Communication method and device

Abstract

The invention discloses a communication method and device, relates to the technical field of communication, and is used for reducing the measurement overhead of terminal equipment and improving the measurement efficiency. And the network equipment sends the candidate cell list and the first indication information to the terminal equipment. And indicating the range in which the terminal equipment measures the candidate cells in the candidate cell list through the first indication information. Therefore, the terminal equipment only measures the candidate cells in the first range, the number of the measured cells can be reduced, the measurement overhead is reduced, and the measurement efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0002] Cell switching is a very important feature in communication systems. It is mainly triggered by the movement of the terminal device when the terminal device is in a radio resource control (RRC) connection state, so as to switch the terminal device to a neighboring cell with better signal quality before the signal quality of the serving cell becomes incapable of communication, thereby providing continuous and uninterrupted communication services.

[0003] In layer 1 / layer 2 triggered mobility (L1 / L2-triggered mobility, LTM), after the network side configures a candidate cell list for a terminal device, the terminal device measures all cells, which is inefficient. Summary of the invention

[0004] The embodiments of the present application provide a communication method and apparatus for improving cell measurement efficiency.

[0005] In a first aspect, an embodiment of the present application provides a communication method. The method is applied to a terminal device. It can be executed by a terminal device or a module (such as a chip or circuit) in the terminal device. Take execution by a terminal device as an example. In the method, the terminal device receives a candidate cell list and first indication information of a first network device, the first indication information is used to indicate a first range, and the first range is a range for measuring candidate cells in the candidate cell list; and performs measurement on candidate cells within the first range.

[0006] Using the above method, after the terminal device receives the first indication information, it can determine the first measurement range and only perform measurements on candidate cells within the first range without measuring all cells, thereby reducing the measurement overhead of the terminal device and improving measurement efficiency to improve switching efficiency.

[0007] In one possible design, the first network device may only send a candidate cell list to the terminal device, where the candidate cell list includes candidate cells within the first range. After receiving the candidate cell list, the terminal device measures the candidate cells in the candidate cell list, that is, measures the candidate cells within the first range.

[0008] In one possible design, the method further includes: sending a moving path of the terminal device to the first network device. The moving path of the terminal device can be used to determine the first range.

[0009] In a possible design, the first range may be a position range. The first indication information is used to indicate the first range, including: the first indication information is used to indicate the starting position and the ending position corresponding to the first range; or the first indication information is used to indicate the starting position corresponding to the first range.

[0010] In a possible design, when the first indication information indicates the starting position corresponding to the first range, the ending position may be the position where the moving path is updated, or the moving end point of the moving path, etc. The ending position may also be the position where the cell switching instruction is received.

[0011] By adopting the above method, the terminal device obtains the starting position and the ending position of the measurement, so that there is no need to perform measurement on the candidate cell list at positions outside the interval, which can reduce the measurement overhead of the terminal device.

[0012] In one possible design, the starting position is: the waypoint where the terminal device starts to perform the measurement; or, the geographical location where the terminal device starts to perform the measurement; or, a position whose distance from the first position is less than or equal to a first distance threshold.

[0013] In a possible design, the end position is: a waypoint where the terminal device ends the measurement; or a geographical location where the terminal device ends the measurement; or a location whose distance from the second location is greater than or equal to a second distance threshold. For example, the second location can be a waypoint or a geographical location. For example, the geographical location can be a latitude and longitude coordinate or a geographical identifier.

[0014] In one possible design, the first range may be a time range. The first indication information is used to indicate the first range, including: the first indication information is used to indicate the start time and end time corresponding to the first range; or, the first indication information is used to indicate the start time corresponding to the first range. The start time and the end time may be in Coordinated Universal Time (UTC). UTC may also be called Universal Time, World Standard Time, or International Coordinated Time.

[0015] In one possible design, the starting time is: the moment when the terminal device starts to perform the measurement; or the moment when the time difference with the first moment is less than or equal to a first time threshold.

[0016] In one possible design, the end time is: the moment when the terminal device ends the measurement; or the moment when the time difference with the second moment is greater than or equal to a second time threshold.

[0017] In one possible design, the first range may be a location range + time range. The first indication information is used to indicate the first range, and the first indication information is used to indicate the starting location, starting time, ending time, and ending location corresponding to the first range; or the first indication information is used to indicate the starting location and starting time corresponding to the first range; or the first indication information indicates the starting location, starting time, and ending location corresponding to the first range; or the first indication information indicates the starting time, starting location, and ending time corresponding to the first range.

[0018] In one possible design, the method also includes: the terminal device receives second indication information from the first network device, the second indication information is used to indicate a trigger point (or timing) for deleting configuration information of at least one second candidate cell, and the second candidate cell is a candidate cell in the candidate cell list.

[0019] In one possible case, the number of the at least one second candidate cell may be the number of all candidate cells in the candidate cell list, that is, the at least one second candidate cell includes N second candidate cells, the candidate cell list also includes N candidate cells, and the N second candidate cells are the same as the N candidate cells in the candidate cell list. In this case, it can be understood that the second indication information is used to indicate the deletion of configuration information of all candidate cells in the candidate cell list.

[0020] In another possible scenario, the number of the at least one second candidate cell is the number of all candidate cells corresponding to the first range in the candidate cell list. For example, the at least one second candidate cell includes N second candidate cells. The candidate cell list includes M candidate cells. M and N are both positive integers, and M is greater than N. The number of candidate cells within the first range measured by the terminal device is N. The N second candidate cells are the same as the N candidate cells within the first range of the candidate cell list. In this case, it can be understood that the second indication information is used to indicate the deletion of the configuration information of the candidate cells within the first range in the candidate cell list.

[0021] In some embodiments, the second indication information may also indicate a second range of candidate cells to be deleted. The second range may be indicated in a list form, or in a set form, or in other ways, which is not limited in the embodiments of the present application. The second range may be all candidate cells included in the candidate cell list for which measurement has been completed, or may be part of the candidate cells included in the candidate cell list for which measurement has been completed.

[0022] In one possible design, the second indication information is used to indicate a trigger point for deleting the configuration information of at least one second candidate cell, including: the second indication information is used to indicate the location for deleting the configuration information of the at least one second candidate cell; or, the second indication information is used to indicate the time for deleting the configuration information of the at least one second candidate cell.

[0023] In one possible design, the location at which the configuration information of the at least one second candidate cell is deleted is: the first waypoint at which the configuration information of the at least one second candidate cell is deleted; or, the first geographical location at which the configuration information of the at least one second candidate cell is deleted; or, a location between the second waypoint and the third waypoint; or, a location between the second geographical location and the third geographical location; or, a location between the fourth geographical location and the fourth waypoint, the fourth geographical location being a location that is less than a third distance threshold from the fourth waypoint.

[0024] In one possible design, the second indication information is used to indicate a trigger point for deleting the configuration information of at least one second candidate cell, including: the second indication information is used to indicate a time range for deleting the configuration information of at least one second candidate cell, or the second indication information is used to indicate a moment for deleting the configuration information of at least one second candidate cell.

[0025] In one possible design, after completing the switch to the target cell, when it is determined based on the movement path of the terminal device that the second path passed after flying away from the first path corresponding to the first range includes some or all of the candidate cells corresponding to the first range, the configuration information of some or all of the candidate cells in the candidate cell list corresponding to the first range can be retained.

[0026] In one possible design, after completing the switch to the target cell, when it is determined based on the moving path of the terminal device that the second path passed after flying away from the first path corresponding to the first range does not include some or all of the candidate cells corresponding to the first range, the configuration information of some or all of the candidate cells in the candidate cell list corresponding to the first range can be deleted.

[0027] In one possible design, after completing the switch to the target cell, it is determined based on the moving path of the terminal device that the second path passed after flying away from the first path corresponding to the first range includes the second range, and the shortest distance between the second range and the first range is less than or equal to the set threshold, then the configuration information of some or all candidate cells in the candidate cell list corresponding to the first range continues to be saved.

[0028] In a possible design, third indication information may be sent to the first network device, where the third indication information is used to indicate that some or all of the cells in the candidate cell list have been deleted.

[0029] In a possible design, if the terminal device enters the second path from the first path corresponding to the first range and the configuration information of the cell measured in the second path has been applied, the saved measurement results of the cell can be cleared.

[0030] In one possible design, if the terminal device enters the second path from the first path corresponding to the first range and the configuration information of the cell measured in the second path has been applied, only the measurement results of the overlapping cells can be saved. The overlapping cells are cells included in the candidate cell list corresponding to the first path and included in the candidate cell list corresponding to the second path.

[0031] In a possible design, the first range may be a height range. The first indication information is used to indicate the first range, including: the first indication information is used to indicate a starting height and an ending height corresponding to the first range; or, the first indication information is used to indicate an ending height corresponding to the first range; or, the first indication information is used to indicate a starting height corresponding to the first range.

[0032] In a possible design, the first range may be a height range+position. The first indication information is used to indicate the first range, including: the first indication information is used to indicate the starting height, ending height, and position corresponding to the first range; or, the first indication information is used to indicate the ending height and position corresponding to the first range; or, the first indication information is used to indicate the starting height and position corresponding to the first range.

[0033] In one possible design, the receiving of the candidate cell list and the first indication information from the first network device includes: receiving first configuration information from the first network device, the first configuration information including the candidate cell list and the first indication information.

[0034] In one possible design, fourth indication information is received from the first network device, where the fourth indication information is used to instruct the terminal device to use the same configuration information (using the first configuration information) in the ascending phase and the descending phase.

[0035] In one possible design, fifth indication information is received from the first network device, and the fifth indication information is used to instruct the terminal device to use different configuration information in the ascending phase and the descending phase. Second configuration information is received from the first network device, and the second configuration information includes sixth indication information and a second candidate cell list.

[0036] In a second aspect, an embodiment of the present application provides a communication method, which is applied to a first network device. The method can be executed by the first network device or by a module (such as a chip or circuit) in the first network device. Take the method being executed by the first network device as an example. The method includes: the first network device determines a candidate cell list and first indication information; the first indication information is used to indicate a first range, and the first range is the range in which the terminal device measures the candidate cells in the first candidate cell list; and the candidate cell list and the first indication information are sent to the terminal device.

[0037] In one possible design, the first network device may only send a candidate cell list to the terminal device, where the candidate cell list includes candidate cells within the first range. After receiving the candidate cell list, the terminal device measures the candidate cells in the candidate cell list, that is, measures the candidate cells within the first range.

[0038] In one possible design, the method further includes: the first network device receiving a moving path from the terminal device. The moving path of the terminal device can be used to determine the first range.

[0039] In a possible design, the first range may be a position range. The first indication information is used to indicate the first range, including: the first indication information is used to indicate the starting position and the ending position corresponding to the first range; or the first indication information is used to indicate the starting position corresponding to the first range.

[0040] In a possible design, when the first indication information indicates the starting position corresponding to the first range, the ending position may be the position where the moving path is updated, or the moving end point of the moving path, etc. The ending position may also be the position where the cell switching instruction is received.

[0041] By adopting the above method, the terminal device obtains the starting position and the ending position of the measurement, so that there is no need to perform measurement on the candidate cell list at positions outside the interval, which can reduce the measurement overhead of the terminal device.

[0042] In one possible design, the starting position is: the waypoint where the terminal device starts to perform the measurement; or, the geographical location where the terminal device starts to perform the measurement; or, a position whose distance from the first position is less than or equal to a first distance threshold.

[0043] In a possible design, the end position is: a waypoint where the terminal device ends the measurement; or a geographical location where the terminal device ends the measurement; or a location whose distance from the second location is greater than or equal to a second distance threshold. For example, the second location can be a waypoint or a geographical location. For example, the geographical location can be a latitude and longitude coordinate or a geographical identifier.

[0044] In one possible design, the first range may be a time range. The first indication information is used to indicate the first range, including: the first indication information is used to indicate the start time and end time corresponding to the first range; or, the first indication information is used to indicate the start time corresponding to the first range. The start time and the end time may be in Coordinated Universal Time (UTC). UTC may also be called Universal Time, World Standard Time, or International Coordinated Time.

[0045] In one possible design, the starting time is: the moment when the terminal device starts to perform the measurement; or the moment when the time difference with the first moment is less than or equal to a first time threshold.

[0046] In one possible design, the end time is: the moment when the terminal device ends the measurement; or the moment when the time difference with the second moment is greater than or equal to a second time threshold.

[0047] In one possible design, the first range may be a location range + time range. The first indication information is used to indicate the first range, and the first indication information is used to indicate the starting location, starting time, ending time, and ending location corresponding to the first range; or the first indication information is used to indicate the starting location and starting time corresponding to the first range; or the first indication information indicates the starting location, starting time, and ending location corresponding to the first range; or the first indication information indicates the starting time, starting location, and ending time corresponding to the first range.

[0048] In one possible design, the method also includes: the terminal device receives second indication information from the first network device, the second indication information is used to indicate a trigger point (or timing) for deleting configuration information of at least one second candidate cell, and the second candidate cell is a candidate cell in the candidate cell list.

[0049] In one possible design, the second indication information is used to indicate a trigger point for deleting the configuration information of at least one second candidate cell, including: the second indication information is used to indicate the location for deleting the configuration information of the at least one second candidate cell; or, the second indication information is used to indicate the time for deleting the configuration information of the at least one second candidate cell.

[0050] In one possible design, the location at which the configuration information of the at least one second candidate cell is deleted is: the first waypoint at which the configuration information of the at least one second candidate cell is deleted; or, the first geographical location at which the configuration information of the at least one second candidate cell is deleted; or, a location between the second waypoint and the third waypoint; or, a location between the second geographical location and the third geographical location; or, a location between the fourth geographical location and the fourth waypoint, the fourth geographical location being a location that is less than a third distance threshold from the fourth waypoint.

[0051] In one possible design, the second indication information is used to indicate a trigger point for deleting the configuration information of at least one second candidate cell, including: the second indication information is used to indicate a time range for deleting the configuration information of at least one second candidate cell, or the second indication information is used to indicate a moment for deleting the configuration information of at least one second candidate cell.

[0052] In one possible design, third indication information is received from a terminal device, where the third indication information is used to indicate that configuration information of some or all cells in the candidate cell list has been deleted.

[0053] In a possible design, the first range may be a height range. The first indication information is used to indicate the first range, including: the first indication information is used to indicate a starting height and an ending height corresponding to the first range; or, the first indication information is used to indicate an ending height corresponding to the first range; or, the first indication information is used to indicate a starting height corresponding to the first range.

[0054] In a possible design, the first range may be a height range+position. The first indication information is used to indicate the first range, including: the first indication information is used to indicate the starting height, ending height, and position corresponding to the first range; or, the first indication information is used to indicate the ending height and position corresponding to the first range; or, the first indication information is used to indicate the starting height and position corresponding to the first range.

[0055] In one possible design, sending a candidate cell list and first indication information includes: sending first configuration information, where the first configuration information includes the candidate cell list and the first indication information.

[0056] In one possible design, fourth indication information is sent, and the fourth indication information is used to instruct the terminal device to use the same configuration information (using the first configuration information) in the rising phase and the falling phase.

[0057] In a possible design, fifth indication information is sent, and the fifth indication information is used to instruct the terminal device to use different configuration information in the ascending phase and the descending phase. Second configuration information is sent, and the second configuration information includes sixth indication information and a second candidate cell list.

[0058] In one possible design, the method further includes: sending a moving path of the terminal device to a second network device; and receiving a cell list from the second network device, the cell list including an identifier of at least one cell through which the moving path passes. The second network device may be a candidate network device to be switched.

[0059] In one possible design, the method further includes: sending a moving path of the terminal device to a second network device; sending first information to the second network device, the first information being used to indicate at least one cell; and receiving second information from the second network device, the second information being used to indicate whether the moving path passes through the at least one cell. For example, the at least one cell may be a cell belonging to the second network device.

[0060] In a third aspect, an embodiment of the present application provides a communication method, applied to a first network device, comprising: sending a moving path of a terminal device to a second network device; the first network device is a network device that provides services for the terminal device, and the second network device is a candidate network device to be switched; receiving an eighth indication information sent by the second network device, the eighth indication information being used to indicate the timing (or trigger point) for the terminal device to send a preamble code.

[0061] In one possible design, the eighth indication information is used to indicate the timing when the terminal device sends the preamble code, including: the eighth indication information is used to indicate the position where the terminal device sends the preamble code; or, the eighth indication information is used to indicate the time when the terminal device sends the preamble code.

[0062] In one possible design, the location where the terminal device sends the preamble code is: the waypoint where the terminal device sends the preamble code; the fifth geographical location where the terminal device sends the preamble code; or, the location between the fifth waypoint and the sixth waypoint; or, the location between the sixth geographical location and the seventh geographical location; or, the location whose distance from the third location is less than or equal to a fourth distance threshold.

[0063] In one possible design, the time when the terminal device sends the preamble code is: the moment when the terminal device sends the preamble code; or, the moment between the third moment and the fourth moment; the moment when the time difference with the fifth moment is less than or equal to the third time threshold.

[0064] In one possible design, the method further includes:

[0065] Sending the eighth indication information to the terminal device; or,

[0066] The timing of sending the PDCCH command is determined according to the eighth indication information, and the PDCCH command is sent to the terminal device according to the timing of the PDCCH command, wherein the PDCCH command is used to instruct the terminal device to send a preamble code.

[0067] In a fourth aspect, an embodiment of the present application provides a communication method, applied to a second network device, comprising: receiving a moving path of a terminal device from a first network device. The first network device is a network device that provides services for the terminal device, and the second network device is a candidate network device to be switched; and sending eighth indication information to the first network device, wherein the eighth indication information is used to indicate a timing (or trigger point) for the terminal device to send a preamble.

[0068] In one possible design, the eighth indication information is used to indicate the timing when the terminal device sends the preamble code, including: the eighth indication information is used to indicate the position where the terminal device sends the preamble code; or, the eighth indication information is used to indicate the time when the terminal device sends the preamble code.

[0069] In one possible design, the location where the terminal device sends the preamble code is: the waypoint where the terminal device sends the preamble code; the fifth geographical location where the terminal device sends the preamble code; or, the location between the fifth waypoint and the sixth waypoint; or, the location between the sixth geographical location and the seventh geographical location; or, the location whose distance from the third location is less than or equal to a fourth distance threshold.

[0070] In one possible design, the time when the terminal device sends the preamble code is: the moment when the terminal device sends the preamble code; or, the moment between the third moment and the fourth moment; the moment when the time difference with the fifth moment is less than or equal to the third time threshold.

[0071] In a fifth aspect, the present application provides a communication device, which has the function of implementing the functions involved in the first to fourth aspects above. For example, the communication device includes modules or units or means corresponding to the operations involved in the first to fourth aspects above. The functions or units or means can be implemented by software, or by hardware, or the corresponding software can be implemented by hardware.

[0072] In a possible design, the communication device includes a processing unit and a communication unit, wherein the communication unit can be used to send and receive signals to achieve communication between the communication device and other devices, for example, the communication unit is used to send system information to a terminal; the processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the communication unit can correspond to the operations involved in the first to fourth aspects above.

[0073] In one possible design, the communication device includes a processor, which can be used to couple with a memory. The memory can store necessary computer programs or instructions for implementing the functions involved in the first to third aspects above. The processor can execute the computer program or instructions stored in the memory, and when the computer program or instructions are executed, the communication device implements the method in any possible design or implementation of the first to fourth aspects above.

[0074] In one possible design, the communication device includes a processor and a memory, and the memory can store necessary computer programs or instructions for implementing the functions involved in the first to fourth aspects. The processor can execute the computer program or instructions stored in the memory, and when the computer program or instructions are executed, the communication device implements the method in any possible design or implementation of the first to fourth aspects.

[0075] In one possible design, the communication device includes a processor and an interface circuit, wherein the processor is used to communicate with other devices through the interface circuit and execute the method in any possible design or implementation of the first to fourth aspects above.

[0076] It can be understood that in the fifth aspect above, the processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading the software code stored in the memory. In addition, the above processors can be one or more, and the memories can be one or more. The memory can be integrated with the processor, or the memory can be separately set from the processor. In the specific implementation process, the memory can be integrated with the processor on the same chip, or can be set on different chips respectively. The embodiment of the present application does not limit the type of memory and the setting method of the memory and the processor.

[0077] In a sixth aspect, the present application provides a communication system, which may include a first communication device and a second communication device; wherein the first communication device is used to execute the method described in the first aspect above, and the second communication device is used to execute the method described in the second aspect above.

[0078] In a seventh aspect, the present application provides a communication system, which may include a first communication device and a second communication device; wherein the first communication device is used to execute the method described in the third aspect above, and the second communication device is used to execute the method described in the fourth aspect above.

[0079] In an eighth aspect, the present application provides a computer-readable storage medium, in which computer-readable instructions are stored. When a computer reads and executes the computer-readable instructions, the computer executes a method in any possible design of the first to fourth aspects above.

[0080] In a ninth aspect, the present application provides a computer program product. When a computer reads and executes the computer program product, the computer executes the method in any possible design of the first to fourth aspects above.

[0081] In a tenth aspect, the present application provides a chip, comprising a processor, wherein the processor is coupled to a memory and is used to read and execute a software program stored in the memory to implement a method in any possible design of the first to fourth aspects above.

[0082] Based on the implementations provided in the above aspects, the present application can also be further combined to provide more implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 A schematic diagram of a communication system applicable to an embodiment of the present application;

[0084] Figure 2A A schematic diagram of another communication system provided in an embodiment of the present application;

[0085] Figure 2B A schematic diagram of another communication system provided in an embodiment of the present application;

[0086] Figure 3 A schematic diagram of the flight path of a drone provided in an embodiment of the present application;

[0087] Figure 4 A schematic diagram of a network switching method flow provided in an embodiment of the present application;

[0088] Figure 5 A schematic diagram of another network switching method flow chart provided in an embodiment of the present application;

[0089] Figure 6 A flow chart of a communication method provided in an embodiment of the present application;

[0090] Figure 7A schematic diagram of another communication method flow chart provided in an embodiment of the present application;

[0091] Figure 8 A flow chart of another communication method provided in an embodiment of the present application;

[0092] Fig. 9 A flow chart of another communication method provided in an embodiment of the present application;

[0093] Fig.10 A schematic diagram of the structure of a communication device 1000 provided in an embodiment of the present application;

[0094] Fig.11 A schematic diagram of the structure of a communication device 1100 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0095] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application. The technical solutions in the embodiments of the present application can be applied to various communication systems, such as universal mobile telecommunications system (UMTS), wireless local area network (WLAN), wireless fidelity (Wi-Fi) system, 4th generation (4G) mobile communication system, such as long term evolution (LTE) system, fifth generation (5G) mobile communication system, such as new radio (NR) system, and future evolved communication systems, such as sixth generation (6G) mobile communication system, etc.

[0096] The present application will present various aspects, embodiments or features around a system that may include multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the drawings. In addition, combinations of these schemes may also be used. In addition, in the embodiments of the present application, words such as "exemplarily" and "for example" are used to represent examples, illustrations or descriptions. Any embodiment or design described as an "example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present concepts in a specific way. In the embodiments of the present application, "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the distinction is not emphasized, the meanings to be expressed are consistent.

[0097] Figure 1 FIG. 1 is a schematic diagram of the architecture of a communication system 1000 used in an embodiment of the present application. Figure 1 As shown, the communication system includes a wireless access network 100. The wireless access network 100 may include at least one network device (such as Figure 1 110a and / or 110b), and may further include at least one terminal device (such as Figure 1 At least one of 120a-120j in ). The terminal device is connected to the access network device in a wireless manner, and the access network device is connected to the core network device in a wireless or wired manner. The terminal devices and the network devices can be connected to each other in a wired or wireless manner. Figure 1 This is just a schematic diagram. The communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices. Figure 1 Not drawn in.

[0098] A network device is a network-side device with wireless transceiver functions. A network device may be a device in a radio access network (RAN) that provides wireless communication functions for terminal devices, and is called a RAN device. For example, a network device may be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in a fifth generation (5G) mobile communication system, a next generation base station in a sixth generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system; it may also be a module or unit that completes some functions of a base station, for example, a centralized unit (CU) or a distributed unit (DU). The CU here completes the functions of the radio resource control protocol and packet data convergence protocol (PDCP) of the base station, and can also complete the function of the service data adaptation protocol (SDAP); the DU completes the functions of the radio link control layer and medium access control (MAC) layer of the base station, and can also complete the functions of part or all of the physical layer. For detailed descriptions of the above-mentioned protocol layers, please refer to the relevant technical specifications of the 3rd Generation Partnership Project (3GPP). The network equipment can be a macro base station (such as Figure 1 110a), or a micro base station or an indoor station (such as Figure 1 110b), may also be a relay node or a donor node, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device. The embodiments of the present application take the network device as a base station as an example for explanation.

[0099] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, and different RAN nodes respectively implement part of the functions of the base station. For example, the RAN node can be a CU, DU, CU-control plane (CP), CU-user plane (UP), or radio unit (RU). The CU and DU can be set separately, or can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU) or a remote radio head (RRH).

[0100] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, CU may also be called O-CU (open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the convenience of description, this application takes CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. Optionally, the operations of updating the random seed and securely processing the data in the secure communication method provided in the embodiment of the present application may be performed by the RU, and the sending and receiving operations may be performed by the DU.

[0101] The terminal device is a user-side device with wireless transceiver function. The terminal device can also be called user equipment (UE), mobile station, mobile terminal, etc. The terminal device can be widely used in various scenarios, for example, device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), Internet of Things (IOT), virtual reality, augmented reality, industrial control, automatic driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal device can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device. The terminal device in the embodiments of the present application can be a movable device.

[0102] The network equipment and terminal equipment can be fixed or movable. The network equipment and terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on aircraft, balloons and artificial satellites in the air. The embodiments of the present application do not limit the application scenarios of the network equipment and terminal equipment.

[0103] The roles of network devices and terminal devices can be relative, for example, Figure 1 The helicopter or drone 120i in the figure can be configured as a mobile network device. For the terminal devices 120j that access the wireless access network 100 through 120i, the terminal device 120i is a network device; but for the network device 110a, 120i is a terminal device, that is, 110a and 120i communicate through the wireless air interface protocol. Of course, 110a and 120i can also communicate through the interface protocol between network devices. In this case, relative to 110a, 120i is also a network device. Therefore, network devices and terminal devices can be collectively referred to as communication devices. Figure 1 110a and 110b in the figure may be referred to as communication devices having network device functions. Figure 1 120a-120j in the figure can be called communication devices with terminal equipment functions.

[0104] In the embodiments of the present application, the functions of the network device may also be performed by a module (such as a chip) in the network device, or by a control subsystem including the network device function. The control subsystem including the network device function here may be a control center in the above-mentioned application scenarios such as smart grid, industrial control, smart transportation, and smart city. The functions of the terminal device may also be performed by a module (such as a chip or a modem) in the terminal device, or by a device including the terminal device function.

[0105] Take the mobile terminal device, such as a drone, as an example. As a new type of aircraft, uncrewed aerial vehicle (UAV) has become increasingly popular due to its flexibility and convenience. At the same time, cellular networks can provide drones with important features such as wide coverage, high reliability, high security, and continuous mobility, as well as provide supervision to regulators. The communication environment of drones is quite different from that of ordinary terminals. They mainly fly above network devices and connect to network devices through the Uu port. They mainly communicate in the line of sight (LOS) path. Therefore, drones can receive signals from more network devices, such as Figure 2A As shown. Network devices can be connected through Xn ports to achieve signaling exchange. From a logical point of view, Xn port is a point-to-point interface between two network devices. Even if there is no physical direct connection between the two network devices, signaling exchange can be achieved using the point-to-point interface. Figure 2B shown.

[0106] When a drone performs a task, it may fly along a fixed route, such as inspecting a power grid. This route can be called the flight path of the drone. Figure 3As shown. The flight path includes at least one waypoint information. The first waypoint information in the flight path may include the location information corresponding to the take-off point of the drone and the current time point, or include the location information that the drone will fly through in the future and the time point corresponding to the arrival at the location. For other waypoint information in the flight path except the first waypoint information, it may include the location information that the drone will fly through in the future and the time point corresponding to the arrival at the location information. Each waypoint information may also include the number of the waypoint information in the flight path. For example, the number included in the first waypoint information in the flight path is 1. It should be understood that the location information may be location information in a latitude and longitude coordinate system, location information in a city coordinate system, location information in a rectangular coordinate system, etc., which is not limited here. Take the example that each waypoint information in the flight path is the location information that the UAV will fly over in the future and the time point corresponding to the arrival at the location information. For example, the flight path determined by the UAV is Shanghai (10:00:00)-Suzhou (12:00:00)-Beijing (16:00:00). The flight path includes 3 waypoint information. The first waypoint information is Shanghai (10:00:00) for specific description. The UAV will arrive in Shanghai at 10:00:00. The understanding of the second and third waypoint information is similar to that of the first waypoint information, and will not be repeated in the following text.

[0107] The following example uses the network device (i.e., gNB) in the NR network as the network device and the drone as the terminal device. The same applies to the network device being the eNodeB in the 4G network or other devices in the 6G network, and this application does not limit this. The NR protocol supports the reporting of the flight path of drones. Among them, the maximum number of waypoints in the flight path currently specified by the NR protocol is 20. In addition, the standard also supports the updating of the drone's flight path. For example, when the flight path of the drone changes, it can first send a flight path update indication message to the network device to notify the network device that the flight path has been updated. If the network device needs to update the flight path, it can send a flight path request message to the drone, requesting the drone to send the flight path to the network device.

[0108] When the drone is flying, it will pass through the coverage of different network devices. In this case, the drone needs to communicate with different network devices within the coverage of different network devices. The drone is currently flying within the coverage of the source network device. The drone communicates with the source network device and uploads the flight path of the drone to the source network device. The source network device performs network configuration based on the flight path. When the drone flies out of the coverage of the source network device and into the coverage of the target network device, the network device connected to the drone will switch from the source network device to the target network device, and the drone will communicate with the target network device.

[0109] Specifically, the switching process of the network device, such as Figure 4 As shown, the network device switching method is interactively executed by the user equipment UE, the source network device, the target network device, the AMF network element and the UPF network element, and may include the following steps:

[0110] Before the handover is completed, the user device interacts with the UPF through the source network device to exchange user data.

[0111] S401: The source network device sends measurement control information to the user equipment.

[0112] In the embodiment of the present application, the measurement control information is determined by the source network device according to information such as roaming and access restrictions.

[0113] After receiving the measurement control information, the user equipment generates a measurement report based on the measurement control information.

[0114] S402: The user equipment sends a measurement report to the source network equipment.

[0115] S403, the source network device determines whether to switch the network device based on the measurement report and radio resource measurement (RMM) information. If so, execute S404; otherwise, end.

[0116] S404: The source network device sends a switching request message to the target network device.

[0117] In the embodiment of the present application, the handover request message includes information such as the target cell identification (Identification, ID).

[0118] S405: The target network device performs access control.

[0119] S406: The target network device sends a switching request confirmation message to the source network device.

[0120] In the embodiment of the present application, the handover request confirmation message includes an RRC reconfiguration (radio resource control reconfiguration, RRC Reconfiguration) message that the target network device needs to send to the user equipment.

[0121] After receiving the handover request confirmation message, the source network device obtains the RRC reconfiguration message from the handover request confirmation message.

[0122] S407, the source network device sends an RRC reconfiguration message to the user equipment.

[0123] In the embodiment of the present application, the RRC reconfiguration message also includes information such as the target cell ID.

[0124] Optionally, if the data radio bearers (DRBs) of the source network device are configured with a dual active protocol stack (DAPS), the source network device may also send an early status transfer message to the target network device. The early status transfer message is used to instruct the target network device to clear the data packets that the source network device has completed sending from the stored data.

[0125] S408, the source network device sends a sequence number status transfer (SN status transfer) message to the target network device.

[0126] In an embodiment of the present application, the sequence number status transmission information is used to inform the target network device of the packet data convergence protocol (PDCP) sequence number.

[0127] S409, the user equipment sends an RRC reconfiguration complete (radio resource control reconfiguration complete, RRC Reconfiguration Complete) message to the target network device.

[0128] S410, the target network device sends a switching completion message to the source network device.

[0129] S411, the source network device sends SN status transfer information to the target network device.

[0130] S412, the target network device sends a path switching request message to the AMF network.

[0131] S413, the AMF network element performs path switching in the UPF network element.

[0132] S414, the AMF network element sends a path switching request confirmation message to the target network device.

[0133] S415: The target network device sends a context release message to the source network device.

[0134] Currently, cell handover can be divided into two types, one of which is cell handover based on layer 1 / layer 2, which can be called layer 1 / layer 2 handover or layer 1 / layer 2 triggered mobility (L1 / L2 triggered mobility, LTM), and the other is cell handover based on layer 3, which can be called layer 3 handover (L3 handover). Layer 1 can refer to the physical layer, layer 2 can refer to any one or more layers of the media access control (MAC) layer, the radio link control (RLC) layer, the packet data convergence protocol (PDCP), and the service data adaptation protocol (SDAP) layer, and layer 3 can refer to the RRC layer. It can be understood that layer 1 / layer 2 handover can also be understood as layer 1 and / or layer 2 handover; when it is an "and" relationship, the operations related to the handover process are mainly completed by layer 1 and layer 2; when it is an "or" relationship, the operations related to the handover process are mainly completed by layer 1 or layer 2. Since Layer 1 and Layer 2 are located at a lower level of the protocol stack than the RRC layer (Layer 3), Layer 1 / Layer 2 switching may also be referred to as low-layer switching, bottom layer switching, or lower-layer switching.

[0135] For Layer 3 switching, see Figure 4 As shown, the source network device receives a measurement report from the terminal device, and the measurement report includes a measurement result of layer 3. The source network device can select a candidate neighboring cell according to the measurement result of layer 3, such as Figure 4 Then the source network device sends a handover request message to the target network device of the candidate neighboring cell, that is, execute S406. Then continue the subsequent operations, see Figure 4 shown.

[0136] For layer 1 / layer 2 switching, the source network device selects the target cell based on the L3 measurement results. The subject that performs the target cell selection can be the CU of the source network device, and the switching configuration information of LTM is sent to the terminal device through the RRC reconfiguration message. The difference between layer 1 / layer 2 switching and layer 3 switching is that the switching on the source network device is performed at L1 / L2. Specifically, the terminal device reports the L1 measurement results to the source network device, the DU of the source network device makes a switching decision based on the L1 measurement results, and sends a switching command to the terminal device through the MAC control element (CE). After the switching is completed, the terminal device does not delete the configuration information of the target cell. The next time the terminal device switches to the target cell, it can directly send a switching command, which eliminates the switching configuration process and reduces the switching delay.

[0137] For details on the Layer 1 / Layer 2 switching process, see Figure 5 As shown, the following steps may be included:

[0138] LTM preparation phase:

[0139] S501, the terminal device sends a measurement report to the source network device. The source network device determines to use LTM switching according to the measurement report, and triggers candidate cell preparation, thereby generating a candidate cell list. The candidate cell list can contain one or more candidate cells. The measurement report can be understood as a layer 3 measurement report.

[0140] S502. The source network device sends an RRC reconfiguration message to the terminal device. The RRC reconfiguration message includes the configuration of each candidate cell in the candidate cell list.

[0141] S503: The terminal device saves the configuration information of the candidate cell sent by the source network device, and sends an RRC reconfiguration completion message to the source network device.

[0142] Early synchronous phase:

[0143] S504. Optionally, before the source network device receives the switching command, the terminal device may obtain timing advance (TA) in advance and synchronize to the candidate cell.

[0144] LTM execution phase:

[0145] S505: The terminal device measures each configured candidate cell and reports the L1 measurement result to the source network device.

[0146] S506. The source network device determines whether to perform LTM switching according to the L1 measurement result. If LTM switching is performed, a cell switch command is sent to the terminal device. For example, the execution of the switching can be triggered to the terminal device through MAC CE. MAC CE can carry the identifier of the target cell configuration, and the terminal device uses the corresponding target cell configuration according to the identifier.

[0147] S507: The terminal device determines whether a random access process needs to be performed, and the UE initiates a random access process to a target network device to which a target cell belongs.

[0148] LTM completion stage:

[0149] S508. The UE sends an RRC reconfiguration completion message to the target cell to indicate to the target network device that the handover is completed.

[0150] from Figure 5 It can be seen that in the current LTM measurement, after the network device configures the candidate cell list for the terminal device, the terminal device attempts to measure all candidate cells, resulting in low efficiency.

[0151] In combination with the above description, the present application embodiment provides a communication method, and the method provided by the present application can be applied to Figure 5 The network switching process. Among them, the terminal device can execute Figure 5 The steps that the terminal device performs in the network device can perform Figure 5 The steps performed by the Zhongyuan network device. For details, see Figure 6 As shown, the communication method may include the following steps:

[0152] S601, the network device sends a candidate cell list and first indication information to the terminal device. Correspondingly, the terminal device receives the candidate cell list and the first indication information.

[0153] The first indication information is used to indicate a first range, and the first range may be a range for measuring candidate cells in the candidate cell list.

[0154] In some embodiments, the network device may also send only a candidate cell list to the terminal device, where the candidate cell list includes candidate cells that the terminal device needs to measure within a first range. For example, in this case, the first range may be a default range of the terminal device and the network device. For example, the first range may be an interval between two waypoints where the terminal device is currently located.

[0155] In one possible implementation, the candidate cell list and the first indication information may be carried in configuration information, and the network device sends the configuration information to the terminal device. Exemplarily, the candidate cell list and the first indication information may be carried in an RRC reconfiguration message. In another possible implementation, the candidate cell list and the first indication information may also be sent separately, and the candidate cell list and the first indication information are carried in different information and sent by the network device to the terminal device.

[0156] It should be noted that the candidate cell list includes one or more candidate cells. If the network device configures multiple candidate cells for the terminal device, it can also be sent to the terminal device in a non-list form, such as in a collection or grouping manner. The embodiment of the present application is not limited to this.

[0157] With respect to the first range indicated by the first indication information, the embodiments of the present application may include the following possible implementation methods.

[0158] In a first possible implementation, the first range indicated by the first indication information may be a position or a position range. It may also be understood that the range in which the terminal device measures the candidate cells in the candidate cell list may be determined by the position or the position range indicated by the first indication information.

[0159] In mode 1, the first indication information may indicate a location range for measuring the candidate cells in the candidate cell list, and the location range may include a starting location and an ending location.

[0160] Mode 2, the first indication information may indicate the starting position for measuring the candidate cells in the candidate cell list. In some embodiments, the end position may be the starting position of the updated moving path or the end position of the moving path (such as the last waypoint in the moving path). The terminal device may stop (or end) the measurement of the candidate cells in the candidate cell list when updating the moving path. In some other embodiments, the end position may be the position or time when the switching command is received. The terminal device may also stop measuring the candidate cell list when receiving the switching command.

[0161] The starting position can be a waypoint on the moving path of the terminal device, or a geographical location, or a location interval. The moving path is the moving route planned by the terminal device. Optionally, the route of the drone flight can be called a flight path. The ending position can be a waypoint on the moving path of the terminal device, or a geographical location, or a location interval. Exemplarily, the location interval can be represented in the form of a location point and a distance threshold, or in other forms. The location point can be a waypoint or a geographical location.

[0162] The implementation scheme of the first indication information using method 1 is described below by way of example.

[0163] Example 1-1, the starting position and the ending position can be represented by waypoints. For example, the first indication information includes waypoint 1 and waypoint 2, that is, (waypoint 1, waypoint 2). Thus, when the terminal device arrives at waypoint 1, it starts to perform measurement on the candidate cells in the candidate cell list, and when the terminal device leaves waypoint 2, it stops (or ends) the measurement of the candidate cells in the candidate cell list.

[0164] In example 1-2, both the starting position and the ending position are indicated by geographic location. The geographic location may be in the form of longitude and latitude coordinates. For example, the first indication information includes geographic location 1 and geographic location 2, i.e. (geographic location 1, geographic location 2). Thus, when the terminal device reaches geographic location 1, it starts to measure the candidate cells in the candidate cell list, and when the terminal device leaves geographic location 2, it stops measuring the candidate cells in the candidate cell list.

[0165] In example 1-3, the starting position is a location interval, and the ending position is a geographic location or waypoint. Alternatively, the starting position is a geographic location or waypoint, and the ending position is a location interval.

[0166] For example, the starting position is a position where the distance from the first position is less than or equal to the first distance threshold, and the ending position is waypoint 2. The first indication information may include the first position, the first distance threshold and waypoint 2. The first position may be a waypoint or a geographical location. For example, the first position is waypoint 1, so that the terminal device starts to perform measurements on the candidate cell list at a position where the distance from waypoint 1 is less than the first distance threshold, and the measurement of the candidate cell list may be ended when the terminal device reaches waypoint 2. Exemplarily, the position where the distance from waypoint 1 is less than the first distance threshold may be the position where the distance from waypoint 1 is less than or equal to the first distance threshold during the process of flying to waypoint 1, and the position interval of the starting position may be the range from (waypoint 1-first distance threshold) to waypoint 1. The position where the distance from waypoint 1 is less than or equal to the first distance threshold may also be the position where the distance from waypoint 1 is less than or equal to the first distance threshold after flying away from waypoint 1, and the position interval of the starting position may be the range from waypoint 1 to (waypoint 1+first distance threshold).

[0167] For another example, the starting position is waypoint 1, and the ending position is a position whose distance from the second position is greater than or equal to a second distance threshold. The first indication information may include waypoint 1, the second position, and the second distance threshold. The second position may be a waypoint or a geographical location. For example, the second position is waypoint 2, so that when the terminal device arrives at waypoint 1, it starts to perform measurements on the candidate cell list, and the measurement of the candidate cell list can be ended at a position where the distance from waypoint 2 is greater than or equal to the second distance threshold. Exemplarily, the position where the distance from waypoint 2 is greater than or equal to the second distance threshold may be that in the process of flying away from waypoint 2, the measurement of the candidate cell list is ended when the distance from waypoint 2 is greater than or equal to the second distance threshold.

[0168] In example 1-4, the starting position is a position interval, and the ending position is a position interval. The starting position is a position whose distance from the first position is less than or equal to the first distance threshold, and the ending position may be a position whose distance from the second position is greater than or equal to the second distance threshold. The first position may be a waypoint or a geographical location. The second position may be a waypoint or a geographical location. Take the first position as waypoint 1 and the second position as waypoint 2 as an example. The first indication information may include waypoint 1, a first distance threshold, waypoint 2, and a second distance threshold. Thus, the terminal device starts to perform measurements on the candidate cell list at a position where the distance from waypoint 1 is less than or equal to the first distance threshold, and the measurement of the candidate cell list may be ended at a position where the distance from waypoint 2 is greater than or equal to the second distance threshold. In some possible scenarios, the first distance threshold and the second distance threshold are the same. The first indication information may include waypoint 1, a first distance threshold (or a second distance threshold) and waypoint 2. Thus, the terminal device starts to perform measurements on the candidate cell list at a position where the distance from waypoint 1 is less than or equal to the first distance threshold, and the measurement of the candidate cell list may be ended at a position where the distance from waypoint 2 is greater than or equal to the first distance threshold.

[0169] The implementation scheme when the first indication information adopts mode 2 is described as follows by way of example.

[0170] Example 2-1, the starting position can be represented by a waypoint. For example, the first indication information includes waypoint 1. Thus, the terminal device starts to perform measurements on the candidate cells in the candidate cell list when arriving at waypoint 1. In some embodiments, the terminal device can stop (or end) the measurement of the candidate cells in the candidate cell list when flying away from the moving path. In some other embodiments, the terminal device can also stop measuring the candidate cell list when receiving a switching command.

[0171] Example 2-2, the starting position can be represented by a geographic location. For example, the first indication information includes geographic location 1. Thus, the terminal device starts to perform measurements on the candidate cells in the candidate cell list when arriving at geographic location 1. In some embodiments, the terminal device can stop (or end) the measurement of the candidate cells in the candidate cell list when flying away from the moving path. In some other embodiments, the terminal device can also stop measuring the candidate cell list when receiving a switching command.

[0172] Example 2-3, the starting position can be represented by a position interval. The starting position is a position whose distance from the first position is less than or equal to the first distance threshold. Taking the first position as waypoint 1 as an example, the first indication information includes waypoint 1 and the first distance threshold. Thus, the terminal device starts to perform measurements on the candidate cell list at a position less than the first distance threshold from waypoint 1. In some embodiments, the terminal device can stop (or end) the measurement of the candidate cells in the candidate cell list when flying away from the moving path. In some other embodiments, the terminal device may also stop measuring the candidate cell list upon receiving a switching command.

[0173] In a second possible implementation, the first range indicated by the first indication information may be time or time range. It may also be understood that the range in which the terminal device measures the candidate cells in the candidate cell list may be determined by the time or time range indicated by the first indication information.

[0174] Mode 3: The first indication information may indicate a time range for measuring the candidate cells in the candidate cell list, and the time range may include a start time and an end time.

[0175] Mode 4: The first indication information may indicate the start time of measuring the candidate cells in the candidate cell list. In some embodiments, the terminal device may stop (or end) measuring the candidate cells in the candidate cell list when the terminal device flies away from the moving path. In some other embodiments, the terminal device may also stop measuring the candidate cell list when receiving a handover command.

[0176] The start time can be a moment or a time interval. The end time can be a moment or a time interval.

[0177] The implementation scheme when the first indication information adopts mode 3 is described as follows by way of example.

[0178] Example 3-1, the start time is the moment when the terminal device starts to perform measurements, and the end time is the moment when the terminal device ends the measurements. Taking the start time as moment 1 and the end time as moment 2 as an example, the first indication information indicates that the terminal device starts measuring the candidate cell list at moment 1 and ends the measurement of the candidate cell list at moment 2. Exemplarily, the first indication information may include moment 1 and moment 2, i.e. (moment 1, moment 2).

[0179] Example 3-2, the start time is a time interval, and the end time is a moment. Alternatively, the start time is a moment, and the end time is a time interval. For example, take the start time as a moment whose time difference with the first moment is less than or equal to the first time threshold, and the end time is moment 2. The first indication information indicates that the terminal device starts measuring the candidate cell list at a moment less than the first time threshold from the first moment, and ends the measurement of the candidate cell list at moment 2. Exemplarily, the first indication information may include the first moment, the first time threshold, and moment 2. The moment less than the first time threshold from the first moment may be the time interval from the first moment - the first time threshold to the first moment. Alternatively, the moment less than the first time threshold from the first moment may be the time interval from the first moment to the first moment + the first time threshold.

[0180] For another example, take the starting time moment 1 and the ending time as the moment when the time difference with the second moment is greater than or equal to the second time threshold. The first indication information indicates that the terminal device starts measuring the candidate cell at moment 1, and ends the measurement of the candidate cell list at the moment when the time difference with the second moment is greater than or equal to the second time threshold. Exemplarily, the first indication information may include moment 1, moment 2, and the second time threshold.

[0181] Example 3-3, the start time and the end time can both be time intervals. For example, take the start time as the moment when the time difference with the first moment is less than or equal to the first time threshold, and the end time as the moment when the time difference with the second moment is greater than or equal to the second time threshold. The first indication information instructs the terminal device to start measuring the candidate cell list at a moment when the time difference with the second moment is greater than or equal to the second time threshold. The first indication information can include the first moment, the first time threshold and the second moment, the second time threshold.

[0182] The time 1, the first time, the time 2 and the second time mentioned above may be the estimated arrival time of the waypoint in the flight path, or may be any time in the time interval corresponding to the moving path.

[0183] In a third possible implementation manner, the first range indicated by the first indication information may be location (range)+time (range).

[0184] Mode 5, the first indication information may indicate the starting point where the candidate cells in the candidate cell list are measured. The starting point may include the starting time and the starting position. For the method adopted for the starting time and the starting position, please refer to the description of Modes 1 to 4, which will not be repeated here. For example, the first indication information may include waypoint 1 and time 1. The terminal device starts measuring the candidate cells in the candidate cell list at time 1 and when it reaches waypoint 1. For another example, the first indication information may include waypoint 1, a first distance threshold, time 1 and a first time threshold. The terminal device starts measuring the candidate cells in the candidate cell list at a time when the time difference with time 1 is less than or equal to the first time threshold and the distance from waypoint 1 is less than or equal to the first distance threshold.

[0185] Mode 6, the first indication information may indicate the starting point and the ending point where the candidate cells in the candidate cell list are measured, the starting point may include the starting time and the starting position, and the ending point may include the ending position and the ending time. The methods adopted for the starting time and the starting position, the ending time and the ending position can be referred to the description of Modes 1 to 4, which will not be repeated here. For example, the first indication information may include waypoint 1 and time 1, as well as waypoint 1 and time 2. Then the terminal device starts measuring the candidate cells in the candidate cell list at time 1 and when it arrives at waypoint 1, and ends measuring the candidate cells in the candidate cell list at time 2 and when it leaves waypoint 2. For another example, the first indication information may include waypoint 1, the first distance threshold, time 1 and the first time threshold, as well as waypoint 1, the second distance threshold, time 2 and the second time threshold. The terminal device starts measuring the candidate cells in the candidate cell list at a time when the time difference with time 1 is less than or equal to the first time threshold and the distance from waypoint 1 is less than or equal to the first distance threshold. The terminal device starts measuring the candidate cells among the candidate cells at a time when the time difference from time 2 is greater than or equal to the second time threshold and at a position where the distance from waypoint 2 is greater than or equal to the second distance threshold.

[0186] In a fourth possible implementation manner, the first indication information indicates a height range corresponding to the first range.

[0187] Mode 7, the first indication information indicates the starting altitude and the ending altitude corresponding to the first range. For example, the starting altitude may be the minimum altitude, and the ending altitude may be understood as the maximum altitude. That is, the altitude range is represented by the minimum altitude and the maximum altitude. For another example, the starting altitude and / or the ending altitude may be indicated by altitude information relative to a reference plane, such as altitude information relative to sea level or ground level, or altitude information relative to the maximum value of the flight altitude.

[0188] Mode 8, the first indication information can indicate the altitude range for performing the measurement by indicating the starting altitude or the ending altitude. The starting altitude or the ending altitude can be indicated by the altitude information relative to the reference plane. For another example, the starting altitude and the ending altitude are indicated by an altitude threshold. For example, the first indication information includes an altitude threshold. Then the terminal device can be instructed to end the measurement when it is lower than the altitude threshold, that is, the altitude range for performing the measurement is 0 to the altitude corresponding to the altitude threshold. For another example, if the first indication information includes an altitude threshold, then the terminal device can be instructed to start performing the measurement when it is higher than the altitude threshold, that is, the altitude range for performing the measurement can be the altitude corresponding to the altitude threshold to the maximum flight altitude.

[0189] In the fifth possible implementation, the first indication information indicates the height (or height range) + position (or position range) corresponding to the first range. Considering that the ascending position and the descending position of the drone may be different. Different candidate cell lists are configured for different positions and different height ranges. For example, the first indication information includes a height threshold and a position point, which indicates that the terminal device measures the candidate cells in the candidate cell list at position point 1 and within a height range lower than the height threshold. For another example, the first indication information includes a height threshold and a position range, which indicates that the terminal device measures the candidate cells in the candidate cell list within the position range and within a height range lower than the height threshold. The position range can be the coverage range of the cell, or it can be represented by two position points. The position point can be a latitude and longitude coordinate. The position range can be represented by waypoint + distance threshold.

[0190] S602: The terminal device performs measurement on candidate cells within the first range.

[0191] In the first possible application scenario, the first possible implementation method to the third possible implementation method mentioned above can be applicable to non-UAV (or non-aircraft) terminal devices, and can also be applied to non-take-off and non-landing phases of UAVs (or aircraft).

[0192] In the second possible application scenario, the fourth possible implementation and the fifth possible implementation can be applied to the take-off or landing phase of the drone (or aircraft). Of course, when the flight altitude (or altitude range) corresponding to different positions of the drone (or aircraft) on the flight path is different, the fourth possible implementation and the fifth possible implementation can also be applied to the non-take-off or non-landing phase of the drone (or aircraft).

[0193] The solution provided by the embodiment of the present application is described below in the first possible application scenario.

[0194] See also Figure 7 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application. The method includes:

[0195] S701, see S601. The first indication information adopts any possible implementation manner from the first possible implementation manner to the third possible implementation manner.

[0196] In an embodiment of the present application, the network device may configure different candidate cell lists and the first range associated with the candidate cell lists for the terminal device. For example, the network device segments the moving path according to the moving path of the terminal device, configures multiple candidate cell lists and the first indication information corresponding to each candidate cell list. The terminal device then moves to the corresponding position (or position range) or time (or time range) according to the first indication information to measure the candidate cell in the candidate cell list corresponding to the first indication information.

[0197] Exemplarily, before step S701, S701a, the terminal device may send the moving path of the terminal device to the network device, and correspondingly, the network device receives the moving path of the terminal device, see Figure 7 Further, the network device may configure at least one candidate cell list and first indication information corresponding to (or associated with) each candidate cell list for the terminal device according to the moving path.

[0198] From the perspective of cell switching, the network devices in S701a-S701 can be understood as source network devices. Figure 7 It is described from the perspective of cell switching. Figure 7 It involves terminal devices, source network devices and target network devices.

[0199] Optionally, the source network device may also indicate to the terminal device when to delete the configuration information of the candidate cell that has been configured. This may also be understood as the trigger point or execution point at which the source network device indicates to the terminal device to perform a deletion operation on the configuration information of the candidate cell that has been configured.

[0200] In some possible implementations, before step S701, S7011 may be performed, and the source network device may also send the mobile path of the terminal device to the candidate network device (including the target network device). For example, the mobile path of the terminal device may be carried in a handover request (HO request) message. S7012, the candidate network device may send a cell list to the source network device, and the cells included in the cell list are the cells passed by the mobile path of the terminal device. Further, the source network device may determine the candidate cell list and the first indication information based on the received cell list of the candidate target network device.

[0201] In some other possible implementations, before step S701, S7013 may be further executed, and the source network device may further send the moving path of the terminal device to the candidate network device (including the target network device). S7014, the source network device sends first information to the candidate network device, and the first information is used to indicate at least one cell, such as the at least one cell belonging to the candidate network device. S7015, the candidate network device sends second information to the source network device. The second information is used to indicate whether the moving path of the terminal device passes through the at least one cell. Further, the source network device may determine the candidate cell list and the first indication information according to the second information of the candidate target network device received. Figure 7 Take the candidate network device as the target network device as an example. If the moving path of the terminal device passes through the at least one cell, the second information may be HOACK. If the moving path of the terminal device does not pass through the at least one cell, the second information may be HO prepartion failure (handover preparation failure).

[0202] S702, the source network device sends second indication information to the terminal device. In some embodiments, the source network device can carry the second indication information and the first indication information in the same message and send them to the terminal device, that is, S702 can be combined with S701 into one step. The source network device can also carry the second indication information and the first indication information separately in different messages and send them to the terminal device. The embodiment of the present application does not limit the order of S701 and S702.

[0203] The second indication information is used to indicate a trigger point for deleting configuration information of at least one second candidate cell, where the second candidate cell is a candidate cell in the candidate cell list.

[0204] In one possible case, the number of the at least one second candidate cell may be the number of all candidate cells in the candidate cell list, that is, the at least one second candidate cell includes N second candidate cells, the candidate cell list also includes N candidate cells, and the N second candidate cells are the same as the N candidate cells in the candidate cell list. In this case, it can be understood that the second indication information is used to indicate the deletion of configuration information of all candidate cells in the candidate cell list.

[0205] In another possible scenario, the number of the at least one second candidate cell is the number of all candidate cells corresponding to the first range in the candidate cell list. For example, the at least one second candidate cell includes N second candidate cells. The candidate cell list includes M candidate cells. M and N are both positive integers, and M is greater than N. The number of candidate cells within the first range measured by the terminal device is N. The N second candidate cells are the same as the N candidate cells within the first range of the candidate cell list. In this case, it can be understood that the second indication information is used to indicate the deletion of the configuration information of the candidate cells within the first range in the candidate cell list.

[0206] In some embodiments, the second indication information may also indicate a second range of candidate cells to be deleted. The second range may be indicated in a list form, or in a set form, or in other ways, which is not limited in the embodiments of the present application. The second range may be all candidate cells included in the candidate cell list for which measurement has been completed, or may be part of the candidate cells included in the candidate cell list for which measurement has been completed.

[0207] In a possible implementation manner, the second indication information indicates a trigger point for deleting configuration information of at least one second candidate cell, and the trigger point may be a position.

[0208] The trigger point can be a location point or a location range. The location point can be a waypoint or a geographic location.

[0209] For example, taking the trigger point as the first waypoint as an example, the second indication information indicates the first waypoint where the configuration information of the at least one second candidate cell is deleted. That is, when the terminal device reaches the first waypoint, the configuration information of the at least one second candidate cell is deleted. For another example, taking the trigger point as the first geographical location as an example, the second indication information indicates the first geographical location where the configuration information of the at least one second candidate cell is deleted. That is, when the terminal device reaches the first geographical location, the configuration information of the at least one second candidate cell is deleted.

[0210] For another example, take the trigger point as the location range. The location range can be a range between two waypoints. Taking the second waypoint and the third waypoint as an example, the location where the configuration information of at least one second candidate cell is deleted is the location between the second waypoint and the third waypoint. For another example, the location range is a range between two geographical locations. Taking the second geographical location and the third geographical location as an example, the location where the configuration information of at least one second candidate cell is deleted is the location between the second geographical location and the third geographical location. For another example, the location range is a range between a geographical location and a waypoint. Taking the fourth geographical location and the fourth waypoint as an example, the fourth geographical location is a location that is less than the third distance threshold from the fourth waypoint. Then the location where the configuration information of at least one second candidate cell is deleted is the location between the fourth geographical location and the fourth waypoint.

[0211] In another possible implementation, the second indication information indicates a trigger point for deleting configuration information of at least one second candidate cell, and the trigger point may be a time. The time used by the trigger point may be a moment or a time range. The time range may be represented by two moments or by a moment and a time threshold.

[0212] In another possible implementation, the second indication information indicates the trigger point for deleting the configuration information of at least one second candidate cell, and the trigger point may be a time + location point. For example, the trigger point includes time 3 and time 4, and a third location. The third location may be a waypoint or a geographic location. Then the second indication information indicates that the terminal device is between time 3 and time 4 and reaches the third location, and deletes the configuration information of at least one second candidate cell. For another example, the trigger point includes the third location, the fourth location, and time 3. Then the second indication information indicates that the terminal device is at time 3 and reaches the range between the third location and the fourth location, and deletes the configuration information of at least one second candidate cell.

[0213] It should be noted that the location or time of the trigger point is the location or time point after the measurement of the candidate cells in the candidate cell list is completed. For example, the flight path of the terminal device is Shanghai (10:00:00)-Suzhou (12:00:00)-Beijing (16:00:00). The terminal device configures two candidate cell lists and the first indication information corresponding to each candidate cell list. The two candidate cell lists include candidate cell list 1 and candidate cell list 2, respectively. The first indication information associated with candidate cell list 1 indicates the path segment of Shanghai (10:00:00)-Suzhou (12:00:00). The first indication information associated with candidate cell list 2 indicates the path segment of Suzhou (12:00:00)-Beijing (16:00:00). The trigger point for deleting the configuration information of the candidate cells included in candidate cell list 1 can be the location or time after flying away from Suzhou.

[0214] In another possible implementation, the network device may instruct the terminal device to delete the configuration information of the configured candidate cell after completing the handover.

[0215] S703, the terminal device sends an RRC reconfiguration completion message to the source network device. After receiving the first indication information and / or the second indication information, the terminal device may store the first indication information and / or the second indication information.

[0216] S704, the terminal device measures the candidate cells in the candidate cell list according to the first indication information. The measurement performed by the terminal device in this step may be L1 measurement.

[0217] S705, the terminal device sends an L1 measurement report to the source network device.

[0218] S706, the source network device sends a cell switch command to the terminal device, which is used to instruct the terminal device to switch to a target cell. The target cell may be a cell in the candidate cell list.

[0219] Optionally, when the source network device sends the second indication information to the terminal device, the second indication information may also be carried in the switching command. The step of sending the second indication information to the terminal device may also be after the source network device sends the switching command to the terminal device.

[0220] S707, the terminal device executes switching to the target cell and sends an RRC reconfiguration completion message to the target network device to which the target cell belongs.

[0221] In one possible implementation, when the network device sends the second indication information to the terminal device, the terminal device may perform a deletion operation on the configuration information of all or part of the candidate cells in the candidate cell list according to the second indication information after receiving the second indication information. Optionally, after performing the deletion operation, the terminal device may send a third indication information to the source network device, and the third indication information is used to indicate that the configuration information of some or all cells in the candidate cell list has been deleted. In some possible implementations, the source network device may also send a deletion indication to the network device to which the cell of the deleted configuration information belongs. The deletion indication is used to indicate that one or more candidate cells managed by the network device have been deleted.

[0222] In another possible implementation, when the network device does not send the second indication information to the terminal device, the terminal device can determine whether to delete all or part of the configuration information of the candidate cells in the candidate cell list according to the moving path. For example, after the terminal device completes the switch to the target cell in the candidate cell list, it can determine whether it will pass through the candidate cell in the candidate cell list according to the moving path. If it passes through the candidate cell, the configuration information of the candidate cell can be saved. If it does not pass through the candidate cell, the configuration information of the candidate cell can be deleted.

[0223] In a possible example, after completing the switch to the target cell, when it is determined based on the moving path of the terminal device that the second path passed after leaving the first path corresponding to the first range includes some or all of the candidate cells corresponding to the first range, the configuration information of some or all of the candidate cells in the candidate cell list corresponding to the first range can be retained. For example, the first path corresponding to the first range is the range between waypoint 1 and waypoint 2. If after leaving the range between waypoint 1 and waypoint 2, any waypoint between waypoint 1 and waypoint 2 is required to be passed subsequently, the terminal device can retain the configuration information of the candidate cells covering the range between waypoint 1 and waypoint 2, for example, the configuration information of the candidate cells in the candidate target cell list can be saved first.

[0224] After completing the switch to the target cell, when it is determined based on the moving path of the terminal device that the second path passed after flying away from the first path corresponding to the first range does not include some or all of the candidate cells corresponding to the first range, the configuration information of some or all of the candidate cells in the candidate cell list corresponding to the first range can be deleted.

[0225] In another possible example, after completing the handover to the target cell, when it is determined based on the moving path of the terminal device that the second path passed after leaving the first path corresponding to the first range includes the second range, and the shortest distance between the second range and the first range is less than or equal to the set threshold, the configuration information of some or all candidate cells in the candidate cell list corresponding to the first range continues to be saved. When it is determined based on the moving path that the second path passed after leaving the first path corresponding to the first range includes the second range, and the shortest distance between the second range and the first range is greater than the set threshold, the configuration information of some or all candidate cells in the candidate cell list corresponding to the first range is deleted.

[0226] For example, the first path corresponding to the first range is the range between waypoint 1 and waypoint 2. If after flying out of the range between waypoint 1 and waypoint 2, the distance between the subsequently passed waypoints and waypoint 1 or waypoint 2 is less than or equal to the set threshold, the terminal device can retain the configuration information of the candidate cells covering the range of waypoint 1 and waypoint 2, for example, the configuration information of the candidate cells in the candidate target cell list can be saved first.

[0227] Optionally, after deleting the configuration information of some or all candidate cells in the candidate target cell list, the terminal device may send a third indication message to the source network device, and the third indication message is used to indicate that some or all cells in the candidate cell list have been deleted. In some possible implementations, the source network device may also send a deletion indication to the network device to which the cell of the deleted configuration information belongs. The deletion indication is used to indicate that one or more candidate cells managed by the network device have been deleted. Exemplarily, the third indication information may be carried in an RRC reconfiguration completion message. For example, the third indication information may include an identifier of the cell from which the configuration information has been deleted, such as an ID.

[0228] In a possible implementation, if the terminal device enters the second path from the first path corresponding to the first range, and the configuration information of the cell measured in the second path has been applied, the measurement results of the saved cells can be cleared. Optionally, the terminal device can also end the current measurement, such as currently measuring the candidate cell list corresponding to the second path, and then end the measurement of the candidate cell list corresponding to the second path. In some embodiments, before the terminal device clears the measurement results of the saved cells, it can also report to the source network device and indicate the source network device the location (or location range) or time (or time range) corresponding to the measurement results. Exemplarily, when the terminal device reports the L1 measurement results to the source network device, it can indicate the location (or location range) or time (or time range) corresponding to the L1 measurement results.

[0229] In a possible implementation, if the terminal device enters the second path from the first path corresponding to the first range, and the configuration information of the cell measured in the second path has been applied, only the measurement results of the overlapping cells can be saved. Overlapping cells are cells included in the candidate cell list corresponding to the first path and included in the candidate cell list corresponding to the second path. It can be understood that the overlapping cells are the same cells in the candidate cell list corresponding to the first path and the candidate cell list corresponding to the second path. Optionally, the terminal device can also continue the current measurement, such as currently measuring the candidate cell list corresponding to the second path, and then continue the measurement of the candidate cell list corresponding to the second path. In some embodiments, the terminal device can report the measured L1 measurement result to the source network device, and indicate the source network device to the location (or location range) or time (or time range) corresponding to the measurement result. Exemplarily, when the terminal device reports the L1 measurement result to the source network device, it can indicate the location (or location range) or time (or time range) corresponding to the L1 measurement result.

[0230] In an embodiment of the present application, the first indication information is used to indicate the measurement range of the terminal device for the candidate cell list, so that the terminal device only needs to measure the cells within the measurement range, which can reduce the measurement overhead of the terminal device and improve the switching efficiency.

[0231] The solution provided by the embodiment of the present application is described below in the second possible application scenario, taking the take-off phase and the landing phase as an example.

[0232] See also Figure 8 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application. The method includes:

[0233] S801, see S601. The first indication information adopts any possible implementation manner among the fourth possible implementation manner to the fifth possible implementation manner.

[0234] In an embodiment of the present application, the source network device may configure different candidate cell lists and the first range associated with the candidate cell lists for the terminal device. The source network device may segment the flight altitude of the terminal device, configure multiple candidate cell lists and the first indication information corresponding to each candidate cell list. The terminal device then moves to the corresponding altitude (or altitude range) according to the first indication information to measure the candidate cell in the candidate cell list corresponding to the first indication information.

[0235] In some embodiments, the source network device may also send a fourth indication message to the terminal device, and the fourth indication message is used to instruct the terminal device to use the same configuration information in the ascending phase and the descending phase. In some possible scenarios, the terminal device is in the same position in the ascending phase and the descending phase, and the source network device may send a fourth indication message to the terminal device. For example, when the source network device sends a candidate cell list and a first indication message to the terminal device, the candidate cell list and the first indication message may be included in the first configuration message, and then the first configuration message is sent to the terminal device. If the ascending phase and the descending phase of the terminal device are in the same position, the source network device may send a fourth indication message to the terminal device to instruct the terminal device to use the first configuration information in both the ascending phase and the descending phase.

[0236] In other embodiments, the terminal device is located at different positions in the ascending phase and the descending phase, and the source network device may send a fifth indication information to the terminal device. The fifth indication information is used to indicate that the terminal device uses different configuration information in the ascending phase and the descending phase. In some scenarios, the source network device may also send a second configuration information to the terminal device, and the second configuration information includes a sixth indication information and a second candidate cell list. For ease of distinction, the candidate cell list in the first configuration information may be referred to as a first candidate cell list. Optionally, the range indicated by the sixth indication information and the first indication information sent by the source network device both include a height range and a position (or a position range). The terminal device may determine, based on the position and the moving path, whether the first configuration information is used in the ascending phase or the descending phase, and whether the second configuration information is used in the descending phase or the ascending phase. Exemplarily, the source network device may carry the first configuration information and the second configuration information in the same message, or may carry them in different messages and send them to the terminal device.

[0237] In some possible scenarios, the source network device may also adopt a direct indication method, such as the source network device sends seventh indication information to the terminal device, and the seventh indication information indicates the use phase of the first configuration information and the second configuration information. The first configuration information is used in the rising phase, and the second configuration information is used in the falling phase, or the first configuration information is used in the falling phase, and the second configuration information is used in the rising phase. Exemplarily, the source network device may carry the seventh indication information and the first configuration information and the second configuration information in the same message, or may carry them in different messages and send them to the terminal device.

[0238] Optionally, before configuring the candidate cell list and the first indication information for the terminal device, the source network device may execute S8011 to obtain the height coverage (or height coverage and position) of the candidate network device from the candidate network device (such as the neighbor's network device, including the target network device). Exemplarily, the source network device may send a handover request message to the neighbor's network device, and obtain the height coverage of the neighbor's network device through the handover request message. The candidate cell list and the first indication information may then be determined based on the height coverage of each neighbor. Figure 8 Take the candidate network device as the target network device as an example.

[0239] In a possible implementation, before executing S801, the source network device may also send a moving path to a candidate network device (which may be a neighbor's network device). The candidate network device may determine a list of cells belonging to the candidate network device through which the moving path passes. At least one cell in the cell list is a cell passed by the moving path. In some embodiments, the moving path may be a path passed by the terminal device during the ascending phase and / or a path passed by the descending phase. Further, the source network device may determine the candidate cell list and the first indication information based on the cell list of the candidate network device.

[0240] In some other possible implementations, before step S801, the source network device may also send the moving path of the terminal device to the candidate network device (including the target network device). The source network device sends first information to the candidate network device, and the first information is used to indicate at least one cell. The candidate network device sends second information to the source network device. The second information is used to indicate whether the moving path of the terminal device passes through the at least one cell. Further, the source network device may determine the candidate cell list and the first indication information according to the second information received from the candidate target network device.

[0241] Optionally, before configuring the candidate cell list and the first indication information for the terminal device, the source network device may also determine the current location information of the terminal device, or determine that the terminal device is in an ascending phase, or obtain the ascending information of the terminal device, so as to configure the candidate cell list and the first indication information for the terminal device. In some embodiments, the terminal device may actively report its current flight position, or notify the source network device (i.e., the network device currently providing services to the terminal device) after taking off.

[0242] S802, the terminal device sends an RRC configuration completion message to the source network device.

[0243] S803: The terminal device measures the candidate cells in the candidate cell list according to the first indication information to obtain an L1 measurement report, and sends the L1 measurement report to the source network device.

[0244] S804, the source network device sends a cell switch command to the terminal device. Exemplarily, the cell switch command may carry a configuration information index of the target cell.

[0245] In a possible implementation, when the terminal device enters the second altitude range from the first altitude range during flight and applies the configuration information of the target cell, the measurement results of the saved cells can be cleared. Optionally, the measurement of the candidate cells in the candidate cell list corresponding to the first altitude range can be stopped.

[0246] In another possible implementation, when the terminal device enters the second altitude range from the first altitude range during flight and applies the configuration information of the target cell, the terminal device continues to measure the candidate cells in the candidate cell list corresponding to the first altitude range. Optionally, when the cell measurement of the candidate cell list corresponding to the second altitude range is completed and the L1 measurement result is sent to the source network device, the L1 measurement result sent indicates that it corresponds to the second altitude range. The target cell is a cell in the candidate cell list corresponding to the first altitude range.

[0247] S805, after the terminal device switches to the target cell, it sends an RRC reconfiguration completion message to the target network device to which the target cell belongs.

[0248] In some possible implementations, after the terminal device switches to the target cell during the ascent process, the terminal device may decide whether to delete the configuration information of the candidate cell in the candidate cell list that has been measured during the ascent process according to the distance between the ascent position and the descent position. If the distance is short, the configuration information of the candidate cell may be saved for subsequent use, saving the step of re-acquisition and reducing resource waste.

[0249] In a possible example, after the handover to the target cell is completed during the ascending process, when it is determined that the distance between the position associated with the candidate cell list used in the descending process and the position associated with the candidate cell list to which the target cell belongs is greater than or equal to the set distance threshold, the configuration information of the candidate cell list to which the target cell belongs is deleted. Exemplarily, the terminal device can delete the configuration information of the candidate cells in the candidate cell list in sequence according to the measurement order of the candidate cells in the candidate cell list. The terminal device can also delete the configuration information of the candidate cells in the candidate cell list used in the ascending process after completing the ascending stage. If it is determined that the distance between the position associated with the candidate cell list used in the descending process and the position associated with the candidate cell list to which the target cell belongs is less than the set distance threshold, the configuration information of the candidate cell list used in the ascending process can continue to be saved. In some scenarios, candidate cell lists corresponding to different height ranges are configured in the ascending stage. After completing the measurement of the first height range and switching to the target cell in the candidate cell list corresponding to the first height range, if it is determined that the distance between the position associated with the descending process and the position associated with the candidate cell list to which the target cell belongs is greater than or equal to the set distance threshold, the terminal device can delete the configuration information of the candidate cell list corresponding to the first height range. The terminal device can perform a deletion operation on the candidate cell configuration information in different height intervals according to the height range.

[0250] In another possible example, after completing the switch to the target cell during the ascending process, when it is determined that the position associated with the candidate cell list used in the descending process does not cover the position associated with the candidate cell list to which the target cell belongs, the configuration information of the candidate cell list used in the ascending process is deleted. Exemplarily, the terminal device may delete the configuration information of the candidate cells in the candidate cell list in sequence according to the measurement order of the candidate cells in the candidate cell list. The terminal device may also uniformly delete the configuration information of the candidate cells in the candidate cell list used in the ascending process after completing the ascending stage. If it is determined that the position associated with the candidate cell list used in the descending process covers the position associated with the candidate cell list to which the target cell belongs, the configuration information of the candidate cell list used in the ascending process may continue to be retained.

[0251] Optionally, after deleting the configuration information of some or all candidate cells in the candidate target cell list used in the rising phase, the terminal device may send a third indication message to the source network device, and the third indication message is used to indicate that some or all cells in the candidate cell list have been deleted. In some possible implementations, the source network device may also send a deletion indication to the network device to which the cell of the deleted configuration information belongs. The deletion indication is used to indicate that one or more candidate cells managed by the network device have been deleted. Exemplarily, the third indication information may be carried in an RRC reconfiguration completion message. For example, the third indication information may include an identifier of the cell from which the configuration information has been deleted, such as an ID. The deletion indication may include an identifier of the cell from which the configuration information has been deleted.

[0252] In an embodiment of the present application, the first indication information is used to indicate the height measurement range of the candidate cell list of the terminal device, so that the terminal device only needs to measure the cells within the height measurement range, which can reduce the measurement overhead of the terminal device and improve the switching efficiency.

[0253] At present, when a terminal device performs early random access, the time of sending a preamble code will affect the accuracy of the TA. Based on this, the embodiment of the present application determines the timing of sending the preamble code (the trigger point of sending the preamble code) according to the moving path of the terminal device.

[0254] See also Fig. 9 FIG. 1 is a flow chart of a communication method provided in an embodiment of the present application. The communication method includes the following steps:

[0255] S901, a first network device sends a moving path of a terminal device to a second network device. The first network device is a network device that provides services for the terminal device, and the second network device is a candidate target network device to be switched. The moving path of the terminal device may be sent by the terminal device to the first network device.

[0256] Exemplarily, the first network device may carry the moving path of the terminal device in a handover request (HO request) message and send it to the second network device.

[0257] S902, the second network device sends eighth indication information to the first network device, where the eighth indication information is used to indicate a trigger point (or timing) for the terminal device to send a preamble code.

[0258] Exemplarily, the second network device may carry the eighth indication information in a handover request confirmation (HO request ACK) message and send it to the first network device.

[0259] Exemplarily, the second network device may determine the time and / or location when the terminal device passes through the coverage area of ​​the second network device according to the moving path of the terminal device, thereby determining the trigger point for the terminal device to send the preamble code.

[0260] In a possible implementation, the trigger point may be a position. For example, the eighth indication information is used to indicate the position where the terminal device sends the preamble.

[0261] The location adopted by the trigger point can be a location point or a location range. The location point can be a waypoint or a geographical location. Taking the trigger point adopting waypoint 2-1 as an example, the eighth indication information indicates the waypoint where the preamble is sent, and the eighth indication information may include waypoint 2-1. When the terminal device arrives at waypoint 2-1, it can send a preamble to the source network device. For another example, taking the trigger point adopting the fifth geographical location as an example, the eighth indication information indicates the fifth geographical location where the terminal device sends the preamble. When the terminal device arrives at the fifth geographical location, it can send a preamble to the source network device.

[0262] For another example, take the trigger point as the location range. The location range can be the range between two waypoints, taking the fifth waypoint and the sixth waypoint as an example, then the location where the terminal device sends the preamble code is the location between the fifth waypoint and the sixth waypoint. For another example, the location range can be the range between two geographical locations, taking the sixth geographical location and the seventh geographical location as an example. Then the location where the terminal device sends the preamble code is the location between the sixth geographical location and the seventh geographical location. For another example, the location range is represented by the third location and the fourth distance threshold. Then the location where the terminal device sends the preamble code is the location where the distance from the third location is less than or equal to the fourth distance threshold.

[0263] In another possible implementation, the trigger point may be a time. For example, the eighth indication information is used to indicate the time when the terminal device sends the preamble. The time adopted by the trigger point may be a moment or a time range. The time range may be represented by two moments, such as the third moment and the fourth moment. The time range may also be represented by a moment and a time threshold, such as the fifth moment and the third time threshold.

[0264] In another possible implementation, the trigger point may be time+position. For example, the eighth indication information is used to indicate the time and position at which the terminal device sends the preamble. For example, the trigger points include time 5 and time 6, and position 5. Position 5 may be a waypoint or a geographic location. Then the eighth indication information indicates that the terminal device sends the preamble between time 5 and time 6 and when it reaches position 5. For another example, the trigger points include position 5, position 6, and time 5. Then the eighth indication information indicates that the terminal device sends the preamble at time 5 and when it reaches the range between position 5 and position 6.

[0265] S903, the first network device sends the ninth indication information to the terminal device.

[0266] S904, the terminal device sends a preamble code according to the ninth indication information.

[0267] In some possible embodiments, the ninth indication information may be the eighth indication information, and the terminal device sends the preamble according to the ninth indication information. For example, the terminal device determines the timing of sending the preamble according to the ninth indication information, and then sends the preamble.

[0268] In some other possible embodiments, the ninth indication information is determined based on the eighth indication information. For example, the first network device may determine the timing of sending a physical downlink control channel (PDCCH) order (command) based on the eighth indication information, and then send the PDCCH order to the terminal device. For example, the ninth indication information may be a PDCCH order, and the PDCCH order is used to instruct the terminal device to send a preamble. Thus, the terminal device sends the preamble.

[0269] The embodiment of the present application determines the time or location for sending a preamble code for a terminal device through a candidate network device to improve the accuracy of the TA.

[0270] The above mainly introduces the scheme provided by the embodiment of the present application from the perspective of the interaction between the terminal device and the network device (and between the network devices). It is understandable that in order to achieve the above functions, the terminal device and the network device may include hardware structures and / or software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software in combination with the units and algorithm steps of each example described in the embodiments disclosed herein. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0271] The embodiment of the present application can divide the network device into functional units according to the above method example. For example, each functional unit can be divided according to each function, or two or more functions can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or software functional unit.

[0272] In the case of an integrated unit, Fig.10 A possible exemplary block diagram of the device involved in the embodiments of the present application is shown. Fig.10 As shown, the device 1000 may include: a processing unit 1002 and a communication unit 1003. The processing unit 1002 is used to control and manage the actions of the device 1000. The communication unit 1003 is used to support the communication between the device 1000 and other devices. Optionally, the communication unit 1003 is also called a transceiver unit, and may include a receiving unit and / or a sending unit, which are respectively used to perform receiving and sending operations. The device 1000 may also include a storage unit 1001 for storing program code and / or data of the device 1000.

[0273] (1) The apparatus 1000 may be a terminal device in the above embodiment. The processing unit 1002 may support the apparatus 1000 to execute the actions of the terminal device in each method example above. Alternatively, the processing unit 1002 mainly executes the internal actions of the terminal device in the method example, and the communication unit 1003 may support the communication between the apparatus 1000 and other devices.

[0274] For example, in one embodiment, the communication unit 1003 is used to: receive a candidate cell list and first indication information from a first network device; and the processing unit 1002 is used to: perform measurement on the candidate cells within the first range.

[0275] (2) The apparatus 1000 may be the first network device (or source network device) in the above embodiment. The processing unit 1002 may support the apparatus 1000 in executing the actions of the first network device (or source network device) in each method example above. Alternatively, the processing unit 1002 mainly executes the internal actions of the first network device (or source network device) in the method example, and the communication unit 1003 may support the communication between the apparatus 1000 and other devices.

[0276] For example, in one embodiment, the processing unit 1002 is used to determine the candidate cell list and the first indication information. The communication unit 1003 is used to send the candidate cell list and the first indication information to the terminal device.

[0277] For example, in another embodiment, the communication unit 1000 is used to: send the moving path of the terminal device to the second network device, and receive the eighth indication information sent by the second network device.

[0278] (3) The apparatus 1000 may be the second network device (or candidate network device or target network device) in the above embodiment. The processing unit 1002 may support the apparatus 1000 in executing the actions of the second network device (or candidate network device or target network device) in each method example above. Alternatively, the processing unit 1002 mainly executes the internal actions of the second network device (or candidate network device or target network device) in the method example, and the communication unit 1003 may support the communication between the apparatus 1000 and other devices.

[0279] For example, in one embodiment, the communication unit 1003 is used to: receive a moving path of a terminal device from a first network device, and send eighth indication information to the first network device.

[0280] It should be understood that the division of the units in the above device is only a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. And the units in the device can all be implemented in the form of software calling through processing elements; they can also be all implemented in the form of hardware; some units can also be implemented in the form of software calling through processing elements, and some units can be implemented in the form of hardware. For example, each unit can be a separately established processing element, or it can be integrated in a certain chip of the device. In addition, it can also be stored in the memory in the form of a program, and called and executed by a certain processing element of the device. The function of the unit. In addition, all or part of these units can be integrated together, or they can be implemented independently. The processing element described here can also be a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, each operation of the above method or each unit above can be implemented by an integrated logic circuit of hardware in the processor element or in the form of software calling through a processing element.

[0281] In one example, the unit in any of the above devices may be one or more integrated circuits configured to implement the above method, such as one or more application specific integrated circuits (ASIC), or one or more digital singnal processors (DSP), or one or more field programmable gate arrays (FPGA), or a combination of at least two of these integrated circuit forms. For another example, when the unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a processor, such as a general-purpose central processing unit (CPU), or other processors that can call programs. For another example, these units can be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0282] The above unit for receiving is an interface circuit of the device, which is used to receive signals from other devices. For example, when the device is implemented in the form of a chip, the receiving unit is an interface circuit of the chip used to receive signals from other chips or devices. The above unit for sending is an interface circuit of the device, which is used to send signals to other devices. For example, when the device is implemented in the form of a chip, the sending unit is an interface circuit of the chip used to send signals to other chips or devices.

[0283] Fig.11 A schematic diagram of the structure of a communication device provided in an embodiment of the present application is given. The communication device 1100 may be a circuit system of a terminal device described in any of the above embodiments, and is used to implement the method corresponding to the terminal device in the above method embodiment. Alternatively, the communication device 1100 may be a circuit system of a first network device (or a source network device) in any of the above embodiments, and is used to implement the method corresponding to the first network device in the above method embodiment. Alternatively, the communication device 1100 may be a circuit system of a second network device (or a candidate network device or a target network device) in any of the above embodiments, and is used to implement the method corresponding to the second network device (or a candidate network device or a target network device) in the above method embodiment.

[0284] The specific functions can refer to the description in the above method embodiment. For example, a circuit system is a chip system.

[0285] The communication device 1100 includes at least one processor 1101. The processor 1101 can be used for internal processing of the device to implement certain control processing functions. Optionally, the processor 1101 includes instructions. Optionally, the processor 1101 can store data. Optionally, different processors can be independent devices, can be located in different physical locations, and can be located on different integrated circuits. Optionally, different processors can be integrated into one or more processors, for example, integrated on one or more integrated circuits.

[0286] Optionally, the communication device 1100 includes one or more memories 1103 for storing instructions. Optionally, data may also be stored in the memory 1103. The processor and memory may be provided separately or integrated together.

[0287] Optionally, the communication device 1100 includes a communication line 1102 and at least one communication interface 1104. Since the memory 1103, the communication line 1102 and the communication interface 1104 are all optional, Fig.11 Indicated by dotted lines.

[0288] Optionally, the communication device 1100 may further include a transceiver and / or an antenna. The transceiver may be used to send information to other devices or receive information from other devices. The transceiver may be referred to as a transceiver, a transceiver circuit, an input / output interface, etc., and is used to implement the transceiver function of the communication device 1100 through an antenna. Optionally, the transceiver includes a transmitter and a receiver. Exemplarily, the transmitter may be used to generate a radio frequency signal from a baseband signal, and the receiver may be used to convert the radio frequency signal into a baseband signal.

[0289] The processor 1101 may include a general-purpose central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application.

[0290] The communication link 1102 may include a pathway to transmit information between the above-mentioned components.

[0291] The communication interface 1104 uses any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), wired access networks, etc.

[0292] The memory 1103 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 1103 may exist independently and be connected to the processor 1101 via the communication line 1102. Alternatively, the memory 1103 may also be integrated with the processor 1101.

[0293] Among them, the memory 1103 is used to store computer-executable instructions for executing the solution of the present application, and the execution is controlled by the processor 1101. The processor 1101 is used to execute the computer-executable instructions stored in the memory 1103, so as to implement the steps performed by the terminal device described in any of the above embodiments, or, to implement the steps performed by the first network device (or source network device) described in any of the above embodiments, or, to implement the steps performed by the second network device (or candidate network device or target network device) described in any of the above embodiments.

[0294] Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code, which is not specifically limited in the embodiments of the present application.

[0295] In a specific implementation, as an embodiment, the processor 1101 may include one or more CPUs, such as Fig.11 CPU0 and CPU1 in.

[0296] In a specific implementation, as an embodiment, the communication device 1100 may include multiple processors, such as Fig.11 1 and 1105. Each of these processors may be a single-CPU processor or a multi-CPU processor. A processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0297] when Fig.11 When the device shown is a chip, for example, a chip of a terminal device, or a chip of a first network device (or a source network device) or a second network device (or a candidate network device or a target network device), the chip includes a processor 1101 (and may also include a processor 1105), a communication line 1102 and a communication interface 1104, and optionally, may include a memory 1103. Specifically, the communication interface 1104 may be an input interface, a pin or a circuit, etc. The memory 1103 may be a register, a cache, etc. The processor 1101 and the processor 1105 may be a general-purpose CPU, a microprocessor, an ASIC, or one or more integrated circuits for controlling the execution of the program of the communication method of any of the above embodiments.

[0298] The terms "system" and "network" in the embodiments of the present application can be used interchangeably. "At least one" refers to one or more, and "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B, which can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following (individuals)" or similar expressions thereof refer to any combination of these items, including any combination of single items (individuals) or plural items (individuals). For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC. And, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects.

[0299] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0300] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0301] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0302] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0303] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: Applied to terminal equipment, including: receiving a candidate cell list and first indication information from a first network device, where the first indication information is used to indicate a first range, where the first range is a range for measuring candidate cells in the candidate cell list; Perform measurement on candidate cells within the first range.

2. The method according to claim 1, characterized in that The first indication information is used to indicate the first range, including: The first indication information is used to indicate the starting position and the ending position corresponding to the first range; or, The first indication information is used to indicate a starting position corresponding to the first range.

3. The method according to claim 2, characterized in that The starting position is: The terminal device starts to perform the measured waypoint; or, The geographical location where the terminal device starts to perform the measurement; or A position whose distance from the first position is less than or equal to a first distance threshold.

4. The method according to claim 2 or 3, characterized in that The end position is: The terminal device ends the measured waypoint; or, The geographical location where the terminal device ends the measurement; or A position whose distance from the second position is greater than or equal to a second distance threshold.

5. The method according to any one of claims 1 to 4, characterized in that: The first indication information is used to indicate the first range, including: The first indication information is used to indicate the start time and end time corresponding to the first range; or, The first indication information is used to indicate a start time corresponding to the first range.

6. The method according to claim 5, characterized in that The starting time is: The time when the terminal device starts to perform the measurement; or A moment whose time difference from the first moment is less than or equal to the first time threshold.

7. The method according to claim 5 or 6, characterized in that The end time is: The time when the terminal device ends the measurement; or A moment whose time difference from the second moment is greater than or equal to the second time threshold.

8. The method according to any one of claims 1 to 7, characterized in that: The method further comprises: Second indication information is received from the first network device, where the second indication information is used to indicate a trigger point for deleting configuration information of at least one second candidate cell, where the second candidate cell is a candidate cell in the candidate cell list.

9. The method according to claim 8, characterized in that The second indication information is used to indicate a trigger point for deleting configuration information of at least one second candidate cell, including: The second indication information is used to indicate a location where the configuration information of the at least one second candidate cell is deleted; or, The second indication information is used to indicate a time for deleting the configuration information of the at least one second candidate cell.

10. The method according to claim 9, characterized in that The location where the configuration information of the at least one second candidate cell is deleted is: The first waypoint at which the configuration information of the at least one second candidate cell is deleted; or, a first geographical location where the configuration information of the at least one second candidate cell is deleted; or, A position between the second waypoint and the third waypoint; or, a location between the second geographic location and the third geographic location; or, A position between a fourth geographical position and a fourth waypoint, wherein the fourth geographical position is a position whose distance from the fourth waypoint is less than a third distance threshold.

11. The method according to claim 9, characterized in that The second indication information is used to indicate a trigger point for deleting configuration information of at least one second candidate cell, including: The second indication information is used to indicate a time range for deleting configuration information of at least one second candidate cell, or, The second indication information is used to indicate a time to delete configuration information of at least one second candidate cell.

12. The method according to any one of claims 1 to 4, characterized in that: The first indication information is used to indicate the first range, including: The first indication information is used to indicate the starting height and the ending height corresponding to the first range; or, The first indication information is used to indicate the end height corresponding to the first range; or, The first indication information is used to indicate a starting height corresponding to the first range.

13. The method according to claim 12, characterized in that The receiving the candidate cell list and the first indication information from the first network device includes: First configuration information is received from the first network device, where the first configuration information includes the candidate cell list and the first indication information.

14. A communication method, characterized in that: Applied to the second network device, comprising: Determine a candidate cell list and first indication information; The candidate cell list and the first indication information are sent to a terminal device, where the first indication information is used to indicate a first range, and the first range is a range for measuring the candidate cells in the candidate cell list.

15. The method according to claim 14, characterized in that The first indication information is used to indicate the first range, including: The first indication information is used to indicate the starting position and the ending position corresponding to the first range; or, The first indication information is used to indicate a starting position corresponding to the first range.

16. The method according to claim 15, characterized in that The starting position is: The terminal device starts to perform the measured waypoint; or, The geographical location where the terminal device starts to perform the measurement; or A position whose distance from the first position is less than or equal to a first distance threshold.

17. The method according to claim 14 or 15, characterized in that The end position is: The terminal device ends the measured waypoint; or, The geographical location where the terminal device ends the measurement; or A position whose distance from the second position is greater than or equal to a second distance threshold.

18. The method according to any one of claims 14 to 17, characterized in that: The first indication information is used to indicate the first range, including: The first indication information is used to indicate the start time and end time corresponding to the first range; or, The first indication information is used to indicate a start time corresponding to the first range.

19. The method according to claim 18, characterized in that The starting time is: The time when the terminal device starts to perform the measurement; or A moment whose time difference from the first moment is less than or equal to the first time threshold.

20. The method according to claim 18 or 19, characterized in that The end time is: The time when the terminal device ends the measurement; or A moment whose time difference from the second moment is greater than or equal to the second time threshold.

21. The method according to any one of claims 14 to 20, characterized in that: The method further comprises: Sending second indication information to the terminal device, where the second indication information is used to indicate a trigger point for deleting configuration information of at least one second candidate cell, where the second candidate cell is a candidate cell in the candidate cell list.

22. The method according to claim 21, characterized in that The second indication information is used to indicate a trigger point for deleting configuration information of at least one second candidate cell, including: The second indication information is used to indicate a location where the configuration information of the at least one second candidate cell is deleted; or, The second indication information is used to indicate a time for deleting the configuration information of the at least one second candidate cell.

23. The method of claim 22, wherein: The location where the configuration information of the at least one second candidate cell is deleted is: The first waypoint at which the configuration information of the at least one second candidate cell is deleted; or, a first geographical location where the configuration information of the at least one second candidate cell is deleted; or, A position between the second waypoint and the third waypoint; or, a location between the second geographic location and the third geographic location; or, A position between a fourth geographical position and a fourth waypoint, wherein the fourth geographical position is a position whose distance from the first waypoint is less than a third distance threshold.

24. The method of claim 22, wherein: The second indication information is used to indicate a trigger point for deleting configuration information of at least one second candidate cell, including: The second indication information is used to indicate a time range for deleting configuration information of at least one second candidate cell, or, The second indication information is used to indicate a time to delete configuration information of at least one second candidate cell.

25. The method according to any one of claims 14 to 17, characterized in that: The first indication information is used to indicate the first range, including: The first indication information is used to indicate the starting height and the ending height corresponding to the first range; or, The first indication information is used to indicate the end height corresponding to the first range; or, The first indication information is used to indicate a starting height corresponding to the first range.

26. The method according to any one of claims 14 to 25, characterized in that The method further comprises: Sending the moving path of the terminal device to the second network device; A cell list is received from a second network device, wherein the cell list includes an identifier of at least one cell passed by the moving path.

27. The method according to any one of claims 14 to 25, characterized in that The method further comprises: Sending the moving path of the terminal device to the second network device; Sending first information to the second network device, where the first information is used to indicate at least one cell; Second information is received from a second network device, where the second information is used to indicate whether the moving path passes through the at least one cell.

28. A communication device, characterized in that: The invention comprises a processor and a memory, wherein the processor and the memory are coupled, and the processor is used to implement the method according to any one of claims 1 to 13, or to implement the method according to any one of claims 14 to 26.

29. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and the instructions are executed on a computer to enable the computer to execute the method of any one of claims 1 to 13, or the method of any one of claims 14 to 27.

30. A computer program product, characterized in that The device comprises a computer program or an instruction, and when the computer program or the instruction is executed by the device, the method according to any one of claims 1 to 13 is executed, or the method according to any one of claims 14 to 27 is executed.

Images