Communication method and apparatus

Abstract

An embodiment of the present application provides a communication method and an apparatus. The communication method includes: a terminal device receives first information from a first network device, the first information including information about a moving cell where the terminal device is located, the moving cell being a cell covered by a moving process of a second network device; the second network device communicates with the first network device via a non-terrestrial network NTN; and the terminal device determines whether to perform neighbor cell measurements based on the first information, the neighbor cell being a neighbor cell of the moving cell. Thus, the terminal device in a moving cell scenario can timely determine whether neighbor cell measurements and cell selection or reselection need to be performed based on the information sent by the first network device and including information about the moving cell where the terminal device is located, so that the terminal device can timely obtain paging of the wireless network and start a call.

Description

[Technical Field]

[0001] This application claims priority to Chinese Patent Application No. 202210915959.2, entitled "COMMUNICATION METHOD AND APPARATUS," filed with the State Intellectual Property Office of China on August 1, 2022, which is incorporated herein by reference in its entirety.

[0002] This application claims priority to Chinese Patent Application No. 202210946157.8, entitled "COMMUNICATION METHOD AND APPARATUS," filed with the State Intellectual Property Office of China on August 8, 2022, which is incorporated herein by reference in its entirety.

[0003] TECHNICAL FIELD Embodiments of the present application relate to the field of wireless communication technologies, and more particularly to communication methods and devices. [Background technology]

[0004] Satellite networks are a hot topic of research worldwide today, and satellite communication technology is increasingly being developed. For example, non-terrestrial networks (NTNs) are networks or network segments that use radio frequencies on satellites for communication to provide a wider coverage area. However, the higher the satellite's orbit, the larger the satellite's coverage area and the longer the communication latency.

[0005] For non-geosynchronous orbit (NGSO) satellites, including low-Earth and medium-Earth orbit satellites, a base station may provide quasi-Earth-fixed cell coverage or earth-moving cell coverage. A quasi-fixed cell is a geographic area covered by a steerable beam generated by the satellite, and a moving cell is a geographic area covered by a fixed or non-steerable beam generated by the satellite in a satellite-moving process.

[0006] In order to obtain uninterrupted service in a wireless network, a terminal device needs to perform reselection and handover between cells having different coverage areas. Generally, when a terminal device is in an idle state or an inactive state, the terminal device determines whether the signal quality of a neighboring cell satisfies a cell reselection condition based on the signal quality of a current cell and system information of a network device, and then determines whether to perform neighboring cell measurement and reselection.

[0007] However, the near-far effect of NTN cells is not obvious. In other words, the signal difference between the cell center and the cell edge is small. Therefore, it is difficult to configure the threshold for performing neighbor cell measurements, and it is difficult for the terminal device to identify the cell edge based on the cell signal strength and perform cell reselection when it reaches the cell edge. As a result, neighbor cell measurements cannot be performed in a timely manner. This may result in the terminal device being unable to locate any cell, causing paging failures and delays to calls initiated by the terminal device. Summary of the Invention

[0008] Therefore, for a terminal device in a moving cell scenario, how to make neighbor cell measurements in a timely manner is a problem that needs to be urgently solved.

[0009] An embodiment of the present application provides a communication method, in which a terminal device in a moving cell scenario can timely determine whether neighbor cell measurements need to be made based on information transmitted by a first network device and including information about a moving cell in which the terminal device is located, so that the terminal device can obtain continuous service of a wireless network. [Means for solving the problem]

[0010] According to a first aspect, a communication method is provided. The method may be performed by a terminal device or by a component (e.g., a chip or a circuit) of the terminal device. This is not limited. For ease of explanation, the following uses an example in which the method is performed by a terminal device for explanation.

[0011] The method may include: a terminal device receiving first information from a first network device, the first information including information regarding a moving cell in which the terminal device is located, the moving cell being a cell covered by a movement process of a second network device; the second network device communicating with the first network device via a non-terrestrial network NTN; and the terminal device determining, based on the first information, whether to perform neighbor cell measurements, the neighbor cell being a neighbor cell of the moving cell.

[0012] Based on the above solution, a terminal device in a moving cell scenario may, based on information transmitted by a first network device and relating to the moving cell in which the terminal device is located, timely determine whether neighbor cell measurements and cell selection or reselection need to be performed, so that the terminal device can timely obtain paging of the wireless network and initiate a call timely.

[0013] Regarding the first aspect, in some implementation forms of the first aspect, the first information includes timestamp information and / or a first distance. The timestamp information indicates time information of a reference point of the moving cell. The reference point of the moving cell is a position within the moving cell. The first distance is used to determine a relationship between the position of the terminal device and the coverage area of the moving cell.

[0014] Based on the above solution, the first information transmitted by the first network device includes timestamp information indicating the time information of the reference point of the moving cell and the first distance used to determine the relationship between the position of the terminal device and the coverage area of the moving cell, so that the terminal device can determine whether neighbor cell measurements need to be made based on the above information.

[0015] Optionally, the timestamp information may further indicate that the cell in which the terminal device is located is a moving cell, which increases the flexibility of the solution for the terminal device to determine whether it is in a moving cell.

[0016] Regarding the first aspect, in some implementation forms of the first aspect, the timestamp information indicates a start time of a reference point of the moving cell, and the first information includes the following: The mobile communication device further includes at least one of first indication information, a reference point of the moving cell, a validity period of the reference point of the moving cell, and a positional relationship between the moving cell and the second network device. The first indication information indicates that the cell in which the terminal device is located is the moving cell. The validity period of the reference point of the moving cell indicates a time range during which the reference point is available to the terminal device from a start time. The positional relationship between the moving cell and the second network device is used to determine the position of the reference point of the moving cell.

[0017] Based on the above solution, the first information transmitted by the first network device further includes other information used by the terminal device to determine whether neighbor cell measurements need to be performed, which improves the flexibility and accuracy of the solution for the terminal device to determine whether neighbor cell measurements need to be performed.

[0018] Optionally, the location relationship between the moving cell and the second network device may further indicate that the cell in which the terminal device is located is the moving cell, which increases the flexibility of the solution for the terminal device to determine whether the terminal device is in the moving cell.

[0019] Regarding the first aspect, in some implementation forms of the first aspect, the timestamp information is any one of the following: an absolute time point of a reference point of the moving cell, an offset value of a start time point of the ephemeris information of the second network device, and a start time point of a downlink subframe corresponding to a system frame number and a subframe number in the first information. The ephemeris information of the second network device indicates location information of the second network device.

[0020] Based on the above solution, the timestamp information may be multiple types of time information indicating the reference point of the moving cell, which increases the flexibility of the solution.

[0021] Regarding the first aspect, in some implementation forms of the first aspect, the reference point of the moving cell is the center position of the moving cell at a certain point in time.

[0022] Based on the above solution, the reference point of the moving cell may be the center position of the moving cell at that time, so that the terminal device makes neighboring cell measurements more timely based on the center position of the moving cell.

[0023] With regard to the first aspect, in some implementation forms of the first aspect, the positional relationship between the moving cell and the second network device includes a distance relationship between a reference point of the moving cell and a sub-satellite point of the second network device, and an angular relationship between the reference point of the moving cell and the sub-satellite point of the second network device, or the positional relationship between the moving cell and the second network device includes an angular relationship between a reference point of the moving cell and the second network device, and an angular relationship between the origin of the coordinates and the reference point of the moving cell.

[0024] Based on the above solution, the positional relationship between the moving cell and the second network device may be represented using multiple angle relationships and distance relationships, which increases the flexibility of the manner of representing the positional relationship between the moving cell and the second network device.

[0025] Regarding the first aspect, in some implementation forms of the first aspect, determining whether the terminal device should perform neighbor cell measurements based on the first information includes: determining, based on the first information, that the cell in which the terminal device is located is a moving cell; determining a second distance; and, if the first information includes the first distance, determining whether the terminal device should perform neighbor cell measurements based on the first distance and the second distance. The second distance is a distance between the first position and the second position. The first position is a position of the terminal device at a first time point. The second position is a position of a reference point of the moving cell at the first time point.

[0026] Based on the above solution, after determining that the cell where the terminal device is located is the moving cell, the terminal device further determines whether to perform neighbor cell measurements based on the positional relationship between the position of the terminal device and the position of the reference point of the moving cell, which increases the diversity of solutions for determining whether to perform neighbor cell measurements.

[0027] Regarding the first aspect, in some implementation forms of the first aspect, the terminal device determining the second distance includes the terminal device determining a first position, the terminal device determining a third position based on ephemeris information of the second network device, the third position being the position of the second network device at the first time point, the terminal device determining a second position based on the third position, and the terminal device determining the second distance based on the first position and the second position.

[0028] Regarding the first aspect, in some implementation forms of the first aspect, the terminal device determining the second location based on the third location includes, if the first information includes a locational relationship between the moving cell and the second network device, the terminal device determining the second location based on the third location and the locational relationship between the moving cell and the second network device; or, if the first information includes timestamp information and the first information does not include a locational relationship between the moving cell and the second network device, the terminal device determining the locational relationship between the moving cell and the second network device based on the timestamp information, the location of the second network device at the current time, and the location of a reference point of the moving cell at the current time, and the terminal device determining the second location based on the third location and the locational relationship between the moving cell and the second network device.

[0029] Regarding the first aspect, in some implementation forms of the first aspect, when the first information includes a first distance, determining whether the terminal device should perform neighbor cell measurements based on the first distance and the second distance includes the terminal device determining a service outage time of the moving cell based on the first distance and the second distance, and the terminal device performing neighbor cell measurements before the service outage time of the moving cell.

[0030] Based on the above solution, the terminal device may determine the service stop time of the moving cell based on the positional relationship and the first distance between the position of the terminal device and the position of the reference point of the moving cell, and determine when to perform neighbor cell measurement based on the service stop time of the moving cell, which increases the diversity of solutions for determining whether to perform neighbor cell measurement.

[0031] With regard to the first aspect, in some implementation forms of the first aspect, the terminal device determining a service outage time of the moving cell based on the first distance and the second distance includes, if the second distance is greater than the first distance, the terminal device determining that the first time is the service outage time of the moving cell.

[0032] Regarding the first aspect, in some implementation forms of the first aspect, if the second distance is smaller than the first distance, the method further includes the terminal device determining a third distance, the third distance being the distance between a fourth position and a fifth position, the fourth position being the position of the terminal device at the second time point, the fifth position being the position of a reference point of the moving cell at the second time point, the first time point being before the second time point, and if the third distance is greater than the first distance, the terminal device determining that the second time point is a service outage time of the moving cell.

[0033] Based on the above solution, if the second distance between the position of the terminal device and the position of the reference point of the moving cell at the first time point is smaller than the first distance, the terminal device further determines a third distance between the position of the terminal device and the position of the reference point of the moving cell at the second time point, and determines the service stop time of the moving cell based on the third distance and the second distance, which increases the flexibility of the solution for determining the service stop time of the moving cell.

[0034] Regarding the first aspect, in some implementation forms of the first aspect, when the first information includes a first distance, determining whether the terminal device should perform neighbor cell measurements based on the first distance and the second distance includes the terminal device determining whether the terminal device is located at the edge of the moving cell based on the first distance and the second distance, and if the terminal device is located at the edge of the moving cell, the terminal device performing neighbor cell measurements.

[0035] Based on the above solution, the terminal device determines whether to perform neighbor cell measurements by determining whether the terminal device is at the edge of the moving cell, which increases the flexibility of the solution for determining whether to perform neighbor cell measurements.

[0036] Regarding the first aspect, in some implementation forms of the first aspect, the terminal device determining whether the terminal device is located at the edge of the moving cell based on the first distance and the second distance includes the terminal device determining that the terminal device is located at the edge of the moving cell at the first time point if the second distance is greater than the first distance.

[0037] Regarding the first aspect, in some implementation forms of the first aspect, the terminal device determining whether the terminal device is located at the edge of the moving cell based on the first distance and the second distance includes: if the second distance is smaller than the first distance, the terminal device skips making neighbor cell measurements at the first time point; the terminal device determines a third distance, the third distance being a distance between a fourth position and a fifth position, the fourth position being the position of the terminal device at the second time point, the fifth position being the position of the reference point of the moving cell at the second time point, the first time point being before the second time point; and if the third distance is greater than the first distance, the terminal device determining that the terminal device is located at the edge of the moving cell at the second time point.

[0038] Based on the above solution, if the terminal device is located at the edge of the moving cell at a first time point, the terminal device further determines whether the terminal device is located at the edge of the moving cell at a second time point, which increases the flexibility of the solution for determining whether the terminal device is located at the edge of the moving cell.

[0039] Regarding the first aspect, in some implementation forms of the first aspect, the terminal device determining the third distance includes the terminal device determining a fourth position, the terminal device determining a sixth position based on ephemeris information of the second network device, the sixth position being the position of the second network device at the second time point, the terminal device determining a fifth position based on the sixth position, and the terminal device determining the third distance based on the fourth position and the fifth position.

[0040] Regarding the first aspect, in some implementation forms of the first aspect, the terminal device determining the fifth location based on the sixth location includes, if the first information includes a locational relationship between the moving cell and the second network device, the terminal device determining the fifth location based on the sixth location and the locational relationship between the moving cell and the second network device, or, if the first information includes timestamp information and the first information does not include a locational relationship between the moving cell and the second network device, the terminal device determining the locational relationship between the moving cell and the second network device based on the location of the second network device at the current time, the timestamp information, and the position of the reference point of the moving cell, and the terminal device determining the fifth location based on the sixth location and the locational relationship between the moving cell and the second network device.

[0041] Regarding the first aspect, in some implementation forms of the first aspect, the terminal device determining, based on the first information, that the cell in which the terminal device is located is a moving cell includes: if the first information includes timestamp information, the terminal device determining, based on the timestamp information, that the cell in which the terminal device is located is a moving cell; if the first information includes first indication information, the terminal device determining, based on the first indication information, that the cell in which the terminal device is located is a moving cell; or if the first information includes a locational relationship between the moving cell and a second network device, the terminal device determining, based on the locational relationship between the moving cell and the second network device, that the cell in which the terminal device is located is a moving cell.

[0042] According to the above solution, the terminal device may determine that the terminal device is located in a moving cell based on multiple types of information in the first information, which increases the flexibility of the solution for the terminal device to determine that the cell in which the terminal device is located is a moving cell.

[0043] Regarding the first aspect, in some implementations of the first aspect, the method further includes, before the ephemeris information of the second network device expires, the terminal device obtaining updated ephemeris information of the second network device, and the terminal device re-determining the second distance.

[0044] Based on the aforementioned solution, the terminal device needs to update the ephemeris information of the second network device in a timely manner to ensure that the terminal device can determine in a timely manner whether to perform neighbor cell measurements.

[0045] Regarding the first aspect, in some implementation forms of the first aspect, the method further includes the terminal device determining a validity period of the reference point of the moving cell, and the terminal device updating the reference point of the moving cell before the validity period of the reference point of the moving cell expires.

[0046] Based on the above solution, the terminal device needs to update the reference point of the moving cell in a timely manner to ensure that the terminal device can determine in a timely manner whether to make neighbor cell measurements.

[0047] Regarding the first aspect, in some implementation forms of the first aspect, the terminal device determining the validity period of the reference point of the moving cell includes: if the first information includes the validity period of the reference point of the moving cell, the terminal device determining the validity period of the reference point of the moving cell; or if the first information does not include the validity period of the reference point of the moving cell, the terminal device determining the validity period of the reference point of the moving cell based on the validity period of ephemeris information of the second network device; or if the first information does not include the validity period of the reference point of the moving cell, the terminal device determining the period during which the terminal device is within the moving cell as the validity period of the reference point of the moving cell.

[0048] Based on the above solution, the terminal device may determine the validity period of the reference point of the moving cell based on multiple types of information in the first information, which increases the flexibility of the solution for the terminal device to determine the validity period of the reference point of the moving cell.

[0049] According to a second aspect, a communication method is provided. The method may be performed by a first network device, or may be performed by a component (e.g., a chip or a circuit) of the first network device. This is not limited. For ease of explanation, the following uses an example in which the method is performed by the first network device for explanation.

[0050] The method may include a first network device determining first information, the first information including information regarding a moving cell in which the terminal device is located, the moving cell being a cell covered by a moving process of the second network device, the second network device communicating with the first network device via a non-terrestrial network NTN, and the first network device transmitting the first information to the terminal device.

[0051] Based on the above solution, the first network device may send information about the moving cell in which the terminal device is located to the terminal device in a moving cell scenario, so that the terminal device can timely determine whether neighbor cell measurements and cell selection or reselection need to be performed, timely obtain wireless network paging, and timely initiate a call.

[0052] Regarding the second aspect, in some implementation forms of the second aspect, the first information includes timestamp information and / or a first distance. The timestamp information indicates time information of a reference point of the moving cell. The reference point of the moving cell is a position within the moving cell. The first distance is used to determine a relationship between the position of the terminal device and the coverage area of the moving cell.

[0053] Based on the above solution, the first information transmitted by the first network device includes timestamp information indicating the time information of the reference point of the moving cell and the first distance used to determine the relationship between the position of the terminal device and the coverage area of the moving cell, so that the terminal device can determine whether neighbor cell measurements need to be made based on the above information.

[0054] Optionally, the timestamp information may further indicate that the cell in which the terminal device is located is a moving cell, which increases the flexibility of the solution for the terminal device to determine whether it is in a moving cell.

[0055] Regarding the second aspect, in some implementation forms of the second aspect, the timestamp information indicates a start time of the reference point of the moving cell, and the first information is one of the following: The mobile communication device further includes at least one of first indication information, a reference point of the moving cell, a validity period of the reference point of the moving cell, and a positional relationship between the moving cell and the second network device. The first indication information indicates that the cell in which the terminal device is located is the moving cell. The validity period of the reference point of the moving cell indicates a time range during which the reference point is available to the terminal device from a start time. The positional relationship between the moving cell and the second network device is used to determine the position of the reference point of the moving cell.

[0056] Based on the above solution, the first information transmitted by the first network device further includes other information used by the terminal device to determine whether neighbor cell measurements need to be performed, which improves the flexibility and accuracy of the solution for the terminal device to determine whether neighbor cell measurements need to be performed.

[0057] Optionally, the location relationship between the moving cell and the second network device may further indicate that the cell in which the terminal device is located is the moving cell, which increases the flexibility of the solution for the terminal device to determine whether the terminal device is in the moving cell.

[0058] Regarding the second aspect, in some implementation forms of the second aspect, the timestamp information is any one of the following: an absolute time point of the reference point of the moving cell, an offset value of the start time point of the ephemeris information of the second network device, and a start time point of a downlink subframe corresponding to the system frame number and subframe number in the first information. The ephemeris information of the second network device indicates location information of the second network device.

[0059] Based on the above solution, the timestamp information may be multiple types of time information indicating the reference point of the moving cell, which increases the flexibility of the solution.

[0060] Regarding the second aspect, in some implementation forms of the second aspect, the reference point of the moving cell is the center position of the moving cell at a certain point in time.

[0061] Based on the above solution, the reference point of the moving cell may be the center position of the moving cell at that time, so that the terminal device makes neighboring cell measurements more timely based on the center position of the moving cell.

[0062] With regard to the second aspect, in some implementation forms of the second aspect, the positional relationship between the moving cell and the second network device includes a distance relationship between a reference point of the moving cell and a sub-satellite point of the second network device, and an angular relationship between the reference point of the moving cell and the sub-satellite point of the second network device, or the positional relationship between the moving cell and the second network device includes an angular relationship between a reference point of the moving cell and the second network device, and an angular relationship between the origin of the coordinates and the reference point of the moving cell.

[0063] Based on the above solution, the positional relationship between the moving cell and the second network device may be represented using multiple angle relationships and distance relationships, which increases the flexibility of the manner of representing the positional relationship between the moving cell and the second network device.

[0064] According to a third aspect, there is provided a communication device, the communication device including a unit configured to perform the method according to the first aspect. The communication device may be a terminal device or may be implemented by a chip or circuit located on the terminal device, although this is not a limitation in the present application.

[0065] The communication device includes a transceiver unit configured to receive first information from a first network device, the first information including information regarding a moving cell in which the terminal device is located, the moving cell being a cell covered by a moving process of a second network device, the second network device communicating with the first network device via a non-terrestrial network NTN, and a processing unit that determines whether to perform neighboring cell measurements based on the first information, the neighboring cell being a neighboring cell of the moving cell.

[0066] Regarding the third aspect, in some implementation forms of the third aspect, the first information includes timestamp information and / or a first distance. The timestamp information indicates time information of a reference point of the moving cell. The reference point of the moving cell is a position within the moving cell. The first distance is used to determine a relationship between the position of the terminal device and the coverage area of the moving cell.

[0067] Regarding the third aspect, in some implementation forms of the third aspect, the timestamp information indicates a start time of the reference point of the moving cell, and the first information is one of the following: The mobile communication device further includes at least one of first indication information, a reference point of the moving cell, a validity period of the reference point of the moving cell, and a positional relationship between the moving cell and the second network device. The first indication information indicates that the cell in which the terminal device is located is the moving cell. The validity period of the reference point of the moving cell indicates a time range during which the reference point is available to the terminal device from a start time. The positional relationship between the moving cell and the second network device is used to determine the position of the reference point of the moving cell.

[0068] Regarding the third aspect, in some implementation forms of the third aspect, the timestamp information is any one of the following: an absolute time point of the reference point of the moving cell, an offset value of the start time point of the ephemeris information of the second network device, and a start time point of a downlink subframe corresponding to the system frame number and subframe number in the first information. The ephemeris information of the second network device indicates location information of the second network device.

[0069] Regarding the third aspect, in some implementation forms of the third aspect, the reference point of the moving cell is the center position of the moving cell.

[0070] With regard to the third aspect, in some implementation forms of the third aspect, the positional relationship between the moving cell and the second network device includes a distance relationship between a reference point of the moving cell and a sub-satellite point of the second network device, and an angular relationship between the reference point of the moving cell and the sub-satellite point of the second network device, or the positional relationship between the moving cell and the second network device includes an angular relationship between a reference point of the moving cell and the second network device, and an angular relationship between the origin of the coordinates and the reference point of the moving cell.

[0071] Regarding the third aspect, in some implementation forms of the third aspect, the processing unit is further configured to determine, based on the first information, that the cell in which the terminal device is located is a moving cell. The processing unit is further configured to determine a second distance. If the first information includes the first distance, the processing unit is further configured to determine, based on the first distance and the second distance, whether to perform neighbor cell measurements. The second distance is a distance between the first position and the second position. The first position is a position of the terminal device at a first time point. The second position is a position of a reference point of the moving cell at the first time point.

[0072] Regarding the third aspect, in some implementations of the third aspect, the processing unit is further configured to determine a first location. The processing unit is further configured to determine a third location based on ephemeris information of the second network device. The third location is a location of the second network device at a first time point. The terminal device determines a second location based on the third location. The processing unit is further configured to determine a second distance based on the first location and the second location.

[0073] With regard to the third aspect, in some implementation forms of the third aspect, if the first information includes a positional relationship between the moving cell and the second network device, the processing unit is further configured to determine a second position based on the third position and the positional relationship between the moving cell and the second network device; or if the first information includes timestamp information and the first information does not include a positional relationship between the moving cell and the second network device, the processing unit is further configured to determine a positional relationship between the moving cell and the second network device based on the timestamp information, the position of the second network device at the current time, and the position of a reference point of the moving cell at the current time, and the processing unit is further configured to determine a second position based on the third position and the positional relationship between the moving cell and the second network device.

[0074] Regarding the third aspect, in some implementations of the third aspect, the processing unit is further configured to determine a service outage time of the moving cell based on the first distance and the second distance, and to perform neighbor cell measurements before the service outage time of the moving cell.

[0075] Regarding the third aspect, in some implementation forms of the third aspect, if the second distance is greater than the first distance, the processing unit is further configured to determine that the first time point is a service outage time point of the moving cell.

[0076] Regarding the third aspect, in some implementations of the third aspect, if the second distance is smaller than the first distance, the processing unit is further configured to determine a third distance. The third distance is a distance between a fourth position and a fifth position. The fourth position is a position of the terminal device at a second time point. The fifth position is a position of a reference point of the moving cell at the second time point, and the first time point is before the second time point. If the third distance is larger than the first distance, the processing unit is further configured to determine that the second time point is a service outage time of the moving cell.

[0077] Regarding the third aspect, in some implementation forms of the third aspect, when the first information includes the first distance, the processing unit is further configured to determine whether the terminal device is located at an edge of the moving cell based on the first distance and the second distance. When the terminal device is located at the edge of the moving cell, the processing unit is further configured to perform neighbor cell measurements.

[0078] Regarding the third aspect, in some implementation forms of the third aspect, if the second distance is greater than the first distance, the processing unit is further configured to determine that the terminal device is at the edge of the moving cell at the first time point.

[0079] Regarding the third aspect, in some implementations of the third aspect, if the second distance is smaller than the first distance, the processing unit is further configured to skip performing neighbor cell measurements at the first time point. The processing unit is further configured to determine a third distance. The third distance is a distance between a fourth position and a fifth position. The fourth position is the position of the terminal device at the second time point. The fifth position is the position of a reference point of the moving cell at the second time point, and the first time point is before the second time point. If the third distance is larger than the first distance, the processing unit is further configured to determine that the terminal device is located at an edge of the moving cell at the second time point.

[0080] Regarding the third aspect, in some implementations of the third aspect, the processing unit is further configured to determine a fourth position. The processing unit is further configured to determine a sixth position based on ephemeris information of the second network device. The sixth position is a position of the second network device at a second time point. The terminal device determines a fifth position based on the sixth position. The processing unit is further configured to determine a third distance based on the fourth position and the fifth position.

[0081] Regarding the third aspect, in some implementations of the third aspect, when the first information includes a positional relationship between the moving cell and the second network device, the processing unit is further configured to determine a fifth position based on the sixth position and the positional relationship between the moving cell and the second network device; or when the first information includes timestamp information and the first information does not include a positional relationship between the moving cell and the second network device, the processing unit is further configured to determine a positional relationship between the moving cell and the second network device based on the position of the second network device at the current time, the timestamp information, and the position of the reference point of the moving cell. The processing unit is further configured to determine a fifth position based on the sixth position and the positional relationship between the moving cell and the second network device.

[0082] Regarding the third aspect, in some implementation forms of the third aspect, when the first information includes timestamp information, the processing unit is further configured to determine, based on the timestamp information, that the cell in which the terminal device is located is a moving cell; or when the first information includes first indication information, the processing unit is further configured to determine, based on the first indication information, that the cell in which the terminal device is located is a moving cell; or when the first information includes a locational relationship between the moving cell and a second network device, the processing unit is further configured to determine, based on the locational relationship between the moving cell and the second network device, that the cell in which the terminal device is located is a moving cell.

[0083] Regarding the third aspect, in some implementations of the third aspect, the processing unit is further configured to obtain updated ephemeris information of the second network device before the ephemeris information of the second network device expires. The processing unit is further configured to re-determine the second distance.

[0084] Regarding the third aspect, in some implementations of the third aspect, the processing unit is further configured to determine a validity period of the reference point of the moving cell, and to update the reference point of the moving cell before the validity period of the reference point of the moving cell expires.

[0085] Regarding the third aspect, in some implementation forms of the third aspect, if the first information includes a validity period of the reference point of the moving cell, the processing unit is further configured to determine the validity period of the reference point of the moving cell, or if the first information does not include the validity period of the reference point of the moving cell, the processing unit is further configured to determine the validity period of the reference point of the moving cell based on the validity period of ephemeris information of the second network device, or if the first information does not include the validity period of the reference point of the moving cell, the processing unit is further configured to determine the period during which the terminal device is within the moving cell as the validity period of the reference point of the moving cell.

[0086] For a description of the relevant contents and beneficial effects of the communication device provided in the third aspect, please refer to the description of the method in the first aspect, and the details will not be described again here.

[0087] According to a fourth aspect, there is provided a communication device, the communication device including a unit configured to perform the method according to the second aspect. The communication device may be a first network device, or may be implemented by a chip or circuit located in the first network device, although this is not a limitation in the present application.

[0088] The communication device includes a processing unit configured to determine first information, the first information including information regarding a moving cell in which a terminal device is located, the moving cell being a cell covered by a moving process of a second network device, the second network device communicating with the first network device via a non-terrestrial network NTN, and a transceiver unit configured to transmit the first information to the terminal device.

[0089] Regarding the fourth aspect, in some implementation forms of the fourth aspect, the first information includes timestamp information and / or a first distance. The timestamp information indicates time information of a reference point of the moving cell. The reference point of the moving cell is a position within the moving cell. The first distance is used to determine a relationship between the position of the terminal device and the coverage area of the moving cell.

[0090] Regarding the fourth aspect, in some implementation forms of the fourth aspect, the timestamp information indicates a start time of the reference point of the moving cell, and the first information is one of the following: The mobile communication device further includes at least one of first indication information, a reference point of the moving cell, a validity period of the reference point of the moving cell, and a positional relationship between the moving cell and the second network device. The first indication information indicates that the cell in which the terminal device is located is the moving cell. The validity period of the reference point of the moving cell indicates a time range during which the reference point is available to the terminal device from a start time. The positional relationship between the moving cell and the second network device is used to determine the position of the reference point of the moving cell.

[0091] Regarding the fourth aspect, in some implementation forms of the fourth aspect, the timestamp information is any one of the following: an absolute time point of a reference point of the moving cell, an offset value of a start time point of the ephemeris information of the second network device, and a start time point of a downlink subframe corresponding to the system frame number and the subframe number in the first information. The ephemeris information of the second network device indicates location information of the second network device.

[0092] Regarding the fourth aspect, in some implementation forms of the fourth aspect, the reference point of the moving cell is the center position of the moving cell.

[0093] With regard to the fourth aspect, in some implementation forms of the fourth aspect, the positional relationship between the moving cell and the second network device includes a distance relationship between a reference point of the moving cell and a sub-satellite point of the second network device, and an angular relationship between the reference point of the moving cell and the sub-satellite point of the second network device, or the positional relationship between the moving cell and the second network device includes an angular relationship between a reference point of the moving cell and the second network device, and an angular relationship between the origin of the coordinates and the reference point of the moving cell.

[0094] For a description of the relevant contents and beneficial effects of the communication device provided in the fourth aspect, please refer to the description of the method in the second aspect, and the details will not be described again here.

[0095] According to a fifth aspect, there is provided a communications device, the device including: a memory configured to store a program; and at least one processor configured to execute computer programs or instructions stored in the memory to perform a method according to any one of the possible implementations of the first or second aspect.

[0096] In one implementation, the apparatus is a terminal device.

[0097] In other implementations, the apparatus is a chip, chip system, or circuit used in a terminal device.

[0098] According to a sixth aspect, the application provides a processor configured to perform the method provided in the previous aspect.

[0099] Operations such as transmitting and acquiring / receiving related to a processor may be understood as operations such as transmitting and receiving performed by the processor's output and reception or input, or radio frequency circuits and antennas, unless otherwise specified or unless the operations contradict the actual function or internal logic of the operations in the relevant description, which is not limited in this application.

[0100] According to a seventh aspect, there is provided a computer-readable storage medium storing program code for execution by a device, the program code including a method according to any one of the possible implementation forms of the first or second aspect.

[0101] According to an eighth aspect, there is provided a computer program product comprising instructions which, when run on a computer, enable the computer to perform a method according to any one of the possible implementations of the first or second aspect.

[0102] According to a ninth aspect, there is provided a chip, the chip including a processor and a communication interface, the processor reading instructions stored in a memory via the communication interface to perform a method according to any one of the possible implementation forms of the first or second aspect.

[0103] Optionally, in one implementation, the chip further includes a memory, the memory storing a computer program or instruction, and the processor is configured to execute the computer program or instruction stored in the memory, and when the computer program or instruction is executed, the processor is configured to perform a method according to any one of the possible implementations of the first and second aspects.

[0104] According to a tenth aspect, there is provided a communication system including one or more of the aforementioned terminal devices and first network devices. [Brief explanation of the drawings]

[0105] [Figure 1] FIG. 1 is a diagram of a network architecture applicable to an embodiment of the present application. [Figure 2] 1 is a diagram of an architecture of a communication system applicable to an embodiment of the present application; [Figure 3] FIG. 1 is a diagram of a semi-stationary cell. [Figure 4] FIG. 1 is a diagram of a moving cell. [Figure 5] 5 is a schematic flowchart of a communication method 500 according to an embodiment of the present application. [Figure 6] FIG. 2 is a diagram of the positional relationship between a moving cell and a second network device according to an embodiment of the present application. [Figure 7] FIG. 10 is another diagram of the positional relationship between the moving cell and the second network device according to an embodiment of the present application. [Figure 8] 8 is a schematic flowchart of a communication method 800 according to an embodiment of the present application. [Figure 9] 9 is a schematic flowchart of a communication method 900 according to an embodiment of the present application. [Figure 10] 1 is a schematic block diagram of a communication device 1000 according to an embodiment of the present application. [Figure 11] 11 is a schematic block diagram of another communication device 1100 according to an embodiment of the present application. [Figure 12] FIG. 12 is a diagram of a chip system 1200 according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0106] Hereinafter, the technical solutions in the embodiments of the present application will be described with reference to the accompanying drawings.

[0107] The technical solutions in the embodiments of the present application may be applied to various communication systems, such as a Long Term Evolution (LTE) system, a Long Term Evolution Advanced (LTE-A) system, an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD) system, a Universal Mobile Telecommunications System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a next-generation communication system (e.g., a fifth-generation (5G) communication system), an integrated system of multiple access systems, an evolved system, three major application scenarios of 5G mobile communication systems: enhanced Mobile Broadband (eMBB), ultra-reliable low-latency communication (URLLC), and enhanced Machine Type Communication (eMTC), or new communication systems that will emerge in the future. The technical solutions provided in this application can be further applied to future communication systems, such as sixth generation mobile communication systems, which are not limited in this application.

[0108] The technical solutions provided in this application may further be applied to machine-type communication (MTC), long-term evolution-machine (LTE-M), device-to-device (D2D) networks, machine-to-machine (M2M) networks, Internet of Things (IoT) networks, or other networks. IoT networks may include, for example, the Internet of Vehicles. Communication modes in Internet of Vehicle systems are collectively referred to as vehicle-to-X (V2X, where X can represent anything). For example, V2X may include vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, or vehicle-to-network (V2N) communication.

[0109] The network device in the embodiment of the present application may be referred to as a (radio) access network ((R)AN) device. The (R)AN can manage radio resources, provide access services for user equipment, and complete the transfer of user equipment data between the user equipment and the core network. The (R)AN may also be understood as a base station in the network, which is a device deployed in the radio access network to provide wireless communication functions for mobile stations (MSs).

[0110] For example, the access network device in the embodiments of the present application may be any communication device having wireless transceiver functionality and configured to communicate with user equipment, including, but not limited to, an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (HeNB or HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (WiFi) system, a wireless relay node, a wireless backhaul node, a transmission point (TP), a transmission and reception point (TRP), etc. Alternatively, the access network device may be a gNB or transmission point (TRP or TP) in a 5G system such as an NR system, one antenna panel or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a baseband unit (BBU) or distributed unit (DU) constituting a network node, for example, a gNB or transmission point. It may be understood that all or part of the functions of the access network device in this application may alternatively be implemented using software functions running on hardware or using virtualization functions instantiated on a platform (e.g., a cloud platform).

[0111] Additionally, in the network structure, the access network device may include a centralized unit (CU) node, a distributed unit (DU) node, or a RAN device including a CU node and a DU node. The RAN device including the CU node and the DU node divides the protocol layers of the gNB in the NR system. Some protocol layer functions are centrally controlled by the CU. Some or all of the remaining protocol layer functions are distributed to the DUs, and the CU centrally controls the DUs. The central unit CU may be further divided into a control plane (CU-CP) and a user plane (CU-UP). The CU-CP is responsible for control plane functions and mainly includes the RRC layer and the PDCP layer, i.e., the PDCP-C layer, which correspond to the control plane. The PDCP-C layer is mainly responsible for data encryption and decryption, integrity protection, data transmission, etc. in the control plane. The CU-UP is responsible for user plane functions and mainly includes the SDAP layer and the PDCP layer, i.e., the PDCP-U layer, which correspond to the user plane. The SDAP layer is mainly responsible for processing core network data and mapping flows to bearers. The PDCP-U layer is responsible for encryption, decryption, integrity protection, header compression, sequence number maintenance, data transmission, etc. in the data plane. The CU-CP and CU-UP are connected via the E1 interface. Instead of the gNB, the CU-CP is connected to the core network via the NG interface and connected to the DU via the F1 interface control plane, i.e., F1-C. The CU-UP is connected to the DU via the F1 interface user plane, i.e., F1-U. Of course, in another possible implementation, the PDCP-C layer is alternatively located within the CU-UP. The RAN device may be responsible for functions such as radio resource management, quality of service (QoS) management, data compression, and encryption on the air interface side. The AN device provides access services for terminal devices and completes the transfer of control signals and user data between the terminal devices and the core network.

[0112] A terminal device in embodiments of the present application may also be referred to as user equipment (UE), terminal, access terminal, subscriber unit, subscriber station, mobile station, remote station, remote terminal, mobile device, user terminal, wireless communication device, user agent, or user equipment. The terminal in an embodiment of the present application may be a mobile phone, a tablet computer (pad), a computer with wireless transceiver functionality, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, 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 wireless terminal in 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 functionality, a computing device, another processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal in a 5G network, or a terminal in a future evolved network.

[0113] Wearable devices, sometimes called wearable intelligent devices, are a collective term for glasses, gloves, watches, clothing, and shoes developed by applying wearable technology to the intelligent design of everyday clothing. Wearable devices are portable devices that can be worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not only hardware devices, but also perform powerful functions through software support, data exchange, and cloud interaction. Typical wearable intelligent devices include full-featured, large devices such as smartwatches and smart glasses that can implement full or partial functionality independently of smartphones, and devices dedicated to a single application function that must be linked to other devices such as smartphones or various smart bands and smart jewelry for monitoring physical signs.

[0114] In an embodiment of the present application, a communication device configured to perform the functions of a network device may be a network device, may be a network device having some functions of a base station, or may be a device, such as a chip system, that can support a network device in performing functions. The device may be installed in a network device.

[0115] In actual network deployment, terrestrial networks cannot cover all areas, especially areas with small populations, such as deserts, oceans, or the Arctic and Antarctic. Non-terrestrial network (NTN) networks cover large areas and are easier to provide coverage in sparsely populated areas, making them suitable for deployment in sparsely populated areas. Embodiments of the present application are applicable to non-terrestrial network (NTN) network communications. An NTN network is a network or network segment that uses radio frequencies on satellites (UAS platforms). In the following, a satellite communication system is used as an example to describe in detail a network architecture applicable to an embodiment of the present application with reference to FIG. 1 . In a satellite communication system, a network device may include a satellite.

[0116] Figure 1 is a diagram of a network architecture applicable to one embodiment of the present application. A terrestrial mobile terminal (UE) accesses the network via 5G new radio. 5G access network devices are deployed on satellites and connected to a terrestrial core network via wireless links. In addition, there are wireless links between satellites to implement signaling exchange and user data transmission between the access network devices. All network elements and their interfaces in Figure 2 are described as follows:

[0117] The terminal device is a mobile device that supports 5G new radio, such as a mobile phone or a tablet. The terminal device may access the satellite network via the air interface and initiate services such as calls and Internet access.

[0118] 5G access network devices mainly provide wireless access services, schedule wireless resources for access terminals, provide reliable wireless transmission protocols and data encryption protocols, etc., and are, for example, base stations.

[0119] The 5G core network provides services such as user access control, mobility management, session management, user security authentication, and charging. The 5G core network includes multiple functional units that can be classified into control plane functional entities and data plane functional entities. The Access and Mobility Management Function (AMF) is responsible for user access management, security authentication, and mobility management. The User Plane Function (UPF) is responsible for managing functions such as user plane data transmission and traffic statistics collection.

[0120] The ground station is responsible for transferring signaling and service data between the satellite access network device and the 5G core network.

[0121] 5G New Radio is the wireless link between the terminal and the access network device.

[0122] The Xn interface is an interface between 5G access network devices and access network devices, and is mainly used for signaling exchange such as handover.

[0123] The NG interface is an interface between 5G access network devices and the 5G core network, and is mainly used to exchange signaling such as the core network's NAS signaling and user service data.

[0124] 2 is a diagram of an architecture of a communication system according to one embodiment of the present application. As shown in FIG. 2, the communication system may include at least one network device, such as the satellite device shown in FIG. 1. The communication system may further include at least one terminal device, such as the terminal device shown in FIG. 1. The network device may communicate with the terminal device via a wireless link.

[0125] It should be understood that a network device in a wireless communication system may be any device having wireless transceiver functionality, including, but not limited to, a base station controller (BSC), a base transceiver station (BTS), etc., and may be one antenna panel or a group of antenna panels (including multiple antenna panels) of a base station such as a 5G system, a satellite, etc.

[0126] It should be understood that Figure 2 shows only one network device and one terminal device. In one example, the communication system is not limited and may include more terminal devices. For example, in a satellite communication network, a satellite may cover multiple terminal devices for communication. Each terminal device is also not limited to communicating with one network device. For example, after a satellite moves, the terminal device may reselect a satellite for access communication.

[0127] It should be understood that Fig. 2 is merely an example and does not constitute any limitation on the scope of protection of the present application. The communication method provided in the embodiments of the present application may further relate to network elements or devices not shown in Fig. 2. Of course, the communication method provided in the embodiments of the present application may alternatively include only some of the network elements shown in Fig. 2.

[0128] It should be understood that the network architecture shown above is merely an example for the purpose of illustration, and the network architecture applicable to this embodiment of the present application is not limited thereto. Any network architecture capable of implementing the functions of the network elements described above is applicable to this embodiment of the present application.

[0129] One or more services may be obtained by partitioning into network elements or functions. Additionally, services may arise that are independent of network functions. In this application, an instance of a function, an instance of a service included in a function, or an instance of a service that exists independent of a network function may be referred to as a service instance.

[0130] It should be further understood that the above names are defined merely to distinguish different functions and should not constitute any limitation to this application. This application does not exclude the possibility of using other names in 6G networks and other future networks.

[0131] It should be further understood that the names of the interfaces between the network elements in Figure 1 or Figure 2 are merely examples. In specific implementations, the names of the interfaces may be other names, which are not specifically limited in this application. In addition, the names of the messages (or signaling) transmitted between the aforementioned network elements are merely examples and do not constitute any limitations on the functions of the messages.

[0132] For ease of reading, the following will explain or define some technical terms or concepts in this application in a uniform way.

[0133] 1. Non-terrestrial networks (NTN): An NTN is a network or network segment that uses radio frequencies transmitted by satellites (unmanned aircraft systems, UAS). Satellite communications have the advantages of wide coverage area, long communication distance, high reliability, high flexibility, and high throughput. Satellites are being introduced into 5th-generation (5G) mobile networks to provide communication services to areas that are difficult to cover with terrestrial networks, such as oceans and forests. This can improve the reliability of 5G communications, provide better quality and more stable communication services for users on trains, airplanes, and similar means of transportation, and provide more data transmission resources and support more connections.

[0134] 2. Quasi-Earth-Fixed Cell: A quasi-earth-fixed cell may also be referred to as a quasi-fixed cell for short. A quasi-fixed cell is a geographical area covered by a beam in a limited period of time, and the beam covers a different geographical area in another period of time (e.g., when a non-geosynchronous orbit (NGSO) satellite generates a steerable beam). Specifically, as shown in FIG. 3, the geographical area covered by the steerable beam generated by satellite 1 at times t1, t2, and t3 is geographical area 1. In other words, geographical area 1 may be referred to as a quasi-fixed cell.

[0135] 3. Earth moving cell: An Earth moving cell may also be referred to as a moving cell for short. A moving cell is an area covered by a beam. A moving cell moves on the surface of the Earth as the satellite moves (e.g., when an NGSO satellite generates a fixed or non-steerable beam). Specifically, as shown in FIG. 4, the geographical areas covered by the fixed or non-steerable beam generated by satellite 1 at times t1, t2, and t3 are geographical area 1, geographical area 2, and geographical area 3, respectively. In other words, geographical area 1, geographical area 2, and geographical area 3 may all be referred to as moving cells.

[0136] 4. NTN-based NG-RAN architectures NTN-based NG-RAN architectures include an architecture with a transparent satellite, a regenerative satellite without ISL, gNB processed payload, a regenerative satellite with ISL, gNB processed payload, an NG-RAN with a regenerative satellite based on gNB-DU, and a gNB processed payload based on relay-like architectures.

[0137] For a specific description of the NTN-based NG-RAN architecture, please refer to the description of the prior art, and to avoid repetition, the details will not be described here in this application.

[0138] It should be noted that some NTN-based NG-RAN architectures are merely examples, and there may be other architectures that are the same as or similar to the NTN-based NG-RAN architectures, which is not a limitation of this application.

[0139] It should be noted that all the above terms or techniques belong to the prior art and are not limiting.

[0140] It should be understood that the term "and / or" herein describes only an associative relationship for associated objects and indicates that three relationships may exist. For example, A and / or B may indicate the following three cases: when only A is present, when both A and B are present, and when only B is present. Additionally, the character " / " herein generally indicates an "or" relationship between associated objects.

[0141] The above is a brief explanation of the terms used in this application, and the details will not be described again in the following embodiments. Hereinafter, the communication method provided in the embodiments of this application will be described in detail with reference to the accompanying drawings. The embodiments provided in this application may be applied to the network architectures shown in Figures 1 and 2, but are not limited thereto.

[0142] Based on the architectures shown in Figures 1 and 2, when a terminal device is in a moving cell scenario, it is difficult for the terminal device to identify a cell edge based on cell signal strength and determine whether to perform cell reselection when the terminal device reaches the cell edge, resulting in failure to perform neighbor cell measurement and reselection in a timely manner.

[0143] The present application provides a communication method, in which a terminal device in a moving cell scenario can timely determine whether neighbor cell measurements and cell selection or reselection need to be performed, so that the terminal device can timely obtain paging of a wireless network and the terminal device can timely initiate a call.

[0144] 5 is a diagram of a communication method 500 according to an embodiment of the present application. The method 500 may include the following steps.

[0145] S510: The first network device determines first information.

[0146] The first information includes information about a moving cell in which the terminal device is located.

[0147] A moving cell is a cell covered by the moving process of a second network device. It should be understood that a geographical area covered by a fixed or non-steerable beam generated by the second network device is a moving cell. For example, as shown in Figure 4, satellite 1 is the second network device, and geographical area 1, geographical area 2, and geographical area 3 are moving cells covered by the moving process of the second network device.

[0148] The second network device communicates with the first network device via the NTN.

[0149] For example, the first network device may be a base station, a chip, a chip system, or a processor that supports a method that can be implemented by the first network device, or a logic module or software that can implement all or part of the functions of an access network device, which is not limited in this application.

[0150] For example, the second network device may be a device such as a satellite, an unmanned aerial vehicle, or a high-altitude communication platform that communicates with the first network device via an NTN. Alternatively, the second network device may be the same as the first network device. For example, the second network device may alternatively be a base station, or may be a logical module or software that can perform all or part of the functions of an access network device. This is not a limitation of the present application.

[0151] For example, the first information includes timestamp information and / or a first distance.

[0152] The time stamp information indicates the time information of the reference point of the moving cell.

[0153] Optionally, the timestamp information may further indicate that the cell in which the terminal device is located is a moving cell.

[0154] Optionally, the timestamp information may further indicate the start time of the reference point of the moving cell.

[0155] The reference point of a moving cell is a position within the moving cell. For example, the reference point of a moving cell may be the center position within the moving cell. This is not limited in the present application.

[0156] Specifically, the timestamp information may be any one of the following: an absolute time point of the reference point of the moving cell, an offset value of the start time of the ephemeris information of the second network device, and a start time point of a downlink subframe corresponding to the system frame number and subframe number in the first information.

[0157] The absolute time of the reference point of the moving cell is the time of the reference point of the moving cell relative to 00:00:00 on January 1, 1900 in the Gregorian calendar.

[0158] The offset value of the start time of the ephemeris information of the second network device indicates the time difference between the absolute time of the reference point of the moving cell and the start time of the ephemeris information of the second network device.

[0159] It should be understood that the offset value may be 0. In other words, the absolute time point of the reference point of the moving cell is the same as the start time point of the ephemeris information of the second network device.

[0160] The ephemeris information of the second network device indicates the location information of the second network device. For example, if the second network device is a satellite, the ephemeris information of the second network device indicates the orbital position of the satellite. This is not limited in the present application.

[0161] The start time of the downlink subframe corresponding to the system frame number and the subframe number in the first information indicates the time when the first information is transmitted.

[0162] Optionally, when the system frame number and subframe number are default and the network device transmits the first information via dedicated signaling, the start time of the downlink subframe corresponding to the system frame number and subframe number in the first information is the time to transmit the first information.

[0163] Optionally, when the system frame number and subframe number are default and the network device transmits the first information by broadcasting, the time corresponding to the system frame number and subframe number in the first information is the end time of a system message window for scheduling the first information.

[0164] The first distance is used to determine a relationship between the location of the terminal device and the coverage area of the moving cell.

[0165] Optionally, when the first distance is a radius of the moving cell, the positional relationship between the terminal device and the moving cell may be determined based on the first distance and the position of the terminal device.

[0166] Optionally, if the first distance is a distance value smaller than the radius of the moving cell, the positional relationship between the terminal device and the moving cell may be determined based on the first distance and the position of the terminal device.

[0167] Optionally, the first information is: The information further includes at least one of the first indication information, the reference point of the moving cell, the validity period of the reference point of the moving cell, the positional relationship between the moving cell and the second network device, and a system frame number and a subframe number.

[0168] The first indication information indicates that the cell in which the terminal device is located is a moving cell.

[0169] The validity period of a reference point of a moving cell indicates the time range during which the reference point is available to a terminal device from the start of the reference point of the moving cell.

[0170] For example, the starting time of the reference point of the moving cell is 8:00 am and the validity period of the reference point of the moving cell is 10 minutes, in other words, the validity period of the reference point of the moving cell is from 8:00 am to 8:10 am.

[0171] The positional relationship between the moving cell and the second network device is used to determine the position of the reference point of the moving cell.

[0172] Optionally, the timestamp information may further indicate that the cell in which the terminal device is located is a moving cell.

[0173] In a possible implementation, the positional relationship between the moving cell and the second network device includes a distance relationship between a reference point of the moving cell and a sub-satellite point of the second network device, and an angular relationship between the reference point of the moving cell and a sub-satellite point of the second network device.

[0174] The sub-satellite point of the second network device is the intersection of the Earth's surface and the connecting line between the second network device's instantaneous position and the Earth's center, and the sub-satellite point of the second network device is represented by geographic longitude and latitude. In other words, the ground point directly below the second network device is the sub-satellite point.

[0175] For example, the positional relationship between the moving cell and the second network device may be represented by (r, θ) or (rsinθ,rcosθ).

[0176] Here, r represents the distance from the sub-satellite point of the second network device to the reference point of the moving cell at a certain time, and θ represents the angular relationship between the sub-satellite point of the second network device and the reference point of the moving cell at that time. For details, see Figure 6.

[0177] In a possible implementation, the positional relationship between the moving cell and the second network device includes an angular relationship between a reference point of the moving cell and the second network device, and an angular relationship between the origin of the coordinates and the reference point of the moving cell.

[0178] For example, the positional relationship between the moving cell and the second network device may be represented by (α, β, φ).

[0179] Here, α represents the information about the angle between the second network device and the reference point of the moving cell at a certain time, and β and φ represent the angular relationship between the coordinate origin (geocenter) and the reference point of the moving cell at that time. For details, see Figure 7.

[0180] It should be noted that the location relationship between the moving cell and the second network device is merely an example, which is not limiting in this application.

[0181] The system frame number and subframe number are the system frame number and subframe number corresponding to the subframe at any point in time, which is not limited in this application.

[0182] S520: The first network device sends the first information to the terminal device.

[0183] In response, the terminal device receives first information from the first network device.

[0184] In a possible implementation, the first network device transmits the first information via a common message (eg, a broadcast message).

[0185] In a possible implementation, the first network device transmits the first information via a dedicated message (eg, a paging message).

[0186] It should be noted that the manner of transmitting the first information to the terminal device by the first network device is merely an example, which is not limited in this application.

[0187] S530: The terminal device determines whether to perform neighbor cell measurements based on the first information.

[0188] It should be understood that after receiving the first information from the first network device, the terminal device determines whether to perform neighbor cell measurements based on the first information.

[0189] The neighboring cells are the neighboring cells of the moving cell.

[0190] Based on the above solution, the terminal device in a moving cell scenario determines, based on information transmitted by the first network device and including information about the moving cell in which the terminal device is located, whether neighboring cell measurement and cell selection or reselection need to be performed in a timely manner, so that the terminal device can obtain paging of the wireless network in a timely manner and initiate a call in a timely manner.

[0191] Furthermore, the terminal device determining whether to perform neighbor cell measurement based on the first information includes S531 to S534. In the following, S531 to S534 will be described separately in detail.

[0192] S531: The terminal device determines, based on first information, that the cell in which the terminal device is located is a moving cell.

[0193] In a possible implementation form, when the first information includes timestamp information, the terminal device determines, based on the timestamp information, that the cell in which the terminal device is located is a moving cell.

[0194] In a possible implementation form, when the first information includes first indication information, the terminal device determines, based on the first indication information, that the cell in which the terminal device is located is a moving cell.

[0195] In a possible implementation, the terminal device implicitly determines that the cell in which the terminal device is located is the moving cell based on other information in the first information (e.g., the location relationship between the moving cell and the second network device).

[0196] It should be noted that the manner in which the terminal device determines that the cell in which the terminal device is located is a moving cell based on the first information is merely an example, which is not limited in the present application.

[0197] S532: The terminal device determines a second distance.

[0198] It should be understood that after determining that the cell in which the terminal device is currently located is a moving cell, the terminal device further determines the distance between the terminal device and the reference point of the moving cell to determine the positional relationship between the terminal device and the moving cell.

[0199] The second distance is the distance between the first location and the second location, the first location being the location of the terminal device at the first time point, and the second location being the location of the reference point of the moving cell at the first time point.

[0200] The first time point is any time point after the present time, which is not limited in this application.

[0201] Specifically, the terminal device first determines a first position and a second position, and further determines a second distance based on the first position and the second position.

[0202] Optionally, at S533, the terminal device determines a second location.

[0203] In a possible implementation, when the first information includes a positional relationship between the moving cell and the second network device, the terminal device determines a third position based on ephemeris information of the second network device, and the terminal device determines a second position based on the third position and the positional relationship between the moving cell and the second network device.

[0204] The third location is the location of the second network device at the first point in time.

[0205] In a possible implementation, if the first information includes timestamp information and the first information does not include a positional relationship between the moving cell and the second network device, the terminal device determines a positional relationship between the moving cell and the second network device based on the timestamp information, the current position of the second network device, and the current position of the reference point of the moving cell, and determines a third position based on the ephemeris information of the second network device. Further, the terminal device determines a second position based on the third position and the positional relationship between the moving cell and the second network device.

[0206] It should be noted that the manner in which the terminal device determines the third location based on the ephemeris information of the second network device and the terminal device determines the second location based on the third location is merely an example, which is not limited in the present application.

[0207] Furthermore, after the terminal device determines the second distance, the terminal device determines whether to perform neighbor cell measurements, and the method 500 may further include the following steps.

[0208] S534: If the first information includes the first distance, the terminal device determines whether to perform neighbor cell measurement based on the first distance and the second distance.

[0209] In a possible implementation, the terminal device determines a service outage time of the moving cell based on the first distance and the second distance, and performs neighbor cell measurements before the service outage time of the moving cell.

[0210] It should be understood that if the distance between the position of the terminal device at a certain time and the position of the reference point of the moving cell at that time is greater than the first distance, that time is determined to be the service outage time of the moving cell, and the terminal device performs neighbor cell measurements before the service outage time of the moving cell.

[0211] It should be understood that the service outage time of the moving cell can be understood as follows: when the terminal device is out of the moving cell, the terminal device cannot receive the message sent by the moving cell and obtain the service provided by the moving cell.

[0212] For example, if the second distance is greater than the first distance, the terminal device determines that the first time point is an out-of-service time point of the moving cell.

[0213] For example, if the second distance is smaller than the first distance, the terminal device determines a third distance. The third distance is the distance between a fourth position and a fifth position. The fourth position is the position of the terminal device at the second time point. The fifth position is the position of the reference point of the moving cell at the second time point. The first time point is before the second time point. If the third distance is larger than the first distance, the terminal device determines that the second time point is the service outage time of the moving cell.

[0214] The second time point is any time point after the first time point, which is not limited in this application.

[0215] In a possible implementation, the terminal device determines whether the terminal device is at an edge of the moving cell based on the first distance and the second distance. If the terminal device is at the edge of the moving cell, the terminal device performs neighbor cell measurements.

[0216] It should be understood that if the distance between the position of the terminal device at a certain time and the position of the reference point of the moving cell at that time is greater than the first distance, the terminal device is determined to be at the edge of the moving cell at that time, and the terminal device performs neighboring cell measurements.

[0217] For example, if the second distance is greater than the first distance, the terminal device determines that the terminal device is located at the edge of the moving cell at the first time point, and the terminal device performs neighbor cell measurements.

[0218] For example, if the second distance is smaller than the first distance, the terminal device skips performing neighbor cell measurements at the first time point. Further, the terminal device determines a third distance. The third distance is the distance between a fourth position and a fifth position. The fourth position is the position of the terminal device at the second time point. The fifth position is the position of the reference point of the moving cell at the second time point. The first time point is before the second time point. If the third distance is larger than the first distance, the terminal device determines that the terminal device is located at the edge of the moving cell at the second time point, and the terminal device performs neighbor cell measurements.

[0219] Furthermore, when the terminal device receives the updated ephemeris information of the second network device, the terminal device needs to re-determine whether to perform neighbor cell measurements, and the method 300 may further include the following steps:

[0220] Optionally, S540: After updating the ephemeris information of the second network device, the terminal device re-determines whether to make neighbor cell measurements.

[0221] Specifically, the terminal device obtains updated ephemeris information of the second network device before the ephemeris information of the second network device expires, and the terminal device re-determines whether to perform neighbor cell measurements, i.e., performs S531 to S534 again.

[0222] It should be noted that if the terminal device acquires updated ephemeris information of the second network device within the validity period of the reference point of the moving cell, the terminal device does not need to re-determine whether to perform neighbor cell measurements.

[0223] Furthermore, before the validity period of the reference point of the moving cell expires, the terminal device needs to update the reference point of the moving cell, and the method 300 may further include the following steps:

[0224] Optionally, S550: The terminal device updates the reference point of the moving cell.

[0225] Specifically, the terminal device determines the validity period of the reference point of the moving cell, and the terminal device updates the reference point of the moving cell before the validity period of the reference point of the moving cell expires.

[0226] It should be noted that after the terminal device updates the reference point of the moving cell, the terminal device needs to re-determine whether to perform neighbor cell measurements, i.e., perform S531 to S534 again.

[0227] Specifically, the terminal device may determine the validity period of the reference point of the moving cell in the following manner.

[0228] In a possible implementation form, if the first information includes the validity period of the reference point of the moving cell, the terminal device determines the validity period of the reference point of the moving cell in the first information as the validity period of the reference point of the moving cell.

[0229] In a possible implementation form, if the first information does not include the validity period of the reference point of the moving cell, the terminal device determines the validity period of the ephemeris information of the second network device as the validity period of the reference point of the moving cell.

[0230] In a possible implementation form, if the first information does not include the validity period of the reference point of the moving cell, the terminal device determines the period during which the terminal device is in the moving cell as the validity period of the reference point of the moving cell.

[0231] It should be noted that the period during which the terminal device is in the moving cell can be understood as the period before the terminal device leaves the moving cell. In other words, before the terminal device leaves the moving cell, the reference point of the moving cell is within the validity period of the reference point of the moving cell.

[0232] It should be noted that the manner in which the terminal device determines the validity period of the reference point of the moving cell is merely an example, which is not a limitation of the present application.

[0233] 8 is a diagram of a communication method 800 according to an embodiment of the present application. The method 800 may include the following steps.

[0234] S801: A first network device determines first information.

[0235] The first information includes information about a moving cell in which the terminal device is located.

[0236] The moving cell is a cell covered in the moving process of the second network device.

[0237] It should be noted that the process of S801 is similar to the process of S510, and its detailed description will be omitted here to avoid repetition.

[0238] S802: The first network device sends first information to the terminal device.

[0239] In response, the terminal device receives first information from the network device.

[0240] In a possible implementation, the first network device transmits the first information via a common message (eg, a broadcast message).

[0241] In a possible implementation, the first network device transmits the first information via a dedicated message (eg, a paging message).

[0242] It should be noted that the manner of transmitting the first information to the terminal device by the first network device is merely an example, which is not limited in this application.

[0243] S803: The terminal device determines, based on the first information, that the cell in which the terminal device is located is a moving cell.

[0244] It should be understood that after the terminal device receives the first information, the terminal device determines, based on the first information, that the cell in which the terminal device is located is a moving cell.

[0245] It should be noted that the process of S803 is similar to the process of S531, and its detailed description will be omitted here to avoid repetition.

[0246] Furthermore, after determining that the cell in which the terminal device is currently located is a moving cell, the terminal device further determines the distance between the terminal device and the reference point of the moving cell at a first time point to determine the positional relationship between the terminal device and the moving cell, and method 800 may further include the following steps:

[0247] S804: The terminal device determines a first location and a second location.

[0248] The first location is the location of the terminal device at the first time point, and the second location is the location of the reference point of the moving cell at the first time point.

[0249] The first time point is any time point after the present time, which is not limited in this application.

[0250] Specifically, the terminal device determines the second location in the following manner.

[0251] In a possible implementation, when the first information includes a positional relationship between the moving cell and the second network device, the terminal device determines a third position based on ephemeris information of the second network device, and the terminal device determines a second position based on the third position and the positional relationship between the moving cell and the second network device.

[0252] The third location is the location of the second network device at the first point in time.

[0253] In a possible implementation, if the first information includes timestamp information and the first information does not include a positional relationship between the moving cell and the second network device, the terminal device determines a positional relationship between the moving cell and the second network device based on the timestamp information, the current position of the second network device, and the current position of the reference point of the moving cell, and determines a third position based on the ephemeris information of the second network device. Further, the terminal device determines a second position based on the third position and the positional relationship between the moving cell and the second network device.

[0254] It should be noted that the manner in which the terminal device determines the second location is merely an example, which is not limiting in this application.

[0255] S805: The terminal device determines a second distance.

[0256] Additionally, the terminal device determines a second distance based on the first location and the second location.

[0257] The second distance is the distance between the first position and the second position.

[0258] Furthermore, after the terminal device determines the second distance, the terminal device determines a service outage time of the moving cell based on the second distance, and the method 800 may further include the following steps:

[0259] S806: The terminal device determines a service outage time of the moving cell based on the first distance and the second distance.

[0260] Specifically, if the first information includes the first distance, the terminal device determines the service outage time of the moving cell based on the first distance and the second distance.

[0261] It should be understood that if the distance between the position of the terminal device at a certain time and the position of the reference point of the moving cell at that time, i.e., the second distance, is greater than the first distance, then that time is determined to be the service outage time of the moving cell, and the terminal device performs neighbor cell measurements before the service outage time of the moving cell.

[0262] In a possible implementation, if the second distance is greater than the first distance, the terminal device determines that the first time point is an out-of-service time point of the moving cell.

[0263] Optionally, if the second distance is smaller than the first distance, the terminal device further determines a third distance at the second time point, and determines a service outage time point of the moving cell based on the third distance and the first distance, and method 800 may further include S807 to S809.

[0264] S807: The terminal device determines a fourth location and a fifth location.

[0265] The fourth position is the position of the terminal device at the second time point, and the fifth position is the position of the reference point of the moving cell at the second time point.

[0266] The second time point is any time point after the first time point, which is not limited in this application.

[0267] Specifically, the terminal device determines the fifth position in the following manner.

[0268] In a possible implementation, when the first information includes a positional relationship between the moving cell and the second network device, the terminal device determines a sixth position based on ephemeris information of the second network device, and the terminal device determines a fifth position based on the sixth position and the positional relationship between the moving cell and the second network device.

[0269] The fifth location is the location of the second network device at a second point in time.

[0270] In a possible implementation, if the first information includes timestamp information and the first information does not include a positional relationship between the moving cell and the second network device, the terminal device determines a positional relationship between the moving cell and the second network device based on the timestamp information, the current position of the second network device, and the current position of the reference point of the moving cell, and determines a sixth position based on the ephemeris information of the second network device. Further, the terminal device determines a fifth position based on the sixth position and the positional relationship between the moving cell and the second network device.

[0271] It should be noted that the manner of determining the fifth position by the terminal device is merely an example, which is not limiting in this application.

[0272] For the manner in which the terminal device determines the fifth location, please refer to the manner in which the terminal device determines the second location in S804, which is not limited in this application.

[0273] S808: The terminal device determines a third distance.

[0274] Furthermore, the terminal device determines a third distance based on the fourth position and the fifth position.

[0275] The third distance is the distance between the fourth position and the fifth position.

[0276] S809: The terminal device determines a service outage time of the moving cell based on the third distance and the first distance.

[0277] Specifically, if the third distance is greater than the first distance, the terminal device determines that the second time point is a service outage time point of the moving cell.

[0278] S810: The terminal device determines the validity period of the reference point of the moving cell.

[0279] In a possible implementation form, if the first information includes the validity period of the reference point of the moving cell, the terminal device determines the validity period of the reference point of the moving cell in the first information as the validity period of the reference point of the moving cell.

[0280] In a possible implementation form, if the first information does not include the validity period of the reference point of the moving cell, the terminal device determines the validity period of the ephemeris information of the second network device as the validity period of the reference point of the moving cell.

[0281] In a possible implementation form, if the first information does not include the validity period of the reference point of the moving cell, the terminal device determines the period during which the terminal device is in the moving cell as the validity period of the reference point of the moving cell.

[0282] It should be noted that the period during which the terminal device is in the moving cell can be understood as the period before the terminal device leaves the moving cell. In other words, before the terminal device leaves the moving cell, the reference point of the moving cell is within the validity period of the reference point of the moving cell.

[0283] It should be noted that the manner in which the terminal device determines the validity period of the reference point of the moving cell is merely an example, which is not a limitation of the present application.

[0284] Optionally, S811: Before the validity period of the reference point of the moving cell expires, the terminal device updates the reference point of the moving cell.

[0285] After updating the reference point of the moving cell, the terminal device re-determines the service outage time of the moving cell, that is, performs S804 to S809 again.

[0286] Optionally, S812: After updating the ephemeris information of the second network device, the terminal device re-determines the service outage time of the moving cell.

[0287] Specifically, when the ephemeris information of the second network device is updated, the first network device transmits the updated ephemeris information of the second network device to the terminal device by broadcasting, etc. After receiving the updated ephemeris information of the second network device, the terminal device re-determines the service outage time of the moving cell, i.e., performs S804 to S809 again.

[0288] It should be noted that if the terminal device acquires the updated ephemeris information of the second network device within the validity period of the reference point of the moving cell, the terminal device does not need to re-determine the service outage time of the moving cell.

[0289] S813: The terminal device performs neighbor cell measurement before the service outage time of the moving cell.

[0290] The neighboring cells are the neighboring cells of the moving cell.

[0291] Specifically, after determining the service outage time of the moving cell, the terminal device performs neighbor cell measurements before the service outage time of the moving cell.

[0292] It should be understood that the terminal device making neighbor cell measurements before the service outage time of the moving cell may mean that the terminal device making neighbor cell measurements at any time before the service outage time of the moving cell.

[0293] It should be noted that for the method for performing neighbor cell measurements by a terminal device, please refer to the prior art, and a detailed description thereof will be omitted in this application.

[0294] Based on the above solution, the terminal device in the moving cell scenario determines the service outage time of the moving cell based on the information transmitted by the first network device, including information about the moving cell in which the terminal device is located. In this way, the terminal device may perform neighbor cell measurement and cell selection or reselection in a timely manner before the service outage time of the moving cell, so that the terminal device can timely obtain paging from the wireless network and timely start a call.

[0295] 9 is a diagram of a communication method 900 according to an embodiment of the present application. The method 900 may include the following steps.

[0296] S901: A first network device determines first information.

[0297] The first information includes information about a moving cell in which the terminal device is located.

[0298] The moving cell is a cell covered in the moving process of the second network device.

[0299] It should be noted that the process of S901 is similar to the process of S510, and its detailed description will be omitted here to avoid repetition.

[0300] Step S902: The network device sends first information to the terminal device.

[0301] In response, the terminal device receives first information from the network device.

[0302] In a possible implementation, the first network device transmits the first information via a common message (eg, a broadcast message).

[0303] In a possible implementation, the first network device transmits the first information via a dedicated message (eg, a paging message).

[0304] It should be noted that the manner of transmitting the first information to the terminal device by the first network device is merely an example, which is not limited in this application.

[0305] S903: The terminal device determines, based on the first information, that the cell in which the terminal device is located is a moving cell.

[0306] It should be understood that after the terminal device receives the first information, the terminal device determines, based on the first information, that the cell in which the terminal device is located is a moving cell.

[0307] It should be noted that the process of S903 is similar to the process of S531, and its detailed description will be omitted here to avoid repetition.

[0308] Furthermore, after determining that the cell in which the terminal device is currently located is a moving cell, the terminal device further determines the distance between the terminal device and the reference point of the moving cell at a first time point to determine the positional relationship between the terminal device and the moving cell, and method 900 may further include the following steps:

[0309] S904: The terminal device determines a first location and a second location.

[0310] The first location is the location of the terminal device at the first time point, and the second location is the location of the reference point of the moving cell at the first time point.

[0311] It should be noted that the process of S904 is similar to the process of S804, and its detailed description will be omitted here to avoid repetition.

[0312] S905: The terminal device determines a second distance.

[0313] Additionally, the terminal device determines a second distance based on the first location and the second location.

[0314] The second distance is the distance between the first position and the second position.

[0315] Furthermore, after the terminal device determines the second distance, the terminal device determines a service outage time of the moving cell based on the second distance, and the method 900 may further include the following steps.

[0316] S906: The terminal device determines whether the terminal device is located at the edge of the moving cell based on the first distance and the second distance.

[0317] Specifically, if the first information includes the first distance, the terminal device determines whether the terminal device is located at the edge of the moving cell based on the first distance and the second distance.

[0318] It should be understood that if the distance between the position of the terminal device at a certain time and the position of the reference point of the moving cell at that time, i.e., the second distance, is greater than the first distance, the terminal device is determined to be at the edge of the moving cell at that time.

[0319] In a possible implementation, if the second distance is greater than the first distance, the terminal device determines that the terminal device is located at the edge of the moving cell at the first time point.

[0320] Optionally, if the second distance is smaller than the first distance, the terminal device further determines a third distance at the second time point, and determines whether the terminal device is at the edge of the moving cell based on the third distance and the first distance, and method 900 may further include S907 to S909.

[0321] S907: The terminal device determines a fourth location and a fifth location.

[0322] The fourth position is the position of the terminal device at the second time point. The fifth position is the position of the reference point of the moving cell at the second time point. The first time point is before the second time point.

[0323] It should be noted that the process of S907 is similar to the process of S808, and its detailed description will be omitted here to avoid repetition.

[0324] S908: The terminal device determines a third distance.

[0325] Furthermore, the terminal device determines a third distance based on the fourth position and the fifth position.

[0326] The third distance is the distance between the fourth position and the fifth position.

[0327] S909: The terminal device determines whether the terminal device is located at the edge of the moving cell based on the third distance and the first distance.

[0328] Specifically, if the third distance is greater than the first distance, the terminal device determines that the terminal device is located at the edge of the moving cell at the second time point.

[0329] S910: The terminal device determines the validity period of the reference point of the moving cell.

[0330] It should be noted that the process of S910 is similar to the process of S810, and its detailed description will be omitted here to avoid repetition.

[0331] Optionally, S911: Before the validity period of the reference point of the moving cell expires, the terminal device updates the reference point of the moving cell.

[0332] After updating the reference point of the moving cell, the terminal device re-determines whether the terminal device is located at the edge of the moving cell, that is, performs S904 to S909 again.

[0333] Optionally, S912: After updating the ephemeris information of the second network device, the terminal device re-determines whether the terminal device is located at the edge of the moving cell.

[0334] Specifically, when the ephemeris information of the second network device is updated, the first network device transmits the updated ephemeris information of the second network device to the terminal device by broadcasting, etc. After receiving the updated ephemeris information of the second network device, the terminal device re-determines whether the terminal device is at the edge of the moving cell, i.e., performs S904 to S909 again.

[0335] It should be noted that if the terminal device acquires the updated ephemeris information of the second network device within the validity period of the reference point of the moving cell, the terminal device does not need to re-determine whether the terminal device is at the edge of the moving cell.

[0336] Optionally, S913: The terminal device periodically determines whether the terminal device is located at the edge of the moving cell.

[0337] The periodicity parameter information may be transmitted to the terminal device by the network device, which is not limited in this application.

[0338] Specifically, after receiving the periodicity parameter information, the terminal device periodically determines whether the terminal device is located at the edge of the moving cell based on the periodicity parameter information.

[0339] S914: When the terminal device is located at the edge of the moving cell, the terminal device performs neighbor cell measurement.

[0340] The neighboring cells are the neighboring cells of the moving cell.

[0341] Specifically, after the terminal device determines that the terminal device is currently at the edge of the moving cell, the terminal device performs neighbor cell measurements.

[0342] It should be noted that for the method for performing neighbor cell measurements by a terminal device, please refer to the prior art, and a detailed description thereof will be omitted in this application.

[0343] Based on the above solution, the terminal device in the moving cell scenario determines whether the terminal device is located at the edge of the moving cell based on information transmitted by the first network device and including information about the moving cell in which the terminal device is located. In this way, when the terminal device is located at the edge of the moving cell, the terminal device can timely perform neighbor cell measurement and cell selection or reselection, so that it can timely obtain paging from the wireless network and timely initiate a call. This avoids paging failures.

[0344] It can be understood that the examples in Figures 5 to 9 in the embodiments of the present application are merely intended to help those skilled in the art understand the embodiments of the present application, and are not intended to limit the embodiments of the present application to specific scenarios in the examples. It is apparent that those skilled in the art can make various equivalent modifications or changes to the examples in Figures 5 to 9, and such modifications or changes also fall within the scope of the embodiments of the present application.

[0345] It will be further understood that some optional features in the embodiments of the present application may be independent of other features in some scenarios and may be combined with other features in some scenarios, without limitation.

[0346] It can be further understood that the solutions in the embodiments of the present application may be appropriately combined for use, and the explanations or descriptions of terms in the embodiments may be mutually referenced or explained in the embodiments. This is not limited.

[0347] It may be further understood that the various numeric sequence numbers in the embodiments of the present application do not imply an execution sequence, but are merely for distinction to facilitate explanation, and therefore should not constitute any limitation on the implementation process of the embodiments of the present application.

[0348] It is further understood that in the embodiments of the present application, some message names such as first information are used, and it should be understood that these names do not limit the protection scope of the embodiments of the present application.

[0349] It may be further understood that in the foregoing method embodiments, the methods and operations performed by the terminal device may alternatively be performed by components (e.g., chips or circuits) of the terminal device. In addition, the methods and operations performed by the first network device may alternatively be performed by components (e.g., chips or circuits) of the first network device. This is not limited thereto. Corresponding to the methods provided in the foregoing method embodiments, an embodiment of the present application further provides a corresponding apparatus. The apparatus includes corresponding modules configured to perform the foregoing method embodiments. The modules may be software, hardware, or a combination of software and hardware. It may be understood that the technical features described in the foregoing method embodiments are also applicable to the following apparatus embodiments.

[0350] It should be understood that the first network device and the terminal device may perform some or all of the steps of the above-described embodiments. These steps or operations are merely examples. Other operations or variations of various operations may also be performed in the embodiments of the present application. Furthermore, steps may be performed in a different order from the order presented in the above-described embodiments, and all operations of the above-described embodiments may not be performed.

[0351] The above describes in detail the communication method provided in the embodiment of the present application with reference to Figures 5 to 9. Hereinafter, the communication device provided in the embodiment of the present application will be described in detail with reference to Figures 10 to 12. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment. Therefore, for the contents not described in detail, please refer to the above method embodiment. For the sake of brevity, some contents will not be described again here.

[0352] 10 is a block diagram of a communication device according to an embodiment of the present application. The device 1000 includes a transceiver unit 1010. The transceiver unit 1010 may be configured to implement corresponding communication functions. The transceiver unit 1010 may also be referred to as a communication interface or a communication unit.

[0353] Optionally, the apparatus 1000 may further include a processing unit 1020. The processing unit 1020 may be configured to process data.

[0354] Optionally, the apparatus 1000 further includes a storage unit. The storage unit may be configured to store instructions and / or data. The processing unit 1020 may read the instructions and / or data in the storage unit, so that the apparatus performs the operations of different terminal devices in the aforementioned method embodiments, for example, the actions of the first network device or the terminal device.

[0355] The apparatus 1000 may be configured to perform the actions performed by the first network device or terminal device in the aforementioned method embodiments. In this case, the apparatus 1000 may be the first network device or terminal device, or may be a component of the first network device or terminal device. The transceiver unit 1010 is configured to perform the reception / transmission-related operations of the first network device or terminal device in the aforementioned method embodiments. The processing unit 1020 is configured to perform the processing-related operations of the first network device or terminal device in the aforementioned method embodiments.

[0356] It should be further understood that the apparatus 1000 is presented in the form of a functional unit. The term "unit" here 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) configured to execute one or more software or firmware programs, a memory, a merge logic circuit, and / or another suitable component supporting the described functionality. Those skilled in the art will understand that, in an optional example, the apparatus 1000 may specifically be a first network device or a terminal device in the aforementioned embodiments and may be configured to perform procedures and / or steps corresponding to the first network device or the terminal device in the aforementioned method embodiments. To avoid repetition, details will not be described again here.

[0357] The apparatus 1000 in the above solution has a function of performing a corresponding step performed by a first network device or a terminal device in the above method, or the apparatus 1000 in the above solution has a function of performing a corresponding step performed by a first network device or a terminal device in the above method. This function may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above function. For example, a transceiver unit may be replaced with a transceiver (e.g., a transmitting unit in a transceiver unit may be replaced with a transmitter, and a receiving unit in a transceiver unit may be replaced with a receiver), and other units such as a processing unit may be replaced with a processor, and the transmitting and receiving operations and related processing operations in the method embodiment may be performed separately.

[0358] Also, the transceiver unit 1010 may be a transceiver circuit (eg, the transceiver circuit may include a receiver circuit and a transmitter circuit), and the processing unit may be a processing circuit.

[0359] It should be noted that the apparatus in Fig. 10 may be a network element or device in the above-mentioned embodiments, or may be a chip or a chip system, such as a system on chip (SoC). The transceiver unit may be an input / output circuit or a communication interface. The processing unit is a processor, a microprocessor, or an integrated circuit integrated on a chip. This is not limited in this specification.

[0360] As shown in Fig. 11, an embodiment of the present application provides another communication device 1100. The device 1100 includes a processor 1110. The processor 1110 is coupled to a memory 1120. The memory 1120 is configured to store computer programs or instructions and / or data. The processor 1110 is configured to execute computer programs or instructions stored in the memory 1120 or read data stored in the memory 1120 to perform the methods in the aforementioned method embodiments.

[0361] Optionally, there are one or more processors 1110.

[0362] Optionally, one or more memories 1120 are present.

[0363] Optionally, the memory 1120 and the processor 1110 are integrated together or located separately.

[0364] 11, the apparatus 1100 further includes a transceiver 1130. The transceiver 1130 is configured to receive and / or transmit signals. For example, the processor 1110 is configured to control the transceiver 1130 to receive and / or transmit signals.

[0365] In the solution, the apparatus 1100 is configured to perform the operations performed by the first network device or the terminal device in the above method embodiments.

[0366] For example, the processor 1110 is configured to execute computer programs or instructions stored in the memory 1120 to perform relevant operations of the first network device in the aforementioned method embodiments, such as the method performed by the first network device in any one of the embodiments shown in Figures 5 to 9, or the method performed by the first network device in any one of the embodiments shown in Figures 5 to 9.

[0367] It will be understood that the processors described in embodiments herein may be a central processing unit (CPU), or may be another general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc.

[0368] It should be further understood that the memory referred to in the embodiments of the present application may be volatile memory and / or non-volatile memory. Non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM). For example, RAM may be used as an external cache. By way of example and not limitation, RAM includes several forms such as static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchlink dynamic random access memory (synchlink DRAM, SLDRAM), and direct rambus random access memory (direct rambus RAM, DR RAM).

[0369] It should be noted that if the processor is a general-purpose processor, a DSP, an ASIC, an FPGA or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, the memory (storage module) may be integrated into the processor.

[0370] It should be further noted that memory as described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0371] 12, an embodiment of the present application provides a chip system 1200. The chip system 1200 (which may also be referred to as a processing system) includes a logic circuit 1210 and an input / output interface 1220.

[0372] The logic circuit 1210 may be a processing circuit in the chip system 1200. The logic circuit 1210 may be coupled to a storage unit and may call instructions in the storage unit so that the chip system 1200 implements the methods and functions in the embodiments of the present application. The input / output interface 1220 may be an input / output circuit in the chip system 1200, and outputs information processed by the chip system 1200 or inputs data or signaling information to be processed into the chip system 1200 for processing.

[0373] In the solution, the chip system 1200 is configured to perform the operations performed by the first network device or terminal device in the above-mentioned method embodiments.

[0374] For example, logic circuit 1210 is configured to perform processing-related operations of the first network device in the aforementioned method embodiments, such as the processing-related operations of the first network device in any one of the embodiments shown in Figures 5 to 9. Input / output interface 1220 is configured to perform transmission- and / or reception-related operations of the first network device in the aforementioned method embodiments, such as the transmission- and / or reception-related operations of the first network device in any one of the embodiments shown in Figures 5 to 9.

[0375] An embodiment of the present application further provides a computer-readable storage medium, which stores computer instructions used to implement the method performed by the first network device or the terminal device in the above-described method embodiment.

[0376] For example, when the computer program is executed by a computer, the computer is enabled to perform the method performed by the first network device or the terminal device in the method embodiments described above.

[0377] An embodiment of the present application further provides a computer program product including instructions, which are executed by a computer to perform the method performed by the first network device or the terminal device in the aforementioned method embodiments.

[0378] For the relevant content description and beneficial effects of any one of the above-provided devices, please refer to the corresponding method embodiments provided above, and the details will not be described again here.

[0379] In some embodiments provided in the present application, it should be understood that the disclosed devices and methods may be implemented in other manners. For example, the described device embodiments are merely examples. For example, the division into units is merely a logical division of function. In actual implementation, other division schemes are possible. For example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not implemented. Furthermore, the shown or described mutual couplings or direct couplings or communication connections may be implemented using some interfaces. Indirect couplings or communication connections between devices or units may be implemented in electronic, mechanical, or other forms.

[0380] All or part of the above embodiments may be implemented using software, hardware, firmware, or any combination thereof. When software is used to realize the embodiments, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded into a computer and executed, all or part of the procedures or functions according to the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or another programmable device. For example, the computer may be a personal computer, a server, or a network device. The computer instructions may be stored in a computer-readable storage medium or transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or wireless (e.g., infrared, radio, or microwave) methods. The computer-readable storage medium may be any available medium accessible by a computer, or may be a data storage device, such as a server or a data center, incorporating one or more available media. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk drive, or a magnetic tape), an optical medium (e.g., a DVD), a semiconductor medium (e.g., a solid state disk (SSD)), etc. For example, the available medium may include, but is not limited to, any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0381] The above description is merely a specific implementation of the present application and does not limit the scope of protection of the present application. Any modifications or replacements that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application shall fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims. [Explanation of symbols]

[0382] 1 satellite 1 Geographical area 2 Geographic area 3 Geographic area 500 Communication Method 800 Communication Methods 900 Communication Methods 1000 Communication Equipment 1010 Transceiver Unit 1020 Processing Unit 1100 Communication equipment 1110 processor 1120 memory 1130 Transceiver 1200 Chip System 1210 Logic Circuits 1220 Input / Output Interface

Claims

1. 1. A communication method comprising: receiving, by a terminal device, first information from a first network device, the first information including information about a moving cell in which the terminal device is located, the moving cell being a cell covered by a moving process of a second network device, the second network device communicating with the first network device via a non-terrestrial network NTN; determining, by the terminal device, based on the first information, whether to perform neighbor cell measurements, wherein the neighbor cells are neighbor cells of the moving cell; A method comprising:

2. the first information includes timestamp information and / or a first distance; The timestamp information indicates time information of a reference point of the moving cell, the reference point of the moving cell is a position within the moving cell, and the first distance is used to determine a relationship between the position of the terminal device and a coverage area of the moving cell; The method of claim 1.

3. The timestamp information indicates the start time of the reference point of the moving cell, and the first information is: First indication information, the reference point of the moving cell, a validity period of the reference point of the moving cell, and a positional relationship between the moving cell and the second network device; and further comprising at least one of The first indication information indicates that the cell in which the terminal device is located is the moving cell, the validity period of the reference point of the moving cell indicates a time range in which the reference point is available to the terminal device from the start time, and the positional relationship between the moving cell and the second network device is used to determine the position of the reference point of the moving cell. The method of claim 2.

4. The timestamp information may include the following: an absolute time point of the reference point of the moving cell, an offset value of a start time point of the ephemeris information of the second network device, and a start time point of a downlink subframe corresponding to the system frame number and subframe number in the first information; One of the following: the ephemeris information of the second network device indicates location information of the second network device; 4. The method according to claim 2 or 3.

5. The positional relationship between the moving cell and the second network device includes a distance relationship between the reference point of the moving cell and a sub-satellite point of the second network device, and an angle relationship between the reference point of the moving cell and the sub-satellite point of the second network device; or the positional relationship between the moving cell and the second network device includes an angular relationship between the reference point of the moving cell and the second network device, and an angular relationship between an origin of coordinates and the reference point of the moving cell; 5. The method of claim 3 or 4.

6. The step of determining, by the terminal device, whether to perform neighbor cell measurements based on the first information, comprises: determining, by the terminal device, based on the first information, that the cell in which the terminal device is located is the moving cell; determining, by the terminal device, a second distance; if the first information includes the first distance, determining, by the terminal device, whether to perform neighbor cell measurements based on the first distance and the second distance; Including, The second distance is a distance between a first position and a second position, the first position being a position of the terminal device at a first time point, and the second position being a position of the reference point of the moving cell at the first time point; 6. The method according to any one of claims 2 to 5.

7. The step of determining a second distance by the terminal device further comprises: determining, by the terminal device, the first location; determining, by the terminal device, a third location based on the ephemeris information of the second network device, wherein the third location is a location of the second network device at the first time point; determining, by the terminal device, the second location based on the third location; determining, by the terminal device, the second distance based on the first location and the second location; 7. The method of claim 6, comprising:

8. determining, by the terminal device, the second location based on the third location, if the first information includes the positional relationship between the moving cell and the second network device, determining, by the terminal device, the second position based on the third position and the positional relationship between the moving cell and the second network device; or If the first information includes the timestamp information and the first information does not include the location relationship between the moving cell and the second network device, determining, by the terminal device, the positional relationship between the moving cell and the second network device based on the timestamp information, the position of the second network device at the current time, and the position of the reference point of the moving cell at the current time; determining, by the terminal device, the second location based on the third location and the location relationship between the moving cell and the second network device; 8. The method of claim 7, comprising:

9. If the first information includes the first distance, the step of determining, by the terminal device, whether to perform neighbor cell measurements based on the first distance and the second distance includes: determining, by the terminal device, a time point at which the moving cell is out of service based on the first distance and the second distance; performing, by the terminal device, neighbor cell measurements before the outage time of the moving cell; 9. The method of any one of claims 6 to 8, comprising:

10. The step of determining, by the terminal device, a service outage time of the moving cell based on the first distance and the second distance, If the second distance is greater than the first distance, determining by the terminal device that the first time point is the service outage time point of the moving cell.

10. The method of claim 9, comprising:

11. If the second distance is less than the first distance, the method further comprises: determining, by the terminal device, a third distance, the third distance being a distance between a fourth position and a fifth position, the fourth position being a position of the terminal device at a second time point, the fifth position being a position of the reference point of the moving cell at the second time point, and the first time point being before the second time point; if the third distance is greater than the first distance, determining by the terminal device that the second time point is the service outage time point of the moving cell; 11. The method of claim 10, further comprising:

12. If the first information includes the first distance, the step of determining, by the terminal device, whether to perform neighbor cell measurements based on the first distance and the second distance includes: determining, by the terminal device, whether the terminal device is located at an edge of the moving cell based on the first distance and the second distance; performing neighbor cell measurements by the terminal device when the terminal device is located at the edge of the moving cell; 9. The method of any one of claims 6 to 8, comprising:

13. The step of determining, by the terminal device, whether the terminal device is located at the edge of the moving cell based on the first distance and the second distance, comprises: determining, by the terminal device, that the terminal device is located at the edge of the moving cell at the first time point if the second distance is greater than the first distance; 13. The method of claim 12, comprising:

14. The step of determining, by the terminal device, whether the terminal device is located at the edge of the moving cell based on the first distance and the second distance, comprises: skipping, by the terminal device, performing neighbor cell measurements at the first time point if the second distance is smaller than the first distance; determining, by the terminal device, a third distance, the third distance being a distance between a fourth position and a fifth position, the fourth position being a position of the terminal device at a second time point, the fifth position being a position of the reference point of the moving cell at the second time point, and the first time point being before the second time point; if the third distance is greater than the first distance, determining by the terminal device that the terminal device is located at the edge of the moving cell at the second time point; 13. The method of claim 12, comprising:

15. The step of determining, by the terminal device, based on the first information, that the cell in which the terminal device is located is the moving cell includes: If the first information includes the timestamp information, determining, by the terminal device, based on the timestamp information, that the cell in which the terminal device is located is the moving cell; or If the first information includes the first indication information, determining, by the terminal device, based on the first indication information, that the cell in which the terminal device is located is the moving cell; or When the first information includes the positional relationship between the moving cell and the second network device, determining, by the terminal device, that the cell in which the terminal device is located is the moving cell based on the positional relationship between the moving cell and the second network device.

15. The method of any one of claims 6 to 14, comprising:

16. The method comprises: obtaining, by the terminal device, updated ephemeris information of the second network device before the ephemeris information of the second network device expires; re-determining, by the terminal device, the second distance; 16. The method of any one of claims 6 to 15, further comprising:

17. The method comprises: determining, by the terminal device, the validity period of the reference point of the moving cell; updating, by the terminal device, the reference point of the moving cell before the validity period of the reference point of the moving cell expires; 17. The method of any one of claims 2 to 16, further comprising:

18. The step of determining, by the terminal device, the validity period of the reference point of the moving cell comprises: if the first information includes the validity period of the reference point of the moving cell, determining, by the terminal device, the validity period of the reference point of the moving cell; or if the first information does not include the validity period of the reference point of the moving cell, determining, by the terminal device, the validity period of the reference point of the moving cell based on the validity period of the ephemeris information of the second network device; or If the first information does not include the validity period of the reference point of the moving cell, determining, by the terminal device, a period during which the terminal device is in the moving cell as the validity period of the reference point of the moving cell.

18. The method of claim 17, comprising:

19. 1. A communication method comprising: determining, by a first network device, first information, the first information including information about a moving cell in which a terminal device is located, the moving cell being a cell covered by a moving process of a second network device, the second network device communicating with the first network device via a non-terrestrial network NTN; transmitting, by the first network device, the first information to the terminal device; A method comprising:

20. the first information includes timestamp information and / or a first distance; The timestamp information indicates time information of a reference point of the moving cell, the reference point of the moving cell is a position within the moving cell, and the first distance is used to determine a relationship between the position of the terminal device and a coverage area of the moving cell; 20. The method of claim 19.

21. A communication device, a processor configured to execute a computer program stored in a memory, the processor configured to execute a computer program stored in a memory, the computer program being configured to execute a method according to any one of claims 1 to 20, A communication device comprising:

22. 21. A computer-readable storage medium storing a computer program or instructions that, when executed by a processor, perform the method of any one of claims 1 to 20.

23. 21. A computer program product comprising instructions which, when run on a computer, cause the method of any one of claims 1 to 20 to be performed.

24. A chip system comprising a processor, wherein a communication device in which the chip system is installed is configured to call a computer program or instructions from a memory and to operate the computer program or the instructions in order to perform the method of any one of claims 1 to 20.

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