unit, configured to determine a first cell according to a measurement result of a third cell and information of the third cell, where at least one same carrier exists between an active carrier of the third cell and an active carrier of the second cell;

In a possible implementation manner, the transceiver unit is further configured to send request information to a first network device, where the request information is used to request the terminal device to access the first network device.

In a possible implementation manner, the transceiver unit is further configured to receive uplink transmission information sent by the terminal device when the fourth network device is the second network device, where the uplink transmission information includes second information, and the second information is used to confirm handover to the first network device.

In a fourteenth aspect, a communication apparatus is provided, where the communication apparatus may be a first network device, and may also be a module (e.g., a chip) in the first network device. The communication apparatus may include: a transceiving unit, configured to receive uplink transmission information sent by a terminal device when a fourth network device is a first network device, where the uplink transmission information includes second information, and the second information is used to confirm handover to the first network device.

In a possible implementation manner, the transceiver unit is further configured to receive request information sent by a second network device, where the request information is used to request the terminal device to access the first network device.

In a fifteenth aspect, a communication apparatus is provided, where the communication apparatus may be a terminal device or a module (e.g., a chip) in the terminal device. The communication apparatus may include: a processing unit, configured to determine N fourth cells according to information of a third cell and a measurement result of a fifth cell, where N is an integer greater than or equal to 1, and at least one same carrier exists between an effective carrier of the third cell and an effective carrier of the second cell;

a transceiver unit, configured to send instruction information of the N fourth cells to a second network device, where the second network device is a network device corresponding to the second cell;

the transceiver unit is further configured to receive second indication information sent by the second network device, where the second indication information is used to indicate the first cell, the second indication information includes an ID of the first cell, and the first cell is one of the N fourth cells.

In one possible implementation manner, the determining, by the processing unit, N fourth cells according to the information of the third cell and the measurement result of the fifth cell includes: under the condition that the third cell exists in the fifth cell, determining the corresponding priority of each cell in the third cell according to the information of the third cell; and determining the N fourth cells according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In one possible implementation manner, the determining, by the processing unit, N fourth cells according to the information of the third cell and the measurement result of the fifth cell includes: determining the N fourth cells according to the measurement result of the fifth cell when a third cell does not exist in the fifth cell.

In a possible implementation manner, the transceiver unit is further configured to receive a measurement configuration sent by a second network device, where the second network device is a network device corresponding to the second cell;

the processing unit is further configured to determine a measurement result of the fifth cell according to the measurement configuration.

In a possible implementation manner, the transceiver unit is further configured to receive information of the third cell sent by the second network device.

In a possible implementation manner, the transceiver unit is further configured to receive a measurement configuration sent by a second network device, where the second network device is a network device corresponding to the second cell; and reporting the measurement result of the fifth cell to the second network equipment according to the measurement configuration.

In a sixteenth aspect, a communication apparatus is provided, where the communication apparatus may be a second network device and may also be a module (e.g., a chip) in the second network device. The communication apparatus may include:

and the processing unit is used for determining the first cell according to the information of a third cell and the measurement result of a fifth cell, wherein at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell.

In one possible implementation, the determining, by the processing unit, the first cell according to the information of the third cell and the measurement result of the fifth cell includes: under the condition that the third cell exists in the fifth cell, determining the corresponding priority of each cell in the third cell according to the information of the third cell; and determining the first cell according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In one possible implementation, the determining, by the processing unit, the first cell according to the information of the third cell and the measurement result of the fifth cell includes: determining the first cell according to a measurement result of the fifth cell in a case where the third cell does not exist in the fifth cell.

In one possible implementation, the communication apparatus further includes:

a receiving and sending unit, configured to send measurement configuration to the terminal device; and receiving the measurement result of the fifth cell sent by the terminal equipment.

In a possible implementation manner, the transceiver unit is further configured to receive indication information of N fourth cells sent by the terminal device, where N is an integer greater than or equal to 1, where the N fourth cells are determined by the terminal device according to information of a third cell and a measurement result of a fifth cell, and at least one same carrier exists between an effective carrier of the third cell and an effective carrier of the second cell;

the processing unit is further configured to determine a first cell according to the N fourth cells, where the first cell is one of the N fourth cells.

In a possible implementation manner, the transceiver unit is further configured to send a measurement configuration to the terminal device.

In a possible implementation manner, the transceiver unit is further configured to send information of the third cell to the terminal device.

In a seventeenth aspect, a communication apparatus is provided, where the communication apparatus may be a terminal device or a module (e.g., a chip) in the terminal device. The communication apparatus may comprise a processor for executing a computer program which, when executed, causes the communication apparatus to perform

The communication method provided by the first aspect or any implementation manner of the first aspect; or

The fourth aspect or any embodiment of the fourth aspect provides a communication method; or

The seventh aspect or any implementation manner of the seventh aspect provides a communication method.

In one possible implementation, the communication device may further comprise a memory for storing the computer program.

In an eighteenth aspect, a communication apparatus is provided, where the communication apparatus may be a second network device, and may also be a module (e.g., a chip) in the second network device. The communication apparatus may comprise a processor for executing a computer program which, when executed, causes the communication apparatus to perform

The communication method provided by the second aspect or any embodiment of the second aspect; or

The communication method provided by any embodiment of the fifth aspect or the fifth aspect; or

The eighth aspect or any embodiment of the eighth aspect provides a communication method.

In a nineteenth aspect, a communication apparatus is provided, which may be a first network device and may also be a module (e.g., a chip) in the first network device. The communication apparatus may comprise a processor for executing a computer program which, when executed, causes the communication apparatus to perform

The third aspect or any embodiment of the third aspect provides a communication method; or

The sixth aspect or any embodiment of the sixth aspect provides a communication method.

In a twentieth aspect, there is provided a communication system comprising the communication apparatus of the ninth aspect, the communication apparatus of the tenth aspect, the communication apparatus of the eleventh aspect, the communication apparatus of the twelfth aspect, the communication apparatus of the thirteenth aspect, the communication apparatus of the fourteenth aspect, the communication apparatus of the fifteenth aspect and the communication apparatus of the sixteenth aspect.

A twenty-first aspect provides a computer-readable storage medium having stored thereon a computer program or computer instructions which, when run, causes part or all of the steps of the communication method described in the above first aspect and any one of its possible implementations, the second aspect and any one of its possible implementations, the third aspect and any one of its possible implementations, the fourth aspect and any one of its possible implementations, the fifth aspect and any one of its possible implementations, the sixth aspect and any one of its possible implementations, the seventh aspect and any one of its possible implementations, and the eighth aspect and any one of its possible implementations to be performed.

A twenty-second aspect further provides a computer program product comprising executable instructions which, when run on a user equipment, cause part or all of the steps of the communication method described in the above first aspect and any one of its possible implementations, the second aspect and any one of its possible implementations, the third aspect and any one of its possible implementations, the fourth aspect and any one of its possible implementations, the fifth aspect and any one of its possible implementations, the sixth aspect and any one of its possible implementations, the seventh aspect and any one of its possible implementations, and the eighth aspect and any one of its possible implementations to be performed.

A twenty-third aspect provides a chip system, which includes a processor and may further include a memory, and is configured to implement the communication method described in the first aspect and any possible implementation thereof, the second aspect and any possible implementation thereof, the third aspect and any possible implementation thereof, the fourth aspect and any possible implementation thereof, the fifth aspect and any possible implementation thereof, the sixth aspect and any possible implementation thereof, the seventh aspect and any possible implementation thereof, and the eighth aspect and any possible implementation thereof. The chip system may be formed by a chip, and may also include a chip and other discrete devices.

Drawings

Fig. 1 is a schematic diagram of uplink carrier coverage provided in an embodiment of the present application;

fig. 2 is a schematic diagram of a relationship between uplink and downlink timing sequences of data according to an embodiment of the present application;

fig. 3 is a schematic diagram of a network architecture provided in an embodiment of the present application;

fig. 4 is a flowchart illustrating a communication method according to an embodiment of the present application;

fig. 5 is a schematic diagram illustrating a relationship between uplink and downlink timing of another data provided in the embodiment of the present application;

fig. 6 is a schematic flow chart of another communication method provided in the embodiments of the present application;

Fig. 7 is a flowchart illustrating another communication method provided in an embodiment of the present application;

fig. 8 is a schematic flowchart of another communication method provided in the embodiment of the present application;

fig. 9 is a schematic flowchart of another communication method provided in an embodiment of the present application;

fig. 10 is a schematic flowchart of another communication method provided in the embodiment of the present application;

fig. 11 is a schematic view of a switching scenario provided in an embodiment of the present application;

fig. 12 is a schematic view of another switching scenario provided in an embodiment of the present application;

fig. 13 is a schematic view of a further switching scenario provided in an embodiment of the present application;

FIG. 14 is a schematic diagram of a scenario of another handover provided in an embodiment of the present application;

FIG. 15 is a schematic diagram of a scenario of another handover provided in an embodiment of the present application;

fig. 16 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of another communication device provided in an embodiment of the present application;

fig. 18 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 19 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 20 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

Fig. 21 is a schematic structural diagram of another communication device provided in an embodiment of the present application;

fig. 22 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 23 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 24 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 25 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 26 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 27 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 28 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 29 is a schematic structural diagram of another communication device provided in an embodiment of the present application;

fig. 30 is a schematic structural diagram of another communication device provided in the embodiment of the present application;

fig. 31 is a schematic structural diagram of another communication device according to an embodiment of the present application.

Detailed Description

To facilitate an understanding of the present application, relevant technical knowledge related to embodiments of the present application will be first introduced herein.

1. Auxiliary uplink

A cell (cell) generally includes an uplink carrier (NUL carrier) and a downlink carrier (DL carrier), and the uplink carrier and the DL carrier are in the same frequency band. However, in the 5G era, the frequency bands and frequency points used are relatively high, such as millimeter waves. The higher the frequency band, the greater the signal transmission loss. This results in limited uplink coverage for the terminal device since the transmit power of the terminal device is limited. Therefore, the 3rd generation partnership project (3 GPP) NR protocol introduces a SUL carrier in an uplink carrier, and the NR supports that a cell may be configured with a SUL carrier in addition to a NUL carrier, and a terminal device may perform uplink transmission through the NUL carrier and/or the SUL carrier of the cell. A System Information Block (SIB) of the serving cell may include whether the cell is configured with the SUL carrier.

The SUL carrier is generally in a low frequency band, such as a Long Term Evolution (LTE) frequency band, and may be used to ensure uplink coverage of the terminal device. If the SUL carrier frequency is lower than the NUL carrier frequency, the coverage area of the SUL carrier is larger than that of the NUL carrier due to propagation loss and the like, so that the uplink coverage area of the cell can be improved by using the SUL carrier; due to the fact that the coverage of the NUL carrier wave caused by frequency points, devices, time slot ratios and the like is smaller than that of the DL carrier wave corresponding to the NUL, the coverage of the uplink carrier wave of the cell can be aligned with that of the DL carrier wave corresponding to the NUL by using the SUL carrier wave. When the difference between the SUL carrier frequency and the NUL carrier frequency is larger, the SUL coverage is larger than the coverage of the DL carrier corresponding to the NUL.

Referring to fig. 1, fig. 1 is a schematic diagram of an uplink carrier coverage according to an embodiment of the present application. As shown in fig. 1, a cell of a station 1 has a NUL carrier and a DL carrier corresponding to the NUL carrier; the cell of the station 2 has a NUL carrier, and a DL carrier and a SUL carrier corresponding to the NUL carrier. If the SUL carrier frequency point in the station 2 is lower than the NUL carrier frequency point, the uplink coverage of the SUL carrier may be larger than the coverage of the DL carrier corresponding to the NUL carrier of the common station site. Thus, multiple cells may be covered by the same SUL carrier, e.g., a cell in site 1 is also covered by a SUL carrier in site 2 at the same time.

2、TA

The TA exists to ensure that the time of uplink data sent by terminal devices at different distances in the same cell reaches the network device falls within the cyclic prefix. N is a radical of_TA-offsetThe offset of the uplink transmission time relative to the downlink reception time is used to ensure that the terminal device in a Time Division Duplex (TDD) mode has enough time to complete the switching from the uplink transmission to the downlink reception at the same frequency point. N is a radical of_TA-offsetThe values may be configured by RRC, and if not signaled by higher layers, may take on values predefined by the protocol.

The NUL carrier and the SUL carrier may belong to the same Timing Advance Group (TAG), and two uplink carriers in one TAG use the same timing reference cell and the same TA value. TA offset value N for NUL and SUL carriers_TA-offsetThe same applies.

Referring to fig. 2, fig. 2 is a schematic structural diagram of uplink data transmission according to an embodiment of the present disclosure. As shown in fig. 2, the terminal device sends the ith uplink frame, which should be T before the start position of the downlink frame corresponding to the terminal device_TA＝(N_TA+N_TA-offset)T_CAnd starting. T is_C＝1/(Δf_max·N_f)，Δf_max＝480·10³Hz and N_f4096. In other words, T_TA＝(N_TA+N_TA-offset)T_CIt can also be understood as the gap between the terminal device transmission timing and the downlink timing, where the downlink timing is defined as the time (in time) when the first detection path of the corresponding downlink frame is received from the reference cell. For a serving cell in a Primary Timing Advance Group (PTAG), a terminal device should use a special cell (SpCell) as a reference cell to obtain a terminal device sending timing of the cell in the PTAG. For a serving cell in a Secondary Timing Advance Group (STAG), a terminal device may use any activated SpCell as a reference cell to obtain a terminal device transmission timing of the cell in the STAG. The terminal device transmission timing can also be understood as the terminal device uplink frame transmission start time in fig. 2.

In NR, when performing handover, the terminal device needs to perform random access (random access) on a NUL carrier or a SUL carrier of the first cell to obtain a TA value of an uplink carrier of the terminal device in the first cell, and then completes uplink synchronization of the terminal device in the first cell according to the TA value. However, the terminal device may generate a delay and an interruption during the handover to the target cell, which requires random access, so that the communication efficiency is reduced.

In view of the foregoing problems, embodiments of the present application provide a communication method capable of improving communication efficiency.

In this embodiment of the present application, in a case that signal quality of a current cell is degraded, a terminal device may perform handover, and compared with the prior art, that is, the terminal device needs random access in a handover process to determine a TA value of a first carrier after the terminal device is handed over to a first cell, in the terminal device according to this embodiment of the present application, after the terminal device is handed over from a second cell to the first cell, a carrier in which the terminal device performs uplink transmission is the first carrier in the first cell, the first carrier may be a carrier of the terminal device in the first cell, the second carrier may be a carrier of the terminal device in the second cell, and then the TA value of the terminal device in the first carrier is determined. For example, if the carrier of the second cell is an SUL carrier, after the handover to the first cell, the terminal device may continue to send uplink transmission on the SUL carrier in the first cell, that is, before the terminal device switches until after the handover, the terminal device may send uplink transmission on the same carrier, that is, the SUL carrier, in the second cell and the first cell, and then determine the TA value of the SUL carrier of the terminal device in the first cell. Thus, the uplink synchronization of the terminal device on the SUL carrier of the first cell can be realized without random access. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

In order to better understand a communication method, a communication apparatus, and a computer-readable storage medium provided in the embodiments of the present application, a network architecture used in the embodiments of the present application is described below. Referring to fig. 3, fig. 3 is a schematic diagram of a network architecture according to an embodiment of the present application. As shown in fig. 3, the network architecture may include at least two cells, for example, a first cell belonging to a first network device and a second cell belonging to a second network device, and the network architecture may further include at least one terminal device, and when the terminal device moves from the second cell to the first cell, a handover may occur, that is, a handover from the second cell to the first cell may occur.

It should be understood that the first cell may be a neighboring cell of the second cell, in other words, in this application, the first cell is one of at least one neighboring cell of the second cell, the neighboring cell of the second cell may also be a candidate cell, and the first cell may be one of the candidate cells, which is not limited in this embodiment of the present application.

It should be understood that "first", "second", "third", "fourth", etc. in the embodiments of the present application are for distinguishing only, and the first, second, third, fourth, etc. are not intended to limit the embodiments of the present application.

It should be understood that in the embodiment of the present application, one network device may correspond to one or more cells. The second cell and the first cell may belong to the same network device, that is, the first network device and the second network device may be the same network device. In this case, the terminal device performs handover within the network device. Alternatively, the second cell and the first cell may belong to different network devices, that is, the first network device and the second network device may be different network devices. In this case, the terminal device performs handover between network devices.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a global system for mobile communication (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a General Packet Radio Service (GPRS), an LTE system, an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD) system, a Universal Mobile Telecommunications (UMTS) system, an enhanced data rate GSM (enhanced data rate for GSM evolution, EDGE) system, and a Worldwide Interoperability for Microwave Access (WiMAX) system. The technical solution of the embodiment of the present application may also be applied to other communication systems, for example, a Public Land Mobile Network (PLMN) system, a fifth generation (5G) system, or a communication system after 5G, or a New Radio (NR) system, and the like, which is not limited in the embodiment of the present application.

The terminal device in the embodiment of the present application may also be referred to as a user terminal. The user terminal may be a device that includes a wireless transceiving function and can cooperate with a network device to provide a communication service for a user. Specifically, the user terminal may refer to a UE, a user, a satellite phone, a satellite terminal, a subscriber unit (subscriber unit), a cellular phone (cellular phone), a smart phone (smart phone), a smart watch (smart watch), a wireless data card, a Personal Digital Assistant (PDA) computer, a tablet computer, a wireless modem (modem), a handheld device (handset), a laptop computer (laptop computer), a Machine Type Communication (MTC) terminal, and the like. For example, the terminal device may be a vehicle-mounted device or a wearable device, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), a terminal device in 5G network or future communication network, and the like, which is not particularly limited in the embodiment of the present application.

The network device in this embodiment may be a device for communicating with a terminal device, and for example, may be a Base Transceiver Station (BTS) in a global system for mobile communications (GSM) system or a code division multiple access (code division multiple access) system, may also be a base station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA) system, may also be an evolved base station (NodeB, eNB, or eNodeB) in an LTE system, may also be a wireless controller in a cloud radio access network (cra) scenario, or may be a network device in a relay station, an access point, a vehicle-mounted device, a wearable device, a network after a future 5G network or a future 5G network, or a network device in a future evolved PLMN network, and the like, for example, a transmission point (cra) in an NR system or a transmission point (TRP) in a future 5G network, or the like, A base station (gNB) in the NR system, one or a group (including multiple antenna panels) of antenna panels of a base station in the 5G system, and the like, which are not limited in this embodiment of the present application.

Optionally, the base station in the embodiment of the present application may include various forms of base stations, for example: macro base stations, micro base stations (also referred to as small stations), relay stations, access points, next generation base stations (gnnodebs, gnnbs), transmission points (TRPs), Transmission Points (TPs), mobile switching centers, and devices-to-devices (D2D), vehicle-to-outside association (V2X), and devices that assume a base station function in machine-to-machine (M2M) communication, which is not particularly limited in the embodiments of the present application.

The embodiment of the present application does not particularly limit a specific structure of an execution subject of the method provided by the embodiment of the present application, as long as the execution subject can communicate according to the method provided by the embodiment of the present application by running a program recorded with codes of the method provided by the embodiment of the present application, for example, the execution subject of the method provided by the embodiment of the present application may be a terminal device or a network device, or a functional module capable of calling a program and executing the program in the terminal device or the network device.

In addition, various aspects or features of the present application may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disk, floppy disk, or magnetic tape), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROM), card, stick, or key drive, etc.). In addition, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.

Based on the network architecture, please refer to fig. 4, where fig. 4 is a flowchart illustrating a communication method according to an embodiment of the present application. In this application, the function performed by the terminal device may also be performed by a module (e.g., a chip) in the terminal device, the function performed by the first network device in this application may also be performed by a module (e.g., a chip) in the first network device, and the function performed by the second network device in this application may also be performed by a module (e.g., a chip) in the second network device. As shown in fig. 4, the communication method may include the following steps.

401. The second network device sends the measurement configuration to the terminal device.

Accordingly, the terminal device may receive the measurement configuration sent by the second network device.

The second network device may configure a measurement process of the terminal device and a report of the terminal device according to the measurement configuration, and may send the measurement configuration message to the terminal device through an RRC message, where the measurement configuration message may include an object to be measured by the terminal device, a cell list, a reporting mode, a measurement identifier, and an event parameter, and may further include a measurement signal, and the like, for example, the measurement signal may be an SSB signal or a reference signal. When the measurement conditions change, the second network device may send new measurement conditions to the terminal device. The second network device may be a network device corresponding to the second cell.

402. And the terminal equipment sends the measurement result of the fifth cell to the second network equipment.

Accordingly, the second network device may receive the measurement result of the fifth cell sent by the terminal device.

After receiving the measurement configuration sent by the second network device, the terminal device may measure the second cell, and may further determine whether measurement on a neighboring cell of the second cell needs to be performed according to the RRC message, so as to obtain a measurement result of the fifth cell. The fifth cell includes a cell corresponding to the measurement configuration, may include the second cell, and may also include a neighboring cell of the second cell. The measurement result of the fifth cell may include the measurement result of the second cell and may also include the measurement result of the neighboring cell.

After determining the measurement result of the fifth cell according to the measurement configuration, the terminal device may send the measurement result of the fifth cell to the second network device. The sending, by the terminal device, the measurement result of the fifth cell to the second network device may be periodic or event-triggered, for example, when the measurement report condition is satisfied, the terminal device reports the measurement result of the fifth cell to the second network device. The measurement results may include Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), and signal-to-noise and interference and noise ratio (SINR).

403. The second network device determines the first cell according to the information of the third cell and the measurement result of the third cell.

After receiving the measurement result of the fifth cell sent by the terminal device, the second network device may determine whether the terminal device needs to be handed over according to the measurement result of the fifth cell, that is, whether the terminal device needs to be handed over, and in a case that the terminal device needs to be handed over, the first cell may be determined according to information of the third cell and the measurement result of the third cell, where the third cell may be at least one cell in the fifth cell, and at least one same carrier exists between an active carrier of the third cell and an active carrier of the second cell.

The information of the third cell is known by the second terminal device, and since the third cell is at least one cell in the fifth cells, the measurement result of the third cell can be obtained from the measurement result of the fifth cell reported by the terminal device, so that the second network device can determine the first cell according to the measurement result of the third cell and the information of the third cell.

The information of the third cell may include an ID of each cell in the third cell, and effective carrier information of each cell. Specifically, in one embodiment, the information of the third cell may be as shown in table 1.

TABLE 1

Carrier wave	Cell
		Carrier wave 1 (frequency)	Cell 1, cell 2 …, cell 5
Carrier wave 2 (frequency)	Cell 1, cell 6 … cell 10
		…	…
Carrier n (frequency)	Cell 11, …, cell m, cell n

As shown in table 1, the information of the third cell may include an ID of each cell, for example, cell 1, cell 2, …, cell m, cell n, m being integers greater than or equal to 1. The information of the third cell may also include information of which cells each carrier is configured to, e.g., carrier 1 is configured in cell 1, cell 2, …, cell 5; carrier 2 is configured in cell 1, cell 6, …, cell 10; …, respectively; the carrier n is configured in the cell 11, …, the cell m, the cell n; frequency information for each carrier may also be included, e.g., what the frequency of carrier 1 is, what the frequency of carrier 2 is, …, what the frequency of carrier n is. The cell IDs and numbers, and the carrier IDs and numbers in table 1 are only for illustration, and the application is not limited thereto.

The carrier wave and the cell where the carrier wave is located can be co-site or different site. For example, carrier 1, cell 2, …, and cell 5 may be co-sited or co-sited; the carrier 2, the cell 1, the cell 6, the cell … and the cell 10 may be co-sited or different sited; the carrier n may be co-sited with the cells 11 and …, the cell m, and the cell n, or may be co-sited with different sites.

The carrier 1, the carrier 2, the carrier …, and the carrier n include a second carrier, and also include other carriers except the second carrier in the active carriers of the second cell.

In one embodiment, the information of the third cell may be as shown in table 2.

TABLE 2

As shown in table 2, the information of the third cell may include an ID of each cell, for example, cell 1, cell 2, …, cell n, n being an integer greater than or equal to 1; carriers for each cell may also be included, e.g., cell 1 has carrier 1, carrier 2, …, carrier 5; cell 2 has carrier 1, carrier 6, …, carrier 10; …, respectively; the cell n comprises carriers 11 and …, a carrier m and a carrier n, wherein m is an integer greater than or equal to 1; frequency information for each carrier may also be included, e.g., what the frequency of carrier 1 is, what the frequency of carrier 2 is, …, what the frequency of carrier n is. The cell IDs and numbers, and the carrier IDs and numbers in table 2 are only for illustration, and the application is not limited thereto.

The carriers of the cells can be co-site or different site. For example, cell 1, carrier 2, …, and carrier 5 may be co-sited or co-sited; cell 2, carrier 1, carrier 6, …, and carrier 10 may be co-sited or co-sited; the cell n, the carrier 11, …, the carrier m, and the carrier n may be co-sited or co-sited.

The second network device determines the first cell according to the information of the third cell and the measurement result of the third cell, specifically:

the second network device may determine, according to the information of the third cell, the priority corresponding to each cell in the third cell, and then determine, according to the priority corresponding to each cell in the third cell and the measurement result of the third cell, the first cell:

the priority may be embodied in a priority value corresponding to each cell, and the priority value may be determined based on at least one of the values.

In one embodiment, the priority value may have a first value, a second value, a third value, and a fourth value, wherein:

if the effective carrier of the cell has a carrier which is co-sited with a second carrier, a first value can be assigned to the cell, and the second carrier can be the carrier of the second cell;

if the effective carrier of the cell has a carrier with a station address different from that of the second carrier, a second value can be assigned to the cell;

if the effective carrier of the cell has a carrier which shares the same site with other carriers except the second carrier in the effective carrier of the second cell, a third value can be assigned to the cell;

if there is a carrier with a site different from that of the other carriers except the second carrier in the effective carrier of the second cell in the effective carrier of the cell, a fourth value may be assigned to the cell.

It should be understood that the co-site may be characterized by a co-site between carriers, a co-site between cells, a co-site between a network device and a network device, a co-site between a cell and a carrier, a co-site between a carrier and a network device, and a co-site between a cell and a network device. For example, if the network device corresponding to a certain uplink carrier is at the same site as the network device corresponding to the downlink carrier of the cell, it may indicate that the uplink carrier and the cell are co-located, and if the network device corresponding to a certain uplink carrier is at a different site from the network device corresponding to the downlink carrier of the cell, it may indicate that the uplink carrier and the cell are at different sites. The network device corresponding to the uplink carrier may be understood as a network device that can receive the uplink transmission sent by the terminal device on the carrier. The network device corresponding to the downlink carrier may be understood as that the terminal device may receive downlink transmission of the network device on the carrier.

For example, two uplink carriers share a common site, and it can be characterized that cells or network devices receiving data on the two carriers are at the same site, or the same cell or the same network device. For another example, two carriers are co-sited, and it can be characterized that the cells or network devices communicating with the terminal devices on the two carriers are at the same site, or the same cell or the same network device.

It should be understood that the different site may be characterized by a different site between carriers, a different site between cells, a different site between network devices, a different site between cells and carriers, a different site between carriers, and a different site between cells and network devices. For example, two uplink carriers are different sites, and it can be characterized that the cells or network devices receiving data on the two carriers are at different sites. For another example, two carriers are different sites, and it can be characterized that the cells or network devices communicating with the terminal device on the two carriers are at different sites.

The first value, the second value, the third value and the fourth value may be different values, and a cell in which a carrier having a station address common to the second carrier exists in the active carrier is preferentially selected. For example, the first value may be greater than the second value, the second value may be greater than the third value, and the third value may be greater than the fourth value; alternatively, the first value may be greater than the third value, the third value may be greater than the second value, and the second value may be greater than the fourth value. Correspondingly, the higher the priority value, the higher the priority of the cell.

In one embodiment, the highest value may be selected as the priority of the cell, and each cell may be assigned once, for example, if the cell satisfies both the first value and the third value, the first value may be assigned to the cell according to the first value being greater than the third value.

In one embodiment, the sum of at least one of the first, second, third and fourth values may be taken as the priority value of the cell; or taking the weighted sum of at least one of the first numerical value, the second numerical value, the third numerical value and the fourth numerical value as the priority numerical value of the cell. For example, if the cell satisfies the first numerical value and the third numerical value assigned to the cell, the sum of the first numerical value and the third numerical value may be used as the priority numerical value of the cell, or the weighted sum of the first numerical value and the third numerical value may be used as the priority numerical value of the cell.

After determining the priority corresponding to each cell in the third cell according to the information of the third cell, the second network device may determine the first cell according to the priority corresponding to each cell in the third cell and the measurement result of the third cell, specifically:

The measurement result of the third cell is quantified, the total number value of each cell is determined according to the priority value and the measurement result value corresponding to each cell in the third cell, and the second network device may determine the first cell according to the total number value of each cell, for example, the first cell may be a cell with the highest total number value.

In one embodiment, in the case that the priorities of the cells are the same, a cell with a good measurement result may be preferentially selected as the first cell according to the measurement result of the cell; in the case where the measurement results of the cells are the same, a cell with a high priority may be preferentially selected as the first cell according to the priority of the cell.

It should be understood that the first numerical value, the second numerical value, the third numerical value, and the fourth numerical value may be set in advance by the second network device, may be predefined in a protocol, and may also be set in real time when the information of the third cell is obtained, which is not limited in this application.

404. The second network device sends request information for requesting the terminal device to access the first network device to the first network device.

Accordingly, the first network device may receive request information sent by the second network device for requesting the terminal device to access the first network device.

After the second network device determines the first cell, request information may be sent to the first network device through the transparent RRC container, where the request information may be used to request the terminal device to access the first network device. The first network device may be a network device corresponding to the first cell.

The RRC container may carry information required for preparing handover at the target side, where the information may include a first cell ID, a cell-radio network temporary identifier (C-RNTI) of a terminal device in the second network device, RRM configuration including a terminal device deactivation time, system information block one (SIB 1) from the second network device, terminal device capability for different Radio Access Technologies (RATs), and measurement information (including beam related information, if available) reported by the terminal device.

Accordingly, the first network device may determine whether to allow the terminal device to access after receiving request information sent by the second network device for requesting the terminal device to access the first network device.

In the case of allowing the terminal device to access, the first network device may send, to the second network device, permission information for allowing the terminal device to access the first network device, and may also send, to the second network device, a transparent container to be sent to the terminal device as an RRC message, so that the terminal device performs handover.

In the case that the terminal device is not allowed to access, the second network device may re-determine the first cell according to step 403, and then send request information for requesting the terminal device to access a third network device to the third network device, where the third network device may be a network device corresponding to the first cell re-determined by the second network device.

Accordingly, the third network device may receive request information sent by the second network device for requesting the terminal device to access the third network device, and determine whether to allow the terminal device to access.

And under the condition that the terminal equipment is allowed to access, the third network equipment sends permission information for allowing the terminal equipment to access the third network equipment to the second network equipment.

405. The second network device sends second indication information for indicating the information of the first cell to the terminal device.

Accordingly, the terminal device may receive second indication information for indicating information of the first cell, which is transmitted by the second network device.

After receiving the permission information for permitting the terminal device to access, which is sent by the network device corresponding to the first cell, the second network device may send second indication information to the terminal device, where the second indication information is used to indicate the information of the first cell, and may also trigger the terminal device to perform handover by sending a message to the terminal device, where the message may include information required for accessing the first cell: a first cell ID, a first network device security algorithm identifier of the selected security algorithm, and the like, where the message may be carried in an RRC message or a physical downlink shared channel (PDCCH) message. The terminal device receives the second indication information sent by the second network device, and the terminal device can determine which cell the first cell to be switched to is according to the ID of the first cell included in the second indication information, so that the terminal device can access the first cell without reading system information, and the communication efficiency can be improved.

406. And determining that the carrier wave for uplink transmission of the terminal equipment in the first cell is the first carrier wave after the terminal equipment is switched from the second cell to the first cell.

After the terminal device receives the second indication information sent by the second network device, it may be determined that the carrier in the first cell, where the terminal device performs uplink transmission, is the first carrier after the terminal device is switched from the second cell to the first cell. Before the terminal equipment is switched until after the terminal equipment is switched, uplink transmission can be carried out on a first carrier wave which has the same frequency band with a second carrier wave in a second cell and a first cell; it can also be understood that, before the terminal device switches to the second cell, the uplink transmission can be performed in the first carrier at the same frequency position as the second carrier in the second cell and the first cell; it can also be understood that, before the terminal device is handed over, until after the terminal device is handed over, uplink transmission may continue on the same carrier, i.e. the second carrier, in the second cell and the first cell.

In a first possible implementation, the same carrier as the second carrier is present in the active carrier of the first cell. If the effective carrier of the first cell has the carrier same as the second carrier, the terminal equipment can be ensured to carry out uplink transmission on the first carrier after being switched from the second cell to the first cell; in an embodiment, if there is a carrier in the same frequency band as the second carrier in the active carrier of the first cell, and uplink transmission sent by the terminal device on the active carrier of the first cell and the second carrier is received by the same network device, it may also be ensured that the terminal device performs uplink transmission on the first carrier after being switched from the second cell to the first cell. Thus, the switching can be realized without random access, and the communication efficiency can be improved. If the same carrier as the second carrier does not exist in the effective carrier of the first cell, random access is also performed in the switching process of the terminal equipment, which may cause problems of time delay and interruption.

One of the effective carriers of the first cell is the same carrier as the second carrier, and it can be understood that uplink transmission sent by the terminal device on one of the effective carriers of the first cell and the second carrier is received by the same network device, and at least one of the following conditions is satisfied: one carrier in the effective carriers of the first cell is the same as the carrier frequency of the second carrier; one carrier in the effective carriers of the first cell is the same as the frequency reference point of the second carrier; one carrier in the effective carriers of the first cell has the same frequency position with the second carrier; the carrier bandwidths of the first carrier and the second carrier are the same.

In another possible implementation manner, when the carrier of the second cell is a third carrier and there is no carrier that is the same as the third carrier in the active carrier of the first cell, the terminal device may first switch to the second carrier in the second cell, where the second carrier is the same carrier as the active carrier of the first cell. Therefore, the carrier same as the second carrier can be ensured to exist in the effective carrier of the first cell, and the terminal equipment can be ensured to perform uplink transmission on the first carrier after switching. Thus, the switching can be realized without random access, and the communication efficiency can be improved.

In one embodiment, when the carrier of the second cell is a third carrier, and there is no carrier in the active carrier of the first cell that has the same frequency band as the third carrier, and the terminal device sends a carrier in which uplink transmission is not received by one network device on the active carrier of the first cell and the third carrier, the terminal device may switch to the second carrier in the second cell first, where the second carrier is a carrier in the same frequency band as the active carrier of the first cell, and uplink transmission sent by the terminal device on the second carrier and the active carrier of the first cell is received by the same network device.

In another possible implementation manner, the second network device may send, to the terminal device, first indication information for indicating that a carrier for uplink transmission by the terminal device in the first cell is the first carrier. After the terminal device receives the first indication information sent by the second network device, it may be determined, according to the first indication information, that the carrier where the terminal device performs uplink transmission in the first cell is the first carrier. The information for determining that the carrier for the terminal device to perform uplink transmission in the first cell is the first carrier may be sent to the terminal device by the second network device, and is not determined by the terminal device. Therefore, the resource consumption of the terminal device can be reduced.

In one embodiment, the second network device may send fourth indication information to the terminal device, where the fourth indication information may be used to indicate whether the terminal device skips random access in a handover procedure, and when the fourth indication information indicates that the terminal device skips random access in the handover procedure, the terminal device may determine the first carrier according to the first indication information or carrier information of the terminal device in the second cell. For example, if the terminal device has only one SUL carrier in the second cell, and the SUL carrier and at least one SUL carrier in the active carriers of the first cell are carriers of the same frequency band, and the terminal device sends uplink transmission on the SUL carrier and at least one SUL carrier in the active carriers of the first cell and receives the uplink transmission by the same network device, the terminal device skips the random access process after receiving the fourth indication information, and determines that the first carrier is the SUL carrier. For another example, if the terminal device has only one SUL carrier in the second cell, the terminal device receives first indication information indicating that the SUL carrier and at least one SUL carrier in the active carriers of the first cell are carriers of the same frequency band, and the terminal device sends uplink transmission on the SUL carrier and at least one SUL carrier in the active carriers of the first cell and receives the uplink transmission by the same network device, and after receiving the fourth indication information, the terminal device skips the random access process and determines that the first carrier is the SUL carrier. Thus, the switching can be realized without random access, and the communication efficiency can be improved.

In one embodiment, the second network device may further send fifth indication information to the terminal device, where the fifth indication information may include indication information indicating that the terminal device continues to use the second carrier resource, for example, continues to use a certain bandwidth part (BWP) in the second carrier resource, and the certain BWP may be the initial BWP or the first BWP to be activated. The fifth indication information may further include indicating that the terminal device is no longer using the resource of the second carrier, and using a new uplink resource, where the new uplink resource may be an uplink grant, and the uplink grant may be that the terminal device is on the first carrier or the fourth carrier. The uplink grant may also be obtained by the terminal device detecting a PDCCH message of the first cell. Through the fifth indication information, the terminal device may directly utilize all or part of the resources of the second carrier for communication without reacquiring the configuration information of the first carrier from the first cell.

In one possible implementation, the carrier of the terminal device in the second cell or the first cell may be one or more.

For example, assuming that the terminal device has one carrier in the second cell, and after the terminal device is handed over to the first cell, the first cell also has one carrier, the carrier of the terminal device in the first cell and the carrier of the terminal device in the second cell may be carriers of the same frequency band, and uplink transmissions sent by the terminal device in the two carriers are received by the same network device.

For another example, assuming that the terminal device has one carrier in the second cell, and after the terminal device is handed over to the first cell, the first cell has multiple carriers, one carrier of the multiple carriers of the terminal device in the first cell and the carrier in the second cell may be carriers of the same frequency band, and uplink transmissions sent by the terminal device on the two carriers are received by the same network device.

For another example, assuming that the terminal device has multiple carriers in the second cell, and after the terminal device is handed over to the first cell, the first cell has one carrier, the carrier of the terminal device in the first cell and one carrier of the multiple carriers in the second cell may be carriers of the same frequency band, and uplink transmissions sent by the terminal device in the two carriers are received by the same network device.

For another example, assuming that the terminal device has multiple carriers in the second cell, and after the terminal device is handed over to the first cell, the first cell has multiple carriers, then the multiple carriers of the terminal device in the first cell and part or all of the multiple carriers in the second cell are carriers of the same frequency band, and uplink transmission sent by the terminal device in the part or all of the carriers is received by the same network device. For example, one carrier of the multiple carriers of the terminal device in the first cell and one carrier of the multiple carriers of the second cell are carriers of the same frequency band, and uplink transmissions sent by the terminal device on the two carriers are received by the same network device; for another example, two carriers of the terminal device in the plurality of carriers of the first cell are the same carrier as two carriers of the plurality of carriers of the second cell.

In a possible implementation manner, the first carrier or the second carrier may be a NUL carrier, an SUL carrier, or at least one of the following carriers: TDD carriers, uplink time units of TDD carriers, FDD carriers, and uplink time units of FDD carriers, which are time slots or subframes, can thus expand the range of carriers that can be used as SUL carriers.

In a possible implementation manner, the carrier of the terminal device in the second cell is an SUL carrier, and after the terminal device is handed over to the first cell, the carrier of the terminal device in the first cell may be an SUL carrier, or a NUL carrier (the carrier may be an SUL carrier with respect to the second cell, and may be a NUL carrier with respect to the first cell), or may be another carrier.

In a possible implementation manner, the carrier of the terminal device in the second cell is a NUL carrier, and after the terminal device is handed over to the first cell, the carrier of the terminal device in the first cell may be a SUL carrier (the carrier may be a NUL carrier with respect to the second cell and may be a SUL carrier with respect to the first cell), may also be a NUL carrier, and may also be another carrier.

In a possible implementation manner, when the second network device sends the first indication information, the first network device may further include information that the first carrier may be used as an uplink time resource, and the information that is used as the uplink time resource may include a slot that is used as the uplink, a position of a subframe, and an uplink and downlink slot ratio. Therefore, the terminal equipment can acquire the configuration information of the first carrier in advance.

407. The second network device sends the first information to the terminal device.

Accordingly, the terminal device may receive the first information transmitted by the second network device.

After determining that the carrier for performing uplink transmission in the first cell is the first carrier, the terminal device may receive first information sent by the second network device, where the first information may include a TA offset value of the first cell, and may further include at least one of a timeslot offset value between the first cell and the second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell.

408. The terminal device determines a first TA value.

After the terminal device receives the first information sent by the second network device, the first TA value may be determined according to the first information, the sending timing of the terminal device in the second carrier, the downlink timing of the first cell, and the TA offset value of the first cell. Since the carrier for performing uplink transmission in the first cell is the first carrier, that is, before and after the handover, the terminal device sends uplink transmission in the second cell and the first cell using the carrier of the same frequency band, and the uplink transmission sent by the terminal device in the first cell and the second cell is received by the same network device, the sending timing of sending the uplink transmission by the terminal device should be kept unchanged. When the first cell performs uplink transmission, the terminal device needs to refer to the downlink timing of the first cell, and does not need to refer to the downlink timing of the second cell any more, so that the terminal device needs to perform corresponding adjustment on the TA value of the first carrier. Specifically, the first information may be sent by the second network device to the terminal device, the transmission timing of the second carrier is determined by the terminal device, and the downlink timing of the first cell may be obtained by the terminal device by detecting Synchronization Signal Block (SSB) information or other reference signals of the first cell. Therefore, the terminal device may determine the first TA value according to the first information, the transmission timing in the second carrier, the downlink timing of the first cell, and the TA offset value of the first cell, thereby implementing uplink synchronization of the terminal device in the first carrier of the first cell.

If the uplink carrier only has the first carrier after the terminal equipment is switched to the first cell, determining the TA value of the terminal equipment in the first carrier, which can also be understood as determining the TA value of the terminal equipment in the first cell; if the uplink carrier has the first carrier and also has other carriers after the terminal device is switched to the first cell, determining the TA value of the terminal device in the first carrier under the condition that the TA values of the first carrier and the other carriers are the same, which can also be understood as determining the TA value of the terminal device in the first cell.

The first carrier and the second carrier may be uplink carriers. In a possible implementation manner, if the carrier is an uplink carrier, the transmission timing of the terminal device on the carrier may be understood as the uplink timing of the terminal device on the carrier. For example, the transmission timing of the terminal device on the second carrier may be understood as the uplink timing of the terminal device on the second carrier. The first TA value is the TA value of the terminal equipment in the first carrier. Therefore, the TA value of the first carrier can be determined without random access, and the uplink synchronization of the terminal equipment in the first carrier of the first cell is realized.

Specifically, the first TA value may satisfy the following equation:

Wherein N is_TAIs a first TA value, T is a downlink timing of the first cell, T_ttTiming of transmission, T, for terminal equipment on the second carrier_C＝1/(Δf_max·N_f)，Δf_max＝480·10³Hz and N_f＝4096，N_TA-offsetIs the TA offset value of the first cell.

In one possible implementation, N_TA-offsetThe TA offset values for the first carrier and the first cell downlink carrier.

The first TA value may also satisfy the following equation:

or

Wherein, T_slot-offsetIs the slot offset value between the first cell and the second cell.

The first TA value may also satisfy the following equation:

or

Wherein, T_sfn-offsetIs a system frame number offset value between the first cell and the second cell.

The first TA value may also satisfy the following equation:

or

The first TA value may also satisfy the following equation:

or

Wherein, T_Fb-offsetIs a frame boundary offset value between the first cell and the second cell.

In a possible implementation manner, please refer to fig. 5, where fig. 5 is a schematic diagram of a relationship between uplink and downlink timings of another data provided in the embodiment of the present application. As shown in fig. 5, the terminal device transmits an uplink frame on the first carrier, and may be T before the start position of the downlink frame corresponding to the uplink frame_TA＝(N_TA+N_TA-offset)×T_CThe start (the downlink frame is a downlink frame corresponding to the uplink frame in the first cell) may also be understood as a difference between the transmission timing of the terminal device in the first carrier and the downlink timing of the first cell being (N) _TA+N_TA-offset)×T_C. That is, the sending timing of the terminal device on the first carrier is consistent with the initial position of the terminal device sending the uplink frame on the first carrier; the downlink timing of the terminal equipment in the first cell is consistent with the initial position of a downlink frame corresponding to an uplink frame sent by the terminal equipment in the first carrier. Therefore, after the handover, the TA value of the terminal device in the first carrier may be calculated from the sending start time of the uplink frame of the second carrier and the start time of the downlink frame corresponding to the uplink frame in the first cell.

Specifically, the formula of the first TA value may also be:

wherein S is the sending start time of the uplink frame of the second carrier wave of the terminal equipment, T₁The start time of the downlink frame corresponding to the uplink frame in the first cell may be considered. For example, if the frame number of the uplink frame is i, the frame number of the downlink frame corresponding to the uplink frame in the first cell may be i, or i + j, j may be notified to the terminal device by the second network device or the first network device. For another example, the downlink frame corresponding to the uplink frame in the first cell may be a downlink frame having the smallest difference between the start time and the transmission start time of the first carrier uplink frame i, or may be the start time The downlink frame j with the smallest difference from the transmission start time of the first carrier uplink frame i + j may be notified to the terminal device by the second network device or the first network device, or may be determined by the terminal device.

The first TA value may also satisfy the following equation:

or

The first TA value may also satisfy the following equation:

or

The first TA value may also satisfy the following equation:

or

The first TA value may also satisfy the following equation:

or

In a possible implementation manner, the second network device sends sixth indication information to the terminal device, where the sixth indication information is used to indicate the first TA value. After receiving the sixth indication information, the terminal device may skip random access in the handover process, and the terminal device may determine, according to the TA value in the sixth indication information, that the terminal device is handed over to the first cell, where the first TA value is the TA value in the sixth indication information, or the terminal device may determine, according to the TA value in the sixth indication information, that the terminal device is handed over to the first cell, where the first TA value is the TA value of the second carrier, or the terminal device may determine, according to the TA value in the sixth indication information, that the terminal device is handed over to the first cell, where the first TA value is determined according to the first information, the transmission timing of the terminal device in the second carrier, and the downlink timing of the first cell.

409. And the second network equipment sends third indication information used for indicating whether the second TA value is the same as the first TA value or not to the terminal equipment.

Accordingly, the terminal device may receive third indication information sent by the second network device to indicate whether the second TA value is the same as the first TA value.

The second network device may send third indication information to the terminal device, where the third indication information may be used to indicate whether a second TA value is the same as the first TA value, the second TA value is a TA value of the terminal device in a fourth carrier, and the fourth carrier is a carrier, different from the first carrier, of the terminal device in the first cell.

In a possible implementation manner, the third indication information may also be used to indicate whether the fourth carrier and the first carrier are co-sited.

In a possible implementation manner, the third indication information may also be used to indicate a second TA value.

410. The terminal device determines a second TA value.

The terminal device may determine the second TA value according to the third indication information, specifically:

in a case where the third indication information indicates that the second TA value is the same as the first TA value, the second TA value may be determined to be the first TA value.

In a case that the third indication information indicates that the fourth carrier is co-sited with the first carrier, the second TA value may be determined to be the first TA value.

The second network device may send the second TA value to the terminal device through the third indication information after determining the second TA value according to the information whether the second TA value is the same as the first TA value or the information whether the fourth carrier and the first carrier are co-located.

In one embodiment, the fourth carrier may be a SUL carrier or a NUL carrier. The first carrier and the fourth carrier may also be adapted for 5G, 6G adaptation. It should be understood that the names of all carriers in this application are only examples, and in future communications, such as 6G, other names may also be called, and this application is not limited thereto. The unified description is made here, and the description is not repeated.

It should be understood that, in the embodiment of the present application, part or all of the first information, the first indication information, the second indication information, the third indication information, the fourth indication information, the fifth indication information, and the sixth indication information may be carried in an RRC message or a PDCCH message, and part or all of the information may be issued by the second network device to the terminal device at the same time, or may be issued in time sequence, which is not limited in this application.

411. And the terminal equipment sends the second information to the first network equipment.

Accordingly, the first network device may receive the second information transmitted by the terminal device.

In one embodiment, after the terminal device determines the TA value of at least one carrier of the first cell, the second information may be transmitted in the at least one carrier according to the corresponding TA value. Specifically, the method comprises the following steps:

the terminal device communicates with the first network device in the first cell, and the first network device may send downlink transmission to the terminal device. After the terminal device determines the first TA value, the second information may be transmitted on the first carrier according to the first TA value. The terminal device may send uplink transmission to the fourth network device according to the first carrier of the first cell according to the first TA value, where the fourth network device is a network device that can receive the uplink transmission sent by the terminal device on the second carrier, and the fourth network device sends the uplink transmission data to the first network device, for example, the fourth network device may send the uplink transmission data to the first network device through a backhaul. If the first network device is the fourth network device, that is, the second carrier and the first cell are co-sited, or the second carrier and the first network device are co-sited, the terminal device may directly continue to send uplink transmission to the first network device on the second carrier. The uplink transmission information may be second information, where the second information is used to confirm handover to the first network device, and the confirmation of handover may be to confirm that the terminal device is handed over from the second cell to the first cell. Therefore, the terminal equipment does not need random access, the uplink synchronization of the terminal equipment on the first carrier of the first cell can be realized, and the communication efficiency can be improved.

The terminal device may keep the first TA value to continue sending uplink transmission to the fourth network device or the first cell on the second carrier until the first network device or the first cell sends a message for modifying the first TA value to the terminal device.

The terminal device communicates with the first network device in the first cell, and the first network device may send downlink transmission to the terminal device. After the terminal device determines the second TA value, the second information may be sent on the fourth carrier according to the second TA value. The terminal device may send uplink transmission to a sixth network device on a fourth carrier according to the second TA value, where the sixth network device is a network device that can receive the uplink transmission sent by the terminal device on the fourth carrier, and the sixth network device sends uplink transmission data to the first network device, and if the first network device is the sixth network device, that is, the fourth carrier and the first cell share a common site, or the fourth carrier and the first network device share a common site, the terminal device may send uplink transmission to the first network device on the fourth carrier. The information transmitted in uplink may be second information, and the second information is used to confirm the handover to the first network device. Therefore, the terminal equipment does not need random access, the uplink synchronization of the terminal equipment on the fourth carrier wave of the first cell can be realized, and the communication efficiency can be improved.

The terminal device may keep the second TA value to send the uplink transmission information to the sixth network device or the first cell on the fourth carrier until the first network device or the first cell sends a message for modifying the second TA value to the terminal device.

For another example, the terminal device may simultaneously send the uplink transmission information to the fifth network device or the first cell on the first carrier and to the sixth network device or the first cell on the fourth carrier according to the first TA value and the second TA value.

In an embodiment, after the terminal device is handed over, if the first carrier and the fourth carrier are not located at the same site, transmission paths of the first carrier and the fourth carrier are different, distances between the terminal device and the fourth network device and between the terminal device and the sixth network device are different, and the first TA value and the second TA value are independent, so that the first TA value and the second TA value need to be independently indicated and/or adjusted. The terminal device may adjust the first TA value and the second TA value respectively through two signaling sent by the first network device or the first cell, or may adjust the first TA value and the second TA value respectively through different fields of one signaling sent by the first network device or the first cell.

In a possible implementation manner, the terminal device may assist the fourth network device in adjusting the first TA value by sending a periodic signal to the fourth network device; the terminal device may assist the sixth network device in adjusting the second TA value by sending a periodic signal to the sixth network device.

In one embodiment, the second information may be an RRC reconfiguration complete message. The terminal device synchronizes to the first cell and completes the handover procedure by sending an RRC reconfiguration complete message to the fourth network device or the sixth network device.

Accordingly, after receiving the second information, the first network device may send a reconfiguration complete response to the terminal device, and the response message may also be used to indicate that the terminal device does not use the semi-static uplink resource any more.

Referring to fig. 6 based on the above network architecture, fig. 6 is a schematic flowchart of another communication method according to an embodiment of the present application. In this application, the function performed by the terminal device may also be performed by a module (e.g., a chip) in the terminal device, the function performed by the first network device in this application may also be performed by a module (e.g., a chip) in the first network device, and the function performed by the second network device in this application may also be performed by a module (e.g., a chip) in the second network device. As shown in fig. 6, the communication method may include the following steps.

601. The second network device sends the measurement configuration to the terminal device.

It should be understood that step 601 corresponds to step 401, and the related description in step 601 may refer to the description of step 401, and is not repeated herein to avoid repetition.

602. And the terminal equipment determines the measurement result of the fifth cell according to the measurement configuration.

After receiving the measurement configuration sent by the second network device, the terminal device may measure the second cell, and may further determine whether to perform measurement on the neighboring cell according to the RRC message.

The terminal device may determine a measurement result of the fifth cell according to the measurement configuration. The fifth cell includes a cell corresponding to the measurement configuration, may include the second cell, and may also include a neighboring cell of the second cell. The measurement result of the fifth cell may include the measurement result of the second cell and may also include the measurement result of the neighboring cell. The measurement results may include RSRP, RSRQ, and SINR.

603. And the second network equipment sends the information of the third cell to the terminal equipment.

Accordingly, the terminal device may receive the information of the third cell transmitted by the second network device.

In a possible implementation manner, after determining the measurement result of the fifth cell according to the measurement configuration, the terminal device may determine whether handover is required according to the measurement result of the fifth cell without reporting the measurement result of the fifth cell to the second network device, and in a case that handover is required, the terminal device may obtain information of the third cell from the second network device. The third cell may be at least one of the fifth cells, and the active carrier of the third cell and the active carrier of the second cell have at least one same carrier. In one embodiment, an acquisition request message for acquiring information of the third cell may be sent to the second network device to acquire the information of the third cell. The information of the third cell may refer to the description in step 403, and is not described herein again.

The information of the third cell may be sent to the terminal device by the second network device through a system message, or may be sent to the terminal device through a dedicated signaling. The system message may be an on demand (on demand) system message. If the information of the third cell is sent to the terminal device by the on-demand system message, the system message is not always in a broadcast state, and only when the terminal device needs to acquire the information of the third cell, the acquisition request message is sent to the second network device, so that interference can be reduced.

It should be understood that, in this embodiment of the present application, the second network device may send the information of the third cell to the terminal device before sending the measurement configuration, or simultaneously with sending the measurement configuration, or after sending the measurement configuration, which is not limited in this application.

If the information of the third cell is sent before the second network device sends the measurement configuration to the terminal device, it can be understood that the terminal device may not only obtain the information of the third cell only during handover, but also obtain the information of the third cell before receiving the measurement configuration due to some other services or requirements. In this way, the terminal device does not need to acquire the information of the third cell but directly uses the information of the third cell during the handover, so that the signaling received by the terminal device can be reduced, and the handover efficiency can be improved.

If the information and the measurement configuration of the third cell are simultaneously sent to the terminal device by the second network device, the signaling received by the terminal device can be reduced, and the switching efficiency can be improved.

If the third cell information is sent by the second network device after the measurement configuration is sent to the terminal device, it can be understood that the terminal device obtains the third cell information from the second network device as needed when the terminal device needs to use the third cell information during switching, and waste of resource storage space of the terminal device can be avoided.

In one embodiment, the obtaining request message may also be used to obtain a timeslot ratio, and the terminal device may obtain the timeslot ratio of the third cell in advance through the obtaining request message. The terminal device may obtain the timeslot ratio when obtaining the information of the third cell, or obtain the timeslot ratio to the second network device before the terminal device determines that the carrier for performing uplink transmission in the first cell is the first carrier, which is not limited in this application.

In a possible implementation manner, the terminal device determines a measurement result of the fifth cell according to the measurement configuration and reports the measurement result to the second network device, and the second network device may determine to handover the terminal device according to the measurement result of the fifth cell, and send a handover instruction and information of the third cell to the terminal device in case of handover. For specific steps, reference may be made to the description in step 403, which is not described herein again.

In one embodiment, the information of the third cell may further include a value L1 or L2 specified by the second network device, L1 and L2 are positive integers greater than or equal to 1, and the information of the third cell may have at least one value L1 or at least one value L2.

The value L1 may characterize the presence of a carrier co-sited with the second carrier among the active carriers of the first L1 cells in the third cell. For example, as shown in table 1, if carrier 1 and the second carrier are co-located, or carrier 1 refers to the second carrier, carrier 1 is located in cell 1, cell 2, …, and cell 5, and a value L1 may represent that carrier co-located with the second carrier exists in the first L1 cell active carrier, and if a value L1 is 1, it may represent that a carrier co-located with the second carrier exists in the active carriers of the first cell in cell 1, cell 2, …, and cell 5, that is, a carrier co-located with the second carrier exists in the active carriers of cell 1; if the value L is 2, it may indicate that a carrier co-sited with the second carrier exists in the active carriers of the first 2 cells of cell 1, cell 2, …, and cell 5, that is, a carrier co-sited with the second carrier exists in the active carriers of cell 1 and cell 2. Since there are n carriers in table 1, there may be at least one of the values L1.

The value L2 may also indicate that the first L2 carriers of a cell in the third cell are co-sited carriers with the cell, which may indicate that the cell is co-sited with the second carrier if the second carrier is among the first L2 carriers. For example, as shown in table 2, the value L2 may characterize the first L2 carriers of each cell in the third cell as being co-sited with the cell, it may be understood that the first L2 carriers of carrier 1, carrier 2, …, carrier 5 are co-sited with cell 1, and if there is a second carrier in the first L2 carriers, it may be determined that cell 1 is co-sited with the second carrier; it can also be understood that the first L2 carriers of the carrier 1, the carrier 6, the carrier …, and the carrier 10 are co-sited with the cell 2, and if there is a second carrier in the first L2 carriers, it can be determined that the cell 2 is co-sited with the second carrier; …, respectively; and so on. Since there are n cells in table 2, there may be at least one of the values L2.

The value L may not be specified in the information of the first cell sent by the first network device, and it may be determined that a carrier co-located with the second carrier exists in the active carriers of the first or previous cells by default, or that which cell or cells are co-located with the second carrier by default, according to predefined in the protocol.

In one embodiment, when the second network device sends the information of the third cell to the terminal device, the slot ratio may also be sent. The terminal device may obtain the timeslot ratio of the first cell in advance, and the second network device may correspondingly reduce the number of bits (bits) in the instruction notifying the terminal device to perform handover. The information of the third cell may be carried in an RRC message or a PDCCH message and sent to the terminal device through the second network device.

604. And the terminal equipment determines N fourth cells according to the information of the third cell and the measurement result of the third cell.

After the terminal device receives the information of the third cell sent by the second network device, N fourth cells may be determined according to the information of the third cell and the measurement result of the third cell, where the fourth cells may be candidate cells, and N is an integer greater than or equal to 1. The terminal device determines N fourth cells according to the information of the third cell and the measurement result of the third cell, and may refer to the description of the second network device determining the first cell according to the information of the third cell and the measurement result of the third cell in step 403, which is not described herein again.

605. And the terminal equipment sends the indication information of the N fourth cells to the second network equipment.

Accordingly, the second network device may receive the indication information of the N fourth cells sent by the terminal device.

After determining the N fourth cells according to the information of the third cell and the measurement result of the third cell, the terminal device may report the indication information of the N fourth cells to the second network device according to its own capability and/or service requirement.

In a possible implementation manner, when the terminal device reports the indication information of the N fourth cells to the second network device, the terminal device may also report measurement results of the N fourth cells.

In a possible implementation manner, when the terminal device reports the indication information of the N fourth cells to the second network device, the terminal device may also report the measurement result of the fifth cell.

606. And the second network equipment determines the first cell according to the indication information of the N fourth cells.

After the second network device receives the indication information of the N fourth cells sent by the terminal device, a first cell may be determined from the N fourth cells.

In a possible implementation manner, N may be 1, and the second network device receives information of a cell sent by the terminal device, so that it may be determined that the first cell is the cell.

In a possible implementation manner, N may be an integer greater than 1, and then the second network device receives information of multiple cells sent by the terminal device, and may further determine the first cell from the multiple cells, specifically:

The second network device may determine the first cell according to the total number value of each of the N fourth cells, and may use a cell with a highest total number value among the N fourth cells as the first cell.

Since at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell, the N fourth cells are determined according to the measurement result of the third cell and the information of the third cell, and it can be ensured that the effective carrier of each cell in the N fourth cells has the carrier same as the effective carrier of the second cell, and then the second network device determines a first cell from the N fourth cells, and it can be ensured that the terminal device determines the carrier performing uplink transmission in the first cell as the first carrier, so that the terminal device does not need random access in the switching process, the uplink synchronization of the terminal device on the first carrier of the first cell is realized, and the communication efficiency can be improved.

607. The second network device sends request information for requesting the terminal device to access the first network device to the first network device.

After determining the first cell according to the indication information of the N fourth cells, the second network device may send request information for requesting the terminal device to access the first network device to the first network device. For a detailed description, reference may be made to the description of step 404, which is not described herein again.

608. The second network device sends second indication information for indicating the information of the first cell to the terminal device.

It should be understood that step 608 corresponds to step 405, and the related description in step 608 may refer to the description of step 405 above, and will not be repeated here to avoid repetition.

609. And determining that the carrier wave for uplink transmission of the terminal equipment in the first cell is the first carrier wave after the terminal equipment is switched from the second cell to the first cell.

It should be understood that step 609 corresponds to step 406, and the related description in step 609 can refer to the description of step 406, which is not repeated herein to avoid repetition.

610. The second network device sends the first information to the terminal device.

It should be understood that step 610 corresponds to step 407, and the related description in step 610 may refer to the description of step 407, and is not repeated herein to avoid repetition.

611. The terminal device determines a first TA value.

It should be understood that step 611 corresponds to step 408, and the related description in step 611 can refer to the description of step 408, and is not repeated herein to avoid repetition.

612. And the second network equipment sends third indication information used for indicating whether the second TA value is the same as the first TA value or not to the terminal equipment.

It should be understood that step 612 corresponds to step 409, and the related description in step 612 may refer to the description of step 409, and is not repeated here to avoid repetition.

613. The terminal device determines a second TA value.

It should be understood that step 613 corresponds to step 410, and the related description in step 613 can refer to the description of step 410, and will not be described again here to avoid repetition.

614. And the terminal equipment sends the second information to the first network equipment.

It should be understood that step 614 corresponds to step 411, and the related description in step 614 can refer to the description of step 411, and will not be repeated here to avoid repetition.

Referring to fig. 7 based on the above network architecture, fig. 7 is a schematic flowchart of another communication method according to an embodiment of the present application. In this application, the function performed by the terminal device may also be performed by a module (e.g., a chip) in the terminal device, the function performed by the first network device in this application may also be performed by a module (e.g., a chip) in the first network device, and the function performed by the second network device in this application may also be performed by a module (e.g., a chip) in the second network device. As shown in fig. 7, the communication method may include the following steps.

701. The second network device sends the measurement configuration to the terminal device.

It should be understood that step 701 corresponds to step 401, and the related description in step 701 may refer to the description of step 401, and is not repeated here to avoid repetition.

702. And the terminal equipment sends the measurement result of the fifth cell to the second network equipment.

It should be understood that step 702 corresponds to step 402, and the description of step 702 can refer to the description of step 402, and will not be repeated herein to avoid repetition.

703. The second network device determines the first cell according to the information of the third cell and the measurement result of the third cell.

It should be understood that step 703 corresponds to step 403, and the description of step 703 may refer to the description of step 403, and is not repeated herein to avoid repetition.

704. The second network device sends request information for requesting the terminal device to access the first network device to the first network device.

It should be understood that step 704 corresponds to step 404, and the related description in step 704 may refer to the description of step 404, which is not repeated herein to avoid redundancy.

705. The second network device sends second indication information for indicating the information of the first cell to the terminal device.

It should be understood that step 705 corresponds to step 405, and the related description in step 705 may refer to the description of step 405, and will not be repeated herein to avoid repetition.

706. And the second network equipment sends the third information to the terminal equipment.

Accordingly, the terminal device receives the third information sent by the second network device.

The third information may include first indication information and an ID of the first cell, and the first indication information may be used to instruct the terminal device to continue to send uplink transmission to the fourth network device. The terminal device may determine which cell the first cell to handover to is from the ID of the first cell. And determining to continue sending uplink transmission to the fourth network device in the first cell according to the first indication information, where the fourth network device is a network device that can receive the uplink transmission sent by the terminal device in the second cell.

In an embodiment, the second network device may send fourth indication information to the terminal device, where the fourth indication information may be used to indicate whether the terminal device skips random access in a handover process, and when the fourth indication information indicates that the terminal device skips random access in the handover process, the terminal device may determine to continue sending uplink transmission to the fourth network device in the first cell according to the first indication information.

In a possible implementation manner, when the second network device sends the third information, the method may further include continuing to send information of time resources for uplink transmission to the fourth network device, where the information of the time resources may include an uplink slot, a position of a subframe, and a ratio of the uplink slot to the downlink slot. Therefore, the terminal equipment can acquire the configuration information in advance.

707. The second network device sends the first information to the terminal device.

It should be understood that step 707 corresponds to step 407, and the related description in step 707 may refer to the description of step 407, and is not repeated here to avoid repetition.

708. The terminal device determines a first TA value.

After receiving the first information sent by the second network device, the terminal device may determine a first TA value according to the first information, the first sending timing, the downlink timing of the first cell, and the TA offset value of the first cell, where the first TA value is used to continue sending uplink transmission to the fourth network device.

It should be understood that step 708 corresponds to step 408, and the description of determining the first TA value in step 708 may refer to the description of step 408, and will not be repeated herein to avoid redundancy.

It is to be understood that T in step 408 _ttFor transmission of terminal equipment on the second carrierThen, in step 708, T_ttFor the first transmission timing, the first transmission timing may be a transmission timing at which the terminal device transmits uplink transmission in the second cell, and the first transmission timing may also be referred to as a first uplink timing.

Since the terminal device may continue to send the uplink transmission to the fourth network device in the first cell, that is, before the handover until after the handover, the terminal device may send the uplink transmission to the same network device, that is, the fourth network device, in the second cell and the first cell, the sending timing of the uplink transmission sent by the terminal device should be kept unchanged. When the first cell performs uplink transmission, the terminal device needs to refer to the downlink timing of the first cell, and does not need to refer to the downlink timing of the second cell any more, so that the terminal device continues to send the TA value according to the uplink transmission, that is, the first TA value, to the fourth network device, and needs to perform corresponding adjustment.

Specifically, the first information may be sent by the second network device to the terminal device, the first sending timing is determined by the terminal device, and the downlink timing of the first cell may be obtained by the terminal device by detecting SSB information or other reference signals of the first cell. Accordingly, the terminal device may determine the first TA value from the first information, the first transmission timing, the downlink timing of the first cell, and the TA offset value of the first cell. Therefore, the first TA value can be determined without random access, so that uplink synchronization of the terminal equipment in the first cell is realized, and the communication efficiency can be improved.

It should be understood that, in this embodiment of the present application, part or all of the first information, the third information, the second indication information, the fourth indication information, and the sixth indication information may be carried in an RRC message or a PDCCH message, and part or all of the information may be simultaneously issued to the terminal device by the second network device, or may be issued in time sequence, which is not limited in this application.

709. And the terminal equipment sends the uplink transmission information.

In the case that the fourth network device is the first network device, the terminal device may send uplink transmission information to the first network device; or in the case that the fourth network device is the second network device, the uplink transmission information may be sent to the second network device. The uplink transmission information may include second information, where the second information is used to confirm handover to the first network device, and the confirmation of handover may refer to that the terminal device is handed over from the second cell to the first cell.

Specifically, before the terminal device is switched, until after the terminal device is switched, the uplink transmission may be sent to the same network device, that is, the fourth network device, in the second cell and the first cell. If the fourth network device is the second network device, the terminal device may directly send the uplink transmission to the second network device; if the fourth network device is the first network device, the terminal device may send the uplink transmission directly to the first network device.

In one embodiment, the terminal device may further send uplink transmission according to the first TA value. Therefore, uplink synchronization of the terminal equipment in the first cell can be realized without random access. Therefore, the scheme provided by the application can effectively avoid the problems of time delay and interruption possibly generated in the process of switching the terminal equipment to the first cell, which needs random access, and can improve the communication efficiency.

The terminal device may keep sending the uplink transmission information to the fourth network device at the first TA value until the first network device or the first cell sends a message for modifying the first TA value to the terminal device.

In a possible implementation manner, the terminal device may assist the fourth network device in adjusting the first TA value by sending a periodic signal to the fourth network device.

In one embodiment, the second information may be an RRC reconfiguration complete message. The terminal device synchronizes to the first cell and completes the handover procedure by sending an RRC reconfiguration complete message to the fourth network device.

Referring to fig. 8, fig. 8 is a schematic flowchart illustrating another communication method according to an embodiment of the present disclosure. In this application, the function performed by the terminal device may also be performed by a module (e.g., a chip) in the terminal device, and the function performed by the first network device in this application may also be performed by a module (e.g., a chip) in the first network device. As shown in fig. 8, the communication method may include the following steps.

801. The second network device sends the measurement configuration to the terminal device.

It should be understood that step 801 corresponds to step 701, and the description of step 801 may refer to the description of step 701, and is not repeated herein to avoid redundancy.

802. And the terminal equipment determines the measurement result of the fifth cell according to the measurement configuration.

It should be understood that step 802 corresponds to step 602, and the related description in step 802 may refer to the description of step 602, and is not repeated herein to avoid repetition.

803. And the second network equipment sends the information of the third cell to the terminal equipment.

It should be understood that step 703 corresponds to step 603, and the related description in step 803 may refer to the description of step 603, and will not be repeated here to avoid repetition.

804. And the terminal equipment determines N fourth cells according to the information of the third cell and the measurement result of the third cell.

It should be understood that step 804 corresponds to step 604, and the related description in step 804 may refer to the description of step 604, and will not be repeated herein to avoid repetition.

805. And the terminal equipment sends the indication information of the N fourth cells to the second network equipment.

It should be understood that step 805 corresponds to step 605, and the related description in step 805 can refer to the description of step 605, and will not be repeated herein to avoid repetition.

806. And the second network equipment determines the first cell according to the indication information of the N fourth cells.

It should be understood that step 806 corresponds to step 606, and the description of step 806 can refer to the description of step 606, and is not repeated herein to avoid repetition.

807. The second network device sends request information for requesting the terminal device to access the first network device to the first network device.

It should be understood that step 807 corresponds to step 607, and the related description in step 807 can refer to the description of step 607, and will not be repeated here to avoid repetition.

808. The second network device sends second indication information for indicating the information of the first cell to the terminal device.

It should be understood that step 808 corresponds to step 705, and the related description in step 808 may refer to the description of step 705 above, and will not be repeated here to avoid repetition.

809. And the second network equipment sends the third information to the terminal equipment.

It should be understood that step 809 corresponds to step 706, and the related description in step 809 can refer to the description of step 706, and is not repeated herein to avoid repetition.

810. The second network device sends the first information to the terminal device.

It should be understood that step 810 corresponds to step 707, and the related description in step 810 may refer to the description of step 707, and is not repeated here to avoid repetition.

811. The terminal device determines a first TA value.

It should be understood that step 811 corresponds to step 708, and the related description in step 811 can refer to the description of step 708, and will not be repeated herein to avoid repetition.

812. And the terminal equipment sends the uplink transmission information.

It should be understood that step 812 corresponds to step 709, and the related description in step 811 can refer to the description of step 709 above, and will not be repeated here to avoid repetition.

Referring to fig. 9, fig. 9 is a schematic flowchart illustrating another communication method according to an embodiment of the present disclosure. In this application, the function performed by the terminal device may also be performed by a module (e.g., a chip) in the terminal device, the function performed by the first network device in this application may also be performed by a module (e.g., a chip) in the first network device, and the function performed by the second network device in this application may also be performed by a module (e.g., a chip) in the second network device. As shown in fig. 9, the communication method may include the following steps.

901. The second network device sends the measurement configuration to the terminal device.

It should be understood that step 901 corresponds to step 401, and the related description in step 901 may refer to the description of step 401, and is not repeated here to avoid repetition.

902. And the terminal equipment sends the measurement result of the fifth cell to the second network equipment.

It should be understood that step 902 corresponds to step 402, and the related description in step 902 may refer to the description of step 402, which is not repeated herein to avoid repetition.

903. And the second network equipment determines the first cell according to the information of the third cell and the measurement result of the fifth cell.

After receiving the measurement result of the fifth cell sent by the terminal device, the second network device may first determine whether a third cell exists in the fifth cell, where the third cell may be a cell in which at least one same carrier exists as an active carrier of the second cell, and when the third cell exists in the fifth cell, the first cell may be determined according to information of the third cell and the measurement result of the third cell, where the information of the third cell is known by the second network device, and since the third cell is at least one cell in the fifth cell, the measurement result of the third cell may be obtained from the measurement result of the fifth cell reported by the terminal device, and therefore the second network device may determine the first cell according to the measurement result of the third cell and the information of the third cell; in the case where the third cell does not exist in the fifth cell, the first cell may be determined according to a measurement result of the fifth cell. Specifically, the method comprises the following steps:

In a possible implementation manner, when a third cell exists in the fifth cell, the second network device may preferentially select a cell in the third cell as the first cell, and the specific determination of the first cell according to the information of the third cell and the measurement result of the third cell may refer to the description in step 403, which is not described herein again.

Although the carrier having the same effective carrier of each cell in the third cell as the effective carrier of the second cell may be preferentially selected as the first cell, if the measurement result of each cell is not good, the first cell determined from the third cell does not meet the condition for handover of the terminal device, as compared with the determination of the first cell only from the measurement result of the third cell and the information of the third cell.

Therefore, if the measurement result of each cell in the third cell is poor, the sixth cell may be selected again, and the first cell is determined again according to the measurement result of the sixth cell, where the sixth cell may be a cell other than the third cell in the fifth cell, and the sixth cell may include a cell in which the effective carrier does not intersect with the effective carrier of the second cell, but does not intersect with the effective carrier of the cell other than the second cell, or may include a cell in which the effective carrier does not intersect with the effective carrier of the second cell and the effective carrier of the cell other than the second cell.

In one embodiment, the second network device preferentially selects a cell in the sixth cell, in which the effective carrier does not intersect with the effective carrier of the second cell, but intersects with effective carriers of other cells except the second cell, as the first cell. For example, if the active carriers of some of the sixth cells include SUL carriers, and the SUL carriers are shared by other cells except the second cell, and the active carriers of some of the sixth cells do not include SUL carriers, the second network device may preferentially select a cell with a SUL carrier in the active carriers. If the cell without the SUL carrier in the effective carrier is selected as the first cell, the terminal equipment cannot utilize the SUL carrier to carry out uplink continuity during the next switching, and if the cell with the SUL carrier in the effective carrier is selected as the first cell, the terminal equipment can also continue to use the SUL carrier to carry out uplink continuity during the next switching, so that the time delay and interruption caused by random access during the switching are avoided.

In one possible implementation, in a case that the third cell does not exist in the fifth cell, the second network device may determine the first cell according to a measurement result of the fifth cell.

In one embodiment, the measurement result of the fifth cell may be quantified, and the first cell may be determined based on the measurement result values of each of the fifth cells. For example, the first cell may be a cell having the highest measurement result value.

In an embodiment, if the first cell is one of the third cells, the method in steps 404 to 411 or the method in steps 704 to 709 may be further performed, so that, in the handover process, no random access is needed, uplink synchronization of the terminal device in the first cell may be achieved, and the efficiency of communication may be improved.

Referring to fig. 10, fig. 10 is a schematic flow chart of another communication method according to an embodiment of the present application. In this application, the function performed by the terminal device may also be performed by a module (e.g., a chip) in the terminal device, and the function performed by the first network device in this application may also be performed by a module (e.g., a chip) in the first network device. As shown in fig. 10, the communication method may include the following steps.

1001. The second network device sends the measurement configuration to the terminal device.

It should be understood that step 1001 corresponds to step 601, and the related description in step 1001 may refer to the description of step 601, which is not repeated herein to avoid redundancy.

1002. And the terminal equipment determines the measurement result of the fifth cell according to the measurement configuration.

It should be understood that step 1002 corresponds to step 602, and the related description in step 902 may refer to the description of step 602, which is not repeated herein to avoid repetition.

1003. And the second network equipment sends the information of the third cell to the terminal equipment.

It should be understood that step 1003 corresponds to step 603, and the related description in step 1003 may refer to the description of step 603, and is not repeated here to avoid repetition.

1004. And the terminal equipment determines N fourth cells according to the information of the third cell and the measurement result of the fifth cell.

After receiving the information of the third cell sent by the second network device, the terminal device may first determine whether the fifth cell has the third cell, and may determine, when the fifth cell has the third cell, N fourth cells according to the information of the third cell and the measurement result of the third cell, where the information of the third cell is issued by the second network device to the terminal device, and since the third cell is at least one cell in the fifth cell and the measurement result of the third cell is obtainable from the measurement result of the fifth cell, the terminal device may determine the N fourth cells according to the measurement result of the third cell and the information of the third cell; in the case where the third cell does not exist in the fifth cells, N fourth cells may be determined according to the measurement result of the fifth cell. Specifically, the method comprises the following steps:

In a possible implementation manner, in a case that a third cell exists in the fifth cell, the terminal device may preferentially select a cell in the third cell as N fourth cells, and the step 604 may be referred to for determining the N fourth cells according to information of the third cell and a measurement result of the third cell, which is not described herein again.

Compared with the determination of the N fourth cells only according to the measurement result of the third cell and the information of the third cell, although the carrier with the same effective carrier of each cell in the third cell and the effective carrier of the second cell can be preferentially selected as the N fourth cells, if the measurement result of each cell is not good, the first cell determined from the N fourth cells does not meet the condition of the handover of the terminal device.

Therefore, if the measurement result of each cell in the third cell is poor, the sixth cell may be selected again, and N fourth cells are determined again according to the measurement result of the sixth cell, where the sixth cell may be another cell in the fifth cell except the third cell, and the sixth cell may include a cell in which the effective carrier does not intersect with the effective carrier of the second cell, but does not intersect with the effective carrier of another cell except the second cell, or may include a cell in which the effective carrier does not intersect with the effective carrier of the second cell and the effective carrier of another cell except the second cell.

In one embodiment, the terminal device preferentially selects, as the N fourth cells, a cell in the sixth cell in which the effective carrier does not intersect with the effective carrier of the second cell but intersects with effective carriers of cells other than the second cell. For example, if the active carriers of some of the sixth cells include SUL carriers, and the SUL carriers are shared by other cells except the second cell, and the active carriers of some of the sixth cells do not include SUL carriers, the terminal device may preferentially select the cell with the SUL carrier in the active carriers as the N fourth cells. Because the first cell is one of the N fourth cells, if a cell without the SUL carrier in the effective carrier is selected as the N fourth cells, the terminal device cannot perform uplink continuity by using the SUL carrier at the next handover, and if a cell with the SUL carrier in the effective carrier is selected as the N fourth cells, the terminal device can continue to perform uplink continuity by using the SUL carrier at the next handover, thereby avoiding delay and interruption caused by random access during the handover.

In a possible implementation manner, in a case that the third cell does not exist in the fifth cells, the terminal device may determine N fourth cells according to a measurement result of the fifth cells.

In one embodiment, the measurement result of the fifth cell may be quantified, and the N fourth cells may be determined from the measurement result values of each of the fifth cells. For example, the N fourth cells may be cells whose measurement result values are greater than a certain threshold value.

1005. And the terminal equipment sends the indication information of the N fourth cells to the second network equipment.

It should be understood that step 1005 corresponds to step 605, and the related description in step 1005 may refer to the description of step 605, and will not be repeated herein to avoid repetition.

1006. And the second network equipment determines the first cell according to the indication information of the N fourth cells.

It should be understood that step 1006 corresponds to step 606, and the description of step 1006 may refer to the description of step 606, and is not repeated herein to avoid repetition.

In an embodiment, if the first cell is one of the third cells, the method in steps 607 to 614 or the method in steps 704 to 709 may be further performed, so that, in the handover process, no random access is needed, uplink synchronization of the terminal device in the first cell may be achieved, and the efficiency of communication may be improved.

Referring to fig. 11 in an embodiment of the communication method in conjunction with fig. 4 and fig. 6, fig. 11 is a schematic view of a handover scenario provided in the embodiment of the present application. As shown in fig. 11, the scenario includes a cell of site 1 and a cell of site 2, and a site can be understood as a site. Wherein, the cell of the station 1 has a NUL carrier and a DL carrier corresponding to the NUL carrier; the cell of the station 2 has a NUL carrier, and a DL carrier and a SUL carrier corresponding to the NUL carrier. The SUL carrier covers part or all of the cells of site 1, i.e. part or all of the cells of site 1 and the cells of site 2 have the SUL carrier.

The terminal device is handed over from the cell of site 2 to the cell of site 1.

The cell in site 1 having the SUL carrier may be a first cell, and the cell in site 2 may be a second cell. The first cell may perform the method of steps 401 to 403 or the method of steps 601 to 606. The network device of the station 2 may be the second network device mentioned in the above method embodiment, and the network device of the station 1 may be the first network device mentioned in the above method embodiment.

The terminal device switches from the second cell to the first cell, and may determine that the SUL carrier of the terminal device in the first cell is the SUL carrier of the terminal device in the second cell, that is, before and after the switching, the SUL carriers of the terminal device in the first cell and the second cell may be carriers of the same frequency band, and uplink transmissions sent by the SUL carriers of the terminal device in the first cell and the second cell are received by the same network device. The terminal device may send uplink transmission to the network device of site 2 on the SUL carrier. Specifically, the method comprises the following steps:

before the terminal equipment is switched, the SUL carrier of the second cell and the second cell are co-sited. When the terminal device sends information to the network device of site 2 or the second cell on the SUL carrier of the second cell, the terminal device may send uplink transmission including the information to the network device of site 2 or the second cell, and the network device of site 2 may send downlink transmission to the terminal device.

After the terminal equipment is switched, the SUL carrier of the first cell and the first cell are different station addresses. This information that the SUL carrier of the first cell is different from the first cell in site may be notified to the terminal device by the network device of the station 2 through an RRC message, or a PDCCH message, or a system message. For example, the system message may be an on-demand system message. Because the terminal device determines that the SUL carrier in the first cell is the SUL carrier of the terminal device in the second cell, when the terminal device sends information to the network device of the site 1 or the first cell on the SUL carrier of the first cell, the terminal device may first send uplink transmission including the information to the network device of the site 2 on the SUL carrier of the first cell, and then the network device of the site 2 sends the information to the network device of the site 1 or the first cell, for example, the network device of the site 2 may send the information to the network device of the site 1 or the first cell through a backhaul, and the network device of the site 1 may send downlink transmission to the terminal device.

In an embodiment, when the network device of the site 2 determines that the first TA value needs to be adjusted, the first TA value may be a TA value of an SUL carrier of the terminal device in the first cell, the network device of the site 1 may send an adjustment amount of the first TA value to the network device of the site 1 through a backhaul, and the network device of the site 1 sends a signaling to the terminal device to notify the terminal device of adjusting the first TA value. The terminal device may assist the network device of the station 2 in adjusting the first TA value by sending a periodic signal to the network device of the station 2.

In an embodiment, when the network device of the station 1 determines that the second TA value needs to be adjusted, the second TA value may be a TA value of a NUL carrier of the terminal device in the first cell, and the network device of the station 1 may send a signaling to the terminal device to notify the terminal device of adjusting the second TA value. The terminal device may assist the network device of the station 1 in adjusting the second TA value by sending a periodic signal to the network device of the station 1.

Because the SUL carrier in the first cell and the first cell are different sites, the NUL carrier in the first cell and the SUL carrier in the first cell of the terminal device are not in the same site, the transmission paths of the two carriers are different, the distances between the terminal device and the network device at site 1 and the network device at site 2 are different, and the first TA value and the second TA value are independent. Therefore, there is a need to independently indicate and/or adjust the first and second TA values. The terminal device may adjust the first TA value and the second TA value respectively through two signaling sent by the network device of the site 1 or the first cell, or may adjust the first TA value and the second TA value respectively through different fields of one signaling sent by the network device of the site 1 or the first cell.

In combination with the communication methods of fig. 7 and fig. 8, in an embodiment, as shown in fig. 11, the first cell may perform the method of steps 701 to 703 or the method of steps 801 to 806. The terminal device switches from the second cell to the first cell, and may determine that the terminal device continues to send uplink transmission to the network device of the site 2, that is, before switching until after switching, the terminal device may send uplink transmission to the same network device, that is, the network device of the site 2, in the first cell and the second cell. Specifically, the method comprises the following steps:

Before the terminal device is switched, the second cell and the network device of the site 2 are co-sited. When the second cell sends information to the network device of site 2 or the second cell, the terminal device may send uplink transmission including the information to the network device of site 2 or the second cell, and the network device of site 2 may send downlink transmission to the terminal device.

After the terminal device is switched, the first cell and the network device of the site 2 are in different sites. This information that the first cell is an alien site to the network device of station 2 may be notified to the terminal device by the network device of station 2 through an RRC message or a PDCCH message or a system message. For example, the system message may be an on-demand system message. Since the terminal device continues to send the uplink transmission to the network device of the site 2 in the first cell, when the terminal device sends information to the network device of the site 1 or the first cell in the first cell, the terminal device may first send the uplink transmission including the information to the network device of the site 2 in the first cell, and then the network device of the site 2 sends the information to the network device of the site 1 or the first cell through the backhaul, and the network device of the site 1 may send the downlink transmission to the terminal device.

In one implementation, when the network device of the site 2 determines that the first TA value needs to be adjusted, the first TA value is used to continue to send uplink transmission to the network device of the site 2, the adjusted amount of the first TA value may be sent to the network device of the site 1 through a backhaul, and the network device of the site 1 sends a signaling to the terminal device to notify the terminal device of adjusting the first TA value. The terminal device may assist the network device of the station 2 in adjusting the first TA value by sending a periodic signal to the network device of the station 2.

Referring to fig. 12 in an embodiment of a communication method in conjunction with fig. 4 and fig. 6, fig. 12 is a schematic view of another handover scenario provided in the embodiment of the present application. As shown in fig. 12, the scenario includes a cell of a site 1 and a cell of a site 2, where the cell of the site 1 has a NUL carrier and a DL carrier corresponding to the NUL carrier; the cell of the station 2 has a NUL carrier, and a DL carrier and a SUL carrier corresponding to the NUL carrier. The SUL carrier covers part or all of the cells of site 1, i.e. part or all of the cells of site 1 and the cells of site 2 have the SUL carrier.

The terminal device is handed over from the cell of site 1 to the cell of site 2.

The cell of site 2 may be a first cell and the cell of site 1 having the SUL carrier may be a second cell. The first cell may perform the method of steps 401 to 403 or the method of steps 601 to 606. The network device of the station 1 may be the second network device mentioned in the above method embodiment, and the network device of the station 2 may be the first network device mentioned in the above method embodiment.

before the terminal equipment is switched, the SUL carrier of the second cell and the second cell are different station addresses. When the terminal device sends information to the network device of site 1 or the second cell on the SUL carrier of the second cell, the terminal device may first send uplink transmission including the information to the network device of site 2 on the SUL carrier of the second cell, and then the network device of site 2 sends the information to the network device of site 1 or the second cell, for example, the network device of site 2 may send the information to the network device of site 1 or the second cell through a backhaul, and the network device of site 1 may send downlink transmission to the terminal device.

After the terminal equipment is switched, the SUL carrier of the first cell and the first cell are co-sited. This information that the SUL carrier of the first cell is co-sited with the first cell may be notified to the terminal device by the network device of station 1 through an RRC message or a PDCCH message or a system message. For example, the system message may be an on-demand system message. Because the terminal device determines that the SUL carrier in the first cell is the SUL carrier of the terminal device in the second cell, when the terminal device sends information to the network device of the site 2 or the first cell on the SUL carrier of the first cell, the terminal device may send uplink transmission including the information to the network device of the site 2 or the first cell, and the network device of the site 2 may send downlink transmission to the terminal device.

In an embodiment, when the network device of the station 2 determines that the first TA value needs to be adjusted, the first TA value may be a TA value of an SUL carrier of the terminal device in the first cell, and the network device of the station 2 may send a signaling to the terminal device to notify the terminal device of adjusting the first TA value. The terminal device may assist the network device of the station 2 in adjusting the first TA value by sending a periodic signal to the network device of the station 2.

In an embodiment, when the network device of the station 2 determines that the second TA value needs to be adjusted, the second TA value may be a TA value of a NUL carrier of the terminal device in the first cell, and the network device of the station 2 may send a signaling to the terminal device to notify the terminal device of adjusting the second TA value. The terminal device may assist the network device of the station 2 in adjusting the second TA value by sending a periodic signal to the network device of the station 2.

Since the SUL carrier in the first cell and the first cell are co-sited, the NUL carrier in the first cell and the SUL carrier in the first cell of the terminal device are in the same site, the transmission paths of the two carriers are the same, and the first TA value and the second TA value may be the same. Thus, the first and second TA values need not be independently indicated and/or adjusted. The terminal device may adjust the first TA value and the second TA value through a signaling sent by the network device of the station 2 or the first cell.

In combination with the communication methods of fig. 7 and fig. 8, in an embodiment, as shown in fig. 12, the first cell may perform the method of steps 701 to 703 or the method of steps 801 to 806. The terminal device switches from the second cell to the first cell, and may determine that the terminal device continues to send uplink transmission to the network device of the site 2, that is, before switching until after switching, the terminal device may send uplink transmission to the same network device, that is, the network device of the site 2, in the first cell and the second cell. Specifically, the method comprises the following steps:

Before the terminal device is switched, the second cell and the network device of the site 2 are in different sites. When the terminal device sends information to the network device of site 1 or the second cell in the second cell, the terminal device may first send uplink transmission including the information to the network device of site 2 in the second cell, and then the network device of site 2 sends the information to the network device of site 1 or the second cell, for example, the network device of site 2 may send the information to the network device of site 1 or the second cell through a backhaul, and the network device of site 1 may send downlink transmission to the terminal device.

After the terminal device is switched, the first cell and the network device of the site 2 are co-sited. This information that the first cell is co-sited with the network device of station 2 may be notified to the terminal device by the network device of station 1 via an RRC message or a PDCCH message or a system message. For example, the system message may be an on-demand system message. Since the terminal device continues to send the uplink transmission to the network device of the site 2 in the first cell, when the first cell sends the information to the network device of the site 2 or the first cell, the terminal device may send the uplink transmission including the information to the network device of the site 2 or the first cell, and the network device of the site 2 may send the downlink transmission to the terminal device.

In an embodiment, when the network device of the station 2 determines that the first TA value needs to be adjusted, the first TA value is used to continue to send uplink transmission to the network device of the station 2, and the network device of the station 2 may send a signaling to the terminal device to notify the terminal device of adjusting the first TA value. The terminal device may assist the network device of the station 2 in adjusting the first TA value by sending a periodic signal to the network device of the station 2.

In an embodiment, please refer to fig. 13, and fig. 13 is a schematic view of a further switching scenario provided in the embodiment of the present application. As shown in fig. 13, the scenario includes a cell of a site 1, a cell of a site 2, and a cell of a site 3, where the cell of the site 1 has a NUL carrier and a DL carrier corresponding to the NUL carrier; a cell of the site 2 is provided with a NUL carrier, a DL carrier and a SUL carrier corresponding to the NUL carrier; the cell of the station 3 has a NUL carrier and a DL carrier corresponding to the NUL carrier. The SUL carrier covers part or all of the cells of site 1 and part or all of the cells of site 3, i.e. part or all of the cells of site 1 and part or all of the cells of site 3 have the SUL carrier.

When the terminal device communicates in the cell of site 1, if it needs to perform handover, when the downlink quality of the cells of site 2 and site 3 is equal or has a small difference, the cell of site 2 may be preferentially selected as the first cell, so that the SUL carrier after handover shares the site with the first cell.

The terminal device may switch from the cell of the site 1 to the cell of the site 2, please refer to the detailed description of fig. 12 above in conjunction with the communication methods and specific embodiments of fig. 4, fig. 6, fig. 7, and fig. 8, and details thereof are not repeated herein.

Referring to fig. 14 in an embodiment of the communication method in conjunction with fig. 4 and fig. 6, fig. 14 is a schematic view of a further handover scenario provided in the embodiment of the present application. As shown in fig. 14, the scenario includes a cell of a site 1, a cell of a site 2, and a cell of a site 3, where the cell of the site 1 has a NUL carrier and a DL carrier corresponding to the NUL carrier; a cell of the site 2 is provided with a NUL carrier, a DL carrier and a SUL carrier corresponding to the NUL carrier; the cell of the station 3 has a NUL carrier and a DL carrier corresponding to the NUL carrier. The SUL carrier covers part or all of the cells of site 1 and part or all of the cells of site 3, i.e. part or all of the cells of site 1 and part or all of the cells of site 3 have the SUL carrier.

The terminal device is handed over from the cell of site 1 to the cell of site 3.

The cell having the SUL carrier in the station 3 may be a first cell, the cell having the SUL carrier in the station 1 may be a second cell, and the first cell may be obtained by performing the method of steps 401 to 403 or the method of steps 601 to 606. The network device of the station 1 may be the second network device mentioned in the above method embodiment, and the network device of the station 3 may be the first network device mentioned in the above method embodiment.

After the terminal equipment is switched, the SUL carrier of the first cell and the first cell are different station addresses. The information that the SUL carrier of the first cell and the first cell are different sites may be notified to the terminal device by the network device of the station 1 through an RRC message, a PDCCH message, or a system message. For example, the system message may be an on-demand system message. Because the terminal device determines that the SUL carrier in the first cell is the SUL carrier of the terminal device in the second cell, when the terminal device sends information to the network device of the site 3 or the first cell on the SUL carrier of the first cell, the terminal device may first send uplink transmission including the information to the network device of the site 2 on the SUL carrier of the first cell, and then the network device of the site 2 sends the information to the network device of the site 3 or the first cell, for example, the network device of the site 2 may send the information to the network device of the site 3 or the first cell through a backhaul, and the network device of the site 3 may send downlink transmission to the terminal device.

In an embodiment, when the network device of the site 2 determines that the first TA value needs to be adjusted, the first TA value may be a TA value of an SUL carrier of the terminal device in the first cell, the network device of the site 3 may send an adjustment amount of the first TA value to the network device of the site through a backhaul, and the network device of the site 3 sends a signaling to the terminal device to notify the terminal device of adjusting the first TA value. The terminal device may assist the network device of the station 2 in adjusting the first TA value by sending a periodic signal to the network device of the station 2.

In an embodiment, when the network device of the station 3 determines that the second TA value needs to be adjusted, the second TA value may be a TA value of a NUL carrier of the terminal device in the first cell, and the network device of the station 3 may send a signaling to the terminal device to notify the terminal device of adjusting the second TA value. The terminal device may assist the network device of the station 3 in adjusting the second TA value by sending a periodic signal to the network device of the station 3.

Because the SUL carrier in the first cell and the first cell are different sites, the NUL carrier in the first cell and the SUL carrier in the first cell of the terminal device are not in the same site, the transmission paths of the two carriers are different, the distances between the terminal device and the network device at the site 3 and the network device at the site 2 are different, and the first TA value and the second TA value are independent. Therefore, there is a need to independently indicate and/or adjust the first and second TA values. The terminal device may adjust the first TA value and the second TA value respectively through two signaling sent by the network device of the station 3 or the first cell, or may adjust the first TA value and the second TA value respectively through different fields of one signaling sent by the network device of the station 3 or the first cell.

In combination with the communication methods of fig. 7 and fig. 8, in an embodiment, as shown in fig. 14, the first cell may perform the method of steps 701 to 703 or the method of steps 801 to 806. The terminal device switches from the second cell to the first cell, and may determine that the terminal device continues to send uplink transmission to the network device of the site 2, that is, before switching until after switching, the terminal device may send uplink transmission to the same network device, that is, the network device of the site 2, in the first cell and the second cell. Specifically, the method comprises the following steps:

After the terminal device is switched, the first cell and the network device of the site 2 are in different sites. This information that the network device of the first cell and the station 2 are different sites may be notified to the terminal device by the network device of the station 1 through an RRC message or a PDCCH message or a system message. For example, the system message may be an on-demand system message. Since the terminal device continues to send the uplink transmission to the network device of the site 2 in the first cell, when the terminal device sends information to the network device of the site 3 or the first cell in the first cell, the terminal device may first send the uplink transmission including the information to the network device of the site 2 in the first cell, and then the network device of the site 2 sends the information to the network device of the site 3 or the first cell through the backhaul, and the network device of the site 3 may send the downlink transmission to the terminal device.

In one implementation, when the network device of the site 2 determines that the first TA value needs to be adjusted, the first TA value is used to continue to send uplink transmission to the network device of the site 2, the adjusted amount of the first TA value may be sent to the network device of the site 3 through a backhaul, and the network device of the site 3 sends a signaling to the terminal device to notify the terminal device of adjusting the first TA value. The terminal device may assist the network device of the station 2 in adjusting the first TA value by sending a periodic signal to the network device of the station 2.

Referring to fig. 15 in an embodiment of the communication method in conjunction with fig. 4 and fig. 6, fig. 15 is a schematic view of a further handover scenario provided in the embodiment of the present application. As shown in fig. 15, the scenario includes a site, a cell 1 in the site, and a cell 2 in the site, where the site has a NUL carrier, and a DL carrier and a SUL carrier corresponding to the NUL carrier.

It should be understood that in the embodiment of the present application, one network device may correspond to one or more cells. The second cell and the first cell may belong to the same network device, that is, the first network device and the second network device may be the same network device. In this case, the terminal device performs handover within the network device.

And the terminal equipment is switched from the cell 1 to the cell 2, and the cell 1 and the cell 2 belong to the same site.

Cell 1 may be a second cell, cell 2 may be a first cell, and cell 1 and cell 2 correspond to the same network device. The first cell may perform the method of steps 401 to 403 or the method of steps 601 to 606.

The terminal device switches from the second cell to the first cell, and may determine that the SUL carrier of the terminal device in the first cell is the SUL carrier of the terminal device in the second cell, that is, before and after the switching, the SUL carriers of the terminal device in the first cell and the second cell may be carriers of the same frequency band, and uplink transmissions sent by the SUL carriers of the terminal device in the first cell and the second cell are received by the same network device. The terminal device may send uplink transmission to the network device of the station on the SUL carrier. Specifically, the method comprises the following steps:

before the terminal equipment is switched, the SUL carrier of the second cell and the second cell are co-sited. When the terminal device sends information to the network device of the site or the second cell on the SUL carrier of the second cell, the terminal device may send uplink transmission including the information to the network device of the site or the second cell, and the network device of the site may send downlink transmission to the terminal device.

After the terminal equipment is switched, the SUL carrier of the first cell and the first cell are co-sited. The information that the SUL carrier of the first cell and the first cell are co-sited may be notified to the terminal device by the network device of the station through an RRC message, or a PDCCH message, or a system message. For example, the system message may be an on-demand system message. Because the terminal device determines that the SUL carrier in the first cell is the SUL carrier of the terminal device in the second cell, when the terminal device sends information to the network device of the site or the first cell on the SUL carrier of the first cell, the terminal device may send uplink transmission including the information to the network device of the site or the first cell, and the network device of the site may send downlink transmission to the terminal device.

In an embodiment, when the network device of the station determines that the first TA value needs to be adjusted, the first TA value may be a TA value of an SUL carrier of the terminal device in the first cell, and the network device of the station may send a signaling to the terminal device to notify the terminal device of adjusting the first TA value. The terminal device may assist the network device of the station in adjusting the first TA value by sending a periodic signal to the network device of the station.

In an embodiment, when the network device of the station determines that the second TA value needs to be adjusted, the second TA value may be a TA value of a NUL carrier of the terminal device in the first cell, and the network device of the station may send a signaling to the terminal device to notify the terminal device of adjusting the second TA value. The terminal device may assist the network device of the station in adjusting the second TA value by sending a periodic signal to the network device of the station.

Since the SUL carrier in the first cell and the first cell are co-sited, the NUL carrier in the first cell and the SUL carrier in the first cell of the terminal device are in the same site, the transmission paths of the two carriers are the same, and the first TA value and the second TA value may be the same. Thus, the first and second TA values need not be independently indicated and/or adjusted. The terminal device may adjust the first TA value and the second TA value through a signaling sent by the network device of the station or the first cell.

In combination with the communication methods of fig. 7 and fig. 8, in an embodiment, as shown in fig. 15, the first cell may perform the method of steps 701 to 703 or the method of steps 801 to 806. The terminal device switches from the second cell to the first cell, and may determine that the terminal device continues to send uplink transmission to the network device of the site, that is, before switching until after switching, the terminal device may send uplink transmission to the same network device, that is, the network device of the site, in the first cell and the second cell. Specifically, the method comprises the following steps:

before the terminal equipment is switched, the second cell and the network equipment of the site are co-sited. When the second cell sends information to the network device of the site or the second cell, the terminal device may send uplink transmission including the information to the network device of the site or the second cell, and the network device of the site may send downlink transmission to the terminal device.

After the terminal equipment is switched, the first cell and the network equipment of the site are co-sited. This information that the first cell is co-sited with the network equipment of the station may be notified to the terminal equipment by the network equipment of the station by an RRC message or a PDCCH message or a system message. For example, the system message may be an on-demand system message. Because the terminal device continues to send the uplink transmission to the network device of the site in the first cell, when the first cell sends the information to the network device of the site or the first cell, the terminal device may send the uplink transmission including the information to the network device of the site or the first cell, and the network device of the site may send the downlink transmission to the terminal device.

In an embodiment, when the network device of the station determines that the first TA value needs to be adjusted, the first TA value is used to continue to send uplink transmission to the network device of the station, and the network device of the station may send a signaling to the terminal device to notify the terminal device of adjusting the first TA value. The terminal device may assist the network device of the station in adjusting the first TA value by sending a periodic signal to the network device of the station.

Based on the above network architecture, please refer to fig. 16, and fig. 16 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication device may be a terminal device, or may be a module (e.g., a chip) in the terminal device. As shown in fig. 16, the communication apparatus 1600 includes at least: a processing unit 1601 and a transceiving unit 1602; wherein:

A processing unit 1601, configured to determine that a carrier in the first cell where the terminal device performs uplink transmission is a first carrier after the terminal device is handed over from the second cell to the first cell; the first carrier and the second carrier belong to the same frequency band, and the second carrier is a carrier of the terminal device in a second cell.

In an embodiment, the processing unit 1601 is further configured to determine a first TA value according to a transmission timing of the terminal device on the second carrier, a downlink timing of the first cell, and a TA offset value of the first cell, where the first TA value is a TA value of the terminal device on the first carrier.

In one embodiment, the same carrier as the second carrier is present in the active carriers of the first cell.

In one embodiment, the terminal device switches to the second carrier in the second cell when the carrier of the terminal device in the second cell is a third carrier and the same carrier as the third carrier does not exist in the active carrier of the first cell.

In one embodiment, the communication device further comprises:

a transceiver unit 1602, configured to receive first indication information sent by a second network device, where the first indication information is used to indicate that a carrier used by the terminal device to perform uplink transmission in the first cell is the first carrier, and the second network device is a network device corresponding to the second cell.

In an embodiment, the transceiver unit 1602 is further configured to receive first information sent by a second network device, where the first information includes a TA offset value of the first cell.

In one embodiment, the first information further comprises: at least one of a time slot offset value between the first cell and the second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell;

the processing unit 1601, according to the transmission timing of the terminal device on the second carrier, the downlink timing of the first cell, and the TA offset value of the first cell, determining the first TA value includes: and determining a first TA value according to the sending timing of the terminal equipment in the second carrier, the downlink timing of the first cell and the first information.

In one embodiment, the first TA value may satisfy the following equation:

or

Or

Or

Or

Wherein N is_TAIs the first TA value, T_ttTiming of transmission of the terminal device on the second carrier, T being downlink timing of the first cell, N _TA-offsetIs TA offset value, T, of the first cell_C＝1/(Δf_max·N_f)，Δf_max＝480·10³Hz and N_f＝4096，T_slot-offsetIs a slot offset value, T, between the first cell and the second cell_sfn-offsetIs a system frame number offset value, the T, between the first cell and the second cell_Fb-offsetIs a frame boundary offset value between the first cell and the second cell.

In an embodiment, the transceiver unit 1602 is further configured to receive second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell.

In an embodiment, the transceiver unit 1602 is further configured to receive a measurement configuration sent by the second network device; reporting a measurement result of a fifth cell to the second network equipment according to the measurement configuration; the third cell is at least one cell in the fifth cells.

In an embodiment, the processing unit 1601 is further configured to determine N fourth cells according to a measurement result of the third cell and information of the third cell, where N is an integer greater than or equal to 1, and there is at least one same carrier for an active carrier of the third cell and an active carrier of the second cell;

The transceiver unit 1602, is further configured to send the indication information of the N fourth cells to the second network device; receiving second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell, and the first cell is one of the N fourth cells.

In one embodiment, the processing unit 1601, determining N fourth cells according to the measurement result of the third cell and the information of the third cell includes: determining the priority corresponding to each cell in the third cell according to the information of the third cell; and determining the N fourth cells according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In an embodiment, the transceiver unit 1602 is further configured to receive a measurement configuration sent by the second network device;

the processing unit 1601 is further configured to determine a measurement result of a fifth cell according to the measurement configuration.

In an embodiment, the transceiver unit 1602 is further configured to receive information of the third cell sent by the second network device, where the third cell is at least one cell in the fifth cells.

In an embodiment, the transceiver unit 1602 is further configured to send second information on the first carrier, where the second information is used to confirm handover to the first network device, and the first network device is a network device corresponding to the first cell.

In an embodiment, the transceiver unit 1602 is further configured to receive third indication information sent by the second network device, where the third indication information is used to indicate whether a second TA value is the same as the first TA value, where the second TA value is a TA value of the terminal device in a fourth carrier, and the fourth carrier is a carrier of the terminal device in the first cell, which is different from the first carrier.

In an embodiment, the transceiving unit 1602 is further configured to send second information on the fourth carrier, where the second information is used to confirm the handover to the first network device.

It is understood that the processing unit 1601 in the embodiments of the present application may be implemented by a processor or a processor-related circuit component, and the transceiver unit 1602 may be implemented by a transceiver or a transceiver-related circuit component.

Referring to fig. 17 based on the above network architecture, fig. 17 is a schematic structural diagram of another communication device according to an embodiment of the present application. As shown in fig. 17, the communication device 1700 may include a processor 1701, a memory 1702, a transceiver 1703, and a bus 1704. The memory 1702 may be self-contained and may be coupled to the processor 1701 via the bus 1704. The memory 1702 may also be integrated with the processor 1701. The memory 1702 stores instructions or program codes therein, and may also store data. The processor 1701 is used to execute instructions or program code stored in the memory 1702. A bus 1704 is used to enable connections between these components. In fig. 17, the bus lines are shown by thick lines, and the connection manner between other components is merely illustrative and not limited thereto. The bus 1704 may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 17, but this does not mean only one bus or one type of bus.

When the instructions or program codes stored in the memory 1702 are executed, the processor 1701 is configured to perform the operations performed by the processing unit 1601 in the above embodiments, and the transceiver 1703 is configured to perform the operations performed by the transceiver 1602 in the above embodiments.

It should be noted that the

communication apparatus

1600 or 1700 in the embodiment of the present application may correspond to the terminal device in the method embodiment provided in the present application, and operations and/or functions of each module in the

communication apparatus

1600 or 1700 may respectively implement corresponding flows of each method in fig. 4 and fig. 6, which is not described herein again for brevity.

Referring to fig. 18, based on the network architecture, fig. 18 is a schematic structural diagram of another communication device according to an embodiment of the present application. The communication device may be the second network device, or may be a module (e.g., a chip) in the second network device. As shown in fig. 18, the communication device 1800 includes at least: a transceiving unit 1801 and a processing unit 1802; wherein:

a transceiving unit 1801, configured to send first indication information to a terminal device, where the first indication information is used to indicate that a carrier for uplink transmission of the terminal device in the first cell is a first carrier, where the first carrier and a second carrier belong to a same frequency band, and the second carrier is a carrier of a second cell.

In an embodiment, the transceiving unit 1801 is further configured to send first information to the terminal device, where the first information includes a TA offset value of the first cell.

In one embodiment, the first information further comprises: at least one of a time slot offset value between the first cell and the second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell.

In one embodiment, the communication device further comprises:

a processing unit 1802, configured to determine, according to a measurement result of a third cell and information of the third cell, that an active carrier of the third cell and an active carrier of the second cell have at least one same carrier;

the transceiver 1801 is further configured to send second indication information to the terminal device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell.

In one embodiment, the processing unit 1802 determining the first cell based on the measurement result of the third cell and the information of the third cell includes: determining the priority corresponding to each cell in the third cell according to the information of the third cell; and determining the first cell according to the priority corresponding to each cell in the third cell and the measurement result of the third region.

In an embodiment, the transceiving unit 1801 is further configured to send a measurement configuration to a terminal device;

in an embodiment, the transceiving unit 1801 is further configured to receive a measurement result of a fifth cell sent by the terminal device; the third cell is at least one cell in the fifth cells.

In an embodiment, the transceiving unit 1801 is further configured to receive indication information of N fourth cells sent by the terminal device, where N is an integer greater than or equal to 1, where the N fourth cells are determined by the terminal device according to a measurement result of a third cell and information of the third cell, and at least one same carrier exists between an active carrier of the third cell and an active carrier of the second cell;

the processing unit 1802 is further configured to determine the first cell according to the N fourth cells, where the first cell is one of the N fourth cells;

In an embodiment, the transceiving unit 1801 is further configured to send a measurement configuration to a terminal device.

In an embodiment, the transceiving unit 1801 is further configured to send information of the third cell to the terminal device, where the third cell is at least one cell in the fifth cell.

In an embodiment, the transceiving unit 1801 is further configured to send third indication information to the terminal device, where the third indication information is used to indicate whether a second TA value is the same as the first TA value, where the second TA value is a TA value of the terminal device in a fourth carrier, and the fourth carrier is a carrier of the terminal device in the first cell, which is different from the first carrier.

In an embodiment, the transceiving unit 1801 is further configured to send request information to a first network device, where the request information is used to request the terminal device to access the first network device, and the first network device is a network device corresponding to the first cell.

It is to be understood that the transceiver unit 1801 in the embodiments of the present application may be implemented by a transceiver or transceiver-related circuit components, and the processing unit 1802 may be implemented by a processor or processor-related circuit components.

Referring to fig. 19 based on the network architecture, fig. 19 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. As shown in fig. 19, the communications device 1900 may include a processor 1901, a memory 1902, a transceiver 1903, and a bus 1904. The memory 1902, which may be separate, may be coupled to the processor 1901 via a bus 1904. The memory 1902 may also be integrated with the processor 1901. The memory 1902 stores therein instructions or program codes, and may also store data. The processor 1901 is used to execute instructions or program code stored in the memory 1902. A bus 1904 is used to implement the connections between these components. In fig. 19, the bus lines are shown by thick lines, and the connection manner between other components is merely illustrative and not limited. The bus 1904 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 19, but it is not intended that there be only one bus or one type of bus.

When the instructions or program codes stored in the memory 1902 are executed, the processor 1901 is configured to perform the operations performed by the processing unit 1802 in the above-described embodiment, and the transceiver 1903 is configured to perform the operations performed by the transceiver unit 1801 in the above-described embodiment.

It should be noted that the communication apparatus 1800 or the communication apparatus 1900 according to the embodiment of the present application may correspond to the terminal device in the method embodiment provided by the present application, and the operation and/or the function of each module in the communication apparatus 1800 or the communication apparatus 1900 may respectively implement the corresponding flow of each method in fig. 4 and fig. 6, which is not described herein again for brevity.

Referring to fig. 20, fig. 20 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. The communication device may be the first network device, or may be a module (e.g., a chip) in the first network device. As shown in fig. 20, the communication apparatus 2000 includes at least: a transmitting/receiving unit 2001; wherein:

the transceiving unit 2001 is configured to receive request information sent by a second network device, where the request information is used to request the terminal device to access the first network device, and the second network device is a network device corresponding to a second cell.

It is understood that the transceiver unit 2001 in the embodiment of the present application may be implemented by a transceiver or a transceiver-related circuit component.

Referring to fig. 21, fig. 21 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. As shown in fig. 21, the communication device 2100 may include a processor 2101, a memory 2102, a transceiver 2103, and a bus 2104. The memory 2102 may be separate and may be connected to the processor 2101 by a bus 2104. The memory 2102 may also be integrated with the processor 2101. The memory 2102 stores instructions or program codes, and may also store data, among other things. The processor 2101 is configured to execute instructions or program code stored in the memory 2102. A bus 2104 is used to enable connection between these components. In fig. 21, the bus lines are shown by thick lines, and the connection manner between other components is merely illustrative and not limited. The bus 2104 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 21, but this does not mean only one bus or one type of bus.

When the instructions or program codes stored in the memory 2102 are executed, the transceiver 2103 is used to perform the operations performed by the transceiver unit 2001 in the above-described embodiments.

It should be noted that the communication apparatus 2000 or the communication apparatus 2100 according to the embodiment of the present application may correspond to a terminal device in the method embodiment provided in the present application, and operations and/or functions of each module in the communication apparatus 2000 or the communication apparatus 2100 may respectively implement corresponding flows of each method in fig. 6, which is not described herein again for brevity.

Referring to fig. 22, fig. 22 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. The communication device may be a terminal device, or may be a module (e.g., a chip) in the terminal device. As shown in fig. 22, the communication device 2200 includes at least: a transceiver unit 2201 and a processing unit 2202; wherein:

a transceiving unit 2201, configured to receive third information sent by a second network device, where the third information includes first indication information and an ID of a first cell, and the first indication information is used to indicate the terminal device to continue sending uplink transmission to a fourth network device.

In one embodiment, the communication apparatus may further include: a processing unit 2202, configured to determine a first TA value according to a first transmission timing, a downlink timing of the first cell, and a TA offset value of the first cell, where the first TA value is used to continue to send uplink transmission to the fourth network device.

In an embodiment, the transceiving unit 2201 is further configured to receive first information sent by a second network device, where the first information includes a TA offset value of the first cell.

In one embodiment, the first information further comprises: at least one of a time slot offset value between the first cell and a second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell.

In one embodiment, the processing unit 2202 determining the first TA value from the first transmit timing, the downlink timing of the first cell, and the TA offset value of the first cell comprises: determining a first TA value based on a first transmit timing, a downlink timing of the first cell, and the first information.

In one embodiment, the first TA value may satisfy the following equation:

or

Or

Or

Or

Wherein N is_TAIs the first TA value, T_ttFor the first transmission timing, T is the downlink timing of the first cell, N_TA-offsetIs TA offset value, T, of the first cell_C＝1/(Δf_max·N_f)，Δf_max＝480·10³Hz and N_f＝4096，T_slot-offsetIs a slot offset value, T, between the first cell and the second cell _sfn-offsetIs a system frame number offset value, the T, between the first cell and the second cell_Fb-offsetIs a frame boundary offset value between the first cell and the second cell.

In an embodiment, the transceiver 2201 is further configured to receive second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell.

In one embodiment, the transceiving unit 2201 is further configured to receive a measurement configuration sent by the second network device; reporting a measurement result of a fifth cell to the second network equipment according to the measurement configuration; the third cell is at least one cell in the fifth cells.

In an embodiment, the processing unit 2202 is further configured to determine N fourth cells according to a measurement result of a third cell and information of the third cell, where N is an integer greater than or equal to 1, and at least one same carrier exists between an active carrier of the third cell and an active carrier of the second cell;

the transceiver 2201 is further configured to send, to the second network device, indication information of the N fourth cells; receiving second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell, and the first cell is one of the N fourth cells.

In one embodiment, the processing unit 2202 determining N fourth cells according to the measurement result of the third cell and the information of the third cell includes: determining the priority corresponding to each cell in the third cell according to the information of the third cell; and determining the N fourth cells according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In one embodiment, the transceiving unit 2201 is further configured to receive a measurement configuration sent by the second network device; and determining a measurement result of the fifth cell according to the measurement configuration.

In an embodiment, the transceiver 2201 is further configured to receive information of the third cell sent by the second network device, where the third cell is at least one cell in the fifth cells.

In one embodiment, the transceiving unit 2201 is further configured to, if the fourth network device is the first network device, send uplink transmission information to the first network device, where the uplink transmission information includes second information, and the second information is used to confirm handover to the first network device; or sending uplink transmission information to the second network device when the fourth network device is the second network device, where the uplink transmission information includes second information, and the second information is used to confirm handover to the first network device.

It is to be understood that the transceiver unit 2201 in the embodiments of the present application may be implemented by a transceiver or transceiver-related circuit components, and the processing unit 2202 may be implemented by a processor or processor-related circuit components.

Referring to fig. 23, fig. 23 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. As shown in fig. 23, the communication device 2300 may include a processor 2301, a memory 2302, a transceiver 2303 and a bus 2304. The memory 2302 may be self-contained and may be coupled to the processor 2301 via the bus 2304. The memory 2302 may also be integrated with the processor 2301. The memory 2302 stores instructions or program codes and may store data. The processor 2301 is used to execute instructions or program code stored in the memory 2302. A bus 2304 is used to enable connections between these components. In fig. 23, the bus lines are shown by thick lines, and the connection manner between other components is merely illustrative and not limited thereto. The bus 2304 may be divided into an address bus, a data bus, a control bus, and so on. For ease of illustration, only one thick line is shown in FIG. 23, but it is not intended that there be only one bus or one type of bus.

When the instructions or program codes stored in the memory 2302 are executed, the processor 2301 is configured to perform the operations performed by the processing unit 2202 in the above embodiments, and the transceiver 2303 is configured to perform the operations performed by the transceiver 2201 in the above embodiments.

It should be noted that the communication apparatus 2200 or the communication apparatus 2300 of the embodiment of the present application may correspond to the terminal device in the embodiment of the method provided in the present application, and operations and/or functions of each module in the communication apparatus 2200 or the communication apparatus 2300 may implement corresponding flows of each method in fig. 7 and fig. 8, respectively, which is not described herein again for brevity.

Referring to fig. 24, fig. 24 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. The communication device may be the second network device, or may be a module (e.g., a chip) in the second network device. As shown in fig. 24, the communication apparatus 2400 includes at least: a transceiver unit 2401 and a processing unit 2402; wherein:

a transceiving unit 2401, configured to send third information to a terminal device, where the third information includes first indication information and an ID of a first cell, and the first indication information is used to indicate the terminal device to continue sending uplink transmission to a fourth network device.

In an embodiment, the transceiving unit 2401 is further configured to send first information to the terminal device, where the first information includes a TA offset value of the first cell.

In one embodiment, the communication apparatus may further include: a processing unit 2402, configured to determine, according to a measurement result of a third cell and information of the third cell, that the first cell has at least one same carrier as an active carrier of the second cell;

the transceiver 2401 is further configured to send second indication information to the terminal device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell.

In one embodiment, the processing unit 2402 determining the first cell according to the measurement result of the third cell and the information of the third cell includes: determining the priority corresponding to each cell in the third cell according to the information of the third cell; and determining the first cell according to the priority corresponding to each cell in the third cell and the measurement result of the third region.

In an embodiment, the transceiving unit 2401 is further configured to send a measurement configuration to a terminal device.

In an embodiment, the transceiving unit 2401 is further configured to receive a measurement result of a fifth cell sent by the terminal device; the third cell is at least one cell in the fifth cells.

In an embodiment, the transceiving unit 2401 is further configured to receive indication information of N fourth cells sent by the terminal device, where N is an integer greater than or equal to 1, where the N fourth cells are determined by the terminal device according to a measurement result of a third cell and information of the third cell, and at least one same carrier exists between an active carrier of the third cell and an active carrier of the second cell;

the processing unit 2402 is further configured to determine the first cell according to the N fourth cells, where the first cell is one of the N fourth cells;

In an embodiment, the transceiver 2401 is further configured to send information of the third cell to the terminal device, where the third cell is at least one cell in the fifth cells.

In an embodiment, the transceiving unit 2401 is further configured to send request information to a first network device, where the request information is used to request the terminal device to access the first network device.

In an embodiment, the transceiving unit 2401 is further configured to receive uplink transmission information sent by the terminal device when the fourth network device is the second network device, where the uplink transmission information includes second information, and the second information is used to confirm handover to the first network device.

It is understood that the transceiver unit 2401 in the embodiments of the present application may be implemented by a transceiver or transceiver-related circuit components, and the processing unit 2402 may be implemented by a processor or processor-related circuit components.

Based on the above network architecture, please refer to fig. 25, and fig. 25 is a schematic structural diagram of another communication device according to an embodiment of the present application. As shown in fig. 25, the communication device 2500 may include a processor 2501, a memory 2502, a transceiver 2503, and a bus 2504. The memory 2502 may be separate and may be coupled to the processor 2501 via the bus 2504. The memory 2502 may also be integrated with the processor 2501. The memory 2502 stores instructions or program codes, and may store data. The processor 2501 is configured to execute instructions or program code stored in the memory 2502. A bus 2504 is used to enable connection between these components. In fig. 25, the bus lines are shown by thick lines, and the connection manner between other components is merely illustrative and not limited thereto. The bus 2504 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 25, but it is not intended that there be only one bus or one type of bus.

When the instructions or program codes stored in the memory 2502 are executed, the processor 2501 is configured to perform the operations performed by the processing unit 2402 in the above embodiments, and the transceiver 2503 is configured to perform the operations performed by the transceiver unit 2401 in the above embodiments.

It should be noted that the communication device 2400 or the communication device 2500 in the embodiment of the present application may correspond to the terminal device in the embodiment of the method provided in the present application, and operations and/or functions of each module in the communication device 2400 or the communication device 2500 may respectively implement corresponding flows of each method in fig. 7 and fig. 8, which is not described herein again for brevity.

Referring to fig. 26, fig. 26 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. The communication device may be the first network device, or may be a module (e.g., a chip) in the first network device. As shown in fig. 26, the communication device 2600 includes at least: a transmitting/receiving unit 2601; wherein:

a transceiving unit 2601, configured to receive uplink transmission information sent by a terminal device when a fourth network device is a first network device, where the uplink transmission information includes second information, and the second information is used to confirm handover to the first network device.

In an embodiment, the transceiving unit 2601 is further configured to receive request information sent by a second network device, where the request information is used to request the terminal device to access the first network device.

It is understood that the transceiver unit 2601 in the embodiments of the present application may be implemented by a transceiver or a transceiver-related circuit component.

Based on the above network architecture, please refer to fig. 27, and fig. 27 is a schematic structural diagram of another communication device according to an embodiment of the present application. As shown in fig. 27, the communication device 2700 may include a processor 2701, a memory 2702, a transceiver 2703, and a bus 2704. The memory 2702 may be separate and may be connected to the processor 2701 by a bus 2704. The memory 2702 may also be integrated with the processor 2701. The memory 2702 stores therein instructions or program codes, and may also store data. The processor 2701 is configured to execute instructions or program code stored in the memory 2702. Bus 2704 is used to implement the connections between these components. In fig. 27, the bus lines are shown by thick lines, and the connection form between other components is merely illustrative and not limited. The bus 2704 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 27, but this is not intended to represent only one bus or type of bus.

When instructions or program codes stored in the memory 2702 are executed, the transceiver 2703 is configured to perform the operations performed by the transceiver unit 2601 in the above-described embodiments.

It should be noted that the communication device 2600 or the communication device 2700 in the embodiment of the present application may correspond to a terminal device in the embodiment of the method provided by the present application, and operations and/or functions of the respective modules in the communication device 2600 or the communication device 2700 may implement the corresponding flows of the respective methods in fig. 7 and fig. 8, respectively, which are not described herein again for brevity.

Referring to fig. 28, fig. 28 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. The communication device may be a terminal device, or may be a module (e.g., a chip) in the terminal device. As shown in fig. 28, the communication apparatus 2800 includes at least: a processing unit 2801 and a transceiving unit 2802; wherein:

a processing unit 2801, configured to determine N fourth cells according to information of a third cell and a measurement result of a fifth cell, where N is an integer greater than or equal to 1, and at least one same carrier exists for an effective carrier of the third cell and an effective carrier of the second cell;

A transceiver unit 2802, configured to send instruction information of the N fourth cells to a second network device, where the second network device is a network device corresponding to the second cell;

the transceiver unit 2802 is further configured to receive second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell, and the first cell is one of the N fourth cells.

In one embodiment, the processing unit 2801 determining N fourth cells according to the information of the third cell and the measurement result of the fifth cell includes: under the condition that the third cell exists in the fifth cell, determining the corresponding priority of each cell in the third cell according to the information of the third cell; and determining the N fourth cells according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In one embodiment, the processing unit 2801 determining N fourth cells according to the information of the third cell and the measurement result of the fifth cell includes: determining the N fourth cells according to the measurement result of the fifth cell when a third cell does not exist in the fifth cell.

In an embodiment, the transceiver unit 2802 is further configured to receive a measurement configuration sent by a second network device, where the second network device is a network device corresponding to the second cell;

the processing unit 2801 is further configured to determine a measurement result of the fifth cell according to the measurement configuration.

In an embodiment, the transceiver 2802 is further configured to receive information of the third cell sent by the second network device.

In an embodiment, the transceiver unit 2802 is further configured to receive a measurement configuration sent by a second network device, where the second network device is a network device corresponding to the second cell; and reporting the measurement result of the fifth cell to the second network equipment according to the measurement configuration.

It is to be appreciated that the processing unit 2801 in embodiments of the present application may be implemented by a processor or processor-related circuit components, and the transceiver unit 2802 may be implemented by a transceiver or transceiver-related circuit components.

Based on the above network architecture, please refer to fig. 29, where fig. 29 is a schematic structural diagram of another communication device according to an embodiment of the present application. As shown in fig. 29, the communication device 2900 may include a processor 2901, a memory 2902, a transceiver 2903, and a bus 2904. The memory 2902 may be self-contained and may be coupled to the processor 2901 via the bus 2904. The memory 2902 may also be integrated with the processor 2901. The memory 2902 stores instructions or program codes, and may store data. The processor 2901 is operable to execute instructions or program code stored in the memory 2902. A bus 2904 is used to enable connection between these components. In fig. 29, the bus lines are shown by thick lines, and the connection manner between other components is merely illustrative and not limited thereto. Bus 2904 can be divided into an address bus, data bus, control bus, and so forth. For ease of illustration, only one thick line is shown in FIG. 29, but this does not mean only one bus or one type of bus.

When the instructions or program codes stored in the memory 2902 are executed, the processor 2901 is configured to perform the operations performed by the processing unit 2801 in the above embodiments, and the transceiver 2903 is configured to perform the operations performed by the transceiver unit 2802 in the above embodiments.

It should be noted that the communication apparatus 2800 or the communication apparatus 2900 according to this embodiment may correspond to a terminal device in the method embodiment provided in this application, and operations and/or functions of each module in the communication apparatus 2800 or the communication apparatus 2900 may implement corresponding flows of each method in fig. 9 and fig. 10, respectively, which is not described herein again for brevity.

Referring to fig. 30, fig. 30 is a schematic structural diagram of another communication device according to an embodiment of the present disclosure. The communication device may be the second network device, or may be a module (e.g., a chip) in the second network device. As shown in fig. 30, the communication device 3000 includes at least: a processing unit 3001 and a transmitting/receiving unit 3002; wherein:

a processing unit 3001, configured to determine a first cell according to information of a third cell and a measurement result of a fifth cell, where at least one same carrier exists between an active carrier of the third cell and an active carrier of the second cell.

In one embodiment, the processing unit 3001, determining the first cell according to the information of the third cell and the measurement result of the fifth cell, comprises: under the condition that the third cell exists in the fifth cell, determining the corresponding priority of each cell in the third cell according to the information of the third cell; and determining the first cell according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

In one embodiment, the processing unit 3001, determining the first cell according to the information of the third cell and the measurement result of the fifth cell, comprises: determining the first cell according to a measurement result of the fifth cell in a case where the third cell does not exist in the fifth cell.

In one embodiment, the communication device further comprises:

a transceiving unit 3002, configured to send a measurement configuration to the terminal device; and receiving the measurement result of the fifth cell sent by the terminal equipment.

In an embodiment, the transceiver 3002 is further configured to receive indication information of N fourth cells sent by a terminal device, where N is an integer greater than or equal to 1, where the N fourth cells are determined by the terminal device according to information of a third cell and a measurement result of a fifth cell, and at least one same carrier exists between an active carrier of the third cell and an active carrier of the second cell;

The processing unit 3001 is further configured to determine a first cell according to the N fourth cells, where the first cell is one of the N fourth cells.

In an embodiment, the transceiver 3002 is further configured to send a measurement configuration to the terminal device.

In an embodiment, the transceiver 3002 is further configured to transmit information of the third cell to the terminal device.

It is to be understood that the processing unit 3001 in the embodiments of the present application may be implemented by a processor or a processor-related circuit component, and the transceiver unit 3002 may be implemented by a transceiver or a transceiver-related circuit component.

Referring to fig. 31, fig. 31 is a schematic structural diagram of another communication device according to an embodiment of the present application. As shown in fig. 31, the communication device 3100 may include a processor 3101, a memory 3102, a transceiver 3103, and a bus 3104. The memory 3102, which may be separate, may be coupled to the processor 3101 by a bus 3104. The memory 3102 may also be integrated with the processor 3101. The memory 3102 stores instructions, program codes, and data, among others. The processor 3101 is used to execute instructions or program code stored in the memory 3102. A bus 3104 is used to implement the connections between these components. In fig. 31, the bus lines are shown by thick lines, and the connection form between other components is merely illustrative and not limited. The bus 3104 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 31, but this does not mean only one bus or one type of bus.

When the instructions or program codes stored in the memory 3102 are executed, the processor 3101 is configured to perform the operations performed by the processing unit 3001 in the above-described embodiment, and the transceiver 3103 is configured to perform the operations performed by the transceiver unit 3002 in the above-described embodiment.

It should be noted that the communication apparatus 3000 or the communication apparatus 3100 according to this embodiment may correspond to the terminal device in the method embodiment provided in this application, and operations and/or functions of each module in the communication apparatus 3000 or the communication apparatus 3100 may respectively implement corresponding flows of each method in fig. 9 and 10, which is not described herein again for brevity.

The embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, can implement the flow related to the terminal device in the communication method provided by the foregoing method embodiment.

Embodiments of the present application further provide a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, can implement the process related to the first network device in the communication method provided in the foregoing method embodiments.

Embodiments of the present application further provide a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, can implement a flow related to a second network device in a communication method provided in the foregoing method embodiments.

Embodiments of the present application also provide a computer program product, which when run on a computer or a processor, causes the computer or the processor to perform one or more steps of any of the above-described communication methods. The respective constituent modules of the above-mentioned apparatuses may be stored in the computer-readable storage medium if they are implemented in the form of software functional units and sold or used as independent products.

The embodiment of the present application further provides a communication system, where the communication system may include a terminal device, a first network device, and a second network device, and the communication method shown in fig. 4, fig. 6, fig. 7, fig. 8, fig. 9, and fig. 10 may be referred to in detail for description.

It will be appreciated that the memory referred to in the embodiments of the application may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The nonvolatile memory may be a Hard Disk Drive (HDD), a solid-state drive (SSD), a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM). The memory is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such. The memory in the embodiments of the present application may also be circuitry or any other device capable of performing a storage function for storing program instructions and/or data.

It should also be understood that the processor mentioned in the embodiments of the present application may be a Central Processing Unit (CPU), and may also be other general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should be noted that when the processor is a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, the memory (memory module) is integrated in the processor.

It should be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments provided herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed 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 can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

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

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

The steps in the method of the embodiment of the application can be sequentially adjusted, combined and deleted according to actual needs.

The modules/units in the device of the embodiment of the application can be combined, divided and deleted according to actual needs.

The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of communication, comprising:

determining that a carrier for uplink transmission of the terminal equipment in the first cell is a first carrier after the terminal equipment is switched from the second cell to the first cell;

the first carrier and the second carrier belong to the same frequency band, and the second carrier is a carrier of the terminal device in a second cell.

2. The method of claim 1, further comprising:

And determining a first TA value according to the sending timing of the terminal equipment on the second carrier, the downlink timing of the first cell and the TA offset value of the timing advance of the first cell, wherein the first TA value is the TA value of the terminal equipment on the first carrier.

3. The method according to claim 1 or 2,

the same carrier as the second carrier exists in the active carriers of the first cell.

4. The method of claim 3, further comprising:

and under the condition that the carrier of the terminal equipment in the second cell is a third carrier and the same carrier as the third carrier does not exist in the effective carrier of the first cell, the terminal equipment is switched to the second carrier in the second cell.

5. The method according to any one of claims 1-4, further comprising:

receiving first indication information sent by a second network device, where the first indication information is used to indicate that a carrier for the terminal device to perform uplink transmission in the first cell is the first carrier, and the second network device is a network device corresponding to the second cell.

6. The method of claim 2, further comprising:

receiving first information sent by a second network device, where the first information includes a TA offset value of the first cell.

7. The method of claim 6,

the first information further includes: at least one of a time slot offset value between the first cell and the second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell;

the determining, according to the transmission timing of the terminal device on the second carrier, the downlink timing of the first cell, and the TA offset value of the first cell, a first TA value includes:

and determining a first TA value according to the sending timing of the terminal equipment in the second carrier, the downlink timing of the first cell and the first information.

8. The method of claim 7, wherein the first TA value satisfies the following equation:

or

Or

Or

Or

9. The method of claim 1, further comprising:

and receiving second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an identifier ID of the first cell.

10. The method of claim 1, further comprising:

determining N fourth cells according to the measurement result of the third cell and the information of the third cell, wherein N is an integer greater than or equal to 1, and at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell;

sending indication information of the N fourth cells to the second network equipment;

receiving second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an ID of the first cell, and the first cell is one of the N fourth cells.

11. The method of claim 10, wherein the determining N fourth cells according to the measurement result of the third cell and the information of the third cell comprises:

determining the priority corresponding to each cell in the third cell according to the information of the third cell;

and determining the N fourth cells according to the priority corresponding to each cell in the third cells and the measurement result of the third cells.

12. The method according to any one of claims 1-11, further comprising:

and sending second information on the first carrier, where the second information is used to confirm handover to the first network device, and the first network device is a network device corresponding to the first cell.

13. A method of communication, comprising:

and sending first indication information to a terminal device, wherein the first indication information is used for indicating that a carrier for uplink transmission of the terminal device in the first cell is a first carrier, the first carrier and a second carrier belong to the same frequency band, and the second carrier is a carrier of the terminal device in a second cell.

14. The method of claim 13, further comprising:

And sending first information to the terminal equipment, wherein the first information comprises a Timing Advance (TA) offset value of the first cell.

15. The method of claim 14,

the first information further includes: at least one of a time slot offset value between the first cell and the second cell, a system frame number offset value between the first cell and the second cell, and a frame boundary offset value between the first cell and the second cell.

16. The method of claim 13, further comprising:

determining the first cell according to the measurement result of the third cell and the information of the third cell, wherein at least one same carrier exists between the effective carrier of the third cell and the effective carrier of the second cell;

and sending second indication information to the terminal equipment, wherein the second indication information is used for indicating the first cell, and the second indication information comprises the identification ID of the first cell.

17. The method of claim 16, wherein the determining the first cell according to the measurement result of the third cell and the information of the third cell comprises:

and determining the first cell according to the priority corresponding to each cell in the third cell and the measurement result of the third region.

18. The method of claim 13, further comprising:

receiving indication information of N fourth cells sent by the terminal equipment, wherein N is an integer greater than or equal to 1, the N fourth cells are determined by the terminal equipment according to a measurement result of a third cell and information of the third cell, and at least one same carrier exists between an effective carrier of the third cell and an effective carrier of the second cell;

determining the first cell according to the N fourth cells, wherein the first cell is one of the N fourth cells;

and sending second indication information to the terminal equipment, wherein the second indication information is used for indicating the first cell, and the second indication information comprises the ID of the first cell.

19. A communications apparatus, comprising:

a processing unit, configured to determine that a carrier in the first cell, where the terminal device performs uplink transmission after the terminal device is switched from the second cell to the first cell, is a first carrier;

20. The apparatus of claim 19, comprising:

the processing unit is further configured to determine a first TA value according to the transmission timing of the terminal device on the second carrier, the downlink timing of the first cell, and the TA offset value of the timing advance of the first cell, where the first TA value is the TA value of the terminal device on the first carrier.

21. The apparatus of claim 19 or 20,

22. The apparatus of claim 21, further comprising:

23. The apparatus of any one of claims 19-22, further comprising:

24. The apparatus of claim 20, wherein the transceiver unit is further configured to receive first information sent by a second network device, and the first information comprises a TA offset value of the first cell.

25. The apparatus of claim 24,

the determining, by the processing unit, a first TA value according to the transmission timing of the terminal device on the second carrier, the downlink timing of the first cell, and the TA offset value of the first cell includes:

26. The apparatus of claim 25, wherein the first TA value satisfies the following equation:

or

Or

Or

Or

27. The apparatus of claim 19,

the transceiver unit is further configured to receive second indication information sent by the second network device, where the second indication information is used to indicate the first cell, and the second indication information includes an identifier ID of the first cell.

28. The apparatus of claim 19,

the processing unit is further configured to determine N fourth cells according to a measurement result of the third cell and information of the third cell, where N is an integer greater than or equal to 1, and at least one same carrier exists between an effective carrier of the third cell and an effective carrier of the second cell;

the transceiver unit is further configured to send the indication information of the N fourth cells to the second network device;

29. The apparatus of claim 28, wherein the processing unit determines N fourth cells according to the measurement result of the third cell and the information of the third cell comprises:

30. The apparatus of any one of claims 19 to 29, wherein the transceiver unit is further configured to send second information on the first carrier, where the second information is used to confirm handover to the first network device, and the first network device is a network device corresponding to the first cell.

31. A communications apparatus, comprising:

the receiving and sending unit is configured to send first indication information to a terminal device, where the first indication information is used to indicate that a carrier used for performing uplink transmission in the first cell by the terminal device is a first carrier, where the first carrier and a second carrier belong to a same frequency band, and the second carrier is a carrier used in a second cell by the terminal device.

32. The apparatus of claim 31,

the transceiver unit is further configured to send first information to the terminal device, where the first information includes a TA offset value of the first cell.

33. The apparatus of claim 32,

34. The apparatus of claim 31, further comprising:

the transceiver unit is further configured to send second indication information to the terminal device, where the second indication information is used to indicate the first cell, and the second indication information includes an identifier ID of the first cell.

35. The apparatus of claim 34, wherein the processing unit determines the first cell according to the measurement result of the third cell and the information of the third cell comprises:

36. The apparatus of claim 31,

the transceiver unit is further configured to receive indication information of N fourth cells sent by the terminal device, where N is an integer greater than or equal to 1, where the N fourth cells are determined by the terminal device according to a measurement result of a third cell and information of the third cell, and at least one same carrier exists between an effective carrier of the third cell and an effective carrier of the second cell;

37. A communication apparatus, comprising a processor for executing a computer program, which when executed, causes the apparatus to

Performing the method of any one of claims 1-12; or

Performing the method of any one of claims 13-18.

38. The communications apparatus of claim 37, further comprising a memory for storing the computer program.

39. A computer-readable storage medium, in which a computer program or computer instructions are stored which, when executed,

the method of any one of claims 1-12 is performed; or

The method of any one of claims 13-18 being performed.

40. A chip system, comprising at least one processor, a memory, and an interface circuit, the memory, the interface circuit, and the at least one processor being interconnected by a line, the at least one memory having instructions stored therein; the instructions, when executed by the processor, cause the system on a chip to

Performing the method of any one of claims 1-12; or

Performing the method of any one of claims 13-18.