Communication method and communication device

Abstract

Provided are a communication method and a communication device, the method comprising: when a terminal device determines that the signal quality of a current serving cell is less than or equal to a first threshold, and the distance between the current position of the terminal device and the center position of the serving cell is greater than a first distance, determining that the signal quality of the current serving cell is less than or equal to the first threshold; in the embodiment of the invention, the cell search can be immediately triggered or the RRC connection reestablishment can be immediately triggered, and the current service cell is the NTN cell, so that the resident cell can be more quickly determined, the signal loss time is reduced, and the service experience of a user is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of communications, and more specifically, to a communication method and a communication device. Background Art

[0002] The low-orbit satellite communication technology currently under development has gradually brought satellite communication into the lives of ordinary people, similar to ground base station cellular cells. Since it is a low-orbit satellite, not a geostationary satellite, the satellite's position relative to the earth is constantly moving, which can also be understood as the coverage of satellite cellular cells is constantly changing. However, when the satellite flies around the earth at high altitude, the change in signal strength at the edge and center of the cell is not obvious, so the terminal equipment is not sensitive to triggering neighbor cell measurements.

[0003] In order to solve the above problems, the concept of "distance threshold" is currently introduced. In idle state, if the terminal device moves within the distance threshold, the terminal device may not start measuring neighboring cells; if the terminal device moves outside the distance threshold, it needs to start measuring neighboring cells. In connected state, distance-related measurements and reports are also added. Although the "distance threshold" is introduced to solve the problem of terminal devices triggering neighboring cell measurements, if the network device does not configure a suitable neighboring cell for the terminal device or the configured measurement conditions are not suitable, at this time, even if the signal quality of the current service cell of the terminal device is not good and meets the measurement conditions for triggering neighboring cells, the terminal device cannot measure the signal quality of the neighboring cell. In this scenario, the terminal device cannot perform neighboring cell measurements in time, and cannot perform cell reselection, resulting in a long signal interruption time and a poor user service experience. Similarly, in the connected state, if the network device does not trigger switching and the terminal device itself does not trigger the radio resource control (RRC) connection re-establishment, it may also cause signal interruption, affecting the user's service experience. Summary of the invention

[0004] The present application provides a communication method. When the signal quality of the service cell of the terminal device is poor, the cell search or RRC connection re-establishment is triggered in time by judging the conditions, which can reduce the signal interruption time and ensure the user's service experience.

[0005] In a first aspect, a communication method is provided. The method may be executed by a terminal device, or may be executed by a component of the terminal device (eg, a chip or a circuit), without limitation.

[0006] The method includes: a terminal device resides in a service cell, which is a non-terrestrial network NTN cell; when the signal quality of the service cell is less than or equal to a first threshold, and the distance between a first position and a center position of the service cell is greater than or equal to a first distance, the terminal device triggers a cell search or a radio resource control RRC connection re-establishment; wherein the first distance is used to characterize the distance between the center position of the service cell and the edge position of the service cell, and the first position is the current position of the terminal device.

[0007] In other scenarios, when air interface resource desynchronization occurs between the terminal device and the NTN in a connected state (for example, the synchronization signal (synchronization signal and PBCH block, SSB) sent by the NTN cannot be received due to poor signal quality of the serving cell), and the terminal device determines that the distance between the first position and the center position of the serving cell is greater than or equal to the first distance, the terminal device triggers the cell radio resource control RRC connection re-establishment.

[0008] Exemplarily, when the terminal device is in an idle state, the terminal device triggers a cell re-search; exemplary, when the terminal device is in a connected state, the terminal device triggers RRC connection re-establishment.

[0009] In the present application, "the signal quality of the serving cell is less than or equal to the first threshold value" can be understood as the signal quality of the serving cell has deteriorated, for example, the signal quality of the serving cell is so poor that it affects the user service quality. Alternatively, it can also be understood that the first threshold value is used to determine whether the signal quality of the serving cell has deteriorated. For example, the signal quality of the serving cell does not meet the S criterion; or, the reference signal received quality (reference signal received quality, RSRQ) of the serving cell is less than or equal to a certain threshold value; or, the reference signal received power (reference signal receiving power, RSRP) is less than or equal to a certain threshold value; or, the signal to interference plus noise ratio (signal to interference plus noise ratio, SINR) is less than or equal to a certain threshold value. For example, the terminal device can receive a synchronization signal block (synchronization signal block, synchronization signal block) from the serving cell, measure the signal quality of the serving cell, and thereby determine whether the signal quality of the current serving cell meets the S criterion. For another example, the terminal device can measure the reference signal to determine whether the RSRP or RSRQ of the current serving cell meets the threshold value.

[0010] The "first threshold" and "threshold value" mentioned in this application may be pre-configured values ​​according to actual conditions. For example, if it is generally determined that when RSRP is less than a certain value, it means that the signal quality of the current serving cell has deteriorated, then the "first threshold" or "threshold value" here may be this value.

[0011] In the present application, "the terminal device triggers a cell search or RRC connection re-establishment" can also be understood as the terminal device immediately triggering a cell search or immediately triggering an RRC re-establishment. In other words, in the solution provided in the present application, as long as the terminal device determines that the signal quality of the serving cell is less than or equal to the first threshold, and the distance between the first position and the serving cell is greater than the first distance, if the terminal device is in an idle state, the cell re-search is immediately triggered, and if the terminal device is in a connected state, the RRC connection re-establishment is immediately triggered. The terminal device does not need to wait, or wait for instructions from the network device, and can autonomously trigger the corresponding action.

[0012] It should be understood that, in general, the system message of the serving cell will carry satellite ephemeris information, and the satellite ephemeris information includes the current serving satellite ephemeris and the neighboring satellite ephemeris. In general, the satellite ephemeris includes information about the location of the satellite, for example, including the satellite's orbit and the satellite's current location at the moment. The terminal device can determine the satellite's orbit based on the satellite's location information, and the terminal device can determine the center location of the serving cell through the satellite's current location at the moment.

[0013] In one possible implementation, the terminal device can determine the position of the satellite at the next moment through the satellite's orbit and the satellite's current position at the next moment, and then determine the projection of the satellite on the ground (i.e., the sub-satellite point) based on the determined satellite at the next moment, thereby determining the center position of the current service cell.

[0014] In another possible implementation, the satellite position information also includes a reference point, through which the terminal device can determine the center position of the current service cell.

[0015] In the present application, the location information of the terminal device itself can be obtained through methods such as the global navigation satellite system (GNSS) and the global positioning system (GPS).

[0016] The "first distance" in this application is used to represent the distance between the center position of the current serving cell and the edge position of the current serving cell. It should be noted that the specific value of the "first distance" in this application can be understood as the distance between the center position of the current serving cell and the edge position of the current serving cell. The edge position of the cell is usually estimated. For example, Figure 4 In the satellite #1 coverage shown, the actual coverage of satellite #1 may be the coverage shown by the outermost dotted line, while the coverage shown by the inner solid line may be an estimate. Therefore, the edge position of the cell may be the position of the outermost dotted line or the position of the inner solid line. Alternatively, it can be understood that the edge position of the cell cannot be accurately determined. For example, Figure 4 A schematic diagram of the “first distance” is shown in FIG. Therefore, the “first distance” in the present application is actually an approximate value or an estimated value.

[0017] Based on the above scheme, in this application, if the terminal device determines that the signal quality of the current service cell is less than or equal to the first threshold, and the distance between the current position of the terminal device and the center position of the service cell is greater than the first distance, it can immediately trigger a cell search or immediately trigger RRC connection re-establishment, thereby determining the resident cell more quickly, reducing the time of signal loss, and ensuring the user's service experience.

[0018] In combination with the first aspect, in a possible implementation manner, the first distance may be preconfigured.

[0019] In combination with the first aspect, in a possible implementation, the method also includes: the terminal device receives a system message from a serving cell, the system message carries a distance threshold corresponding to the serving cell; the terminal device determines the first distance based on the distance threshold corresponding to the serving cell and a first offset value, wherein the first offset value is preconfigured.

[0020] Based on the above solution, in the present application, for example, when the terminal device executes the technical solution of the present application for the first time, multiple implementation methods for obtaining the first distance are provided, so that the terminal device can flexibly obtain the first distance.

[0021] In combination with the first aspect, in a possible implementation, the method also includes: the terminal device resides in the first cell; the terminal device receives a system message from the first cell, the system message carrying measurement information of the first cell and measurement information of the neighboring cells of the first cell; according to the system message of the first cell, when the signal quality of the first cell does not meet the S criterion and the signal quality of the neighboring cells of the first cell meets the S criterion, reselecting to the neighboring cell of the first cell.

[0022] In combination with the first aspect, in a possible implementation, the system message of the first cell also carries the location information of the satellite, the location information of the satellite includes the satellite's orbit and the satellite's current location, and / or the satellite's location information includes the satellite's reference point. The method also includes: determining the center position of the first cell based on the system message of the first cell.

[0023] The above technical solution can also be understood as follows: if the terminal device performs a cell search and finds that the distance between its current position and the center position of the first cell is less than the first distance among the multiple candidate cells searched, it can reside in the first cell. Later, the terminal device may be at the edge of the first cell due to position movement, so it triggers measurement in the first cell. After the measurement, it is found that the neighboring cell of the first cell can be reselected (that is, after the measurement, it is found that the signal quality of the first cell is poor, and the signal quality of the neighboring cell of the first cell is better). At this time, the terminal device can update the first distance according to the distance between its current position and the center position of the first cell. For example, the updated first distance is used for the terminal device to trigger a cell re-search or RRC connection re-establishment in the reselected cell. For another example, the updated first distance can be used to maintain the first offset value.

[0024] In combination with the first aspect, in a possible implementation method, the system message of the first cell carries a distance threshold corresponding to the first cell, and the method also includes: updating the first offset value according to the updated first distance and the distance threshold corresponding to the first cell, receiving a system message from a second cell, the system message of the second cell carries the distance threshold corresponding to the second cell, and the second cell is a neighboring cell of the reselected first cell; determining the first distance according to the updated first offset value and the distance threshold corresponding to the second cell.

[0025] The above technical solution can also be understood as that when the terminal device is reselecting, the first distance can be updated, and the first offset value can be updated based on the updated first distance. The terminal device receives the distance threshold corresponding to the second cell in the second cell after reselection, and then determines the first distance according to the distance threshold corresponding to the second cell and the updated first offset value. When the terminal device subsequently moves and finds that the signal quality in the second cell is less than or equal to the first threshold, and determines that the distance between its current position and the center position of the second cell is greater than the determined first distance, it can trigger a cell search or RRC re-establishment in the second cell.

[0026] Based on the above technical solution, in this application, it is proposed that the terminal device can flexibly update and maintain the first distance based on the current actual situation, so that the first distance is more accurate and better matches the specific scenario of the terminal device.

[0027] In combination with the first aspect, in a possible implementation, the method also includes: among the multiple candidate cells searched, if the distance between the first position and the center position of each candidate cell is greater than or equal to the first distance, the terminal device resides in a third cell, wherein the third cell is a cell among the multiple candidate cells that is closest to the terminal device.

[0028] In combination with the first aspect, in one possible implementation, in another possible implementation, the terminal device may also temporarily determine a second distance, which is the average of the distances between the terminal device and the center positions of the multiple candidate cells that cannot be resided in. In other words, if the terminal device determines that the distances between the multiple candidate cells that have been searched are too far, exceeding the first distance, and cannot reside in any of them, the terminal device can respectively determine the distances between the center positions of each candidate cell, determine an average value temporarily as the second distance, and find the first cell that is less than the second distance from the multiple candidate cells as the cell to reside in. Subsequently, for example, the terminal device may update the first distance based on the method provided above.

[0029] In combination with the first aspect, in a possible implementation, when the terminal device finds that each searched candidate cell cannot be resident, it can also directly temporarily ignore the first distance and randomly select a candidate cell from the searched multiple candidate cells as the resident cell. Subsequently, for example, the terminal device can update the first distance based on the above-provided method.

[0030] Based on the above technical solution, in this application, it is proposed that if the terminal device cannot reside in the multiple candidate cells searched, it means that the first distance is not applicable to the current scenario (for example, in the current scenario, the first distance is configured too small, resulting in the distance between the terminal device and the center position of any candidate cell being greater than the first distance), and the terminal device cannot reside in any of the searched cells. At this time, the terminal device can adopt multiple methods to ensure that the terminal device can reside in one of the cells, and then update the first distance.

[0031] In combination with the first aspect, in a possible implementation, the method also includes: determining a first parameter and a second parameter based on the first position and the position information of the satellite, wherein the first parameter is used to characterize the distance between the first position and the second axis, and the second parameter is used to characterize the distance between the first position and the first axis, the first axis is determined based on the satellite's trajectory, the first axis is used to characterize the satellite's trajectory, the second axis is perpendicular to the first axis, and the intersection of the first axis and the second axis is the center position of the service cell.

[0032] In combination with the first aspect, in a possible implementation method, the first distance includes a third parameter and a fourth parameter, wherein the third parameter is used to characterize the distance between the edge position of the service cell and the second axis, and the fourth parameter is used to characterize the distance between the edge position of the service cell and the first axis. When the signal quality of the service cell is less than or equal to the first threshold, and the distance between the first position and the center position of the service cell is greater than or equal to the first distance, a cell search or RRC connection re-establishment is triggered, including: when the signal quality of the service cell is less than or equal to the first threshold, and the value of the first parameter is greater than or equal to the value of the third parameter, a cell search or a wireless resource control RRC connection re-establishment is triggered, and / or; when the signal quality of the service cell is less than or equal to the first threshold, and the value of the second parameter is greater than or equal to the value of the fourth parameter, a cell search or a wireless resource control RRC connection re-establishment is triggered.

[0033] In the present application, considering that the coverage of the satellite is approximately circular (for example, the coverage is rectangular or square), the configured first distance can be characterized by multiple parameters, and the position of the terminal device can also be characterized by multiple parameters. In this scenario, when the signal quality of the serving cell is less than or equal to the first threshold, and any parameter in the first position is greater than the corresponding parameter in the first distance, the terminal device can trigger a cell search or RRC connection re-establishment.

[0034] Based on the above technical solution and taking into account the diversity of cell coverage shapes, the present application optimizes the representation method of the first distance so that based on cell coverage ranges of different shapes, the terminal device can flexibly determine whether the current position is greater than the first distance from the center position of the cell.

[0035] In combination with the first aspect, in a possible implementation method, the system message of the serving cell also carries a distance threshold, and the distance threshold includes a fifth parameter and a sixth parameter, wherein the fifth parameter is used to characterize the distance between the second axis and the starting measurement point when starting the measurement, and the sixth parameter is used to characterize the distance between the first axis and the starting measurement point when starting the measurement.

[0036] In the present application, when the coverage of the satellite is approximately circular (for example, the coverage is rectangular or square), the distance threshold (distance Thresh) can also be characterized by multiple parameters. For example, in this scenario, the condition for the terminal device to trigger measurement can be: when any parameter in the first position is greater than the corresponding parameter in the distance threshold, the cell measurement can be triggered.

[0037] In this scenario, the terminal device can update and maintain the first distance based on the above technical solution. For example, if the terminal device triggers the measurement of the first axis, the parameters corresponding to the first axis in the first distance can be updated later. For another example, if the terminal device triggers the measurement of the second axis, the parameters corresponding to the second axis in the first distance can be updated later.

[0038] In combination with the first aspect, in a possible implementation manner, the system message of the serving cell further carries the first distance.

[0039] In this scenario, the NTN may also directly notify the terminal device of the multiple parameters corresponding to the first distance. For example, at this time, the terminal device may not need to update and maintain the first distance by itself. For another example, the terminal device may continue to update the corresponding parameters of the first distance maintained locally based on the received multiple parameters corresponding to the first distance.

[0040] In a second aspect, the present application proposes a communication device, which is used to execute the method of the first aspect. Specifically, the device may include units and / or modules, such as a transceiver unit and / or a processing unit, for executing the communication method proposed in the present application.

[0041] In a third aspect, a communication device is provided, the device comprising: at least one processor, configured to execute a computer program or instruction stored in a memory to perform the method of the first aspect. Optionally, the device further comprises a memory, configured to store a computer program or instruction. Optionally, the device further comprises a communication interface, and the processor reads the computer program or instruction stored in the memory through the communication interface.

[0042] In one implementation, the device is a functional communication device for implementing the communication method provided in the present application in a chip.

[0043] In another implementation, the device is a functional chip, chip system or circuit used to implement the communication method provided in the present application in a chip.

[0044] In a fourth aspect, the present application provides a processor, comprising: an input circuit, an output circuit and a processing circuit. The processing circuit is used to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes the method of the first aspect.

[0045] In the specific implementation process, the processor can be one or more chips, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, a gate circuit, a trigger, and various logic circuits. The input signal received by the input circuit can be received and input by, for example, but not limited to, a transceiver, and the signal output by the output circuit can be, for example, but not limited to, output to a transmitter and transmitted by the transmitter, and the input circuit and the output circuit can be the same circuit, which is used as an input circuit and an output circuit at different times. The embodiments of the present application do not limit the specific implementation methods of the processor and various circuits.

[0046] For the operations such as sending and acquiring / receiving involved in the processor, unless otherwise specified, or unless they conflict with their actual function or internal logic in the relevant description, they can be understood as operations such as processor output, reception, input, etc., or as sending and receiving operations performed by the radio frequency circuit and antenna, and this application does not limit this.

[0047] In a fifth aspect, a processing device is provided, comprising a processor and a memory. The processor is used to read instructions stored in the memory, and can receive signals through a transceiver and transmit signals through a transmitter to execute the method of the first aspect.

[0048] Optionally, the number of the processors is one or more, and the number of the memories is one or more.

[0049] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0050] In the specific implementation process, the memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or can be set on different chips respectively. The embodiments of the present application do not limit the type of memory and the setting method of the memory and the processor.

[0051] It should be understood that the related data interaction process, such as sending indication information, can be a process of outputting indication information from the processor, and receiving capability information can be a process of receiving input capability information by the processor. Specifically, the data output by the processor can be output to the transmitter, and the input data received by the processor can come from the transceiver. Among them, the transmitter and the transceiver can be collectively referred to as a transceiver.

[0052] The processing device in the fifth aspect may be one or more chips. The processor in the processing device may be implemented by hardware or by software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor may be a general-purpose processor implemented by reading software code stored in a memory, which may be integrated in the processor or located outside the processor and exist independently.

[0053] In a sixth aspect, a computer-readable storage medium is provided, wherein the computer-readable medium stores a program code for execution by a device, wherein the program code includes a method for executing the above-mentioned first aspect.

[0054] In a seventh aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the method of the first aspect.

[0055] In an eighth aspect, a chip system is provided, comprising a processor for calling and running a computer program from a memory, so that a device equipped with the chip system executes the method of the first aspect above.

[0056] In a ninth aspect, a communication system is provided, the communication system comprising a terminal device and an NTN device, wherein the terminal device is used to execute any possible implementation method in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is a schematic diagram of a scenario to which this application is applicable.

[0058] Figure 2 It is a schematic diagram of a terminal device measuring a neighboring cell as shown in the present application.

[0059] Figure 3 It is a schematic flow chart of a communication method 300 provided in the present application.

[0060] Figure 4 It is a schematic diagram of the first distance provided in this application.

[0061] Figure 5 This is another schematic diagram of a communication method provided by the present application.

[0062] Figure 6 This is another schematic diagram of the first distance provided in this application.

[0063] Figure 7 It is a schematic block diagram of the communication device 100 provided in this application.

[0064] Figure 8 It is a schematic block diagram of the communication device 200 provided in this application. DETAILED DESCRIPTION

[0065] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0066] The wireless communication systems to which the embodiments of the present application can be applied include, but are not limited to: global system of mobile communication (GSM) system, long term evolution (LTE) frequency division duplex (FDD) system, LTE time division duplex (TDD), LTE system, advanced long term evolution (LTE-Advanced, LTE-A) system, next generation communication system (for example, 6G communication system), a fusion system of multiple access systems, or an evolution system.

[0067] The technical solution provided in the present application can also be applied to machine type communication (MTC), long term evolution-machine (LTE-M), device to device (D2D) network, machine to machine (M2M) network, Internet of things (IoT) network or other networks. Among them, IoT network can include vehicle networking, for example. Among them, the communication mode in the vehicle networking system is collectively referred to as vehicle to other devices (vehicle to X, V2X, X can represent anything), for example, the V2X can include: vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) communication or vehicle to network (V2N) communication, etc.

[0068] The terminal devices involved in the embodiments of the present application may include various access terminals, mobile devices, user terminals or user devices with wireless communication functions. For example, the terminal device may be user equipment (UE), such as a mobile phone, a tablet computer (pad), a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, etc. The terminal device may also be a wireless terminal in industrial control, a machine type communication (MTC) terminal, a customer premise equipment (CPE), a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a smart home, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolved public land mobile network (PLMN), etc.

[0069] The satellite mentioned in the embodiments of the present application may also be a satellite base station, or a network-side device carried on a satellite.

[0070] The low-orbit satellite communication technology currently under development has gradually brought satellite communication into the lives of ordinary people, similar to ground base station cellular cells. Since it is a low-orbit satellite, not a geostationary orbit satellite, the satellite's position relative to the earth is constantly moving, which can also be understood as the coverage of satellite cellular cells is constantly changing. Figure 1 This is a schematic diagram of a scenario applicable to this application, such as Figure 1 As shown, when the satellite flies at high altitude around the earth, the change of signal strength at the cell edge and the cell center is not obvious, so the terminal equipment is not sensitive to triggering neighbor cell measurement.

[0071] In order to solve the above problems, the concept of "distance threshold" is introduced. Figure 2 As shown. In idle state, if the terminal device moves within the distance threshold, the terminal device may not start measuring neighboring cells; if the terminal device moves outside the distance threshold, it needs to start measuring neighboring cells. In connected state, distance-related measurements and reports are also added. Although the "distance threshold" is introduced to enable terminal devices to trigger neighboring cell measurements, if the network device does not configure a suitable neighboring cell for the terminal device or the configured measurement conditions are not suitable, even if the signal quality between the terminal device and the current service cell is poor and the conditions for triggering the neighboring cell measurement are met, the terminal device cannot measure the signal quality of the neighboring cell; if the terminal device is located at the cell boundary, the satellite is rotating and the terminal device does not have time to measure the signal quality of the neighboring cell. In these scenarios, the terminal device is actually unable to perform neighboring cell measurements in a timely manner, resulting in a long signal interruption time and a poor user service experience. Similarly, in the connected state, assuming that the link fails, the handover fails, or the radio resource control (RRC) reconfiguration fails, the network device may not trigger the handover, and the terminal device itself may not trigger the RRC connection re-establishment, which may cause signal interruption and affect the user's service experience.

[0072] In view of this, the present application provides a communication method, in the idle state, when the terminal device determines that the signal quality of the current serving cell is less than or equal to the first threshold, and determines that the distance from the serving cell center is greater than the first distance, the cell search can be actively triggered, thereby searching for the corresponding cell to reside in, which can reduce the signal interruption time. In the connected state, when the signal quality of the serving cell is less than or equal to the first threshold, if the terminal device determines that the distance from the serving cell center is greater than the first distance, the RRC connection re-establishment can be actively triggered, thereby restoring the link and reducing the signal interruption time. The method provided by the present application can ensure the user's service experience.

[0073] Figure 3 is a schematic flow chart of a communication method 300 provided in the present application, such as Figure 3 As shown, the method includes:

[0074] 301. The terminal device determines that the signal quality of the service cell is less than or equal to a first threshold, and the distance between the first position and the center position of the service cell is greater than or equal to a first distance, wherein the first position is the current position of the terminal device.

[0075] 302. The terminal device triggers a cell search or RRC connection re-establishment.

[0076] The above steps 301 and 302 can also be understood as that when the signal quality of the serving cell is less than or equal to the first threshold, and the distance between the first position and the center position of the serving cell is greater than or equal to the first distance, the terminal device triggers a cell search or an RRC connection reestablishment. The terminal device resides in the serving cell, which is an NTN cell.

[0077] Exemplarily, when the terminal device is in an idle state, a cell search is triggered, or; when the terminal device is in a connected state, an RRC connection re-establishment is triggered.

[0078] In other scenarios, when air interface resource desynchronization occurs between the terminal device and the NTN in a connected state (for example, the synchronization signal (synchronization signal and PBCH block, SSB) sent by the NTN cannot be received due to poor signal quality of the serving cell), and the terminal device determines that the distance between the first position and the center position of the serving cell is greater than or equal to the first distance, the terminal device triggers the cell radio resource control RRC connection re-establishment.

[0079] In the present application, "the signal quality of the serving cell is less than or equal to the first threshold value" can be understood as the signal quality of the serving cell has deteriorated. Or it can also be understood that the first threshold value is used to determine whether the signal quality of the serving cell has deteriorated. For example, the signal quality of the serving cell does not meet the S criterion; or, the reference signal received quality (reference signal received quality, RSRQ) of the serving cell is less than or equal to a certain threshold value; or, the reference signal received power (reference signal receiving power, RSRP) is less than or equal to a certain threshold value; or, the signal to interference plus noise ratio (signal to interference plus noise ratio, SINR) is less than or equal to a certain threshold value. For example, the terminal device can receive a synchronization signal block (synchronization signal block) from the serving cell, measure the signal quality of the serving cell, and thereby determine whether the signal quality of the current serving cell meets the S criterion. For another example, the terminal device can measure the reference signal to determine whether the RSRP, RSRQ, and SINR of the current serving cell meet the threshold value.

[0080] The "S criterion (Srxlev)" in this application can be described with reference to the definition of the existing S criterion. Normally, the S criterion is used for cell selection or cell reselection. The calculation formula is: Srxlev = Qrxlevmeas-Qrxlevmin-Pcompensation; wherein, the current service cell receiving power measured by Qrxlevmeas refers to the reference signal receiving power (RSRP) value of the P-CCPCH channel; Qrxlevmin is the minimum receiving power of the current service cell. This parameter can be read from the system broadcast message. Generally, the terminal device needs to perform certain arithmetic conversion after reading it; Pcompensation is the compensation value, which can be calculated by the following formula: Pcompensation = max (UE_TXP-WR_MAX_RACH-P_MAX, 0); wherein, UE_TXPWR_MAX_RACH is the maximum transmit power of the terminal on RACH when making random access, which is sent by the system broadcast message and is generally set to 0; P_MAX is the maximum nominal transmit power of the terminal, which is determined by the capabilities of the terminal device.

[0081] The "first threshold" and "threshold value" mentioned in this application can be pre-configured according to actual conditions. For example, if it is generally determined that when RSRP is less than a certain value, it means that the signal quality of the current serving cell is deteriorating, then the first threshold or threshold value here can be this value.

[0082] It should be understood that, in general, the system message of the serving cell carries satellite ephemeris information, which includes the current serving satellite ephemeris and the neighboring satellite ephemeris. In general, the satellite ephemeris includes information about the satellite's operating position, for example, the satellite's operating trajectory and the satellite's current position.

[0083] The terminal device can determine the satellite trajectory based on the satellite's operating position information, and the terminal device can determine the center position of the service cell through the satellite's current position. For example, the terminal device can determine the center position of the current service cell through the satellite's projection on the ground (i.e., the sub-satellite point); for another example, the satellite ephemeris information includes a reference point, and the terminal device can determine the center position of the cell through the reference point.

[0084] In one possible implementation, the terminal device can determine the position of the satellite at the next moment through the satellite's orbit and the satellite's current position at the next moment, and then determine the projection of the satellite on the ground (i.e., the sub-satellite point) based on the determined satellite at the next moment, thereby determining the center position of the current service cell.

[0085] In another possible implementation, the satellite position information also includes a reference point, through which the terminal device can determine the center position of the current service cell.

[0086] In the present application, the location information of the terminal device itself can be obtained through methods such as the global navigation satellite system (GNSS) and the global positioning system (GPS).

[0087] In the present application, "the terminal device triggers a cell search or RRC connection re-establishment" can also be understood as the terminal device immediately triggering a cell search or immediately triggering an RRC re-establishment. In other words, in the solution provided in the present application, as long as the terminal device determines that the signal quality of the serving cell is less than or equal to the first threshold, and the distance between the first position and the serving cell is greater than the first distance, if the terminal device is in an idle state, the cell re-search is immediately triggered, and if the terminal device is in a connected state, the RRC connection re-establishment is immediately triggered. The terminal device does not need to wait, or wait for instructions from the network device, and can autonomously trigger the corresponding action.

[0088] The "first distance" in this application is used to represent the distance between the center position of the current serving cell and the edge position of the current serving cell. It should be noted that the specific value of the "first distance" in this application can be understood as the distance between the center position of the current serving cell and the edge position of the current serving cell. The edge position of the cell is usually estimated. For example, Figure 4 In the satellite #1 coverage shown, the actual coverage of satellite #1 may be the coverage shown by the outermost dotted line, while the coverage shown by the inner solid line may be an estimate. Therefore, the edge position of the cell may be the position of the outermost dotted line or the position of the inner solid line. Alternatively, it can be understood that the edge position of the cell cannot be accurately determined. For example, the "first distance" can be understood as Figure 4 The “edge distance” between the center position of the cell and the edge position of the cell shown in FIG. Therefore, the “first distance” in the present application is actually an approximate value or an estimated value.

[0089] Based on the above scheme, in the present application, if the terminal device determines that the signal quality of the current service cell is less than or equal to the first threshold, and the distance between the current position of the terminal device and the center position of the service cell is greater than the first distance, it can immediately trigger a cell search or immediately trigger RRC connection re-establishment, thereby more quickly determining the resident cell, reducing the time of signal loss, and ensuring the user's service experience.

[0090] The following is a detailed description of how to determine, update, and use the "first distance" mentioned in this application.

[0091] Case 1

[0092] For example, when the terminal device executes the technical solution provided by the present application for the first time, the terminal device needs to know the first distance when determining to trigger a cell search or trigger an RRC connection re-establishment. At this time, the terminal device can obtain the first distance by the following implementation method:

[0093] In the present application, in a possible implementation, the first distance may be preconfigured. It may also be understood that the first distance is preconfigured in the terminal device. For example, a person skilled in the art may set the value of the first distance based on historical experience or actual conditions. In another possible implementation, the terminal device may receive a system message from a serving cell, which carries a distance threshold (distance Thresh) corresponding to the serving cell, and the terminal device may determine the first distance based on the received distance threshold and a preconfigured first offset value. In the present application, the "first offset value" may be preconfigured in the terminal device, for example. For example, the first distance may be obtained based on algebraic operations of the first offset value and the distance threshold. Exemplarily, the value of the first distance is equal to the sum of the first offset value and the distance threshold.

[0094] It should be noted that in this application, the units of "first distance" and "distance threshold" can be meters (m), kilometers (km), etc. The specific units can be set according to actual conditions and are not limited. Among them, the definition of "distance threshold" can be specifically referred to in the technical specification (technical specification, TS) 38.304, and this application will not be detailed.

[0095] Case 2

[0096] When the terminal device has executed the technical solution of the present application once, that is, after residing in a certain cell among the searched candidate cells, the terminal device can also update the value of the first distance. The following introduces the method for updating the first distance provided by the present application.

[0097] Method 1

[0098] Assume that, among the multiple candidate cells searched, the terminal device finds that the distance between its current position and the center position of the first cell is less than the first distance, then it can reside in the first cell, and later the terminal device may be at the edge of the first cell due to the position movement, so it triggers measurement in the first cell, and then measures several neighboring cells of the first cell, and finds that it can reselect to one of the neighboring cells. It should be understood that the terminal device has received a system message (for example, a system information block (SIB)) from the first cell before determining the reselection, and the system message carries the measurement information of the first cell and the measurement information of the neighboring cells of the first cell. In addition, the system message also carries the location information of the satellite. For example, the location information of the satellite includes the trajectory of the satellite and the current position of the satellite. The terminal device determines the position of the satellite at the next moment according to the trajectory of the satellite and the current position of the satellite, so as to determine the center position of the first cell. Since the terminal device can clearly know its own position at the time of reselection when reselecting, at this time, the terminal device can update the first distance according to its own position at the time of reselection and the determined center position of the first cell.

[0099] It should be noted that, usually, the “position of the terminal device at the time of reselection” may be located at the edge of the cell.

[0100] In the present application, the terminal device may update the first distance when reselecting, and then transmit services on the reselected cell. For example, the updated first distance is used by the terminal device to trigger a cell re-search or RRC connection re-establishment in the reselected cell. For another example, the updated first distance is used by the terminal device to update the first offset value.

[0101] Method 2

[0102] Assume that the terminal device resides in the first cell among the multiple candidate cells searched, and then the terminal device may be at the edge of the first cell due to position movement, so the measurement is triggered in the first cell, and the terminal device finds that there are neighboring cells with better signal quality around it, so the terminal device determines that it can reselect to the second cell, and updates the first distance when performing cell reselection. Assume that the system message received by the terminal device in the first cell also carries the distance threshold corresponding to the first cell. At this time, the terminal device can update the first offset value according to the updated first distance and the distance threshold corresponding to the first cell (for example, the value of the first distance minus the value of the distance threshold corresponding to the first cell can obtain the first offset value). Subsequently, the terminal device reselects to the second cell, and the terminal device receives a system message in the second cell, and the system message carries the distance threshold corresponding to the second cell. At this time, the terminal device can determine the first distance according to the updated first offset value and the distance threshold corresponding to the second cell (for example, the updated first offset value is added to the value of the distance threshold corresponding to the second cell to obtain the first distance). When the terminal device subsequently moves and finds that the signal quality in the second cell is less than or equal to the first threshold, and determines that the distance between its current position and the center position of the second cell is greater than the determined first distance, it can trigger a cell search or RRC re-establishment in the second cell.

[0103] It can also be understood that, in method 2, the main purpose of the terminal device updating the first distance based on the distance between the position at the reselection time point and the center position of the first cell is to update the first offset value. Subsequently, when the terminal device reselects in the second cell, the distance threshold received in the second cell and the updated first offset value can be used to determine the first distance. At this time, the determined first distance can be used by the terminal device to determine whether to trigger a cell search or RRC re-establishment in the second cell.

[0104] Based on the above technical solution, in the present application, the terminal device can flexibly update and maintain the first distance based on the current actual situation, so that the first distance is more accurate and better matches the specific scenario of the terminal device.

[0105] Method 3

[0106] It is assumed that, among the multiple candidate cells being searched, if the distance between the current position of the terminal device and the center position of each candidate cell is greater than or equal to the first distance.

[0107] At this time, in a possible implementation, the terminal device can reside in a third cell, where the third cell is a cell that is closest to the current location of the terminal device among the multiple candidate cells. It can also be understood that the terminal device can select a cell that is closest to the terminal device from the searched cells as the cell to reside.

[0108] In another possible implementation, the terminal device may also temporarily determine a second distance, which is the average of the distances between the terminal device and the center positions of the multiple candidate cells that cannot be resided in. In other words, if the terminal device determines that the distances between the multiple candidate cells that have been searched are too far and exceed the first distance, and none of them can be resided in, the terminal device can respectively determine the distances between the center positions of each candidate cell, determine an average value temporarily as the second distance, and find the first cell that is less than the second distance from the multiple candidate cells as the resided cell. Subsequently, for example, the terminal device may update the first distance based on the above-mentioned method one or method two.

[0109] In another possible implementation, when the terminal device finds that each searched candidate cell cannot be resident, it can also temporarily ignore the first distance and randomly select a candidate cell from the searched multiple candidate cells as the resident cell. Subsequently, for example, the terminal device can update the first distance based on the above method 1 or method 2.

[0110] Based on the above technical solution, in the present application, it is proposed that if the terminal device cannot reside in multiple searched candidate cells, it means that the first distance configured in the current scenario is inappropriate (for example, the configured first distance is too small, resulting in the distance between the terminal device and the center position of any candidate cell being greater than the first distance, and the terminal device cannot reside in any of the searched cells). At this time, the terminal device can adopt multiple methods to ensure that the terminal device can reside in one of the cells, and then update the first distance.

[0111] Figure 5It is a schematic block diagram of each module inside a terminal device provided by the present application. Among them, the "cell search management module": has basic functions such as controlling cell search, cell selection, and cell residence; the "cell reselection management module": has basic functions such as processing the measurement results of the resident cell, making responsive measurement start and stop, and reselecting candidate cell selection; the "measurement management module": is used to process the measurement results of the cell received by the terminal device; the "connection state measurement reporting management module": is used to report the measurement results of the terminal device to the NTN according to the protocol requirements; the "reconstruction management module": is used to reconstruct the connection state link according to the protocol description; the "active search management module": is used in the idle state, when the service cell signal is less than or equal to the first threshold, and it is determined that the distance between the terminal device and the center of the current service cell is greater than the first distance, actively triggering the cell search; in the connected state, when the signal quality of the service cell is less than or equal to the first threshold, and it is determined that the distance between the terminal device and the center of the current service cell is greater than the first distance, actively triggering the RRC connection re-establishment; the "signal transceiver system module" has basic functions such as measuring the energy value of the current cell, parsing SIB messages, and communicating with the cell. Among them, the signal transceiver system module periodically measures the signal of the current service cell and reports the signal measurement result to the measurement management module; after the measurement management module performs basic filtering processing, in the idle state, the measurement result is reported to the cell reselection management module; in the connected state, the measurement result is reported to the connected state measurement reporting management module.

[0112] As an example, Figure 5As shown, the cell reselection management module determines that the signal quality of the service cell is less than or equal to the first threshold. In a possible implementation, the cell reselection module will perform cell reselection normally. When the terminal device cannot perform cell reselection, the cell reselection management module can send notification information that the signal quality of the service cell does not meet the first threshold to the active search management module; after the active search management module receives the notification information from the cell reselection management module that the signal quality of the service cell does not meet the first threshold, it will further check whether the distance between the terminal device and the center position of the current service cell is greater than the first distance. If the active search management module determines that the distance from the terminal device to the center position of the current service cell is greater than the first distance, it will notify the cell selection module to perform cell search. In another possible implementation, when the cell reselection management module determines that the signal quality of the service cell is less than or equal to the first threshold, it can directly send a notification message that the signal quality of the service cell does not meet the first threshold to the active search management module; after the active search management module receives the notification information from the cell reselection management module that the signal quality of the service cell does not meet the first threshold, it will further check whether the distance between the terminal device and the center position of the current service cell is greater than the first distance. If the active search management module determines that the distance from the terminal device to the center position of the current service cell is greater than the first distance, it will notify the cell selection module to perform a cell search.

[0113] As another example, Figure 5 As shown, the connection state measurement reporting module reports the measurement result to the NTN periodically or eventually. When the connection state measurement reporting module determines that the signal quality of the service cell is less than or equal to the first threshold, or detects that the air interface resource is out of sync between the terminal device and the NTN, a notification message that the signal quality of the service cell does not meet the first threshold can be sent to the active search management module; after the active search management module receives the notification information that the measurement result of the connection state measurement reporting module does not meet the first threshold, it will further check whether the distance between the terminal device and the center of the current service cell is greater than the first distance. If the active search management module determines that the distance from the terminal device to the center of the current service cell is greater than the first distance, it will notify the cell selection module to re-establish the RRC connection.

[0114] Figure 6 A method of characterizing the first distance provided by the present application is shown. In the present application, it is considered that the coverage of the cell in the cellular network is basically an ellipse, but in the NTN, the coverage of the satellite is too large. If it is still set to an ellipse, the overlapping area of ​​the coverage between satellites will be very large, which will affect the communication efficiency of the terminal device. In view of this, the present application proposes that the coverage of the NTN satellite can be considered to be set to a quadrilateral, such as a rectangle. In this scenario, how to determine the first distance, the technical solution of the present application is described in detail below.

[0115] like Figure 6 As shown, assuming that when the coverage range of the satellite is a rectangle, the location of the terminal device can be characterized by multiple parameters. For example, the terminal device can receive a system message from the service cell, and the system message carries the location information of the satellite. The terminal device determines the satellite trajectory and the center position of the service cell based on the satellite location information. Specifically, the satellite location information includes the satellite trajectory and the current position of the satellite. The terminal device determines the center position of the service cell based on the current position of the satellite. The terminal device determines a first axis (e.g., X-axis) and a second axis (e.g., Y-axis) based on the satellite trajectory and the center position of the service cell, wherein the first axis is used to characterize the satellite trajectory, the second axis is perpendicular to the first axis, and the center position of the service cell is the intersection of the first axis and the second axis; the terminal device determines a first parameter (e.g., k) and a second parameter (e.g., l) based on the first position, the first axis, and the second axis, wherein the first parameter is used to represent the distance between the first position and the second axis, and the second parameter is used to represent the distance between the first position and the first axis, such as Figure 6 As shown in (a) in .

[0116] Similarly, for example, the "first distance" in the present application can also be characterized by multiple parameters. For example, the first distance is characterized by a third parameter (for example, K) and a fourth parameter (for example, L). Among them, the third parameter is used to characterize the distance between the edge position of the serving cell and the second axis, and the fourth parameter is used to characterize the distance between the edge position of the serving cell and the first axis. Therefore, the technical solution of the present application can also be understood as triggering a cell search or a radio resource control RRC connection re-establishment when the signal quality of the serving cell is less than or equal to the first threshold, and the value of the first parameter is greater than or equal to the value of the third parameter, and / or; triggering a cell search or a radio resource control RRC connection re-establishment when the signal quality of the serving cell is less than or equal to the first threshold, and the value of the second parameter is greater than or equal to the value of the fourth parameter. In other words, in this scenario, as long as at least one of the distance between the terminal device and the first axis or the distance between the terminal device and the second axis is greater than the third parameter or the fourth parameter in the first distance, the terminal device can trigger a cell re-search or an RRC connection re-establishment. For example, such as Figure 6 As shown in (c) in Figure 6 In (c), since l (an example of the second parameter) is greater than L (an example of the fourth parameter), if the terminal device determines that the signal quality of the current serving cell is less than or equal to the first threshold, it can immediately trigger a cell search or immediately trigger RRC connection re-establishment.

[0117] Similarly, in this scenario, the "distance threshold" carried by NTN in the system message can also be indicated by multiple parameters. Figure 6 In the illustrated embodiment, the fifth parameter (eg, k th ) is used to indicate the measurement threshold of the first axis, and the sixth parameter (for example, l th ) is used to indicate the measurement threshold of the second axis. Specifically, for example, the fifth parameter is used to characterize the distance between the measurement point and the second axis when the measurement is started, and the sixth parameter is used to characterize the distance between the measurement point and the first axis when the measurement is started. For example, in this scenario, the condition for the terminal device to trigger the measurement may be: when any parameter in the first position is greater than the corresponding parameter in the distance threshold, the cell measurement can be triggered. For example, when the value of the second parameter is greater than the value of the sixth parameter, the terminal device can be triggered to measure the neighboring cell, such as Figure 6 As shown in (b) in .

[0118] In this scenario, similarly, the terminal device can also use the above-mentioned various methods (for example, method one to method three) to update and maintain the first distance. In one possible implementation method, the terminal device triggers the measurement of the first axis, and the parameters corresponding to the first axis in the first distance can be updated subsequently. For another example, the terminal device triggers the measurement of the second axis, and the parameters corresponding to the second axis in the first distance can be updated subsequently. For another example, the terminal device triggers the measurement of the first axis and the second axis at the same time, and the parameters corresponding to the first axis and the parameters corresponding to the second axis in the first distance can be updated respectively subsequently.

[0119] Case 1:

[0120] In this case, when the terminal device executes the technical solution provided by the present application for the first time, the terminal device needs to know the first distance when determining to trigger a cell search or trigger an RRC connection re-establishment. At this time, the terminal device can obtain the first distance by the following implementation method:

[0121] In one possible implementation, the first distance may be preconfigured. For example, multiple parameters characterizing the first distance may be configured in the terminal device, respectively. In another possible implementation, the terminal device may receive a system message from a serving cell, the system message carrying a distance threshold corresponding to the serving cell, the threshold carrying multiple parameters, each parameter being used to indicate a measurement threshold corresponding to each axis, respectively. Assume that the terminal device configures a corresponding first offset value for each parameter, respectively. The terminal device may determine the first distance based on the received distance threshold and the preconfigured first offset value.

[0122] Case 2:

[0123] In this case, when the terminal device has executed the technical solution of the present application once, that is, after residing in a certain cell among the searched candidate cells, the terminal device can also update the value of the first distance. The following introduces the method for updating the first distance provided by the present application.

[0124] Method 1

[0125] Assuming that the terminal device finds that the distance between its current location and the center location of the first cell among the multiple candidate cells searched is less than the first distance, it can reside in the first cell. It can also be understood that the values ​​of multiple parameters characterizing the location of the terminal device are all less than the corresponding values ​​of multiple parameters used to characterize the first distance. For example, the terminal device determines that the value of the first parameter is less than the value of the third parameter, and the value of the second parameter is also less than the value of the fourth parameter, then it can reside in the first cell. Later, the terminal device may be at the edge of the first cell due to position movement, for example, Figure 6 In (b), the value of the second parameter of the terminal device is greater than the value of the sixth parameter in the distance threshold, so the measurement is triggered in the first cell. Then, by measuring several neighboring cells of the first cell, it is found that one of the neighboring cells can be reselected. It should be understood that the terminal device has received a system message (for example, a system information block (SIB)) from the first cell before determining the reselection, and the system message carries the measurement information of the first cell and the measurement information of the neighboring cells of the first cell. In addition, the system message also carries information about the operating position of the satellite position. For example, the location information of the satellite includes the trajectory of the satellite and the current position of the satellite. The terminal device can determine the trajectory of the satellite, and the terminal device can determine the center position of the first cell based on the current position of the satellite. Since the terminal device can clearly know its own position at the time of reselection, at this time, the terminal device can update the fourth parameter in the first distance based on its own position at the time of reselection and the determined center position of the first cell.

[0126] In this scenario, for example, the terminal device can know which axis's corresponding parameter triggers the measurement, and the terminal device can update the parameter accordingly. If the values ​​of the multiple parameters used to characterize the position of the terminal device are all greater than the values ​​of the corresponding multiple parameters used to characterize the first distance, the terminal device can update each parameter in the first distance.

[0127] Method 2

[0128] Assume that the terminal device resides in the first cell among the multiple candidate cells searched, and then the terminal device may be at the edge of the first cell due to position movement, so the measurement is triggered in the first cell (for example, Figure 6In the example, it may be that both the first axis and the second axis trigger the measurement), and the terminal device finds that there are neighboring cells with better signal quality around it. Therefore, the terminal device reselects to the second cell and updates the first distance when performing cell reselection. For example, the terminal device updates the third parameter or the fourth parameter that characterizes the first distance. Assume that the system message received by the terminal device in the first cell also carries the distance threshold corresponding to the first cell. At this time, the terminal device can update the first offset value according to the updated first distance and the distance threshold corresponding to the first cell (for example, the first distance value minus the distance threshold value corresponding to the first cell can obtain the first offset value). For example, the terminal device updates both the first offset value corresponding to the third parameter and the first offset value corresponding to the fourth parameter.

[0129] Subsequently, the terminal device receives a system message in the second cell, and the system message carries the distance threshold corresponding to the second cell. At this time, the terminal device can determine the first distance based on the updated first offset value and the distance threshold corresponding to the second cell (for example, the first distance can be obtained by adding the updated first offset value to the value of the distance threshold corresponding to the second cell). For example, the distance corresponding to the second cell includes a fifth parameter and a sixth parameter, and the terminal device can determine a third parameter for characterizing the first distance based on the first offset value corresponding to the first axis and the fifth parameter, and the terminal device can determine a fourth parameter for characterizing the first distance based on the second offset value corresponding to the second axis and the sixth parameter.

[0130] When the terminal device subsequently moves and finds that the signal quality in the second cell is less than or equal to the first threshold, and determines that the distance between its current position and the center position of the second cell is greater than the determined first distance (for example, the value of the first parameter is greater than the value of the third parameter, and / or the value of the second parameter is greater than the value of the fourth parameter), it can trigger a cell search or RRC re-establishment in the second cell.

[0131] In this scenario, the NTN may also directly notify the terminal device of the multiple parameters corresponding to the first distance. For example, at this time, the terminal device may not need to maintain and update the first distance by itself. For another example, the terminal device may continue to update the corresponding parameters of the first distance maintained locally based on the received multiple parameters corresponding to the first distance.

[0132] It should be noted that the above Figure 6 Just an example, Figure 6 In the illustrated solution, the first distance may include two parameter values. In the present application, it is not limited how many parameters may be used to characterize the first distance. For example, the first distance may also be characterized by three parameters. In this case, the corresponding distance threshold may also be characterized by three parameters.

[0133] Based on the above technical solution and taking into account the diversity of cell coverage shapes, the present application optimizes the representation method of the first distance so that based on cell coverage ranges of different shapes, the terminal device can flexibly determine whether the current position is greater than the first distance from the center position of the cell.

[0134] It can be understood that the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0135] Those skilled in the art should be aware that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed 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 be beyond the scope of this application.

[0136] The embodiment of the present application can divide the functional modules of the communication device according to the above method example. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. The following is an example of dividing each functional module corresponding to each function.

[0137] Figure 7 is a schematic block diagram of a communication device 100 provided in an embodiment of the present application. Figure 7 As shown, the communication device 100 may include: a processing unit 110 , a transceiver unit 120 , and a determination unit 130 .

[0138] Among them, the above-mentioned modules are respectively used to execute the various steps in the aforementioned communication method 300, which will not be repeated here.

[0139] It should also be understood that the communication device 100 herein is embodied in the form of functional units. The term "unit" herein may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (e.g., a shared processor, a dedicated processor, or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combined logic circuit, and / or other suitable components that support the described functionality.

[0140] The communication device 100 of each of the above schemes has the function of implementing the corresponding steps of the above method 300. The function can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions; for example, the determination unit can be replaced by a processor to respectively perform the transceiver operations and related processing operations in each method embodiment. In addition, the determination unit can be a processing circuit.

[0141] It should be pointed out that Figure 7 The communication device in the embodiment may be the communication device in the aforementioned method, or may be a chip or chip system of the communication device, such as a system on chip (SoC). The processing unit is a processor or microprocessor or integrated circuit integrated on the chip. This is not limited here.

[0142] Figure 8 1 is a schematic block diagram of another communication device 200 provided in an embodiment of the present application. As shown in the figure, the device 200 includes: at least one processor 210. The processor 210 is coupled to the memory and is used to execute instructions stored in the memory to send signals and / or receive signals. Optionally, the device 200 also includes a memory 230 for storing instructions. Optionally, the device 200 also includes a transceiver 220, and the processor 210 controls the transceiver 220 to send signals and / or receive signals.

[0143] It should be understood that the processor 210 and the memory 230 can be combined into one processing device, and the processor 210 is used to execute the program code stored in the memory 230 to implement the above functions. In specific implementation, the memory 230 can also be integrated into the processor 210, or independent of the processor 210.

[0144] It should also be understood that the transceiver 220 may include a transceiver (or receiver) and a transmitter (or transmitter). The transceiver may further include an antenna, and the number of antennas may be one or more. The transceiver 220 may also be a communication interface or an interface circuit.

[0145] Specifically, the processor 210 in the device 200 may correspond to the processing unit 110 and the major case determination unit 130 in the communication device 100. The transceiver 220 in the device 200 may correspond to the sending unit 120 in the communication device 100.

[0146] As a solution, the communication device 200 is used to implement each step in the above method 300 embodiment.

[0147] For example, the processor 210 is used to execute the computer program or instructions stored in the memory 230 to implement each step in the above method 300.

[0148] According to the method provided in the embodiment of the present application, the present application also provides a computer program product, on which a computer program code is stored. When the computer program code is run on a computer, the computer executes each step in the embodiment of method 300.

[0149] According to the method provided in the embodiment of the present application, the present application also provides a computer-readable medium, which stores a program code. When the program code is executed on a computer, the computer executes each step in the above method 300.

[0150] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0151] A computer-readable medium stores a program code, and when the program code is executed on a computer, the computer executes each step in the method 300.

[0152] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0153] It should be understood that the specific process of each transceiver and processor executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0154] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software modules in a processor for execution. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0155] It should be noted that the processor in the embodiment of the present application can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiment can be completed by the hardware integrated logic circuit or software instructions in the processor. The above processor can be a general processor, a digital signal processor (digitalsignal processor, DSP), an application-specific integrated circuit (application-specific integrated circuit, ASIC), a field-programmable gate array (field-programmable gate array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to perform, or the hardware and software modules in the decoding processor can be combined and performed. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0156] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disc (SSD)).

[0157] In the above-mentioned various device embodiments, the corresponding modules or units perform the corresponding steps. For example, the transceiver unit (transceiver) performs the steps of receiving or sending in the method embodiment, and other steps except sending and receiving can be performed by the processing unit (processor). The functions of the specific units can refer to the corresponding method embodiments. Among them, there can be one or more processors.

[0158] The terms "component", "module", "system", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program and / or a computer. By way of illustration, both applications running on a communication device and a communication device can be components. One or more components can reside in a process and / or an execution thread, and a component can be located on a computer and / or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can, for example, communicate through local and / or remote processes according to signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system and / or a network, such as the Internet interacting with other systems through signals).

[0159] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software 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 be beyond the scope of this application.

[0160] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0161] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0162] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0163] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0164] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks or optical disks.

[0165] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A communication method, characterized in that: include: Reside in a serving cell, where the serving cell is a non-terrestrial network NTN cell; When the signal quality of the serving cell is less than or equal to a first threshold and the distance between the first position and the center position of the serving cell is greater than or equal to a first distance, a cell search or a radio resource control RRC connection re-establishment is triggered, wherein the first distance is used to characterize the distance between the center position of the serving cell and the edge position of the serving cell, and the first position is the current position of the terminal device.

2. The method according to claim 1, characterized in that The method further comprises: receiving a system message from the serving cell, where the system message of the serving cell carries the location information of the satellite, where the location information of the satellite includes the running track of the satellite and the location of the satellite at a current moment; The center position of the service cell is determined according to the information of the satellite operating position.

3. The method according to claim 1, characterized in that The method further comprises: receiving a system message from the serving cell, where the system message of the serving cell carries location information of a satellite, and the location information of the satellite includes a reference point of the satellite; The center position of the serving cell is determined according to the reference point of the satellite.

4. The method according to any one of claims 1 to 3, characterized in that The first distance is preconfigured.

5. The method according to any one of claims 1 to 3, characterized in that The method further comprises: receiving a system message from the serving cell, where the system message carries a distance threshold corresponding to the serving cell; The first distance is determined according to a distance threshold and a first offset value corresponding to the serving cell, wherein the first offset value is preconfigured.

6. The method according to any one of claims 1 to 5, characterized in that The method further comprises: Reside in the first cell; receiving a system message from the first cell, where the system message carries measurement information of the first cell and measurement information of neighboring cells of the first cell; According to the system message of the first cell, when the signal quality of the first cell does not meet the S criterion and the signal quality of the neighboring cell of the first cell meets the S criterion, reselect to the neighboring cell of the first cell.

7. The method according to claim 6, characterized in that The system message of the first cell further carries location information of a satellite, where the location information of the satellite includes an operating trajectory of the satellite and a current location of the satellite, and / or the location information of the satellite includes a reference point of the satellite. The method further includes: determining a center position of the first cell according to a system message of the first cell; The first distance is updated according to the distance between the position at the reselection time point and the center position of the first cell.

8. The method according to claim 7, characterized in that The system message of the first cell further carries a distance threshold corresponding to the first cell, and the method further includes: updating the first offset value according to the updated first distance and the distance threshold corresponding to the first cell; receiving a system message from a second cell, where the system message of the second cell carries a distance threshold corresponding to the second cell, and the second cell is a neighboring cell of the reselected first cell; The first distance is determined according to the updated first offset value and the distance threshold corresponding to the second cell.

9. The method according to any one of claims 1 to 8, characterized in that The method further comprises: Among the multiple candidate cells searched, if the distance between the first position and the center position of each candidate cell is greater than or equal to the first distance, then reside in a third cell, where the third cell is a cell among the multiple candidate cells that is closest to the terminal device.

10. The method according to claim 2, characterized in that The method further comprises: A first parameter and a second parameter are determined based on the first position and the position information of the satellite, wherein the first parameter is used to characterize the distance between the first position and the second axis, the second parameter is used to characterize the distance between the first position and the first axis, the first axis is determined based on the orbit of the satellite, the first axis is used to characterize the orbit of the satellite, the second axis is perpendicular to the first axis, and the intersection of the first axis and the second axis is the center position of the service cell.

11. The method according to claim 10, characterized in that The first distance includes a third parameter and a fourth parameter, wherein the third parameter is used to characterize the distance between the edge position of the serving cell and the second axis, and the fourth parameter is used to characterize the distance between the edge position of the serving cell and the first axis. The triggering of cell search or RRC connection reestablishment when the signal quality of the serving cell is less than or equal to a first threshold and the distance between the first position and the center position of the serving cell is greater than or equal to a first distance includes: When the signal quality of the serving cell is less than or equal to the first threshold, and the value of the first parameter is greater than or equal to the value of the third parameter, triggering a cell search or a radio resource control RRC connection re-establishment, and / or; When the signal quality of the serving cell is less than or equal to the first threshold and the value of the second parameter is greater than or equal to the value of the fourth parameter, a cell search or a radio resource control RRC connection re-establishment is triggered.

12. The method according to claim 11, characterized in that The system message of the serving cell also carries the first distance.

13. The method according to claim 11 or 12, characterized in that: The system message of the serving cell also carries a distance threshold corresponding to the serving cell, and the distance threshold corresponding to the serving cell includes a fifth parameter and a sixth parameter, wherein the fifth parameter is used to characterize the distance between the measurement point and the second axis when starting the measurement, and the sixth parameter is used to characterize the distance between the measurement point and the first axis when starting the measurement.

14. A communication device, characterized in that: include: Determine the unit and process the unit, wherein: The determining unit is used to determine that the signal quality of the serving cell is less than or equal to a first threshold, and the distance between the first position and the center position of the serving cell is greater than or equal to a first distance, wherein the communication device resides in the serving cell, and the serving cell is a non-terrestrial network NTN cell; The processing unit is used to trigger a cell search or a wireless resource RRC connection re-establishment, wherein the first distance is used to characterize the distance between a center position of the serving cell and an edge position of the serving cell, and the first position is a current position of the terminal device.

15. The communication device according to claim 14, characterized in that The communication device further comprises: a transceiver unit, The transceiver unit is used to receive a system message from the serving cell, where the system message of the serving cell carries the location information of the satellite, where the location information of the satellite includes the running track of the satellite and the location of the satellite at a current moment; The determination unit is used to determine the center position of the service cell according to the information of the satellite operation position.

16. The communication device according to claim 14, characterized in that The communication device further comprises: a transceiver unit, The transceiver unit is used to receive a system message from the serving cell, where the system message of the serving cell carries the location information of the satellite, and the location information of the satellite also includes a reference point of the satellite; The determination unit is used to determine the center position of the service cell according to the reference point of the satellite.

17. The communication device according to any one of claims 14 to 16, characterized in that: The first distance is preconfigured.

18. The communication device according to any one of claims 14 to 16, characterized in that: The transceiver unit is used to receive a system message from the serving cell, where the system message carries a distance threshold corresponding to the serving cell; The determining unit is configured to determine the first distance according to a distance threshold and a first offset value corresponding to the serving cell, wherein the first offset value is preconfigured.

19. The communication device according to any one of claims 14 to 18, characterized in that: The processing unit is used to control the communication device to reside in the first cell; The transceiver unit is used to receive a system message from the first cell, where the system message carries measurement information of the first cell and measurement information of neighboring cells of the first cell; The processing unit is used to control the communication device to reselect to a neighboring cell of the first cell according to the system message of the first cell when the signal quality of the first cell does not meet the S criterion and the signal quality of the neighboring cell of the first cell meets the S criterion.

20. The communication device according to claim 19, characterized in that The system message of the first cell also carries the location information of the satellite, wherein the location information of the satellite includes the running track of the satellite and the location of the satellite at a current moment, and / or the location information of the satellite includes the reference point of the satellite. The determining unit is used to determine the center position of the first cell according to the position information of the satellite; The processing unit is used to update the first distance according to the distance between the position at the reselection time point and the center position of the first cell.

21. The communication device according to claim 20, characterized in that The system message of the first cell also carries a distance threshold corresponding to the first cell; The processing unit is configured to update the first offset value according to the updated first distance and the distance threshold corresponding to the first cell; The transceiver unit is used to receive a system message from a second cell, where the system message of the second cell carries a distance threshold corresponding to the second cell, and the second cell is a neighboring cell of the reselected first cell; The determining unit is configured to determine the first distance according to the updated first offset value and a distance threshold corresponding to the second cell.

22. The communication device according to any one of claims 15 to 21, characterized in that: Among the multiple candidate cells searched, if the distance between the first position and the center position of each candidate cell is greater than or equal to the first distance, the processing unit is used to control the communication device to reside in a third cell, wherein the third cell is a cell among the multiple candidate cells that is closest to the terminal device.

23. The communication device according to claim 15, characterized in that The determination unit is used to determine a first parameter and a second parameter based on the first position and the position information of the satellite, wherein the first parameter is used to characterize the distance between the first position and the second axis, the second parameter is used to characterize the distance between the first position and the first axis, the first axis is determined based on the orbit of the satellite, the first axis is used to characterize the orbit of the satellite, the second axis is perpendicular to the first axis, and the intersection of the first axis and the second axis is the center position of the service cell.

24. The communication device according to claim 23, characterized in that The first distance includes a third parameter and a fourth parameter, wherein the third parameter is used to characterize the distance between the edge position of the serving cell and the second axis, and the fourth parameter is used to characterize the distance between the edge position of the serving cell and the first axis. When the signal quality of the serving cell is less than or equal to the first threshold, and the distance between the first position and the center position of the serving cell is greater than or equal to the first distance, the processing unit is used to trigger a cell search or a radio resource control RRC connection re-establishment, including: When the signal quality of the serving cell is less than or equal to the first threshold, and the value of the first parameter is greater than or equal to the value of the third parameter, the processing unit is used to trigger a cell search or a radio resource control RRC connection re-establishment, and / or; When the signal quality of the serving cell is less than or equal to the first threshold and the value of the second parameter is greater than or equal to the value of the fourth parameter, the processing unit is used to trigger a cell search or a radio resource control RRC connection re-establishment.

25. The communication device according to claim 24, characterized in that The transceiver unit is used to receive a system message from the serving cell, and the system message of the serving cell also carries the first distance.

26. The communication device according to claim 24 or 25, characterized in that: The system message of the serving cell also carries a distance threshold, and the distance threshold includes a fifth parameter and a sixth parameter, wherein the fifth parameter is used to characterize the distance between the measurement point and the second axis when starting the measurement, and the sixth parameter is used to characterize the distance between the measurement point and the first axis.

27. A communication device, characterized in that: It includes a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor is used to implement the method as described in any one of claims 1 to 13 through a logic circuit or executing code instructions.

28. A communication device, characterized in that: include: A processor, the processor is coupled to a memory, the memory is used to store instructions, when the instructions are executed by the processor, the communication device performs the method according to any one of claims 1 to 13.

29. A computer-readable storage medium, characterized in that: The storage medium stores instructions, and when the instructions are executed by the communication device, the method according to any one of claims 1 to 13 is implemented.

30. A computer program product, characterized in that When the method is executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 9.

31. A chip system, characterized in that: It comprises a processor, wherein the processor is used to call and run a computer program from a memory, so that a device equipped with the chip system executes the method as claimed in any one of claims 1 to 13.

32. A communication system, characterized in that: The method comprises at least one communication device for executing the method as claimed in any one of claims 1 to 13 and a non-terrestrial network NTN.

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