CN117812648A

CN117812648A - Communication method and communication device

Info

Publication number: CN117812648A
Application number: CN202211214688.4A
Authority: CN
Inventors: 樊亮亮; 徐海博; 薛丽霞
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-09-30
Filing date: 2022-09-30
Publication date: 2024-04-02
Also published as: WO2024066574A1

Abstract

A method of communication, comprising: the terminal equipment receives a first message from the network equipment, wherein the first message comprises an identification of a target cell, first ephemeris information corresponding to the target cell and first indication information, and the first indication information is used for indicating a frame number of a first system frame corresponding to the target cell; the terminal equipment acquires a frame number of a second system frame corresponding to the target cell; the terminal equipment determines a first effective time of the first ephemeris information according to whether the frame number of the first system frame is the same as the frame number of the second system frame. The terminal equipment receives the first message, acquires the frame number of the current system frame of the target cell, and determines the effective moment of the ephemeris information according to the difference between the frame number of the first system frame indicated by the first indication information in the first message and the acquired frame number of the current system frame, so that the effective moment of the ephemeris information is prevented from being accurately acquired and determined only according to the frame number of the first system frame.

Description

Communication method and communication device

Technical Field

Embodiments of the present application relate to the field of communication technology, and more particularly, to a communication method and a communication device.

Background

Satellite networks are a hot topic of research in the world today, and satellite communication technologies have grown to be mature, for example, non-terrestrial networks (non-terrestrial networks, NTN) use networks of radio frequencies on satellite vehicles to enable communication, provide wider coverage, and are not easily damaged by natural disasters or external forces.

In the NTN network, in the case that the terminal device performs handover (e.g., handover from a source cell to a target cell), the terminal device needs to acquire NTN parameter information, for example, the effective time when the terminal device needs to acquire ephemeris information. How to enable a terminal device to determine the effective time of ephemeris information is a problem to be solved.

Disclosure of Invention

The embodiment of the application provides a communication method, so that when a terminal device performs cell switching, the effective time of acquired ephemeris information can be determined.

In a first aspect, a method of communication is provided, which may be performed by a terminal device, or may also be performed by a component (e.g., a chip or a circuit) of the terminal device, which is not limited. For convenience of description, an example will be described below in terms of execution by the terminal device.

The method comprises the following steps: the method comprises the steps that a terminal device receives a first message from a network device, wherein the first message comprises an identification of a target cell, first ephemeris information corresponding to the target cell and first indication information, and the first indication information is used for indicating a frame number of a first system frame corresponding to the target cell; the terminal equipment acquires a frame number of a second system frame corresponding to the target cell; and the terminal equipment determines a first effective time of the first ephemeris information according to whether the frame number of the first system frame and the frame number of the second system frame are the same. The first ephemeris information and the first indication information may be understood as parameter information included in the NTN parameter information.

Based on the above technical solution, when the terminal device receives the first message, the terminal device may acquire the frame number of the second system frame corresponding to the target cell, and determine whether the frame number of the first system frame indicated by the first indication information in the first message is the same as the frame number of the acquired second system frame, or not, that is, the terminal device in the technical solution does not determine the first effective time of the first ephemeris information only according to the frame number of the first system frame indicated by the first indication information included in the NTN parameter information any more, because the system frame numbers are numbered in 0-1023 cycles, if the first effective time of the first ephemeris information is determined only according to the frame number of the first system frame, the system frame in which system frame period is the first system frame cannot be accurately obtained, where 1024 system frames with the number of each 0-1023 cycles are called as one system frame period. In the technical scheme, when the terminal equipment determines the first effective time of the first ephemeris information, the frame number of the second system frame corresponding to the acquired target cell is considered in addition to the frame number of the first system frame indicated by the first indication information, so that the accuracy of determining the first effective time of the first ephemeris information can be improved.

With reference to the first aspect, in some implementations of the first aspect, in a case that a frame number of the first system frame and a frame number of the second system frame are the same, a first valid time of the first ephemeris information is a time determined based on the first system frame and a first subframe in a system frame period to which the second system frame belongs, where the frame number of the first subframe is indicated by the first indication information, and the first subframe is one subframe in the first system frame.

Based on the above technical solution, when the frame number of the second system frame acquired by the terminal device is the same as the frame number of the first system frame indicated by the first indication information, the terminal device considers that the first effective time of the first ephemeris information is a time determined based on the first system frame and the first subframe in the system frame period to which the second system frame belongs. That is, when the frame number of the second system frame acquired by the terminal device is the same as the frame number of the first system frame indicated by the first indication information, the terminal device specifies that the first valid time of the first ephemeris information is the time determined based on the first system frame and the first subframe in the current system frame period, so that the terminal device accurately understands the time indicated by the first indication information.

With reference to the first aspect, in some implementations of the first aspect, the terminal device executes a cell handover, and starts a first timer, where an end time of the first timer is determined by the first effective time and a first time length, the first time length is determined by information of a first time length included in the first message, where a time length between a time of executing the cell handover and an end time of the first timer is a second time length, where the second time length is a sum of the first time length and a first difference value when the time of executing the cell handover is earlier than the first effective time, and where the second time length is a difference value between the first time length and the first difference value when the time of executing the cell handover is later than the first effective time, where the first difference value is an absolute value of a difference value between the time of executing the cell handover and the first effective time.

Based on the above technical solution, when the frame number of the second system frame acquired by the terminal device is the same as the frame number of the first system frame indicated by the first indication information, the end time of the timer started by the terminal device and the duration between the time of executing the cell handover and the end time of the timer are defined. So that the terminal equipment can accurately know the running time of the started timer during switching.

With reference to the first aspect, in certain implementation manners of the first aspect, in a case that a frame number of the first system frame and a frame number of the second system frame are different, the method further includes: the terminal equipment determines that the first system frame is a system frame before the second system frame in a system frame period to which the second system frame belongs, and the first effective time of the first ephemeris information is a time determined based on the first system frame and the first subframe in the system frame period to which the second system frame belongs; or the terminal device determines that the first system frame is a system frame in a first system frame period, the first system frame period is a system frame period adjacent to a previous system frame period to which the second system frame belongs, and the first effective time of the first ephemeris information is a time determined based on the first system frame and a first subframe in the first system frame period, wherein the frame number of the first subframe is indicated by the first indication information, and the first subframe is one subframe in the first system frame.

Based on the above technical solution, in the case that the first system frame indicated by the first indication information is a previous system frame, where the second system frame acquired by the terminal device is the first system frame, the terminal device considers that the first effective time of the first ephemeris information is a time determined based on the first system frame and the first subframe in the system frame period to which the second system frame belongs or in an adjacent previous system frame period. That is, in the case that the first system frame indicated by the first indication information is the first system frame acquired by the terminal device, the terminal device determines that the first valid time of the first ephemeris information is the time determined based on the first system frame and the first subframe in the current system frame period or in the adjacent previous system frame period, so that the terminal device accurately understands the time indicated by the first indication information.

With reference to the first aspect, in certain implementation manners of the first aspect, the method further includes: the terminal device executes cell switching and starts a second timer, wherein the end time of the second timer is determined by the first effective time and a first time length, the first time length is determined by information of a first time length included in the first message, the time length between the time of executing cell switching and the end time of the second timer is a third time length, the third time length is a difference value between the first time length and a first difference value, and the first difference value is an absolute value of a difference value between the time of executing cell switching and the first effective time.

Based on the above technical solution, when the first system frame indicated by the first indication information is the first system frame acquired by the terminal device and the second system frame is the previous system frame, the end time of the timer started by the terminal device and the duration between the time of executing the cell handover and the end time of the timer are defined. So that the terminal equipment can accurately know the running time of the started timer during switching.

With reference to the first aspect, in certain implementation manners of the first aspect, in a case that a frame number of the first system frame and a frame number of the second system frame are different, the method further includes: the terminal equipment determines that the first system frame is a system frame after the second system frame in a system frame period to which the second system frame belongs; or the terminal equipment determines that the first system frame is a system frame in a second system frame period, wherein the second system frame period is a next system frame period adjacent to the system frame period to which the second system frame belongs.

With reference to the first aspect, in certain implementation manners of the first aspect, the method further includes: the terminal equipment executes cell switching, and determines that the moment indicated by the first system frame is later than the moment of executing cell switching; the terminal equipment acquires a system information block of the target cell, wherein the system information block comprises second ephemeris information and second indication information, and the second indication information is used for indicating a frame number of a third system frame and a frame number of a second subframe; and the terminal equipment determines the second effective time of the second ephemeris information as the time determined by the third system frame and the second subframe.

Based on the above technical solution, in the case that the first system frame indicated by the first indication information is a system frame acquired by the terminal device and the second system frame is a subsequent system frame, the terminal device may acquire the second ephemeris information for use by acquiring the system information block of the target cell, so that the terminal device may perform handover without waiting for a time when the first ephemeris information takes effect, thereby ensuring timeliness of performing handover by the terminal device.

With reference to the first aspect, in certain implementation manners of the first aspect, before the terminal device acquires a system information block of the target cell, the method further includes: the terminal equipment determines that the time length required for acquiring the system information block of the target cell is smaller than a time length threshold; or the terminal equipment determines that the time difference between the first effective time and the time for executing the cell switching is larger than the time length required for acquiring the system information block of the target cell.

Based on the technical scheme, under the condition that the first system frame indicated by the first indication information is the second system frame acquired by the terminal equipment and is the subsequent system frame, the terminal equipment can determine the system information block capable of acquiring the target cell in different modes, so that the flexibility of the scheme is improved.

With reference to the first aspect, in certain implementation manners of the first aspect, the method further includes: and when the terminal equipment performs cell switching, estimating third ephemeris information corresponding to the moment of performing cell switching according to the first ephemeris information, and starting a fourth timer, wherein the timing duration of the fourth timer is a sixth duration from the moment of performing cell switching, the sixth duration is the sum value of the first duration and a third difference value, the first duration is determined by the information of the first duration included in the first message, and the third difference value is the absolute value of the difference value between the moment of performing cell switching and the moment indicated by the first indication information.

Based on the above technical solution, when the first system frame indicated by the first indication information is a system frame acquired by the terminal device and the second system frame is a subsequent system frame, the end time of the timer started by the terminal device and the duration between the time of executing the cell handover and the end time of the timer are defined. So that the terminal equipment can accurately know the running time of the started timer during switching.

With reference to the first aspect, in certain implementation manners of the first aspect, the method further includes: the terminal equipment estimates third ephemeris information corresponding to the time of executing the cell switching according to the first ephemeris information when executing the cell switching, and starts a fourth timer, wherein the ending time of the fourth timer is determined by the first effective time and a first time length, the first time length is determined by the information of the first time length included in the first message,

the duration between the time of executing the cell handover and the end time of the fourth timer is a sixth duration, where the sixth duration is a sum of the first duration and a first difference value, and the first difference value is an absolute value of a difference value between the time of executing the cell handover and the first effective time.

Based on the technical scheme, under the condition that the first system frame indicated by the first indication information is a system frame acquired by the terminal equipment and the second system frame is a later system frame, the terminal equipment can estimate available ephemeris information during switching according to future ephemeris information, so that the terminal equipment can execute switching without waiting for the moment when the first ephemeris information takes effect, and the timeliness of executing switching by the terminal equipment is ensured.

With reference to the first aspect, in some implementation manners of the first aspect, in a case that the first message is used to instruct the terminal device to switch from a source cell to the target cell, the terminal device obtains a frame number of a second system frame corresponding to the target cell, including: and when the terminal equipment performs switching, performing downlink synchronization with the target cell and acquiring a master information block MIB of the target cell, wherein the MIB is used for acquiring a frame number of a second system frame corresponding to the target cell.

With reference to the first aspect, in some implementations of the first aspect, in a case that the first message further includes information of a handover condition, the acquiring, by the terminal device, a frame number of a second system frame corresponding to the target cell includes: when the terminal equipment receives the first message, carrying out downlink synchronization with the target cell and acquiring a Master Information Block (MIB) of the target cell, wherein the MIB is used for acquiring a frame number of a second system frame corresponding to the target cell; or the terminal equipment determines the timing difference between the source cell and the target cell, and determines the frame number of the second system frame corresponding to the target cell according to the third system frame carrying the first message and the timing difference.

Based on the technical scheme, under the condition of conditional switching, the terminal equipment can acquire the frame number of the second system frame corresponding to the target cell in different modes, so that the flexibility of the scheme is improved.

With reference to the first aspect, in certain implementations of the first aspect, the determining, by the terminal device, a timing difference between the source cell and the target cell includes: the time difference is predefined; or the terminal equipment receives information indicating the timing difference from the network equipment; or the terminal equipment measures the signal of the target cell and determines the timing difference according to the measurement result; or, the information of the handover condition indicates a time-based handover condition, where the time-based handover condition includes a first time, and a system frame of a source cell corresponding to the first time and a system frame of a target cell corresponding to the first time are used to determine the timing difference.

Based on the technical scheme, the terminal equipment can determine the timing difference between the source cell and the target cell in different modes, so that the flexibility of the scheme is improved.

With reference to the first aspect, in some implementations of the first aspect, a frame number of a system frame of the target cell corresponding to the first time is carried in the first message; alternatively, the method further comprises: the terminal equipment receives a second message from the network equipment, wherein the second message comprises the frame number of the system frame number of the target cell corresponding to the first time.

Based on the technical scheme, the terminal equipment can determine the frame number of the system frame of the target cell corresponding to the first moment in different modes, so that the flexibility of the scheme is improved.

In a second aspect, a method of communication is provided, which may be performed by a terminal device, or may also be performed by a component (e.g., a chip or a circuit) of the terminal device, which is not limited. For convenience of description, an example will be described below in terms of execution by the terminal device.

The method comprises the following steps: the terminal equipment receives a third message from the network equipment, wherein the third message comprises fourth ephemeris information, third indication information and information of a seventh duration, and the third indication information is used for indicating a second moment when the fourth ephemeris information takes effect; the terminal device executes cell switching, and starts a fifth timer, wherein the end time of the fifth timer is determined by the second time and the seventh time, the time between the time of executing cell switching and the end time of the fifth timer is an eighth time, the eighth time is the sum of the seventh time and a third difference value when the time of executing cell switching is earlier than the second time, and the eighth time is the difference value between the seventh time and the third difference value when the time of executing cell switching is later than the second time, wherein the third difference value is the absolute value of the difference value between the time of executing cell switching and the second time.

Based on the technical scheme, the network equipment indicates the absolute time through the third indication information as the time when the ephemeris information is effective, so that the terminal equipment can accurately determine the time when the ephemeris information is effective according to the third indication information and accurately know the running time of the started timer during switching.

With reference to the second aspect, in some implementations of the second aspect, the third indication information is epoch time information in NTN parameter information; or the second time indicated by the third indication information is the second time indicated implicitly by the time-based switching condition included in the third message.

Based on the technical scheme, the network equipment can indicate an absolute moment in different modes, so that the terminal equipment can accurately determine the moment when the ephemeris information takes effect. For example, an absolute time may be indicated by epoch time; also for example, the time at which the ephemeris information takes effect is indirectly indicated by time condition information in the multiplexing condition switching scenario. The flexibility of the scheme is improved.

In a third aspect, a method of communication is provided, which may be performed by a network device, or may also be performed by a component (e.g., a chip or a circuit) of the network device, which is not limited. For ease of description, the following description will be given by way of example as being executed by a network device.

The network equipment determines a third message, wherein the third message comprises fourth ephemeris information, third indication information and information of a seventh duration, and the third indication information is used for indicating a second moment when the fourth ephemeris information takes effect; and the network equipment sends the third message to the terminal equipment. Wherein the second time is an absolute time.

With reference to the third aspect, in some implementations of the third aspect, the third indication information is epoch time information in NTN parameter information; or the second time indicated by the third indication information is the second time indicated implicitly by the time-based switching condition included in the third message.

The technical effects of the method shown in the above third aspect and its possible designs can be referred to the technical effects in the second aspect and its possible designs.

In a fourth aspect, a method of communication is provided, which may be performed by a terminal device, or may also be performed by a component (e.g., a chip or a circuit) of the terminal device, which is not limited thereto. For convenience of description, an example will be described below in terms of execution by the terminal device.

The method comprises the following steps: the terminal equipment receives a fourth message from the network equipment, wherein the fourth message comprises at least two pieces of ephemeris information, at least two pieces of time duration information and fourth indication information, and the fourth indication information is used for indicating the effective moment of the first ephemeris information in the plurality of pieces of ephemeris information; the terminal equipment uses fifth ephemeris information when executing cell switching, and the terminal equipment determines the effective time of the fifth ephemeris information; the fifth ephemeris information is the nth ephemeris information in the at least two ephemeris information, and the effective time of the fifth ephemeris information is determined by the fourth system frame number and the third subframe number indicated by the fourth indication information and the N-1 time duration information corresponding to the N-1 ephemeris information before the fifth ephemeris information.

Based on the above technical solution, when the terminal device receives a plurality of ephemeris information, the effective time of the ephemeris information used in the handover may be determined according to the effective time of the first ephemeris information and the effective time corresponding to the ephemeris information before the ephemeris information used in the handover. The terminal equipment can accurately acquire the effective time of each ephemeris information under the condition of receiving a plurality of ephemeris information.

In a fifth aspect, there is provided a method of communication, which may be performed by a terminal device, or may also be performed by a component (e.g., a chip or a circuit) of the terminal device, which is not limited. For convenience of description, an example will be described below in terms of execution by the terminal device.

The method comprises the following steps: the terminal equipment receives special signaling from network equipment to which a service cell belongs, wherein the special signaling comprises a system information block, and the system information block comprises ephemeris information of the service cell; the terminal equipment determines that the system information block does not comprise information indicating the effective time of the ephemeris information of the service cell; and the terminal equipment takes the ending time of a system message window SI window for scheduling the system information block as the effective time of the ephemeris information of the service cell, wherein the SI window is the SI window in which the special signaling is positioned or is the SI window adjacent to the special signaling.

Based on the above technical solution, in the case that the network device does not indicate the time of the ephemeris information of the serving cell, the terminal device may determine the time of the ephemeris information to take effect according to the end time of the system message window SI window for scheduling the system information block.

With reference to the fifth aspect, in some implementations of the fifth aspect, in a case where information indicating an ephemeris information effective time of a neighbor is not included in the system information block, the method further includes: and the terminal equipment takes the effective time of the ephemeris information of the service cell as the effective time of the ephemeris information of the neighbor cell.

In a sixth aspect, there is provided a method of communication, which may be performed by a terminal device, or may also be performed by a component (e.g., a chip or a circuit) of the terminal device, which is not limited. For convenience of description, an example will be described below in terms of execution by the terminal device.

The method comprises the following steps: the terminal equipment receives special signaling from network equipment to which a service cell belongs, wherein the special signaling comprises a system information block, and the system information block comprises ephemeris information of the service cell; the terminal equipment determines that the system information block does not comprise information indicating the effective time of the ephemeris information of the service cell; the terminal device receives first information indicating the effective moment of ephemeris information of a service cell from network devices to which the service cell belongs, wherein the first information is not located in the system information block.

Based on the technical scheme, under the condition that the network equipment does not indicate the effective time of the ephemeris information of the service cell, the network equipment can indicate the effective time of the ephemeris information of the service cell by carrying the information indicating the effective time in a system information block, so that the terminal equipment can determine the effective time of the ephemeris information.

With reference to the sixth aspect, in some implementations of the sixth aspect, in a case where information indicating an ephemeris information effective time of a neighbor is not included in the system information block, the method further includes: and the terminal equipment takes the effective time of the ephemeris information of the service cell as the effective time of the ephemeris information of the neighbor cell.

In a seventh aspect, there is provided a method of communication, which may be performed by a terminal device, or may also be performed by a component (e.g., a chip or a circuit) of the terminal device, which is not limited. For convenience of description, an example will be described below in terms of execution by the terminal device.

The method comprises the following steps: the method comprises the steps that a terminal device receives a fifth message from network devices to which a service cell belongs, wherein the fifth message comprises ephemeris information of the service cell and fifth indicating information, the fifth indicating information is used for indicating effective time of the ephemeris information of the service cell, the fifth message comprises the ephemeris information of a neighbor cell, and the fifth message does not comprise information for indicating effective time of the ephemeris information of the neighbor cell; and the terminal equipment takes the effective time of the ephemeris information of the service cell as the effective time of the ephemeris information of the neighbor cell.

Based on the technical scheme, under the condition that the network equipment does not indicate the effective time of the ephemeris information of the neighbor cell, the terminal equipment takes the effective time of the ephemeris information of the service cell as the effective time of the ephemeris information of the neighbor cell, so that the terminal equipment can determine the effective time of the ephemeris information of the neighbor cell.

With reference to the seventh aspect, in certain implementations of the seventh aspect, the fifth indication information is used to indicate a frame number of a sixth system frame, and the method further includes: the terminal equipment determines the sixth system frame as the seventh system frame; or the terminal equipment determines that the sixth system frame is a system frame before the seventh system frame in a system frame period to which the seventh system frame belongs; or the terminal equipment determines that the sixth system frame is a system frame after the seventh system frame in a system frame period to which the seventh system frame belongs; or the terminal equipment determines that the sixth system frame is a system frame in a fourth system frame period, wherein the fourth system frame period is a system frame period adjacent to the system frame period to which the seventh system frame belongs.

In an eighth aspect, there is provided a method of communication, which may be performed by a terminal device, or may also be performed by a component (e.g., a chip or a circuit) of the terminal device, which is not limited thereto. For convenience of description, an example will be described below in terms of execution by the terminal device.

The method comprises the following steps: the terminal equipment receives a system information block from network equipment to which a service cell belongs, wherein the system information block comprises ephemeris information of the service cell and ephemeris information of a neighbor cell, and does not comprise information for indicating the effective time of the ephemeris information of the service cell and information for indicating the effective time of the ephemeris information of the neighbor cell; and the terminal equipment takes the ending time of a system message window SI window for scheduling the system information block as the effective time of the ephemeris information of the service cell and the effective time of the ephemeris information of the neighbor cell.

Based on the technical scheme, under the condition that the network equipment does not indicate the effective time of the ephemeris information of the neighbor cell and the ephemeris information of the service cell, the terminal equipment takes the ending time of the system message window SI window for scheduling the system information block as the effective time of the ephemeris information of the service cell and the effective time of the ephemeris information of the neighbor cell, so that the terminal equipment can determine the effective time of the ephemeris information of the neighbor cell and the ephemeris information of the service cell.

In a ninth aspect, there is provided a communication device for performing the method provided in the first aspect above.

The device comprises: a receiving unit, configured to receive a first message from a network device, where the first message includes an identifier of a target cell, first ephemeris information corresponding to the target cell, and first indication information, where the first indication information is used to indicate a frame number of a first system frame; the processing unit is used for acquiring the frame number of the second system frame corresponding to the target cell;

the processing unit is further configured to determine a first validity time of the first ephemeris information according to whether the frame number of the first system frame and the frame number of the second system frame are the same.

With reference to the ninth aspect, in some implementations of the ninth aspect, in a case that a frame number of the first system frame and a frame number of the second system frame are the same, the first valid time of the first ephemeris information is a time determined based on the first system frame and a first subframe in a system frame period to which the second system frame belongs, where the frame number of the first subframe is indicated by the first indication information, and the first subframe is one subframe in the first system frame.

With reference to the ninth aspect, in certain implementation manners of the ninth aspect, the processing unit is further configured to perform a cell handover, and start a first timer, where an end time of the first timer is determined by the first effective time and a first time length, the first time length is determined by information of a first time length included in the first message, where a time length between the time of performing the cell handover and the end time of the first timer is a second time length,

In case the time of performing the cell handover is earlier than the first time of validity, the second time period is the sum of the first time period and a first difference value,

in case the moment of performing the cell handover is later than the first time of validity, the second time period is the difference between the first time period and the first difference,

wherein the first difference is an absolute value of a difference between the time at which the cell handover is performed and the first effective time.

With reference to the ninth aspect, in some implementations of the ninth aspect, in a case that a frame number of the first system frame and a frame number of the second system frame are different, the processing unit is further configured to determine that the first system frame is a system frame preceding the second system frame in a system frame period to which the second system frame belongs, and the first valid time of the first ephemeris information is a time determined based on the first system frame and the first subframe in the system frame period to which the second system frame belongs; or,

the processing unit is further configured to determine that the first system frame is a system frame within a first system frame period, the first system frame period is a previous system frame period adjacent to the system frame period to which the second system frame belongs, the first validity time of the first ephemeris information is a time determined based on the first system frame and the first subframe within the first system frame period,

The frame number of the first subframe is indicated by the first indication information, and the first subframe is one subframe in the first system frame.

With reference to the ninth aspect, in certain implementations of the ninth aspect, the processing unit is further configured to perform a cell handover, and start a second timer, where an end time of the second timer is determined by the first active time and a first time, and the first time is determined by information of a first time duration included in the first message, where a time duration between a time of performing the cell handover and an end time of the second timer is a third time duration, and the third time duration is a difference between the first time duration and a first difference, and the first difference is an absolute value of a difference between the time of performing the cell handover and the first active time.

With reference to the ninth aspect, in some implementations of the ninth aspect, in a case that a frame number of the first system frame and a frame number of the second system frame are different, the processing unit is further configured to determine that the first system frame is a system frame after the second system frame in a system frame period to which the second system frame belongs; or the processing unit is further configured to determine that the first system frame is a system frame in a second system frame period, where the second system frame period is a next system frame period adjacent to the system frame period to which the second system frame belongs.

With reference to the ninth aspect, in certain implementation manners of the ninth aspect, the processing unit is further configured to perform cell handover, and determine that a time indicated by the first system frame is later than a time at which the cell handover is performed; the processing unit is further configured to obtain a system information block of the target cell, where the system information block includes second ephemeris information and second indication information, and the second indication information is used to indicate a frame number of a third system frame and a frame number of a second subframe; and the terminal equipment determines the second effective time of the second ephemeris information as the time determined by the third system frame and the second subframe.

With reference to the ninth aspect, in some implementations of the ninth aspect, before the terminal device acquires the system information block of the target cell, the processing unit is further configured to determine that a duration required for acquiring the system information block of the target cell is less than a duration threshold; or, the processing unit is further configured to determine that the time difference between the first effective time and the time of performing cell handover is greater than a time period required for acquiring a system information block of the target cell.

With reference to the ninth aspect, in certain implementation manners of the ninth aspect, the processing unit is further configured to perform a cell handover, and start a third timer, where an end time of the third timer is determined by the second effective time and a fourth time length, and the fourth time length is determined by information of a fourth time length included in the system information block, where a time length between a time point of performing the cell handover and an end time point of the third timer is a fifth time length,

In case the moment of performing a cell handover is earlier than the second effective moment, the fifth time period is the sum of the fourth time period and a second difference value,

in case the moment of performing the cell handover is later than the second effective moment, the fifth time period is the difference between the fourth time period and the second difference,

wherein the second difference is an absolute value of a difference between the time at which the cell handover is performed and the second effective time.

With reference to the ninth aspect, in certain implementation manners of the ninth aspect, the processing unit is further configured to estimate, when performing cell handover, third ephemeris information corresponding to a time of performing cell handover according to the first ephemeris information, and start a fourth timer, where an end time of the fourth timer is determined by the first validity time and a first time length, the first time length is determined by information of the first time length included in the first message,

With reference to the ninth aspect, in some implementations of the ninth aspect, in a case that the first message is used to instruct the terminal device to switch from a source cell to the target cell, the processing unit obtains a frame number of a second system frame corresponding to the target cell, including: and when the processing unit performs switching, performing downlink synchronization with the target cell and acquiring a Master Information Block (MIB) of the target cell, wherein the MIB is used for acquiring a frame number of a second system frame corresponding to the target cell.

With reference to the ninth aspect, in some implementations of the ninth aspect, in a case that the first message further includes information of a handover condition, the processing unit obtains a frame number of a second system frame corresponding to the target cell, including: when the processing unit receives the first message, carrying out downlink synchronization with the target cell and acquiring a Master Information Block (MIB) of the target cell, wherein the MIB is used for acquiring a frame number of a second system frame corresponding to the target cell; or the processing unit determines a timing difference between a source cell and the target cell, and determines a frame number of a second system frame corresponding to the target cell according to a third system frame carrying the first message and the timing difference.

With reference to the ninth aspect, in certain implementations of the ninth aspect, the determining, by the processing unit, a timing difference between the source cell and the target cell includes: the time difference is predefined; or the receiving unit receives information indicating the timing difference from the network device; or the processing unit measures the signal of the target cell and determines the timing difference according to the measurement result; or, the information of the handover condition indicates a time-based handover condition, where the time-based handover condition includes a first time, and a system frame of a source cell corresponding to the first time and a system frame of a target cell corresponding to the first time are used to determine the timing difference.

With reference to the ninth aspect, in some implementations of the ninth aspect, a frame number of a system frame of the target cell corresponding to the first time is carried in the first message; or the receiving unit is further configured to receive a second message from the network device, where the second message includes a frame number of a system frame number of the target cell corresponding to the first time.

The advantages of the method according to the above ninth aspect and possible designs thereof may be referred to the advantages of the first aspect and possible designs thereof.

In a tenth aspect, a communication device is provided for performing the method provided in the second aspect above.

The device comprises: a receiving unit, configured to receive a third message from a network device, where the third message includes fourth ephemeris information, third indication information, and information of a seventh duration, where the third indication information is used to indicate a second time at which the fourth ephemeris information takes effect; and a processing unit, configured to perform cell handover, and start a fifth timer, where an end time of the fifth timer is determined by the second time and the seventh time, where a time length between the time of performing cell handover and the end time of the fifth timer is an eighth time length, where the eighth time length is a sum of the seventh time length and a third difference value when the time of performing cell handover is earlier than the second time, and where the eighth time length is a difference value between the seventh time length and the third difference value when the time of performing cell handover is later than the second time, where the third difference value is an absolute value of the difference value between the time of performing cell handover and the second time.

With reference to the tenth aspect, in some implementations of the tenth aspect, the third indication information is epoch time information in NTN parameter information; or the second time indicated by the third indication information is the second time indicated implicitly by the time-based switching condition included in the third message.

The advantages of the method according to the above tenth aspect and possible designs thereof may be referred to the advantages of the second aspect and possible designs thereof.

In an eleventh aspect, a communication device is provided, which is configured to perform the method provided in the third aspect.

The device comprises: the processing unit is used for determining a third message, wherein the third message comprises fourth ephemeris information, third indication information and information of a seventh duration, and the third indication information is used for indicating a second moment when the fourth ephemeris information takes effect; and the sending unit is used for sending the third message to the terminal equipment. Wherein the second time is an absolute time.

With reference to the eleventh aspect, in certain implementation manners of the eleventh aspect, the third indication information is epoch time information in NTN parameter information; or the second time indicated by the third indication information is the second time indicated implicitly by the time-based switching condition included in the third message.

The technical effects of the method shown in the above eleventh aspect and its possible designs can be referred to the technical effects in the third aspect and its possible designs.

In a twelfth aspect, there is provided a communication device for performing the method provided in the fourth aspect.

The device comprises: a receiving unit, configured to receive a fourth message from a network device, where the fourth message includes at least two ephemeris information, at least two duration information, and fourth indication information, where the fourth indication information is used to indicate a time of validity of a first ephemeris information in the plurality of ephemeris information; a processing unit, configured to use fifth ephemeris information when performing cell handover, where the processing unit is further configured to determine an effective time of the fifth ephemeris information; the fifth ephemeris information is the nth ephemeris information in the at least two ephemeris information, and the effective time of the fifth ephemeris information is determined by the fourth system frame number and the third subframe number indicated by the fourth indication information and the N-1 time duration information corresponding to the N-1 ephemeris information before the fifth ephemeris information.

The advantages of the method according to the above twelfth aspect and possible designs thereof may be referred to the advantages of the fourth aspect and possible designs thereof.

In a thirteenth aspect, a communication device is provided, which is configured to perform the method provided in the fifth aspect.

The device comprises: a receiving unit, configured to receive a dedicated signaling from a network device to which a serving cell belongs, where the dedicated signaling includes a system information block, and the system information block includes ephemeris information of the serving cell; a processing unit, configured to determine that the system information block does not include information indicating an ephemeris information effective time of the serving cell; the processing unit is further configured to take an end time of a system message window SI window for scheduling the system information block as an effective time of ephemeris information of the serving cell, where the SI window is an SI window where the dedicated signaling is located or is an SI window adjacent to the dedicated signaling.

With reference to the thirteenth aspect, in some implementations of the thirteenth aspect, in a case where the system information block does not include information indicating an effective time of ephemeris information of a neighboring cell, the processing unit is further configured to use an effective time of ephemeris information of the serving cell as the effective time of ephemeris information of the neighboring cell.

The advantages of the method described in the above thirteenth aspect and its possible designs are referred to as advantages in the fifth aspect and its possible designs.

In a fourteenth aspect, there is provided a communication device for performing the method provided in the sixth aspect above.

The device comprises: a receiving unit, configured to receive a dedicated signaling from a network device to which a serving cell belongs, where the dedicated signaling includes a system information block, and the system information block includes ephemeris information of the serving cell; a processing unit, configured to determine that the system information block does not include information indicating an ephemeris information effective time of the serving cell; the receiving unit is further configured to receive first information from a network device to which a serving cell belongs, the first information indicating a time of validity of ephemeris information of the serving cell, and the first information is not located in the system information block.

With reference to the fourteenth aspect, in some implementations of the fourteenth aspect, in a case where information indicating an effective time of ephemeris information of a neighboring cell is not included in the system information block, the processing unit is further configured to take an effective time of ephemeris information of the serving cell as the effective time of ephemeris information of the neighboring cell.

The advantages of the method according to the above fourteenth aspect and possible designs thereof may be referred to the advantages of the sixth aspect and possible designs thereof.

In a fifteenth aspect, there is provided a communications apparatus for performing the method provided in the seventh aspect above.

The device comprises: a receiving unit, configured to receive a fifth message from a network device to which a serving cell belongs, where the fifth message includes ephemeris information of the serving cell and fifth indication information, where the fifth indication information is used to indicate a time of validity of the ephemeris information of the serving cell, and the fifth message includes ephemeris information of a neighboring cell and does not include information indicating a time of validity of the ephemeris information of the neighboring cell; and the processing unit is used for taking the effective time of the ephemeris information of the service cell as the effective time of the ephemeris information of the neighbor cell.

With reference to the fifteenth aspect, in certain implementations of the fifteenth aspect, the fifth indication information is used to indicate a frame number of a sixth system frame, and the processing unit is further configured to determine that the sixth system frame is the seventh system frame; or the processing unit is further configured to determine that the sixth system frame is a system frame before the seventh system frame in a system frame period to which the seventh system frame belongs; or the processing unit is further configured to determine that the sixth system frame is a system frame after the seventh system frame in a system frame period to which the seventh system frame belongs; or the processing unit is further configured to determine that the sixth system frame is a system frame in a fourth system frame period, where the fourth system frame period is a system frame period adjacent to the system frame period to which the seventh system frame belongs.

The advantages of the method according to the fifteenth aspect and possible designs thereof described above may be referred to as the advantages of the seventh aspect and possible designs thereof.

In a sixteenth aspect, there is provided a communication device for performing the method provided in the eighth aspect above.

The device comprises: a receiving unit, configured to receive a system information block from a network device to which a serving cell belongs, where the system information block includes ephemeris information of the serving cell and ephemeris information of a neighboring cell, and does not include information for indicating an effective time of the ephemeris information of the serving cell and information for indicating an effective time of the ephemeris information of the neighboring cell; and the processing unit is used for taking the ending time of the system message window SI window for scheduling the system information block as the effective time of the ephemeris information of the service cell and the effective time of the ephemeris information of the neighbor cell.

The advantages of the method according to the above sixteenth aspect and possible designs thereof may be referred to as the advantages in the eighth aspect and possible designs thereof.

A seventeenth aspect provides a communication device for performing the methods provided in the first to eighth aspects above. In particular, the communication device may comprise means and/or modules, such as a processing unit and an acquisition unit, for performing the method provided by any one of the implementations of the first to eighth aspects.

In one implementation, the transceiver unit may be a transceiver, or an input/output interface; the processing unit may be at least one processor. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input/output interface may be an input/output circuit.

In another implementation, the transceiver unit may be an input/output interface, interface circuit, output circuit, input circuit, pin or related circuit on the chip, system-on-chip or circuit, etc.; the processing unit may be at least one processor, processing circuit or logic circuit, etc.

In an eighteenth aspect, the present application provides a processor configured to perform the method provided in the above aspects. In executing these methods, the process of transmitting the above information and acquiring/receiving the above information in the above methods can be understood as a process of outputting the above information by a processor and a process of receiving the above information inputted by the processor. When outputting the information, the processor outputs the information to the transceiver for transmission by the transceiver. This information, after being output by the processor, may also require additional processing before reaching the transceiver. Similarly, when the processor receives the input of the above information, the transceiver acquires/receives the above information and inputs it to the processor. Further, after the transceiver receives the information, the information may need to be further processed and then input to the processor.

Based on the above principle, for example, the reception request message mentioned in the foregoing method may be understood as information that the processor receives input.

With respect to operations such as transmitting, transmitting and acquiring/receiving, etc., which are referred to by a processor, unless otherwise specified, or if not contradicted by actual or inherent logic in the relevant description, operations such as outputting and receiving, inputting, etc., by the processor are more generally understood as being operations such as transmitting, transmitting and receiving, etc., rather than directly by radio frequency circuitry and antennas.

In implementation, the processor may be a processor dedicated to performing the methods, or may be a processor that executes computer instructions in a memory to perform the methods, e.g., a general purpose processor. The memory may be a non-transitory (non-transitory) memory, such as a Read Only Memory (ROM), which may be integrated on the same chip as the processor, or may be separately provided on different chips, and the type of the memory and the manner of providing the memory and the processor are not limited in this embodiment of the present application.

In a nineteenth aspect, there is provided a computer readable storage medium storing program code for execution by a device, the program code comprising instructions for performing any one of the methods provided in the first to eighth aspects above.

In a twentieth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform any of the methods provided in the first to eighth aspects above.

In a twenty-first aspect, a chip is provided, the chip comprising a processor and a communication interface, the processor reading instructions stored on a memory via the communication interface, performing any of the methods provided in the first to eighth aspects above.

Optionally, as an implementation manner, the chip may further include a memory, where the memory stores instructions, and the processor is configured to execute the instructions stored on the memory, where the instructions, when executed, are configured to perform any of the methods provided in the first to eighth aspects.

Drawings

Fig. 1 is a schematic diagram of a network architecture suitable for use in embodiments of the present application.

Fig. 2 is a schematic diagram of one architecture of a communication system suitable for use in embodiments of the present application.

Fig. 3 is a schematic diagram of a handoff procedure for a terrestrial cellular network.

Fig. 4 is a schematic diagram of an epoch time indication SFN and subframes.

Fig. 5 is a schematic flow chart of a communication method provided in an embodiment of the present application.

Fig. 6 (a) to (c) are schematic diagrams of the first time period and the second time period provided in the embodiment of the present application.

Fig. 7 (a) and (b) are schematic diagrams of the first duration and the third duration provided in the embodiment of the present application.

Fig. 8 is a schematic flow chart of another communication method provided in an embodiment of the present application.

Fig. 9 is a schematic flow chart of another communication method provided in an embodiment of the present application.

Fig. 10 is a schematic flow chart of another communication method provided in an embodiment of the present application.

Fig. 11 is an SI window schematic diagram of a scheduling SIB19 according to an embodiment of the present application.

Fig. 12 is a schematic flow chart of another communication method provided in an embodiment of the present application.

Fig. 13 is a schematic flow chart of another communication method provided in an embodiment of the present application.

Fig. 14 is a schematic block diagram of a communication device 10 provided in an embodiment of the present application.

Fig. 15 is a schematic diagram of another communication device 20 according to an embodiment of the present application.

Fig. 16 is a schematic diagram of a chip system 30 according to an embodiment of the present application.

Detailed Description

The technical solutions in the present application will be described below with reference to the accompanying drawings.

The technical solution of the embodiment of the application can be applied to various communication systems, for example: a Long Term Evolution (LTE) system, a long term evolution advanced (LTE-a) system, a LTE frequency division duplex (Frequency Division Duplex, FDD) system, a LTE time division duplex (Time Division Duplex, TDD), a universal mobile telecommunication system (Universal Mobile Telecommunication System, UMTS), a worldwide interoperability for microwave access (Worldwide Interoperability for Microwave Access, wiMAX) communication system, a next generation communication system (e.g., a fifth generation (5G) communication system), a converged system of multiple access systems, or a three-major application scenario enhanced mobile bandwidth (enhanced Mobile Broadband, eMBB) of an evolution system, a 5G mobile communication system, ultra-low latency communication (URLLC) and enhanced machine type communication (enhanced Machine Type Communication, eMTC), or a new communication system in the future. The technical scheme provided by the application can also be applied to future communication systems, such as a sixth generation mobile communication system and the like. The present application is not limited in this regard.

The technical solutions provided herein may also be applied to machine-type communication (machine type communication, MTC), inter-machine communication long term evolution technology (long term evolution-machine, LTE-M), device-to-device (D2D) networks, machine-to-machine (machine to machine, M2M) networks, internet of things (internet of things, ioT) networks, or other networks. The IoT network may include, for example, an internet of vehicles. The communication modes in the internet of vehicles system are generally called as vehicle to other devices (V2X, X may represent anything), for example, the V2X may include: vehicle-to-vehicle (vehicle to vehicle, V2V) communication, vehicle-to-infrastructure (vehicle to infrastructure, V2I) communication, vehicle-to-pedestrian communication (vehicle to pedestrian, V2P) or vehicle-to-network (vehicle to network, V2N) communication, etc.

The network device in the embodiment of the present application may also be referred to as a (radio) access network device (radio access network, (R) AN), (R) AN may be capable of managing radio resources, providing access services for the ue, and completing forwarding of ue data between the ue and the core network, where the (R) AN may also be understood as a base station in the network, and is a device deployed in the radio access network to provide a radio communication function for a Mobile Station (MS).

The access network device in the embodiments of the present application may be any communication device with a wireless transceiver function for communicating with a user device. The access network device includes, but is not limited to: an evolved Node B (eNB), a radio network controller (radio network controller, RNC), a Node B (Node B, NB), a base station controller (base station controller, BSC), a base transceiver station (base transceiver station, BTS), a home evolved Node B, heNB, or home Node B, HNB), a baseBand unit (BBU), an Access Point (AP) in a wireless fidelity (wireless fidelity, wiFi) system, a wireless relay Node, a wireless backhaul Node, a transmission point (transmission point, TP), or a transmission reception point (transmission and reception point, TRP), etc., may also be 5G, such as a gNB in an NR system, or a transmission point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or may also be a network Node constituting a gNB or a transmission point, such as a baseBand unit (BBU), or a Distributed Unit (DU), etc. It will be appreciated that all or part of the functionality of the access network device in this application may also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (e.g. a cloud platform).

In some deployments, the gNB may include a Centralized Unit (CU) and DUs. The gNB may also include an active antenna unit (active antenna unit, AAU). The CU implements part of the functionality of the gNB and the DU implements part of the functionality of the gNB. For example, the CU is responsible for handling non-real time protocols and services, implementing the functions of the radio resource control (radio resource control, RRC), packet data convergence layer protocol (packet data convergence protocol, PDCP) layer. The DUs are responsible for handling physical layer protocols and real-time services, implementing the functions of the radio link control (radio link control, RLC), medium access control (media access control, MAC) and Physical (PHY) layers. The AAU realizes part of physical layer processing function, radio frequency processing and related functions of the active antenna. The information of the RRC layer is generated by the CU and finally becomes PHY layer information through PHY layer encapsulation of DU, or is converted from the information of the PHY layer. Thus, under this architecture, higher layer signaling, such as RRC layer signaling, may also be considered to be sent by DUs, or by dus+aaus. It is understood that the access network device may be a device comprising one or more of a CU node, a DU node, an AAU node. In addition, the CU may be divided into access network devices in an access network (radio access network, RAN), or may be divided into access network devices in a Core Network (CN), which is not limited in this application.

The terminal device in the embodiments of the present application may also be referred to as a User Equipment (UE), a terminal, an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The terminals in embodiments of the present application may be mobile phones (mobile phones), tablet computers (pad), computers with wireless transceiving functionality, virtual Reality (VR) terminals, augmented reality (augmented reality, AR) terminals, wireless terminals in industrial control (industrial control), wireless terminals in unmanned aerial vehicle (self driving), wireless terminals in telemedicine (remote media), wireless terminals in smart grid (smart grid), wireless terminals in transportation security (transportation safety), wireless terminals in smart city (smart city), wireless terminals in smart home (smart home), cellular phones, cordless phones, session initiation protocol (session initiation protocol, SIP) phones, wireless local loop (wireless local loop, WLL) stations, personal digital assistants (personal digital assistant, PDA), handheld devices with wireless communication functionality, computing devices or other processing devices connected to a wireless modem, vehicle devices, wearable devices, terminals in a 5G network or future networks, etc.

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

In the embodiment of the present application, the communication device for implementing the function of the network device may be a network device, or may be a network device having a base station part function, or may be a device capable of supporting the network device to implement the function, for example, a chip system, and the device may be installed in the network device.

In practical network deployments, it is not possible for a ground network to cover all areas, especially areas with little personnel, such as deserts, oceans, north-south poles, etc. The non-ground network NTN has wide network coverage, is easier to provide coverage in a less-man area, and is suitable for deployment in a less-man area. The embodiment of the application is applicable to non-ground network (NTN) network communication, wherein the NTN network refers to a network or a network segment using radio frequency on a satellite (or unmanned aerial vehicle system (Unmanned Aircraft System, UAS) platform) satellite. The technical scheme of the present application will be described in detail below by taking a satellite communication system as an example.

The network device may comprise a satellite in a satellite communication system. TR38.821 defines 5 NTN-based RAN architectures, including:

1) Transparent satellite architecture (RAN architecture with transparent satellite), in a transfant scene, the role of the satellite is: radio frequency filtering (Radio Frequency filtering), frequency conversion and amplification (Frequency conversion and amplification), i.e. the satellite, is mainly as an L1 relay, regenerating the physical layer signal and does not have other higher protocol layers.

2) The regenerated satellite without inter-satellite link has the processing function of the base station (Regenerative satellite without ISL, gNB processed payload), where ISL refers to inter-satellite link. In this architecture, the satellite acts as a base station.

3) The regenerated satellite with inter-satellite link has processing function of base station (Regenerative satellite with ISL, gNB processed payload).

4) A regenerated satellite (NG-RAN with a regenerative satellite based on gNB-DU) having a DU processing function of the base station.

5) In this scenario of an IAB-capable base station (gNB processed payload based on relay-like architectures), the satellite is used as an access and backhaul link (integrated access and backhaul, IAB).

Fig. 1 is a schematic diagram of a network architecture suitable for use in embodiments of the present application. The ground mobile terminal UE accesses the network through a 5G new air interface, and the 5G access network equipment is deployed on a satellite and is connected with a core network on the ground through a wireless link. Meanwhile, a wireless link exists between satellites, so that signaling interaction and user data transmission between access network equipment and access network equipment are completed. The interfaces between the various network elements in fig. 1 are illustrated as follows:

terminal equipment: mobile devices supporting a new air interface of 5G, such as mobile phones and pad mobile devices, are typical. The satellite network can be accessed through an air interface, and the services such as calling, surfing the Internet and the like are initiated.

5G access network device: mainly to provide radio access services, to schedule radio resources to access terminals, to provide reliable radio transmission protocols, data encryption protocols, etc., e.g., base stations, etc.

5G core network: user access control, mobility management, session management, user security authentication, charging and other services. It is composed of several functional units, and can be divided into control plane and data plane functional entities. An access and mobility management unit (AMF) responsible for user access management, security authentication, and mobility management. The user plane Unit (UPF) is responsible for managing functions such as transmission of user plane data, traffic statistics, etc.

And the ground station is responsible for forwarding signaling and service data between the satellite access network equipment and the 5G core network.

5G new air interface: a wireless link between a terminal and an access network device.

An Xn interface: the interface between the 5G access network equipment and the access network equipment is mainly used for signaling interaction such as switching and the like.

NG interface: the interface between the 5G access network device and the 5G core network mainly interacts signaling such as NAS of the core network and the like and service data of the user.

Fig. 2 is a schematic diagram of one architecture of a communication system suitable for use in embodiments 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 also comprise at least one terminal device, such as the terminal device shown in fig. 1. The network device and the terminal device may communicate via a wireless link.

In the embodiment of the application, the terminal device or the network device includes a hardware layer, an operating system layer running above the hardware layer, and an application layer running above the operating system layer. The hardware layer includes hardware such as a central processing unit (central processing unit, CPU), a memory management unit (memory management unit, MMU), and a memory (also referred to as a main memory). The operating system may be any one or more computer operating systems that implement business processes through processes (processes), such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a windows operating system. The application layer comprises applications such as a browser, an address book, word processing software, instant messaging software and the like. Further, the embodiment of the present application is not particularly limited to the specific structure of the execution body of the method provided in the embodiment of the present application, as long as the communication can be performed by the method provided in the embodiment of the present application by running the program recorded with the code of the method provided in the embodiment of the present application, and for example, the execution body of the method provided in the embodiment of the present application may be a terminal device or a network device, or a functional module in the terminal device or the network device that can call the program and execute the program.

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

It should be understood that fig. 2 is a simplified illustration of a communication scenario in which the present application can be applied, taking as an example a network device communicating with a terminal device, and is not limited to other scenarios in which the present application can be applied. It should also be appreciated that fig. 2 is a simplified schematic diagram that is merely illustrative for ease of understanding, and that other network devices may be included in the communication system or other terminal devices may be included, not shown in fig. 2.

It should be understood that the network device in the wireless communication system may be any device having a wireless transceiving function. The apparatus includes, but is not limited to: a base station controller (Base Station Controller, BSC), a base transceiver station (Base Transceiver Station, BTS), etc., may also be one or a group (including multiple antenna panels) of antenna panels of a base station in a 5G system, etc., or may also be a satellite, etc.

It should also be understood. Only one network device and one terminal device are shown in fig. 2, and the communication system is not limited to include more terminal devices, for example, in a satellite communication network, a satellite may cover a plurality of terminal devices for communication. Each terminal device is also not limited to communicating with a network device, e.g., the terminal device may need to reselect satellites for access communications after the satellites have moved.

Fig. 1 and fig. 2 are diagrams illustrating a communication system applicable to the embodiments of the present application, and in order to facilitate understanding of the technical solutions of the embodiments of the present application, some terms or concepts related to the embodiments of the present application are first briefly described.

1. NTN network: refers to a network or network segment that uses radio frequencies on board satellites (or UAS platforms). Satellite communication has the advantages of wide coverage, long communication distance, high reliability, high flexibility, high throughput and the like, is not influenced by geographic environment, climate conditions and natural disasters, and has been widely applied to the fields of aviation communication, maritime communication, military communication and the like. The satellite is introduced into 5G, so that communication services can be provided for areas which are difficult to cover by a ground network, such as ocean, forest and the like, the reliability of 5G communication can be enhanced, more stable and better communication services can be provided for users on trains, planes and vehicles, more data transmission resources can be provided, and more numbers of connections are supported. Thanks to the concept of "anytime, anywhere" communication today, the position of satellite communication networks will be further improved in the future.

2. Orbit of the satellite: including Low Earth Orbit (LEO), medium Earth Orbit (MEO), and stationary orbit (GEO). Wherein, LEO: the track height is 160-2 000km; MEO: the track height is 7 000-25000 km; GEO: the orbit height is 35.786 km, and the relative position of the satellite running on the orbit and the earth is not affected by the rotation of the earth.

Non-geosynchronous orbit (Non-Geosynchronous orbit, NGSO) includes low earth orbit about 300 km to 1500 km in height and medium earth orbit about 7000 km to 25000km in height.

3. NTN parameter information: which may also be referred to as satellite assistance information, refers to information required by a terminal device to access a communication system via the NTN.

Illustratively, the NTN parameter information includes satellite ephemeris information, common Timing Advance (TA) parameter information, and the like. The satellite ephemeris information is used to indicate that the position of the satellite includes an orbit parameter, or a satellite position calculated based on the orbit parameter, etc., it is understood that the satellite ephemeris information may be used to calculate, predict, describe, or track the time, position, speed, etc. of the satellite.

Because the satellites are moving in real time, the position of the satellites also changes in real time. The current NTN network transmits satellite ephemeris information at a certain time and indicates the time of day (epoch time) and the NTN-U1 validity duration (NTN-Ul SyncValidity Duration) of the ephemeris information. Wherein epoch time may be understood as representing the time at which the ephemeris information is initially validated; ntn-UlSyncValidityDuration indicates the duration of time that the terminal device can apply the received ephemeris information without acquiring new ephemeris information.

Specifically, the epoch time parameter is represented by a system Frame number (system Frame number, SFN) and a subframe number (sub Frame). The SFN takes on values from 0 to 1023, one system frame is composed of 10 subframes, and one subframe is 1ms. I.e. 10.24 seconds for one SFN cycle. For NGSO scenes, the ntn-UlSyncValidityDuration maximum is 240 seconds, and for GSO scenes, the ntn-UlSyncValidityDuration maximum may be 900 seconds.

4. NTN parameter information transfer: the system message block SIB19 broadcasted by the NTN cell contains NTN parameter information needed by the terminal device to access the NR through the NTN, where the above known NTN parameter information includes satellite ephemeris information, common timing advance TA parameter information, epoch time parameter information, NTN-usyncvvalidityduration parameter information, and the like.

The duration of validity of the ephemeris information is represented by epoch time and ntn-UlSyncValidityduration. If in the SIB19 message, the epoch time parameter exists, it is represented by SFN and subframe number; if the epoch time parameter of the serving cell does not exist in the SIB19 message, then the epoch time is the end time of the system information (system information, SI) window (window) for scheduling SIB19.

In addition, if the epoch time of the neighbor cell is in a time-saving lack, the terminal equipment indicates the epoch time of the neighbor cell by using the epoch time of the serving cell; if ntn-UlSyncValidityDuration of the neighbor cell is short-lived, the terminal uses ntn-UlSyncValidityDuration of the serving cell to indicate ntn-UlSyncValidityDuration of the neighbor cell.

The public search space is not configured on the active Part Bandwidth (BWP) of the connected terminal equipment, and the NTN cell may provide the system message SIB19 to the terminal by means of dedicated signaling. The SIB19 included in the dedication system information delivery parameter in the dedicated signaling is identical to SIB19 information being broadcast by the NTN cell, i.e. the SIB19 information being broadcast is copied.

dedicatedSystemInformationDelivery OCTET STRING(CONTAINING SystemInformation)OPTIONAL

SIB19 information is carried in the systemization field.

5. Handover (HO) and conditional Handover (Conditional Handover, CHO): the handover of the terrestrial cellular network is triggered by RRC signaling, i.e. the network device sends a handover command to the terminal device via an RRC reconfiguration message. For ease of understanding, the handoff procedure of the terrestrial cellular network will be briefly described with reference to fig. 3, and as shown in fig. 3, the handoff procedure of the terrestrial cellular network includes the following steps:

S310, the source gNB initiates switching and sends a switching request to the target gNB through the Xn interface.

S320, the target gNB performs admission control and provides a new RRC configuration as part of the handover request acknowledgement.

S330, the source gNB provides an RRC reconfiguration (rrcrecon configuration) message to the terminal, the RRC reconfiguration message containing the following information:

1)cell ID；

2) All information needed to access the target cell so that the UE can access the target cell without reading the system information.

S340, the UE sends an RRC reconfiguration complete (RRCRECONDUCTION complete) message to the target gNB to complete the RRC handover procedure.

Illustratively, the gNB in fig. 3 is a network device in the NR system, or may be a network device in another system, or may be a radio access network node, where access to the wireless network by the terminal is mainly completed.

The contents carried by the rrcrecon configuration message can be classified into HO and CHO according to the content.

1) The UE determines HO according to the content of rrcrecon configuration, and immediately makes handover to the target gNB according to the configuration in rrcrecon configuration. The configuration parameters are contained in RRCRECONfigure > SpCellConfigure > ReconfigurationWithSync.

In NTN networks, the terminal needs some NTN parameter information to access to the NTN network, such as ephemeris information of satellites, and these specific information are contained in NTN-Config. The current standard includes NTN-Config in ServingCellConfigCommon so that the terminal can access the target cell normally.

2) And if the UE judges that the content of the RRCRECONfigure comprises the configuration of the CHO candidate cell and CHO execution conditions, determining to execute CHO. At this time, the UE does not trigger handover immediately, continues to keep connected with the source gNB, and starts to evaluate CHO execution conditions of the candidate cells; and if the candidate cell meets the corresponding CHO execution condition, completing the switching to the target cell according to the configuration in the RRCRECONfigure. RRCReconfiguration- > Condition Reconfiguration-r16- > CondReconfigurToAddMod-r 16 contains the configuration of the candidate cell and CHO execution conditions.

Wherein RRCRECONfigure-r 16 comprises a ReconfigurationWithSync field containing the configuration of the CHO candidate cell. The UE may switch to the target cell of the target gNB according to the configuration information.

In summary, the RRC reconfiguration message, whether HO or CHO, includes a reconfigurationwisyn field, which includes NTN parameter information required for the terminal device to access the NTN network, such as ephemeris information, epoch time parameter information, NTN-UlSyncValidityDuration parameter information, and the like. The terminal device knows that the ephemeris information of the satellite can be accessed to the target base station.

In case of handover (e.g., HO or CHO), the epoch time field is based on the timing of the target cell, i.e., the SFN and subframe number indicated in the field refer to the SFN and subframe of the target cell, and the field epoch time must exist.

6. CHO trigger conditions: the NTN network currently defines both time-based CHO trigger conditions and location-based CHO trigger conditions.

CHO trigger conditions based on time: time is defined by T1 and T2, where T1 is the absolute time value and T2 is the duration from T1. The terminal device obtains the current time of the terminal device, and if the current time is within the time range of T1 and T1 plus T2, the terminal device considers that the time-based triggering condition is met.

Location-based triggering conditions: the location is defined as the distance of the terminal device from the reference point. The network device configures a CHO trigger condition based on a location for the terminal device, and the CHO trigger condition comprises parameters such as a reference location1 (reference location 1), a reference location2 (reference location 2), a distance threshold 1 (distance from reference 1), a distance threshold 2 (distance from reference 2), hysteresis (hysteresis) and the like. Wherein reference location1 is associated with a serving cell, reference location2 is associated with a candidate target cell, and when a difference between a distance between the terminal device and the serving cell and a hysteresis is greater than the distancethresfromReference1 and a sum of the distance between the terminal device and the candidate target cell and the hysteresis is less than the distancethresfromReference2, the terminal device considers that a distance-based triggering condition is satisfied.

The CHO trigger conditions based on time and the cond event A3/A4/A5 trigger conditions based on measurement are together configured to the terminal device. When both conditions are satisfied at the same time, the terminal device performs handover to the target cell.

The location-based CHO trigger conditions are configured to the terminal together with the measurement-based trigger conditions CondEvent A3/A4/A5. When both conditions are satisfied at the same time, the terminal device performs handover to the target cell.

Conditional event A3: the measurement result of the condition reconfiguration candidate target cell is better than the measurement result of the service cell by one offset value;

conditional event A4: the measurement result of the condition reconfiguration candidate target cell is better than the threshold value;

conditional event A5: the measurement result of the serving cell is worse than the threshold 1; and the condition reconfiguration candidate target cell measurement is better than threshold 2.

As can be seen from the foregoing, when performing handover in the NTN network, NTN parameter information (e.g., epoch time parameter information, NTN-Ulsynclvalidityduration parameter information, common timing advance parameter information, etc.) needs to be considered, specifically, a T430 timer is started from a subframe indicated by epoch time in the reconfigurationWithSync in the procedure of performing handover by the terminal device, and the timer value is set to NTN-Ulsynclvalidityduration. (if epoch time indicates an elapsed time, the time ntn-UlSyncValidityDurate for the T430 timer should be subtracted by the elapsed time).

The description of the above basic concept on the epoch time refers to the epoch time parameter being represented by SFN and subframe number, and SFN values are cycled from 0-1023, one frame being made up of 10 subframes, one subframe being 1ms. I.e. 10.24 seconds for one SFN cycle. The terminal device starts a T430 timer from the SFN and the subframe indicated by the epoch time in the reconfigurationwisync. The terminal device may not be able to determine which SFN and subframe the epoch time indicates are in which SFN cycle, as shown in fig. 4, fig. 4 is a schematic diagram of the epoch time indication SFN and subframe.

It can be seen from fig. 4 that the time indicated by the SFN and the subframe number indicated in the epoch time parameter may occur in each cycle, and the terminal device cannot determine which SFN and subframe in the SFN cycle the SFN and subframe indicated by the epoch time are at the time of performing the handover.

The above description is briefly presented in conjunction with fig. 1 and fig. 2 to describe a scenario applicable to the present application, and describes a basic concept involved in the present application, and illustrates that NTN parameter information needs to be considered when a terminal device performs handover in an NTN network. As can be seen from the above, when the terminal device performs handover in the existing NTN network, it may not be possible to determine which SFN and subframe in the SFN period the epoch time indicates.

In order to avoid the problem that the current terminal equipment cannot judge which SFN period the SFN and the subframe are in by performing switching, the application provides a communication method so as to enable the terminal equipment to determine the positions of the SFN and the subframe.

The embodiments shown below are not particularly limited to the specific structure of the execution body of the method provided in the embodiments of the present application, as long as the communication can be performed by the method provided in the embodiments of the present application by running the program recorded with the code of the method provided in the embodiments of the present application, and for example, the execution body of the method provided in the embodiments of the present application may be a terminal device or a network device, or a functional module in the terminal device or the network device that can call the program and execute the program.

In addition, in order to facilitate understanding of the embodiments of the present application, the following description is made.

First, in this application, "for indicating" may include for direct indication and for indirect indication. When describing that certain indication information is used for indicating a, the indication information may be included to directly indicate a or indirectly indicate a, and does not necessarily indicate that a is included in the indication information.

The information indicated by the indication information is called information to be indicated, and in a specific implementation process, various ways for indicating the information to be indicated exist. The information to be indicated can be sent together as a whole or can be divided into a plurality of pieces of sub-information to be sent separately, and the sending periods and/or sending occasions of the sub-information can be the same or different. The specific transmission method is not limited in this application. The transmission period and/or the transmission timing of the sub-information may be predefined, for example, predefined according to a protocol, or may be configured by the transmitting end device by transmitting configuration information to the receiving end device.

Second, the term "at least one" as used herein means one or more, and the term "plurality" means two or more. In addition, in the embodiments of the present application, "first", "second", and various numerical numbers (e.g., "#1", "#2", etc.) are merely for convenience of description and are not intended to limit the scope of the embodiments of the present application. The following sequence numbers of the processes do not mean the order of execution, which should be determined by its functions and internal logic, but should not constitute any limitation on the implementation process of the embodiments of the present application, and it should be understood that the objects thus described may be interchanged where appropriate so as to be able to describe schemes other than the embodiments of the present application. Moreover, in the embodiments of the present application, the words "510", "610" and the like are merely identifiers for convenience of description, and do not limit the order in which the steps are performed.

Third, in this application, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

Fourth, references to "save" in embodiments of the present application may refer to saving in one or more memories. The one or more memories may be provided separately or may be integrated in an encoder or decoder, processor, or communication device. The one or more memories may also be provided separately in part, and integrated in the decoder, processor, or communication device. The type of memory may be any form of storage medium, and this application is not limited in this regard.

Fifth, the "protocol" referred to in the embodiments of the present application may refer to a standard protocol in the field of communications, and may include, for example, an LTE protocol, an NR protocol, and related protocols applied in a future communication system, which is not limited in this application.

Sixth, the term "and/or" herein is merely an association relationship describing an association object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

Seventh, in the embodiments of the present application, "of", "corresponding" and "associated" may be sometimes used in combination, and it should be noted that the meaning to be expressed is consistent when the distinction is not emphasized.

Eighth, in the examples of the present application, "in the case of …", "when …", "if …" are sometimes used in combination, it should be noted that the meaning of the expression is consistent when the distinction is not emphasized.

Ninth, in the embodiment of the present application, when the time length #a is the sum of the time length #b and the difference #a, and the difference #a is the absolute value of the difference between the time #a and the time #b, when the difference #a is a negative value (e.g., the difference #a is the difference between the smaller value and the larger value in the time #a and the time #b), it may be understood that the time length #a is the difference between the time length #b and the difference #a; similarly, when the time length #a is the difference between the time length #b and the difference #a, and the value of the difference #a is the absolute value of the difference between the time #a and the time #b, the time length #a is the sum of the time length #b and the difference #a when the value of the difference #a is a negative value. In the following, the communication method provided in the embodiment of the present application will be described in detail by taking the interaction between the network device and the terminal device as an example without losing generality.

Fig. 5 is a schematic flowchart of a communication method provided in an embodiment of the present application, including the following steps:

s510, the terminal device receives the first message from the network device, or the network device sends the first message to the terminal device.

Specifically, the first message includes an identification of the target cell, first ephemeris information and first indication information, where the first indication information is used to indicate a frame number of the first system frame. The first ephemeris information and the first indication information may be understood as part of the NTN parameter information described above.

Optionally, other NTN parameter information, such as first common timing advance parameter information, is included in the first message.

Illustratively, the identification of the target cell is information for identifying the target cell, including, but not limited to, an ID of the target cell, a physical cell ID of the target cell, address information of the target cell, or type information of the target cell, etc.

The terminal device may illustratively derive position and velocity information for the satellites from the first ephemeris information. Specifically, the first ephemeris information is used to indicate satellite ephemeris, describe the position and the motion speed of the satellite, and may be represented by a format of a position and speed state vector or a format of an orbit parameter, where the position and other parameters of the satellite obtained by calculation based on the orbit parameter are calculated, and it is understood that the ephemeris information of the satellite may be used to calculate, predict, describe, or track the time, position, speed and other states of the satellite in flight. The embodiment of the ephemeris information is not limited, and reference may be made to the description of the ephemeris information in the related art at present, which is not repeated here.

The first indication information may be information indicating a time when the first ephemeris information is valid, for example, an epoch time as described above. Specifically, the first indication information realizes the function of indicating the effective starting moment of the first ephemeris information through the frame number of the first system frame.

Optionally, the first indication information may also be used to indicate a frame number of the first subframe, so as to more accurately indicate the effective starting time of the first ephemeris information.

Further, in this embodiment, the terminal device obtains the frame number of the second system frame corresponding to the target cell, and the method flow shown in fig. 5 further includes:

s520, the terminal equipment acquires the frame number of the second system frame corresponding to the target cell.

Specifically, the frame number of the second system frame corresponding to the target cell in this embodiment may be understood as: the terminal equipment receives the first message and immediately acquires the frame number of the system frame corresponding to the target cell; alternatively, it can also be understood that: acquiring a frame number of a system frame corresponding to a target cell in a preset time period after the terminal equipment receives the first message, wherein the preset time period can be predefined or negotiated for the terminal equipment and the network equipment; alternatively, it can also be understood that: after receiving the first message, the terminal device reads the frame number of the system frame corresponding to the target cell, which is acquired by the master message block MIB of the target cell for the first time.

It should be understood that, in this embodiment, a specific implementation manner of acquiring, by the terminal device, the frame number of the second system frame corresponding to the target cell is not limited.

As a possible implementation manner, the first message is a message sent by the network device to the terminal device for indicating the terminal device to switch from the source cell to the target cell in the handover scenario shown in the foregoing.

For example, the first message is an RRC reconfiguration message (RRC message); also for example, the first message is a MAC CE message.

It should be understood that, in this implementation, the specific form of the first message is not limited, and any message that can be used to trigger the terminal device to perform cell handover is within the scope of protection of the present application.

It should also be understood that, in this implementation, the identifier of the target cell included in the first message received by the terminal device, i.e. the identifier network device, indicates the cell to which the terminal device is to be handed over.

In this implementation manner, the terminal device obtains a frame number of a second system frame corresponding to the target cell, including:

and when the terminal equipment performs switching, performing downlink synchronization with the target cell and acquiring a Master Information Block (MIB) of the target cell, wherein the MIB is used for acquiring a frame number of a second system frame corresponding to the target cell. For example, the frame number of the system frame is represented by 10 bits, 6 most significant bits (most significant bit, MSB) of 10 bits are included in the MIB of the cell, and 4 least significant bits of 10 bits are transmitted in the PBCH transport block as a part of channel coding (i.e., beyond MIB coding), and the terminal device can obtain the frame number of the system frame of the cell after reading the MIB message, so in this implementation the terminal device can obtain the frame number of the second system frame corresponding to the target cell by obtaining the MIB of the target cell.

In addition, in the handover scenario, the terminal device may start to perform cell handover after receiving the first message, so the time at which the terminal device performs cell handover and the time at which the first message is received may be equivalent in the handover scenario. That is, the description related to the time when the terminal device performs the cell handover is referred to hereinafter, and may be replaced with the time when the terminal device receives the first message or the time when the second system frame of the target cell is acquired in the handover scenario.

As another possible implementation manner, the first message is a message sent by the network device to the terminal device in the condition switching scenario shown in the foregoing, and the first message further includes information of a switching condition.

For example, the first message is a conditional handoff message including, but not limited to: RRC reconfiguration message (RRC message), MAC CE message, etc.

It should be understood that the specific form of the first message is not limited in this implementation, and any message including the above information (such as the identification of the target cell, the first ephemeris information, the first indication message, and the information of the handover condition) is within the scope of protection of the present application.

It should also be appreciated that, in this implementation, the identity of the target cell included in the first message received by the terminal device may be (or be) the identity of the candidate cell.

In this implementation, the target cell described above may also be referred to as a candidate target cell. The first message may include a plurality of NTN parameter information corresponding to each of the plurality of candidate target cells, and for convenience of description, in this embodiment, the first message includes NTN parameter information corresponding to a certain candidate target cell. Also, the description of the candidate target cell and the target cell will not be repeated in the following of this embodiment, that is, the target cell referred to in the following of this embodiment may be described in place of the candidate target cell.

Illustratively, in this implementation, the terminal device obtains a frame number of a second system frame corresponding to the target cell, including:

and when the terminal equipment receives the first message, carrying out downlink synchronization with the target cell and acquiring a master information block MIB of the target cell, wherein the MIB is used for acquiring a frame number of a second system frame corresponding to the target cell.

The terminal equipment firstly determines the timing difference between the source cell and the target cell, and determines the frame number of a second system frame corresponding to the target cell according to the third system frame carrying the first message and the timing difference. For example, after the terminal device receives the first message and determines a third system frame carrying the first message, the sum of the third system frame and the timing difference is taken as the frame number of a second system frame corresponding to the target cell.

Optionally, the timing difference between the source cell and the target cell is a predefined value.

Optionally, the timing difference between the source cell and the target cell is configured for the network device, e.g. the network device sends information indicating the timing difference to the terminal device, from which the terminal device determines the timing difference.

Optionally, the timing difference between the source cell and the target cell is determined by the terminal device according to the measurement result. For example, the terminal device measures signals of the source cell and the target cell and determines a timing difference between the source cell and the target cell from a difference in transmission delays of the signals measured from the source cell and the target cell.

Optionally, the first message is a message carrying a CHO trigger condition based on time, that is, the above-mentioned information of the handover condition indicates a handover condition based on time, where the handover condition based on time includes a first moment, and the terminal device determines the timing difference according to a system frame and/or a subframe of a source cell corresponding to the first moment and a system frame and/or a subframe of a target cell corresponding to the first moment.

For example, the terminal device may determine a system frame and/or a subframe of the source cell corresponding to the first time (e.g., the terminal device determines the system frame of the source cell corresponding to the first time based on information received at the source cell at the first time). In addition, the frame number and/or the subframe of the system frame of the target cell corresponding to the first time may be carried in the first message, so that the terminal device may determine the system frame of the target cell corresponding to the first time according to the frame number of the system frame of the target cell corresponding to the first time in the first message; or, the network device may notify the frame number and/or the subframe of the system frame of the target cell corresponding to the first time through the second message.

In addition, it should be noted that, in the condition handover scenario, the terminal device receives the first message and does not immediately perform handover, but needs to determine the handover condition, that is, in the condition handover scenario, the time when the terminal device receives the first message and the time when the terminal device performs cell handover are not equivalent, and the description cannot be replaced. And in the condition switching scenario, the terminal device acquires the frame number of the second system frame of the target cell when receiving the first message, so that the description cannot be replaced at the time of executing the cell switching and the time indicated by the second system frame of the target cell in the condition switching scenario.

Further, after the terminal device obtains the frame number of the second system frame corresponding to the target cell, the method shown in fig. 5 further includes:

s530, the terminal equipment determines a first effective time of the first ephemeris information.

Specifically, the terminal device in this embodiment may determine the first validity time of the first ephemeris information according to whether the frame number of the first system frame and the frame number of the second system frame are the same.

As a possible implementation, the frame number of the first system frame is the same as the frame number of the second system frame.

In this implementation manner, the first effective time determined by the terminal device is a time indicated by the first system frame and the first subframe in the system frame period to which the second system frame belongs. For example, the starting time of the downlink subframe indicated by the first system frame and the first subframe is the first effective time, or the determined time of the first system frame and the first subframe refers to the starting time of the downlink subframe indicated by the first system frame and the first subframe.

The first system frame and the first subframe are indicated by first indication information, and the first subframe is one subframe in the first system frame.

For example, if the frame number of the first system frame indicated by the first indication information is 24 and the frame number of the current second system frame of the target cell acquired by the terminal device is also 24, the terminal device considers that the first system frame with the frame number indicated by the first indication information being 24 is the current second system frame.

It should be noted that, the system frame period to which the second system frame belongs in this embodiment may be understood as: since the frame numbers of the system frames are cycled from 0-1023, the frame number of any system frame is one of 0-1023, and in this embodiment, the system frame period to which the second system frame belongs represents a cycle of 0-1023 in which the frame number of the second system frame is located.

For example, the frame number of the system frame is numbered from 0-1023 cycles, including 4 cycles, and the frame number of the second system frame is 100 and is 100 in the second 0-1023 cycles, then the system frame period to which the second system frame belongs can be understood as the second 0-1023 cycles.

Specifically, in this implementation manner, when the terminal device performs cell handover, a first timer (e.g., a T430 timer) is started, where an end time of the first timer is determined by a first active time (i.e., a time determined by a first system frame and a first subframe in a system frame period to which a second system frame belongs) and a first time length, e.g., an end time of the first timer is a time after the first time length from the first active time. The first duration is indicated by information of the first duration carried in the first message. For example, the first message includes ntn-UlSyncValidityDuration, which ntn-UlSyncValidityDuration is used to indicate the first duration.

It should be noted that, in this embodiment, the actual starting time of the first timer is the time when the terminal device performs cell handover, and is not the first effective time. That is, the time period between the time of performing the cell handover and the end time of the first timer is not necessarily the first time period, and for the sake of distinction, the time period between the time of performing the cell handover and the end time of the first timer in this implementation is referred to as the second time period.

Optionally, in a case where the time of performing the cell handover is earlier than the first time of validity, the second time period is a sum of the first time period and the first difference value.

Optionally, in a case where the time of performing the cell handover is later than the first time of validity, the second time period is a difference between the first time period and the first difference.

Wherein the first difference is an absolute value of a difference between a time at which the cell handover is performed and the first effective time.

For ease of understanding, the relationship between the first time period and the second time period in this implementation will be described in detail in connection with (a) to (c) in fig. 6.

As can be seen from fig. 6 (a), the first validity time of the first timer is one time before the time when the terminal device performs the cell handover, so that the second time length is the first time length minus the interval between the first validity time and the time when the cell handover is performed, and it can be understood that the epoch time indicates the elapsed time, the first time length is indicated by ntn-UlSyncValidityDuration, and the second time length between the start time and the end time of the T430 timer should be ntn-UlSyncValidityDuration minus the elapsed time.

As can be seen from fig. 6 (b), the first validity time of the first timer is one time after the terminal device performs the cell handover time, so that the second time length is the first time length plus the interval between the first validity time and the cell handover time, and it can be understood that the epoch time indicates a future time, the first time length is indicated by ntn-UlSyncValidityDuration, and the second time length between the start time and the end time of the T430 timer should be ntn-UlSyncValidityDuration plus the future time.

In addition, it should be noted that, in this implementation manner, if the first message is a message sent in the handover scenario and triggering the first terminal device to perform cell handover, and the time when the first terminal device performs cell handover and the time when the second system frame of the target cell acquired by the first terminal device indicates substantially coincide (for example, the first subframe number is the same as the subframe number #1 in the second system frame acquired by the first terminal device), then the relationship between the first duration and the second duration is as shown in fig. 6 (c), that is, the effective time of the first timer is the time when the terminal device performs cell handover.

As another possible implementation manner, the frame number of the first system frame and the frame number of the second system frame are different, and the first system frame is a system frame before the second system frame in a system frame period to which the second system frame belongs.

In this implementation manner, the first effective time determined by the terminal device is a time determined by the first system frame and the first subframe in the system frame period to which the second system frame belongs.

For example, if the frame number of the first system frame indicated by the first indication information is 20 and the terminal device acquires the frame number of the current second system frame of the target cell is 24, the terminal device considers that the first system frame with the frame number indicated by the first indication information being 20 is a system frame 40ms before the second system frame.

As yet another possible implementation manner, the frame number of the first system frame is different from the frame number of the second system frame, and the first system frame is a system frame in the first system frame period, and the first system frame period is a system frame period adjacent to the system frame period to which the second system frame belongs.

In this implementation manner, the first effective time determined by the terminal device is a time determined by the first system frame and the first subframe in the first system frame period.

For example, if the frame number of the first system frame indicated by the first indication information is 25 and the terminal device acquires the frame number of the current second system frame of the target cell is 24, the terminal device considers that the first system frame with the frame number indicated by the first indication information is a system frame 10230ms before the second system frame.

Specifically, in the two implementations described above (the first system frame is before the second system frame), when the terminal device performs cell handover, a second timer (e.g., a T430 timer) is started, where an end time of the second timer is determined by the first effective time (i.e., a time determined based on the first system frame and the first subframe in the system frame period to which the second system frame belongs) and the first time, for example, the end time of the first timer is a time after the first time from the first effective time. The first duration is indicated by information of the first duration carried in the first message. For example, the first message includes ntn-UlSyncValidityDuration, which ntn-UlSyncValidityDuration is used to indicate the first duration.

It should be noted that, in this embodiment, the actual starting time of the first timer is the time when the terminal device performs cell handover, and is not the first effective time. That is, the time period between the time of performing the cell handover and the end time of the first timer is not necessarily the first time period, and for the sake of distinction, the time period between the time of performing the cell handover and the end time of the first timer in this implementation is referred to as the third time period.

Since the first system frame is a system frame preceding the second system frame, the third time period is a difference between the first time period and a first difference value, which is an absolute value of a difference between a time at which the cell handover is performed and the first effective time.

For ease of understanding, the relationship between the first time length and the third time length in the case where the first system frame is a system frame preceding the second system frame is described in detail with reference to (a) and (b) in fig. 7.

As can be seen from fig. 7 (a), the first active time of the second timer is one time before the time when the terminal device performs cell handover, and the first system frame and the second system frame are located in the same system frame period.

The first duration is a first duration from the first time of efficiency, so that the third duration is the first duration minus the interval between the first time of efficiency and the time of performing the cell handover, and it can be understood that the epoch time indicates the elapsed time, the first duration is indicated by ntn-UlSyncValidityDurate, and the second duration between the start time and the end time of the T430 timer should be ntn-UlSyncValidityDurate minus the elapsed time.

As can be seen from fig. 7 (b), the first active time of the second timer is one time before the time when the terminal device performs cell handover, and the first system frame is located in the previous period of the system frame period to which the second system frame belongs.

As yet another possible implementation manner, the frame number of the first system frame is different from the frame number of the second system frame, and the first system frame is a system frame after the second system frame in a system frame period to which the second system frame belongs; or the first system frame is a system frame in a second system frame period, and the second system frame period is a next system frame period adjacent to the system frame period to which the second system frame belongs.

For example, if the frame number of the first system frame indicated by the first indication information is 20 and the terminal device acquires the frame number of the current second system frame of the target cell is 24, the terminal device considers that the first system frame with the frame number indicated by the first indication information being 20 is a system frame after 10200ms of the second system frame.

Also for example, if the frame number of the first system frame indicated by the first indication information is 25 and the frame number of the current second system frame of the target cell is 24, the terminal device considers that the first system frame with the frame number indicated by the first indication information being 25 is a system frame 10ms later than the second system frame.

In this implementation, the terminal device may determine the first validity time of the first ephemeris information in the following ways:

mode one: the terminal equipment acquires a system information block of the target cell. The system information block may be SIB19 of the target cell or other information including NTN parameter information, which is not limited in this application, and is described by taking SIB19 of the target cell as an example for convenience of description.

Specifically, the terminal device performs cell switching, and determines that the time indicated by the first system frame is later than the time at which cell switching is performed. The terminal equipment acquires the SIB19 of the target cell, wherein the SIB19 comprises second ephemeris information and second indication information, the second indication information is used for indicating the frame number of the third system frame and the frame number of the second subframe, and the terminal equipment determines that the second effective time of the second ephemeris information is the time determined by the third system frame and the second subframe.

That is, in a manner, the terminal device determines the first ephemeris information as future ephemeris information, and the first valid time of the first ephemeris information is a time determined by the first system frame and the first subframe indicated by the first indication information. The terminal device may directly read SIB19 message of the target cell to obtain the second ephemeris information, the second indication information (e.g., an epoch time parameter), information of the fourth duration (e.g., a ntn-UlSyncValidityDuration parameter), and so on.

Specifically, in a manner, when the terminal device performs cell handover, a third timer (e.g., T430 timer) is started, and the end time of the third timer is determined by the second effective time and the fourth time, e.g., the end time of the third timer is a time after the fourth time from the second effective time. The fourth duration is indicated by information of the fourth duration carried in the SIB19 message of the target cell. For example, ntn-UlSyncValidityDurate is included in SIB19, and ntn-UlSyncValidityDurate is used to indicate the fourth duration.

It should be noted that, in this embodiment, the actual starting time of the third timer is the time when the terminal device performs the cell handover, and is not the second effective time. That is, the time period between the time point at which the cell switch is performed and the end time point of the third timer is not necessarily the fourth time period, and for the sake of distinction, the time period between the time point at which the cell switch is performed and the end time point of the first timer in this implementation is referred to as the fifth time period.

Optionally, in a case where the time of performing the cell handover is earlier than the second effective time, the fifth time period is a sum of the fourth time period and the second difference value.

Optionally, in a case where the time of performing the cell handover is later than the second effective time, the second time period is a difference between the first time period and the second difference.

Wherein the second difference is an absolute value of a difference between a time at which the cell handover is performed and the second effective time.

Illustratively, in the first mode, the terminal device may determine whether the SIB19 of the target cell needs to be acquired as follows.

For example, the terminal device determines that the time length required to acquire SIB19 of the target cell is less than a time length threshold, where the time length threshold is predefined or negotiated for the terminal device and the network device or configured for the network device.

Also for example, the terminal device determines that the time difference between the first effective time instant and the time instant at which the cell handover is performed is greater than the time period required to acquire the SIB19 of the target cell.

For another example, the terminal device determines that the time difference between the first time of effectiveness and the time of performing the cell handover is greater than a time duration threshold #1, wherein the time duration threshold #1 is predefined or negotiated for the terminal device and the network device or configured for the network device.

For another example, the terminal device determines that the time when the reading SIB19 obtains the second ephemeris information is earlier than the time indicated by the first indication information.

Mode two: the terminal device estimates future ephemeris information.

Specifically, in the second mode, the terminal device estimates, when performing cell handover, third ephemeris information corresponding to a time point of performing cell handover according to the first ephemeris information.

For example, the terminal device may estimate the satellite position at the current handoff moment from the satellite trajectory at a future time.

Specifically, in the second mode, when the terminal device performs cell handover, a fourth timer (e.g., a T430 timer) is started, and the end time of the fourth timer is determined by the first active time and the first time, e.g., the end time of the fourth timer is a time after the first time from the first active time. The first duration is indicated by information of the first duration carried in the first message. For example, the first message includes ntn-UlSyncValidityDuration, which ntn-UlSyncValidityDuration is used to indicate the first duration.

It should be noted that, in this embodiment, the actual starting time of the fourth timer is the time when the terminal device performs cell handover, and is not the first effective time. That is, the duration between the time of performing the cell handover and the end time of the fourth timer is not necessarily the first duration, and for distinction, the duration between the time of performing the cell handover and the end time of the first timer in this implementation is referred to as the sixth duration, where the sixth duration is the sum of the first duration and a first difference, and the first difference is the absolute value of the difference between the time of performing the cell handover and the first effective time.

Mode three: the terminal device waits until the first time of validity of the first ephemeris information to perform the handover.

And the terminal starts to execute switching at the first effective moment. When the terminal device performs cell handover, an eighth timer (e.g., a T430 timer) is started, where the end time of the eighth timer is determined by the first time of validity and the first time, e.g., the end time of the eighth timer is a time after the first time from the first time of validity. The first duration is indicated by information of the first duration carried in the first message.

In the third mode, the terminal device does not perform the switching until the first effective time of the first ephemeris information, so that the time of the terminal device performing the switching is the first effective time. That is, the time period between the time at which the cell handover is performed and the end time of the eighth timer is the first time period.

In summary, in the embodiment shown in fig. 5, the terminal device determines whether the frame number of the first system frame indicated by the first indication information carried in the first message is the same as the frame number of the second system frame of the target cell, or determines that the first system frame is the second system frame or the nearest system frame of the second system frame. The terminal device considers that the first system frame is the nearest system frame of the second system frame comprises:

The terminal equipment considers that the first system frame is the system frame which is closest to the second system frame in the system frame period to which the second system frame belongs; or,

the terminal device considers that the first system frame is a system frame in a system frame period adjacent (preceding or succeeding) to the system frame period to which the second system frame belongs.

As can be seen from the foregoing, in the communication method shown in fig. 5, the terminal device may determine the time corresponding to the epoch time by comparing the system frame indicated by the epoch time in the first message with the system frame corresponding to the acquired target cell.

The present application also provides another communication method, which may be used to indicate the time of day of the ephemeris information by indicating an absolute time, as will be described below with reference to fig. 8.

Fig. 8 is a schematic flow chart of a communication method provided in an embodiment of the present application, including the following steps:

s810, the terminal device receives the third message from the network device, or the network device sends the third message to the terminal device.

The third message comprises fourth ephemeris information, third indication information and information of a seventh duration, wherein the third indication information is used for indicating a second moment when the fourth ephemeris information takes effect.

As a possible implementation manner, the third message is a message sent by the network device to the terminal device for indicating the terminal device to switch from the source cell to the target cell in the handover scenario shown in the foregoing.

For example, the third message is an RRC reconfiguration message (RRC message); also for example, the third message is a MAC CE message.

It should be understood that, in this implementation, the specific form of the third message is not limited, and any message that can be used to trigger the terminal device to perform cell handover is within the scope of protection of the present application.

As another possible implementation manner, the third message is a message sent by the network device to the terminal device in the condition switching scenario shown in the foregoing, and the third message further includes information of a switching condition.

For example, the third message is a conditional handoff message, including but not limited to: RRC reconfiguration message (RRC message), MAC CE message, etc.

It should be understood that the specific form of the third message is not limited in this implementation, and any message including the above information (such as the fourth ephemeris information, the third indication information, and the information of the seventh duration and the information of the handover condition) is within the scope of protection of the present application.

As a possible implementation, the third indication information in this embodiment may be the epoch time parameter information shown in the foregoing, with the difference that the epoch time parameter information is no longer used to indicate the frame number of the system frame and the frame number of the subframe, but is expressed using absolute time, and may be expressed using coordinated universal time (Coordinated Universal Time, UTC) time.

For example, the time is expressed in terms of a multiple of 10 milliseconds (midnight between 31 days of the year 31 and 1 day monday of the year 1900, 12 months of 1899) after 00:00 a of 1 month 1, i.e., 10ms is a step.

As another possible implementation, the second time indicated by the third indication information in this embodiment may be the second time (as indicated by T1 shown in the foregoing) implicitly indicated by the time-based handover condition included in the third message, and in this implementation, the third indication information may be understood as part of the information in the multiplexed time-based handover condition.

For example, the third message is a conditional access message, and the third message includes a time-based conditional access condition, for example, the time parameter information T1 and T2 are used to indicate the time-based conditional access condition, and the third message may further include epoch time parameter information, where the terminal device obtains the epoch time parameter information, and may not interpret the SFN and the subframe number indicated by the epoch time, and considers that the valid start time of the ephemeris information is the time T1. That is, in this implementation, the epoch time parameter information exists in the third message only for the integrity and compatibility of the protocol signaling, or in this implementation, the third message may not carry the epoch time parameter information.

As yet another possible implementation manner, the third indication information in this embodiment may be newly added information for indicating a valid start time of the ephemeris information.

Further, in this embodiment, the terminal device receives the third message, and may perform cell handover, and the method flow shown in fig. 8 further includes:

s820, the terminal device performs cell handover.

Specifically, the terminal device performs cell handover, and starts a fifth timer (e.g., a T430 timer), where an end time of the fifth timer is determined by the second time and the seventh time period, e.g., the end time of the fifth timer is a time after the seventh time period from the second time period. The seventh duration is indicated by the information of the seventh duration carried in the third message. For example, the third message includes ntn-UlSyncValidityDuration, which ntn-UlSyncValidityDuration is used to indicate the seventh duration.

It should be noted that, in this embodiment, the actual starting time of the fifth timer is the time when the terminal device performs the cell handover, and is not the second time. That is, the time period between the time point at which the cell switch is performed and the end time point of the fifth timer is not necessarily the seventh time period, and for the sake of distinction, the time period between the time point at which the cell switch is performed and the end time point of the first timer in this implementation is referred to as the eighth time period.

In the case where the second time is a time before the time at which the cell handover is performed, the eighth time period is a difference between the seventh time period and the third difference;

in the case where the second time is a time subsequent to the time at which the cell handover is performed, the eighth time period is a sum of the seventh time period and the third difference value;

wherein the third difference value is an absolute value of a time difference between a time instant at which the cell handover is performed and the second time instant.

The present application also provides another communication method, which may indicate the effective time of different ephemeris information, and is described below with reference to fig. 9.

Fig. 9 is a schematic flowchart of a communication method provided in an embodiment of the present application, including the following steps:

s910, the terminal device receives the fourth message from the network device, or the network device sends the fourth message to the terminal device.

The fourth message includes a plurality of ephemeris information, a plurality of time duration information, and fourth indication information (epoch time) for indicating a time of validity of a first one of the plurality of ephemeris information.

As a possible implementation manner, the fourth message is a message sent by the network device to the terminal device for indicating the terminal device to switch from the source cell to the target cell in the handover scenario shown in the foregoing.

For example, the fourth message is an RRC reconfiguration message (RRC message); also for example, the fourth message is a MAC CE message.

It should be understood that, in this implementation, the specific form of the fourth message is not limited, and any message that can be used to trigger the terminal device to perform cell handover is within the scope of protection of the present application.

As another possible implementation manner, the fourth message is a message sent by the network device to the terminal device in the condition switching scenario shown in the foregoing, and the fourth message further includes information of a switching condition.

For example, the fourth message is a conditional handoff message including, but not limited to: RRC reconfiguration message (RRC message), MAC CE message, etc.

It should be understood that the specific form of the fourth message is not limited in this implementation, and any message including the above information (such as the plurality of ephemeris information, the plurality of duration information, and the fourth indication information and the handover condition information) is within the scope of protection of the present application.

Specifically, in this embodiment, the number of the plurality of ephemeris information included in the fourth message is the same as the number of the information of the plurality of time periods included. The end time of the previous ephemeris information in the adjacent two ephemeris information is the effective time of the next ephemeris information.

For example, when the fourth message includes the ephemeris information #1, the ephemeris information #2, and the ephemeris information #3 in order, the end time of the ephemeris information #1 is the valid time of the ephemeris information #2, and the end time of the ephemeris information #2 is the valid time of the ephemeris information # 3.

Further, in this embodiment, the terminal device receives the fourth message, and may perform cell handover, and the method flow shown in fig. 9 further includes:

s920, the terminal device executes cell switching.

Specifically, when the terminal equipment performs cell switching, fifth ephemeris information is used, and the terminal equipment determines the effective time of the fifth ephemeris information;

the fifth ephemeris information is the nth ephemeris information in the plurality of ephemeris information, and the effective time of the fifth ephemeris information is determined by the fourth system frame number and the third subframe number indicated by the fourth indication information and the N-1 time duration information corresponding to the N-1 ephemeris information before the fifth ephemeris information.

For example, if the fifth ephemeris information used when the terminal performs the handover is the first one of the plurality of ephemeris information, the effective time of the fifth ephemeris information is the time determined by the fourth system frame number and the third subframe number indicated by the fourth indication information.

Specifically, the terminal device performs cell handover, and starts a sixth timer (e.g., a T430 timer), where an end time of the sixth timer is determined by an effective time of the fifth ephemeris information (i.e., a time determined based on the fourth system frame number and the third subframe number) and the first time, e.g., an end time of the sixth timer is a time after a corresponding time period of the first ephemeris information from an effective time of the fifth ephemeris information. The corresponding duration of the first ephemeris information is indicated by the duration #1 information carried in the fourth message. For example, the first message includes ntn-UlSyncValidityDuration, and ntn-UlSyncValidityDuration is used to indicate the duration corresponding to the first ephemeris information.

It should be noted that, in this embodiment, the actual starting time of the sixth timer is the time when the terminal device performs cell handover, and is not the effective time of the fifth ephemeris information. That is, the time period between the time point at which the cell switch is performed and the end time point of the first timer is not necessarily the time period #1, and for the sake of distinction, the time period between the time point at which the cell switch is performed and the end time point of the first timer in this implementation is referred to as the time period #1'.

In the case where the time indicated by the fourth indication information is a time before the time at which the cell handover is performed, the time length #1' is a difference between the time length #1 and the fourth difference;

in the case where the time indicated by the fourth indication information is a time subsequent to the time at which the cell handover is performed, the time length #1' is a sum of the time length #1 and the fourth difference value;

wherein the fourth difference value is an absolute value of a time difference between a time at which the cell handover is performed and a time indicated by the fourth indication information.

Also for example, if the fifth ephemeris information used when the terminal performs the handover is nth ephemeris information (N is an integer greater than 1) among the plurality of ephemeris information, the fifth ephemeris information effective time is a time indicated by the fourth indication information and a time determined by N-1 time periods information corresponding to N-1 pieces of ephemeris information before the fifth ephemeris information, respectively.

Specifically, the terminal device performs cell handover, and starts a seventh timer (e.g., a T430 timer), where an end time of the seventh timer is determined by an effective time of the fifth ephemeris information (i.e., a time determined based on the fourth system frame number and the third subframe number) and N-1 time periods, e.g., an end time of the seventh timer is a time period after N-1 time periods corresponding to the N-1 ephemeris information from the effective time of the fifth ephemeris information, respectively. N-1 time lengths corresponding to the N-1 ephemeris information are indicated by the N-1 time length information carried in the fourth message. For example, the first message includes N-1 ntn-UlSyncValidityDuration, where N-1 ntn-UlSyncValidityDuration is used to indicate the duration corresponding to the N-1 ephemeris information.

It should be noted that, in this embodiment, the actual starting time of the seventh timer is the time when the terminal device performs the cell handover, and is not the effective time of the fifth ephemeris information. That is, the time period between the time point at which the cell switch is performed and the end time point of the first timer is not necessarily the time period #n, and for the sake of distinction, the time period between the time point at which the cell switch is performed and the end time point of the first timer in this implementation is referred to as the time period #n'.

In the case where the time #n is a time before the time at which the cell handover is performed, the time #n' is a difference between the time #n and the fifth difference;

in the case where the time #n is a time subsequent to the time at which the cell handover is performed, the time #n' is a sum of the time #n and the fifth difference;

the fifth difference is a time difference between a time when the cell handover is performed and a time #n, where the time #n is a time after N-1 durations corresponding to N-1 ephemeris information respectively after the time indicated by the fourth indication information.

The present application also provides another communication method, which proposes a system information block (for example, SIB19 or other information including NTN parameter information) sent to a terminal device without a common search space by means of dedicated signaling, but in the case that the system information block does not carry an epoch time, how the terminal device determines the epoch time of ephemeris information in the system information block, for convenience of description, the system information block is SIB19, and will be described with reference to fig. 10.

Fig. 10 is a schematic flowchart of a communication method provided in an embodiment of the present application, including the following steps:

s1010, the terminal equipment receives the special signaling from the network equipment to which the service cell belongs, or the network equipment to which the service cell belongs sends the special signaling to the terminal equipment.

SIB19 is included in the dedicated signaling, but no information indicating the time instant of validity of the ephemeris information of the serving cell is included in SIB 19.

S1020, the terminal equipment determines the effective time of the ephemeris information of the service cell.

As a possible implementation, the terminal device takes the end time of the system message window SI window of the scheduling SIB19 as the time of validity of the ephemeris information of the serving cell.

The SI window is the SI window where the dedicated signaling is located, or is the SI window adjacent to the dedicated signaling.

For ease of understanding, the relation of dedicated signaling and the end time of SI window of the scheduling SIB19 is explained in connection with fig. 11.

As shown in fig. 11, the SI window #1 is a previous SI window adjacent to the dedicated signaling, and the terminal device may take the end time of the SI window #1 as the effective time of the ephemeris information of the serving cell; the SI window #2 is the SI window after the dedicated signaling is adjacent, and the terminal device may take the end time of the SI window #2 as the effective time of the ephemeris information of the serving cell.

In addition, if the dedicated signaling overlaps with the SI window, the SI window is considered to be the SI window closest to the dedicated signaling.

As another possible implementation, the terminal device receives, from the network device to which the serving cell belongs, first information indicating the time of validity of the ephemeris information of the serving cell, the first information not being located in SIB 19.

Specifically, in this implementation manner, when the network device sends the system message SIB19 to the terminal device through the dedicated signaling, if there is no epochtime parameter of the serving cell in the SIB19, the network device sends the epochtime parameter of the serving cell to the terminal device (the epochtime parameter indicates a valid start time of the ephemeris information of the SIB 19), where the epochtime parameter is not located in the differential system information delivery field, and the terminal device uses the received epochtime parameter as an effective time of the ephemeris of the serving cell.

Optionally, if the dedicated signaling has an epoch time parameter of the neighboring cell, taking the time indicated by the epoch time parameter of the neighboring cell as the effective time of the ephemeris information of the neighboring cell; otherwise, taking the effective time of the ephemeris information of the service cell as the effective time of the ephemeris information of the neighbor cell.

The present application further provides another communication method, which proposes the ephemeris information of the serving cell and the neighboring cell sent to the terminal device by broadcasting, but how the terminal device determines the epoch time of the neighboring cell ephemeris information under the condition that the neighboring cell ephemeris information is not sent, and is described below with reference to fig. 12.

Fig. 12 is a schematic flowchart of a communication method provided in an embodiment of the present application, including the following steps:

s1210, the terminal device receives the fifth message from the network device, or the network device sends the fifth message to the terminal device.

The fifth message includes the ephemeris information of the serving cell and fifth indication information (epoch time), where the fifth indication information is used to indicate the effective time of the ephemeris information of the serving cell, and the fifth message includes the ephemeris information of the neighboring cell and does not include information indicating the effective time of the ephemeris information of the neighboring cell.

S1220, the terminal equipment determines the effective time of the ephemeris information of the neighboring cell.

Specifically, the terminal device takes the effective time of the ephemeris information of the service cell as the effective time of the ephemeris information of the neighbor cell.

The fifth indication information is used for indicating a frame number of a sixth system frame, and the method further includes:

And the terminal equipment determines the sixth system frame as the seventh system frame under the condition that the frame number of the sixth system frame is the same as the frame number of the seventh system frame carrying the fifth message.

For example, the frame number of the sixth system frame indicated by the fifth indication information is 24; the frame number of the seventh system frame carrying the fifth message is 24, and the terminal device considers the sixth system frame as the current seventh system frame.

Or,

and the terminal equipment determines the sixth system frame as the system frame before the seventh system frame in the system frame period to which the seventh system frame belongs.

For example, the frame number of the sixth system frame indicated by the fifth indication information is 20, the frame number of the seventh system frame carrying the fifth message is 24, and the terminal device considers the sixth system frame to be a system frame 40ms before the seventh system frame.

Or,

and the terminal equipment determines the sixth system frame as a system frame after the seventh system frame in a system frame period to which the seventh system frame belongs.

For example, the frame number of the sixth system frame indicated by the fifth indication information is 25; the frame number of the seventh system frame carrying the fifth message is 24, and the terminal device considers the sixth system frame to be a system frame 10ms after the seventh system frame.

Or,

the terminal equipment determines that the sixth system frame is a system frame in a fourth system frame period, wherein the fourth system frame period is a system frame period adjacent to the system frame period to which the seventh system frame belongs.

For example, the frame number of the sixth system frame indicated by the fifth indication information is 20, the frame number of the seventh system frame carrying the fifth message is 24, and the terminal device considers the sixth system frame to be a system frame after 10200ms of the seventh system frame.

The present application further provides another communication method, which proposes the ephemeris information of the serving cell and the neighboring cell sent to the terminal device by broadcasting, but how the terminal device determines the epoch time of the neighboring cell ephemeris information under the condition that the neighboring cell ephemeris information is not sent, and is described below with reference to fig. 13.

Fig. 13 is a schematic flowchart of a communication method provided in an embodiment of the present application, including the following steps:

s1310, the terminal device receives the sixth message from the network device, or the network device sends the sixth message to the terminal device.

The sixth message includes the ephemeris information of the serving cell and the ephemeris information of the neighboring cell, and does not include information indicating the effective time of the ephemeris information of the serving cell and information indicating the effective time of the ephemeris information of the neighboring cell.

S1320, the terminal device determines the effective time of the ephemeris information.

And the terminal equipment takes the ending time of the system message window SI window of the scheduling SIB19 as the effective time of the ephemeris information of the service cell and the effective time of the ephemeris information of the neighbor cell.

In addition, because the ephemeris information and the common Timing Advance (TA) parameter are carried in the same message (e.g., are both information included in the NTN parameter information), the effective time of the ephemeris information and the effective time of the common TA parameter may be the same effective time. The time of validity of the ephemeris information determined by the terminal device may thus also be the time of validity of the common TA parameter. That is, the method for determining the effective time of the acquired ephemeris information by the terminal device provided in the application may also be applied to determining the effective time of the acquired public TA parameter by the terminal device. Specific determination means are not repeated, and reference may be made to the description in the above embodiments.

For example, the terminal device determines the effective time of the common TA parameter according to whether the frame number of the first system frame is the same as the frame number of the second system frame, and specifically refers to the description in step S520 in fig. 5, and replaces the first effective time of the first ephemeris information with the effective time of the common TA parameter; also for example, the definition of the third indication information in step S810 in fig. 8 may be information indicating the time of validity of the TA parameter; for another example, the terminal device may determine the time of validity of the plurality of TA parameters according to the method of determining the time of validity of the plurality of ephemeris information in the embodiment shown in fig. 9, and so on, which is not illustrated here. In addition, in the case of determining that the effective time of the TA parameter is a future time, the terminal device may estimate the TA parameter at the handover time according to the future TA parameter.

It should be understood that the sequence numbers of the above processes do not mean the order of execution, and the execution order of the processes should be determined by the functions and internal logic of the processes, and should not constitute any limitation on the implementation process of the embodiments of the present application.

It is also to be understood that in the various embodiments of the application, terms and/or descriptions of the various embodiments are consistent and may be referenced to one another in the absence of a particular explanation or logic conflict, and that the features of the various embodiments may be combined to form new embodiments in accordance with their inherent logic relationships.

It should also be understood that in some of the above embodiments, the devices in the existing network architecture are mainly used as examples for the explanation (such as terminal devices, network devices, etc.), and it should be understood that the embodiments of the present application are not limited to specific forms of the devices. For example, devices that can achieve the same functionality in the future are suitable for use in the embodiments of the present application.

It will be appreciated that in the foregoing embodiments of the methods and operations implemented by a device (e.g., a terminal device, a network device) may also be implemented by a component of the device (e.g., a chip or circuit).

The method for selecting resources provided in the embodiment of the present application is described in detail above with reference to fig. 5 to 13. The above method of resource selection is mainly described from the point of view of the terminal device. It will be appreciated that, in order to implement the above-mentioned functions, the terminal device includes corresponding hardware structures and/or software modules for performing the respective functions.

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

The following describes in detail the communication device provided in the embodiment of the present application with reference to fig. 14 to 16. It should be understood that the descriptions of the apparatus embodiments and the descriptions of the method embodiments correspond to each other, and thus, descriptions of details not shown may be referred to the above method embodiments, and for the sake of brevity, some parts of the descriptions are omitted.

The embodiment of the application may divide the function modules of the transmitting end device or the receiving end device according to the above method example, for example, each function module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The integrated modules may be implemented in hardware or in software functional modules. It should be noted that, in the embodiment of the present application, the division of the modules is schematic, which is merely a logic function division, and other division manners may be implemented in actual implementation. The following description will take an example of dividing each functional module into corresponding functions.

Fig. 14 is a schematic block diagram of a communication device 10 provided in an embodiment of the present application. The device 10 comprises a transceiver module 11 and a processing module 12. The transceiver module 11 may implement a corresponding communication function, the processing module 12 is configured to perform data processing, or the transceiver module 11 is configured to perform operations related to reception and transmission, and the processing module 12 is configured to perform operations other than reception and transmission. The transceiver module 11 may also be referred to as a communication interface or a communication unit.

Optionally, the apparatus 10 may further include a storage module 13, where the storage module 13 may be configured to store instructions and/or data, and the processing module 12 may read the instructions and/or data in the storage module, so that the apparatus implements the actions of the devices in the foregoing method embodiments.

In one design, the apparatus 10 may correspond to the terminal device in the above method embodiments, or may be a component part (e.g., a chip) of the terminal device.

The apparatus 10 may implement steps or processes performed by a terminal device in the above method embodiment, where the transceiver module 11 may be configured to perform operations related to the transceiver of the terminal device in the above method embodiment, and the processing module 12 may be configured to perform operations related to the processing of the terminal device in the above method embodiment.

In a possible implementation manner, the transceiver module 11 is configured to receive a first message from a network device, where the first message includes an identifier of a target cell, first ephemeris information corresponding to the target cell, and first indication information, where the first indication information is used to indicate a frame number of a first system frame; a processing module 12, configured to obtain a frame number of a second system frame corresponding to the target cell;

the processing module 12 is further configured to determine a first validity time of the first ephemeris information according to whether the frame number of the first system frame and the frame number of the second system frame are the same.

In another possible implementation manner, the transceiver module 11 is configured to receive a third message from the network device, where the third message includes fourth ephemeris information, third indication information, and information of a seventh duration, where the third indication information is used to indicate a second time at which the fourth ephemeris information takes effect; a processing module 12, configured to perform cell handover, and start a fifth timer, where an end time of the fifth timer is determined by the second time and the seventh time, and a time period between the time of performing cell handover and the end time of the fifth timer is an eighth time period, where the eighth time period is a sum of the seventh time period and a third difference value when the time of performing cell handover is earlier than the second time, and where the eighth time period is a difference value between the seventh time period and the third difference value when the time of performing cell handover is later than the second time, and where the third difference value is an absolute value of the difference value between the time of performing cell handover and the second time.

In yet another possible implementation manner, the transceiver module 11 is configured to receive a fourth message from the network device, where the fourth message includes at least two ephemeris information, information of at least two durations, and fourth indication information, where the fourth indication information is used to indicate a time of validity of a first ephemeris information in the plurality of ephemeris information; a processing module 12, configured to use fifth ephemeris information when performing a cell handover, and the processing unit is further configured to determine an effective time of the fifth ephemeris information; the fifth ephemeris information is the nth ephemeris information in the at least two ephemeris information, and the effective time of the fifth ephemeris information is determined by the fourth system frame number and the third subframe number indicated by the fourth indication information and the N-1 time duration information corresponding to the N-1 ephemeris information before the fifth ephemeris information.

In yet another possible implementation manner, the transceiver module 11 is configured to receive dedicated signaling from a network device to which a serving cell belongs, where the dedicated signaling includes a system information block, and the system information block includes ephemeris information of the serving cell; a processing module 12, configured to determine that the system information block does not include information indicating an ephemeris information effective time of the serving cell; the processing module 12 is further configured to take an end time of a system message window SI window for scheduling the system information block as an effective time of ephemeris information of the serving cell, where the SI window is an SI window where the dedicated signaling is located or is an SI window adjacent to the dedicated signaling.

In yet another possible implementation manner, the transceiver module 11 is configured to receive dedicated signaling from a network device to which a serving cell belongs, where the dedicated signaling includes a system information block, and the system information block includes ephemeris information of the serving cell; a processing module 12, configured to determine that the system information block does not include information indicating an ephemeris information effective time of the serving cell; the transceiver module 11 is further configured to receive first information from a network device to which a serving cell belongs, the first information indicating a time of validity of ephemeris information of the serving cell, and the first information is not located in the system information block.

In yet another possible implementation manner, the transceiver module 11 is configured to receive a fifth message from a network device to which the serving cell belongs, where the fifth message includes ephemeris information of the serving cell and fifth indication information, where the fifth indication information is used to indicate a time of validity of the ephemeris information of the serving cell, and the fifth message includes ephemeris information of a neighboring cell and does not include information indicating a time of validity of the ephemeris information of the neighboring cell; and the processing module 12 is used for taking the effective time of the ephemeris information of the service cell as the effective time of the ephemeris information of the neighbor cell.

In yet another possible implementation manner, the transceiver module 11 is configured to receive a system information block from a network device to which a serving cell belongs, where the system information block includes ephemeris information of the serving cell and ephemeris information of a neighboring cell, and does not include information for indicating an effective time of the ephemeris information of the serving cell and information for indicating an effective time of the ephemeris information of the neighboring cell; and the processing module 12 is configured to take the end time of the system message window SI window for scheduling the system information block as the effective time of the ephemeris information of the serving cell and the effective time of the ephemeris information of the neighboring cell.

When the apparatus 10 is used for performing the method in fig. 5, the transceiver module 11 may be used for performing the steps of receiving and transmitting information in the method, as shown in step S510; the processing module 12 may be used to perform the processing steps in the method, as in steps S520 and S530.

When the apparatus 10 is used for performing the method in fig. 8, the transceiver module 11 may be used for performing the steps of receiving and transmitting information in the method, as shown in step S810; the processing module 12 may be used to perform the processing steps in the method, as in step S820.

When the apparatus 10 is used for performing the method in fig. 9, the transceiver module 11 may be used for performing the steps of receiving and transmitting information in the method, as shown in step S910; the processing module 12 may be used to perform the processing steps in the method, as step S920.

When the apparatus 10 is used for performing the method in fig. 10, the transceiver module 11 may be used for performing the steps of receiving and transmitting information in the method, as shown in step S1010; the processing module 12 may be used to perform the processing steps in the method, as step S1020.

When the apparatus 10 is used for performing the method in fig. 12, the transceiver module 11 may be used for performing the steps of receiving and transmitting information in the method, as shown in step S1210; the processing module 12 may be used to perform the processing steps in the method, as in step S1220.

When the apparatus 10 is used for performing the method in fig. 13, the transceiver module 11 may be used for performing the steps of receiving and transmitting information in the method, as shown in step S1310; the processing module 12 may be used to perform the processing steps in the method, as in step S1320.

It should be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

In another design, the apparatus 10 may correspond to the network device in the above method embodiment, or may be a component (e.g., a chip) of the network device.

The apparatus 10 may implement steps or processes performed by the network device in the above method embodiment, where the transceiver module 11 may be configured to perform operations related to the transceiver of the network device in the above method embodiment, and the processing module 12 may be configured to perform operations related to the processing of the network device in the above method embodiment.

In a possible implementation manner, the processing module 12 is configured to determine a third message, where the third message includes fourth ephemeris information, third indication information, and information of a seventh duration, where the third indication information is used to indicate a second time at which the fourth ephemeris information takes effect; and the transceiver module 11 is configured to send the third message to the terminal device. Wherein the second time is an absolute time.

When the apparatus 10 is used for performing the method in fig. 5, the transceiver module 11 may be used for performing the steps of receiving and transmitting information in the method, as shown in step S510; the processing module 12 may be used to perform processing steps in a method.

When the apparatus 10 is used for performing the method in fig. 8, the transceiver module 11 may be used for performing the steps of transceiving information in the method, as shown in step S810.

When the apparatus 10 is used for performing the method in fig. 9, the transceiver module 11 may be used for performing the steps of transceiving information in the method as shown in step S910.

When the apparatus 10 is used for performing the method in fig. 10, the transceiver module 11 may be used for performing the steps of transceiving information in the method, as shown in step S1010.

When the apparatus 10 is used for performing the method in fig. 12, the transceiver module 11 may be used for performing the steps of receiving and transmitting information in the method, as shown in step S1210.

When the apparatus 10 is used for performing the method in fig. 13, the transceiver module 11 may be used for performing the steps of transceiving information in the method, as shown in step S1310.

It should also be appreciated that the apparatus 10 herein is embodied in the form of functional modules. The term module herein may refer to an application specific integrated circuit (application specific integrated circuit, ASIC), an electronic circuit, a processor (e.g., a shared, dedicated, or group processor, etc.) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that support the described functionality. In an alternative example, it will be understood by those skilled in the art that the apparatus 10 may be specifically configured as a mobility management network element in the foregoing embodiments, and may be configured to perform each flow and/or step corresponding to the mobility management network element in the foregoing method embodiments; alternatively, the apparatus 10 may be specifically a terminal device in the foregoing embodiments, and may be configured to execute each flow and/or step corresponding to the terminal device in each foregoing method embodiment, so that repetition is avoided, and details are not repeated herein.

The apparatus 10 of each of the above embodiments has a function of implementing the corresponding steps performed by the devices (e.g., terminal device, network device) in the above method. The functions can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software comprises one or more modules corresponding to the functions; for example, the transceiver module may be replaced by a transceiver (e.g., a transmitting unit in the transceiver module may be replaced by a transmitter, a receiving unit in the transceiver module may be replaced by a receiver), and other units, such as a processing module, etc., may be replaced by a processor, to perform the transceiver operations and associated processing operations, respectively, in various method embodiments.

The transceiver module 11 may be a transceiver circuit (for example, may include a receiving circuit and a transmitting circuit), and the processing module may be a processing circuit.

Fig. 15 is a schematic diagram of another communication device 20 according to an embodiment of the present application. The apparatus 20 comprises a processor 21, the processor 21 being arranged to execute computer programs or instructions stored in a memory 22 or to read data/signalling stored in the memory 22 for performing the methods of the method embodiments above. Optionally, the processor 21 is one or more.

Optionally, as shown in fig. 15, the apparatus 20 further comprises a memory 22, the memory 22 being for storing computer programs or instructions and/or data. The memory 22 may be integrated with the processor 21 or may be provided separately. Optionally, the memory 22 is one or more.

Optionally, as shown in fig. 15, the apparatus 20 further comprises a transceiver 23, the transceiver 23 being used for receiving and/or transmitting signals. For example, the processor 21 is configured to control the transceiver 23 to receive and/or transmit signals.

As an alternative, the apparatus 20 is configured to implement the operations performed by the terminal device in the above method embodiments.

Alternatively, the apparatus 20 is configured to implement the operations performed by the network device in the method embodiments above.

It should be appreciated that the processors referred to in the embodiments of the present application may be central processing units (central processing unit, CPU), but may also be other general purpose processors, digital signal processors (digital signal processor, DSP), application specific integrated circuits (application specific integrated circuit, ASIC), off-the-shelf programmable gate arrays (field programmable gate array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should also be understood that the memories mentioned in the embodiments of the present application may be volatile memories and/or nonvolatile memories. The nonvolatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. The volatile memory may be random access memory (random access memory, RAM). For example, RAM may be used as an external cache. By way of example, and not limitation, RAM includes the following forms: static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous DRAM (SLDRAM), and direct memory bus RAM (DR RAM).

It should be noted that when the processor is a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, the memory (storage module) may be integrated into the processor.

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

Fig. 16 is a schematic diagram of a chip system 30 according to an embodiment of the present application. The system-on-chip 30 (or may also be referred to as a processing system) includes logic circuitry 31 and an input/output interface 32.

The logic circuit 31 may be a processing circuit in the chip system 30. Logic circuitry 31 may be coupled to the memory unit to invoke instructions in the memory unit so that system-on-chip 30 may implement the methods and functions of the various embodiments of the present application. The input/output interface 32 may be an input/output circuit in the chip system 30, and outputs information processed by the chip system 30, or inputs data or signaling information to be processed into the chip system 30 for processing.

As an alternative, the chip system 30 is configured to implement the operations performed by the terminal device in the above method embodiments.

For example, the logic circuit 31 is for implementing the processing-related operations performed by the terminal device in the above method embodiment; the input/output interface 32 is used to implement the transmission and/or reception related operations performed by the terminal device in the above method embodiments.

Alternatively, the system-on-chip 30 is configured to implement the operations performed by the network device in the various method embodiments above.

For example, the logic circuit 31 is configured to implement the operations related to the processing performed by the network device in the above method embodiment; the input/output interface 32 is used to implement the transmission and/or reception related operations performed by the network device in the above method embodiments.

The present application also provides a computer-readable storage medium having stored thereon computer instructions for implementing the method performed by the apparatus in the above-described method embodiments.

For example, the computer program when executed by a computer, enables the computer to implement the method performed by the terminal device or the network device in the embodiments of the method described above.

The embodiments of the present application also provide a computer program product, which contains instructions that, when executed by a computer, implement the method performed by the terminal device or the network device in the above method embodiments.

The embodiment of the application also provides a communication system which comprises the terminal equipment and the network equipment.

The explanation and beneficial effects of the related content in any of the above-mentioned devices can refer to the corresponding method embodiments provided above, and are not repeated here.

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

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. For example, the computer may be a personal computer, a server, or a network device, etc. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, optical fiber, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. For example, the aforementioned usable media include, but are not limited to, U disk, removable hard disk, read-only memory (ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other various media that can store program code.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of communication, comprising:

the method comprises the steps that a terminal device receives a first message from a network device, wherein the first message comprises an identification of a target cell, first ephemeris information corresponding to the target cell and first indication information, and the first indication information is used for indicating a frame number of a first system frame;

the terminal equipment acquires a frame number of a second system frame corresponding to the target cell;

and the terminal equipment determines a first effective time of the first ephemeris information according to whether the frame number of the first system frame and the frame number of the second system frame are the same.

2. The method of claim 1, wherein, in the case where the frame number of the first system frame and the frame number of the second system frame are the same, the first effective time of the first ephemeris information is a time determined based on the first system frame and the first subframe in a system frame period to which the second system frame belongs,

3. The method according to claim 2, wherein the method further comprises:

the terminal device performs cell handover and starts a first timer, the end time of which is determined by the first effective time and a first time length, the first time length is determined by information of a first time length included in the first message,

wherein the duration between the time of performing the cell handover and the end time of the first timer is a second duration,

4. The method of claim 1, wherein in the case where the frame number of the first system frame and the frame number of the second system frame are different, the method further comprises:

The terminal equipment determines that the first system frame is a system frame before the second system frame in a system frame period to which the second system frame belongs, and the first effective time of the first ephemeris information is a time determined based on the first system frame and the first subframe in the system frame period to which the second system frame belongs; or,

the terminal device determines that the first system frame is a system frame in a first system frame period, the first system frame period is a system frame period adjacent to a system frame period to which the second system frame belongs, a first effective time of the first ephemeris information is a time determined based on the first system frame and a first subframe in the first system frame period,

5. The method according to claim 4, wherein the method further comprises:

the terminal device performs cell handover and starts a second timer, the end time of which is determined by the first time of validity and a first time length, the first time length is determined by information of a first time length included in the first message,

The time length between the time of executing the cell switching and the end time of the second timer is a third time length, the third time length is a difference value between the first time length and a first difference value, and the first difference value is an absolute value of a difference value between the time of executing the cell switching and the first effective time.

6. The method of claim 1, wherein in the case where the frame number of the first system frame and the frame number of the second system frame are different, the method further comprises:

the terminal equipment determines that the first system frame is a system frame after the second system frame in a system frame period to which the second system frame belongs; or,

the terminal equipment determines that the first system frame is a system frame in a second system frame period, wherein the second system frame period is a next system frame period adjacent to the system frame period to which the second system frame belongs.

7. The method of claim 6, wherein the method further comprises:

the terminal equipment executes cell switching, and determines that the moment indicated by the first system frame is later than the moment of executing cell switching;

the terminal equipment acquires a system information block of the target cell, wherein the system information block comprises second ephemeris information and second indication information, and the second indication information is used for indicating a frame number of a third system frame and a frame number of a second subframe;

And the terminal equipment determines the second effective time of the second ephemeris information as the time determined by the third system frame and the second subframe.

8. The method of claim 7, wherein prior to the terminal device acquiring the system information block of the target cell, the method further comprises:

the terminal equipment determines that the time length required for acquiring the system information block of the target cell is smaller than a time length threshold; or,

the terminal device determines that the time difference between the first effective time and the time for executing the cell switching is greater than the time length required for acquiring the system information block of the target cell.

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

the terminal device performs a cell handover and starts a third timer, the end time of which is determined by the second effective time and a fourth time length, which is determined by information of a fourth time length included in the system information block,

wherein the duration between the time of performing the cell handover and the end time of the third timer is a fifth duration,

10. The method of claim 6, wherein the method further comprises:

the terminal equipment estimates third ephemeris information corresponding to the time of executing the cell switching according to the first ephemeris information when executing the cell switching, and starts a fourth timer, wherein the ending time of the fourth timer is determined by the first effective time and a first time length, the first time length is determined by the information of the first time length included in the first message,

11. The method according to any one of claims 1 to 10, wherein, in the case where the first message is used to instruct the terminal device to switch from a source cell to the target cell, the terminal device obtains a frame number of a second system frame corresponding to the target cell, including:

When the terminal equipment performs handover, the terminal equipment performs downlink synchronization with the target cell and acquires a master information block MIB of the target cell,

the MIB is configured to obtain a frame number of a second system frame corresponding to the target cell.

12. The method according to any one of claims 1 to 10, wherein, in the case that the first message further includes information of a handover condition, the terminal device obtains a frame number of a second system frame corresponding to the target cell, including:

when the terminal equipment receives the first message, carrying out downlink synchronization with the target cell and acquiring a Master Information Block (MIB) of the target cell, wherein the MIB is used for acquiring a frame number of a second system frame corresponding to the target cell; or,

the terminal equipment determines a timing difference between a source cell and the target cell, and determines a frame number of a second system frame corresponding to the target cell according to a third system frame carrying the first message and the timing difference.

13. The method of claim 12, wherein the terminal device determining a timing difference between the source cell and the target cell comprises:

The time difference is predefined; or,

the terminal equipment receives information indicating the timing difference from the network equipment; or,

the terminal equipment measures the signal of the target cell and determines the timing difference according to the measurement result; or,

the information of the handover condition indicates a time-based handover condition, the time-based handover condition including a first time, a system frame of a source cell corresponding to the first time and a system frame of a target cell corresponding to the first time being used to determine the timing difference.

14. The method of claim 13, wherein the frame number of the system frame of the target cell corresponding to the first time is carried in the first message; or,

the method further comprises the steps of:

the terminal equipment receives a second message from the network equipment, wherein the second message comprises the frame number of the system frame number of the target cell corresponding to the first time.

15. An apparatus for communication, comprising:

a receiving unit, configured to receive a first message from a network device, where the first message includes an identifier of a target cell, first ephemeris information corresponding to the target cell, and first indication information, where the first indication information is used to indicate a frame number of a first system frame;

The processing unit is used for acquiring the frame number of the second system frame corresponding to the target cell;

16. The apparatus of claim 15, wherein the first effective time of the first ephemeris information is a time determined based on the first system frame and the first subframe in a system frame period to which the second system frame belongs in the case that the frame number of the first system frame and the frame number of the second system frame are the same,

17. The apparatus of claim 16, wherein the processing unit is further configured to perform a cell handover and to start a first timer, an end time of the first timer being determined by the first time of validity and a first time length, the first time length being determined by information of a first time length included in the first message,

18. The apparatus of claim 15, wherein the processing unit is further configured to determine that the first system frame is a system frame preceding the second system frame in a system frame period to which the second system frame belongs, and wherein the first time of validity of the first ephemeris information is a time determined based on the first system frame and a first subframe in the system frame period to which the second system frame belongs, if the frame number of the first system frame and the frame number of the second system frame are different; or,

19. The apparatus of claim 18, wherein the processing unit is further configured to perform a cell handover and to start a second timer, an end time of the second timer being determined by the first time of validity and a first time length, the first time length being determined by information of a first time length included in the first message,

20. The apparatus of claim 15, wherein the processing unit is further configured to determine that the first system frame is a system frame subsequent to the second system frame within a system frame period to which the second system frame belongs, if the frame number of the first system frame and the frame number of the second system frame are different; or,

The processing unit is further configured to determine that the first system frame is a system frame in a second system frame period, where the second system frame period is a next system frame period adjacent to the system frame period to which the second system frame belongs.

21. The apparatus of claim 20, wherein the processing unit is further configured to perform a cell handover, and determine that the first system frame indicates a time that is later than the time at which the cell handover was performed;

the processing unit is further configured to obtain a system information block of the target cell, where the system information block includes second ephemeris information and second indication information, and the second indication information is used to indicate a frame number of a third system frame and a frame number of a second subframe;

22. The apparatus of claim 21, wherein the processing unit is further configured to determine that a time period required to acquire the system information block of the target cell is less than a time period threshold before the terminal device acquires the system information block of the target cell; or,

the processing unit is further configured to determine that a time difference between the first effective time and the time of performing the cell handover is greater than a time period required to acquire a system information block of the target cell.

23. The apparatus according to claim 21 or 22, wherein the processing unit is further configured to perform a cell handover and to start a third timer, the end time of which is determined by the second validation time and a fourth time length, which is determined by information of a fourth time length included in the system information block,

24. The apparatus of claim 20 wherein the processing unit is further configured to estimate, based on the first ephemeris information, third ephemeris information corresponding to a time of performing the cell handover and to start a fourth timer whose end time is determined by the first validity time and a first time period, the first time period being determined by information of a first time period included in the first message,

25. The apparatus according to any one of claims 15 to 24, wherein, in the case where the first message is used to instruct the terminal device to switch from a source cell to the target cell, the processing unit obtains a frame number of a second system frame corresponding to the target cell, including:

the processing unit performs downlink synchronization with the target cell and acquires a master information block MIB of the target cell when performing handover,

26. The apparatus according to any one of claims 15 to 24, wherein, in the case where the first message further includes information of a handover condition, the processing unit obtains a frame number of a second system frame corresponding to the target cell, including:

when the processing unit receives the first message, carrying out downlink synchronization with the target cell and acquiring a Master Information Block (MIB) of the target cell, wherein the MIB is used for acquiring a frame number of a second system frame corresponding to the target cell; or,

The processing unit determines a timing difference between a source cell and the target cell, and determines a frame number of a second system frame corresponding to the target cell according to a third system frame carrying the first message and the timing difference.

27. The apparatus of claim 26, wherein the processing unit determining a timing difference between the source cell and the target cell comprises:

the time difference is predefined; or,

the receiving unit receives information indicating the timing difference from the network device; or,

the processing unit measures the signal of the target cell and determines the timing difference according to the measurement result; or,

28. The apparatus of claim 27, wherein a frame number of a system frame of the target cell corresponding to the first time is carried in the first message; or,

the receiving unit is further configured to receive a second message from the network device, where the second message includes a frame number of a system frame number of the target cell corresponding to the first time.

29. A communication device, comprising:

a memory for storing a computer program;

a processor for executing a computer program stored in the memory to cause the communication device to perform the method of any one of claims 1 to 14.

30. A computer readable storage medium having stored therein computer instructions which, when run on a computer, perform the method of any of claims 1 to 14.

31. A computer program product, characterized in that the computer program product comprises instructions for performing the method of any of claims 1 to 14.