Communication method, apparatus and system

Abstract

Disclosed are a communication method, apparatus and system, which relate to the field of communications, and are used for ensuring the accuracy of mobility management executed by a terminal device. The method comprises: a terminal apparatus receiving mobility management configuration information, which is used for indicating a first parameter and a second parameter and is from a network apparatus corresponding to a source cell, and then executing mobility management on the basis of the mobility management configuration information, wherein the first parameter is a mobility management parameter based on positions, and the second parameter is a mobility management parameter based on signal quality. The solutions of the present application can be widely used in the technical fields of communication, and fields such as artificial intelligence, Internet of vehicles, smart home networking.

Description

Communication method, device and system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on February 8, 2024, with application number 202410178313.X and application name “A communication method, device and system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and in particular to a communication method, device, and system. Background Art

[0003] The integration of satellite communication networks and terrestrial fifth-generation (5G) mobile communication technology networks can provide ubiquitous coverage regardless of terrain, connecting multiple dimensions of space: air, space, land, and sea, forming an integrated ubiquitous access network and enabling on-demand access in all scenarios. Compared to terminal devices, satellite communication equipment (i.e., communication equipment deployed on satellites) is in high-speed motion. Therefore, the cells providing services to terminal devices can change rapidly. To ensure service continuity for terminal devices, satellite communication networks frequently trigger terminal devices to perform mobility management, such as cell handover or cell reselection.

[0004] Therefore, how to ensure the accuracy of mobility management performed by terminal devices has become an urgent problem to be solved. Summary of the Invention

[0005] The embodiments of the present application provide a communication method, apparatus, and system to ensure the accuracy of mobility management performed by terminal devices.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, embodiments of the present application provide a communication method that can be executed by a terminal device and a functional module or chip within the terminal device. Taking execution by the terminal device as an example, the method includes: the terminal device receiving mobility management configuration information from a network device corresponding to a source cell, and performing mobility management based on the mobility management configuration information. The mobility management configuration information indicates a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; and the second parameter is a signal quality-based mobility management parameter.

[0008] Based on the method described in the first aspect, the terminal device can flexibly perform mobility management based on the received mobility management configuration information. For example, during long-term communication connections, the terminal device can perform location-based mobility management or signal quality-based mobility management based on the instructions of the mobility management configuration information to select a target cell for access, thereby increasing the probability of accessing a suitable target cell.

[0009] In one possible design, the terminal device performs mobility management based on the mobility management configuration information, including: performing mobility management based on a first parameter when global navigation satellite system (GNSS) measurement information is valid; and performing mobility management based on a second parameter when the GNSS measurement information is invalid and within a first time period. The terminal device uplink transmission is valid within the first time period.

[0010] Based on this possible design, the terminal device can determine the method of performing mobility management according to the validity of the GNSS measurement information, so that the terminal device can adopt different methods to perform mobility management in different communication scenarios, thereby improving the accuracy of the terminal device in performing mobility management.

[0011] In one possible design, when the GNSS measurement information fails and within the first time period, the terminal device performs mobility management based on the second parameter, including: obtaining the accumulated timing advance (TA) of the source cell, and performing mobility management based on the accumulated TA of the source cell.

[0012] Based on this possible design, the terminal device can perform mobility management to achieve uplink synchronization based on the accumulated TA of the source cell, so that the terminal device no longer needs to re-acquire GNSS measurement information to achieve uplink synchronization, reducing the time required to perform mobility management.

[0013] In one possible design, the first duration is the effective duration of a timing advance command (TAC), or the first duration is a portion of the effective duration of the TAC.

[0014] Based on this possible design, different durations to which the first duration can correspond are given, so that the terminal device can flexibly determine the first duration in different communication scenarios, thereby improving the utilization rate of this solution.

[0015] In one possible design, the terminal device sends a request message to the network device corresponding to the target cell, and correspondingly receives a first response message from the network device corresponding to the target cell. The request message is used to request configuration of GNSS measurement, and the first response message is used to trigger GNSS measurement.

[0016] Based on this possible design, after accessing the target cell, the terminal device can perform GNSS measurements based on the GNSS measurement configuration of the target cell's corresponding network device. This eliminates the need for the terminal device to perform GNSS measurements before accessing the target cell, ensuring the timeliness of neighboring cell measurements and reducing the latency of accessing the target cell.

[0017] In one possible design, the request message is carried in a message (message3, MSG3) or a radio resource control (radio resource control, RRC) connection establishment request.

[0018] Based on this possible design, messages that can carry request messages in different communication scenarios are provided. Specifically, during a terminal device's cell handover, the request message can be carried in a radio resource control connection establishment request; during a terminal device's cell reselection, the request message can be carried in MSG3. In this way, different messages are used to carry request messages in different scenarios, allowing for flexible and diverse application of this solution in various communication scenarios, improving its utilization.

[0019] In one possible design, the first response message is carried in downlink data. Based on this possible design, the terminal device can obtain the response message through the downlink data. For example, the downlink data is a message (message4, MSG4).

[0020] In one possible design, the terminal device releases the information configured for it by the source cell in the terminal device and starts a first timer. The running time of the first timer corresponds to the remaining valid time of the TAC.

[0021] Based on this possible design, the terminal device can determine the validity of the first duration by the running time of the first timer when the first duration is part of the valid duration of the TAC, thereby adding an available method for the terminal device to determine the validity of the first duration and improving the utilization rate of the solution.

[0022] In one possible design, the terminal device sends the remaining running time of the first timer to the network device corresponding to the target cell. Based on this possible design, when the running time of the first timer corresponds to the remaining valid time of the TAC, the terminal device sends the remaining running time of the first timer to the network device corresponding to the target cell to trigger a response from the network device corresponding to the target cell.

[0023] In one possible design, after the terminal device sends the remaining running time of the first timer to the network device corresponding to the target cell, it receives a second response message from the network device corresponding to the target cell, and the second response message is used to trigger GNSS measurement; or, it receives a TAC from the network device corresponding to the target cell, and the TAC is used to extend the duration of the uplink transmission; or, when the first moment arrives, it performs GNSS measurement; the first moment is determined according to the moment when the remaining running time of the first timer is sent.

[0024] Based on this possible design, various possible information that a terminal device may receive after sending the remaining duration of the first timer to the network device corresponding to the target cell is provided, allowing the terminal device to perform corresponding operations based on the received information. For example, upon receiving the second response message, the terminal device may perform a GNSS measurement.

[0025] In one possible design, the terminal device reports the time required to perform GNSS measurement to the network device corresponding to the target cell; after the time required to perform GNSS measurement, the terminal device receives uplink scheduling resources from the network device corresponding to the target cell; and sends indication information to the network device corresponding to the target cell on the uplink scheduling resources, where the indication information is used to indicate the valid duration of the GNSS measurement information.

[0026] Based on this possible design, the terminal device can report the time required to perform GNSS measurement and the validity period of the GNSS measurement information to the network device corresponding to the target cell, so that the network device corresponding to the target cell can obtain relevant information about the GNSS measurement and ensure the validity of the relevant information about the GNSS measurement in the network device corresponding to the target cell.

[0027] In one possible design, the indication information is carried in a message (message 5, MSG5). Based on this possible design, the terminal device can send indication information indicating the validity period of the GNSS measurement information to the network device corresponding to the target cell in MSG5, so that the network device corresponding to the target cell receives the validity period of the GNSS measurement information.

[0028] In a second aspect, an embodiment of the present application provides a communication method, which can be executed by a network device corresponding to a source cell and a functional module or chip within the network device corresponding to the source cell. Taking the execution by the network device corresponding to the source cell as an example, the method includes: obtaining mobility management configuration information; the mobility management configuration information is used to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; the second parameter is a signal quality-based mobility management parameter; and sending the mobility management configuration information.

[0029] Based on the method described in the second aspect, the network device corresponding to the source cell sends the mobility management configuration information to the terminal device, so that the terminal device can flexibly perform mobility management according to the mobility management configuration information.

[0030] In a third aspect, an embodiment of the present application provides a communication method, which can be executed by a network device corresponding to a target cell and a functional module or chip within the network device corresponding to the target cell. Taking the execution by the network device corresponding to the target cell as an example, the method includes: receiving a request message for requesting configuration of GNSS measurement, and sending a response message for triggering the execution of GNSS measurement.

[0031] Based on the method described in the third aspect, the network device corresponding to the target cell can send a first response message to the terminal device it serves to perform GNSS measurement based on the received request message, so that the terminal device accessing the target cell does not need to perform GNSS measurement before accessing the target cell, thereby reducing the delay for the terminal device to access the target cell.

[0032] In one possible design, the request message is carried in MSG3 or RRC connection establishment request.

[0033] Based on this possible design, messages that can carry request messages in different communication scenarios are provided. Specifically, during a terminal device's cell handover, the request message can be carried in a radio resource control connection establishment request; during a terminal device's cell reselection, the request message can be carried in MSG3. In this way, different messages are used to carry request messages in different scenarios, allowing for flexible and diverse application of this solution in various communication scenarios, improving its utilization.

[0034] In one possible design, the first response message is carried in downlink data. Based on this possible design, the network device corresponding to the target cell can send the first response message via downlink data. For example, the downlink data is a message (message4, MSG4).

[0035] In one possible design, the network device corresponding to the target cell receives the remaining running time of the first timer, and the running time of the first timer corresponds to the remaining valid time of the TAC.

[0036] Based on this possible design, when the running time of the first timer corresponds to the remaining valid time of the TAC, the network device corresponding to the target cell can receive the remaining running time of the first timer from the terminal device, triggering the network device corresponding to the target cell to send a possible response to the terminal device.

[0037] In one possible design, after the network device corresponding to the target cell receives the remaining running time of the first timer, it sends a second response message, and the second response message is used to trigger the execution of GNSS measurement; or, it sends TAC, and TAC is used to extend the duration of uplink transmission.

[0038] Based on this possible design, various possible information that the network device corresponding to the target cell can send after receiving the remaining duration of the first timer is provided, so that the terminal device can perform corresponding operations based on the received information. For example, after receiving the second response message, the terminal device can perform GNSS measurement.

[0039] In one possible design, the network device corresponding to the target cell receives the time required for GNSS measurement from the terminal device; after performing the time required for GNSS measurement, sends uplink scheduling resources to the terminal device; and receives indication information from the terminal device on the uplink scheduling resources, where the indication information is used to indicate the effective duration of the GNSS measurement.

[0040] Based on this possible design, the network device corresponding to the target cell can receive the time required for the terminal device to perform GNSS measurement and the effective duration of the GNSS measurement information, so that the network device corresponding to the target cell can obtain the relevant information of the GNSS measurement and ensure the validity of the relevant information of the GNSS measurement in the network device corresponding to the target cell.

[0041] In one possible design, the indication information is carried in MSG 5. Based on this possible design, the network device corresponding to the target cell can receive the indication information indicating the valid duration of the GNSS measurement information in MSG 5.

[0042] In a fourth aspect, the present application provides a communication device, which may be a terminal device or a chip or system on chip in a terminal device, or a functional module in a terminal device for implementing the method in the first aspect or any possible design of the first aspect. The communication device can implement the functions performed by the terminal device in the above-mentioned first aspect or any possible design of the first aspect, and the functions can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions. For example, the communication device may include a transceiver unit and a processing unit. Among them,

[0043] A transceiver unit, configured to receive mobility management configuration information; the mobility management configuration information is used to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; the second parameter is a signal quality-based mobility management parameter;

[0044] The processing unit is configured to perform mobility management according to the mobility management configuration information.

[0045] Specifically, the execution actions of each unit of the communication device can refer to the first aspect or any possible design of the first aspect, and will not be repeated here.

[0046] In a fifth aspect, the present application provides a communication device, which may be a network device corresponding to a source cell or a chip or system on chip in a network device corresponding to a source cell, or a functional module in a network device corresponding to a source cell for implementing the second aspect or any possible design of the second aspect. The communication device may implement the functions performed by the network device corresponding to the source cell in the above-mentioned second aspect or any possible design of the second aspect, and the functions may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions. For example, the communication device may include a processing unit and a transceiver unit. Among them,

[0047] A processing unit, configured to obtain mobility management configuration information; the mobility management configuration information is used to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; the second parameter is a signal quality-based mobility management parameter;

[0048] The transceiver unit is used to send mobility management configuration information.

[0049] Specifically, the execution actions of each unit of the communication device can refer to the second aspect or any possible design of the second aspect, and will not be repeated here.

[0050] In a sixth aspect, the present application provides a communication device, which may be a network device corresponding to a target cell or a chip or system on chip in a network device corresponding to a target cell, or a functional module in a network device corresponding to a target cell for implementing the third aspect or any possible design of the third aspect. The communication device may implement the functions performed by the network device corresponding to the target cell in the third aspect or any possible design of the third aspect, and the functions may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. For example, the communication device may include a transceiver unit. Among them,

[0051] A transceiver unit, configured to receive a request message; the request message is used to request configuration of a GNSS measurement;

[0052] The transceiver unit is further configured to send a first response message; the first response message is used to trigger the execution of GNSS measurement.

[0053] Specifically, the execution actions of each unit of the communication device can refer to the third aspect or any possible design of the third aspect, and will not be repeated here.

[0054] In a seventh aspect, the present application provides a communication device. In one possible design, the communication device includes a processor and a communication interface. The processor and the communication interface are used to support the communication device to execute the communication method in the first aspect or any possible design of the first aspect, or the processor and the communication interface are used to support the communication device to execute the communication method in the second aspect or any possible design of the second aspect, or the processor and the communication interface are used to support the communication device to execute the communication method in the third aspect or any possible design of the third aspect. In another possible design, the communication device may further include a memory, which is used to store computer-executable instructions and data necessary for the communication device. When the communication device is running, the processor executes the computer-executable instructions stored in the memory, so that the communication device executes the communication method as described in the first aspect or any possible design of the first aspect, or so that the communication device executes the communication method as described in the second aspect or any possible design of the second aspect, so that the communication device executes the communication method as described in the third aspect or any possible design of the third aspect.

[0055] In an eighth aspect, the present application provides a communication system, which includes the communication device provided by the fourth aspect and the communication device provided by the fifth aspect; or, the communication system includes the communication device provided by the fourth aspect and the communication device provided by the seventh aspect; or, the communication system includes the communication device provided by the fifth aspect and the communication device provided by the seventh aspect; or, the communication system includes the communication device provided by the fourth aspect and the communication device provided by the sixth aspect; or, the communication system includes the communication device provided by the sixth aspect and the communication device provided by the seventh aspect; or, the communication system includes the communication device provided by the fourth aspect, the communication device provided by the fifth aspect, and the communication device provided by the sixth aspect; or, the communication system includes the communication device provided by the fourth aspect, the communication device provided by the fifth aspect, and the communication device provided by the seventh aspect; or, the communication system includes the communication device provided by the fourth aspect, the communication device provided by the sixth aspect, and the communication device provided by the seventh aspect; or, the communication system includes the communication device provided by the fifth aspect, the communication device provided by the sixth aspect, and the communication device provided by the seventh aspect.

[0056] In the ninth aspect, the present application provides a computer-readable storage medium, which stores computer instructions. When the computer instructions are run on a computer, the computer executes the first aspect or any possible communication method in the design of the first aspect; or, the computer executes the second aspect or any possible communication method in the design of the second aspect; or, the computer executes the third aspect or any possible communication method in the design of the third aspect.

[0057] In the tenth aspect, the present application provides a computer program product, which includes computer instructions. When the computer instructions are run on a computer, the computer executes the communication method in the first aspect or any possible design of the first aspect; or, the computer executes the communication method in the second aspect or any possible design of the second aspect; or, the computer executes the communication method in the third aspect or any possible design of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] FIG1 is a schematic diagram of a communication system provided in an embodiment of the present application;

[0059] FIG2 is a schematic diagram of a satellite communication system provided in an embodiment of the present application;

[0060] FIG3 is a flow chart of a communication method provided in an embodiment of the present application;

[0061] FIG4 is a schematic diagram of a TAC process;

[0062] FIG5 is a flow chart of a communication method provided in an embodiment of the present application;

[0063] FIG6 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0064] FIG7 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0065] FIG8 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0066] FIG9 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0067] Before introducing the embodiments of the present application, some technical terms involved in the embodiments of the present application are explained. It should be noted that the following explanations are intended to make the embodiments of the present application easier to understand and should not be regarded as limiting the scope of protection claimed by the embodiments of the present application.

[0068] Mobility management manages the location, security, and service continuity of mobile devices, ensuring optimal connectivity between them and the network, thereby guaranteeing the availability of various network services. In New Radio (NR), mobility management can be categorized into two types: connected mobility management and idle / deactivated mobility management. Connected mobility management includes cell handovers. Idle / deactivated mobility management includes cell reselection.

[0069] Cell handover refers to the movement of a terminal device from one cell to another while it is connected and maintaining data transmission services, or when the original serving cell (or source cell) no longer provides services to the terminal due to factors such as wireless transmission service load adjustment, activation operation maintenance, and equipment failure. In order to maintain data transmission services and service quality, the radio bearer system will search for the most suitable cell (or target cell) or network to continue to provide uninterrupted services to the terminal device, thereby achieving mobility management with seamless wireless network coverage. When the terminal device is in a connected state, a connection is established between the terminal device and the network equipment (e.g., access network equipment, core network equipment), enabling data transmission at any time. Cell handover includes conditional handover (CHO). When performing conditional handover, the terminal device selects any cell that meets the handover conditions as the target cell based on its own measurement results and sends a random access request to the target cell.

[0070] Cell reselection refers to the process of regularly evaluating the signal quality of multiple cells when the terminal device is in an idle state / deactivated state, selecting a cell with the best signal quality for communication, and ensuring that the signal quality of the cell serving the terminal device meets the communication requirements. When the terminal device is in an idle state / deactivated state, it has not yet established a connection with the network device and cannot transmit data. After the cell reselects the cell with the best signal quality, it can access the cell with the best signal quality for data transmission. Cell reselection can also replace the cell reselection described as radio link failure (RLF).

[0071] With the development of information technology, there are increasingly urgent demands for efficient, mobile, and diverse communications. Currently, a key development focus in the communications system field is global mobile communications, and satellite communications are a crucial component of mobile communications. Satellite communications play an irreplaceable role in key areas such as space communications and aeronautical communications. Satellite communications offer long communication distances, wide coverage areas, and flexible networking. They can serve both fixed and mobile devices. In satellite communications, location-based mobility management can be implemented for short-term connected devices. For example, the device acquires global navigation satellite system (GNSS) measurement information and sends a random access request to the network device based on the GNSS measurement information and the network device's location information. After the device completes connecting to the network device and sending uplink data to it, it disconnects from the network device, exiting the connected state and entering the idle state. During this process, the GNSS measurement information acquired by the device remains valid until the device exits the connected state.

[0072] For terminal devices that are connected for a long time, the terminal device needs to perform at least one GNSS measurement to ensure continuous communication services. Since the terminal device is in a connected state for a long time, the position of the terminal device will change, causing the GNSS measurement information obtained by the terminal device before sending the random access request to become invalid. Therefore, the terminal device needs to re-acquire the GNSS measurement information before exiting the connected state to ensure the validity of the GNSS measurement information, and then perform location-based mobility management based on the newly measured GNSS measurement information. However, the terminal device re-acquires the GNSS measurement information, which increases the power consumption of the terminal device and also increases the time it takes for the terminal device to perform mobility management. Another possible scenario is that before exiting the connected state, the terminal device receives a timing advance command (TAC) sent from the network device to extend the uplink transmission time of the terminal device. During the effective time of the TAC, the terminal device performs mobility management based on signal quality. However, when the terminal device performs mobility management based on signal quality, there is a problem of not being able to switch to or reselect a suitable cell.

[0073] For example, in satellite communications, the terminal device of the narrowband internet of things (NB-IoT) measures the signal quality of the source cell and determines that the communication quality provided by the source cell is unacceptably poor and cannot be improved by cell switching. In this case, the NB-IoT terminal device disconnects from the source cell, causing its own connection state to change from the connected state to the idle state, triggering cell reselection based on signal quality. That is, the NB-IoT terminal device measures the signal quality of the neighboring cells and selects the cell with the best signal quality from the measured neighboring cells as the target cell for access; further, the NB-IoT terminal device performs GNSS measurement to obtain valid GNSS measurement information, determines the timing advance (TA) based on the GNSS measurement information and the satellite ephemeris information corresponding to the target cell, and sends a random access request to the target cell based on the TA. At this time, a long time has passed since the NB-IoT terminal device measured the signal quality of the neighboring cell. The measured signal quality results of the neighboring cells have become invalid. The target cell may no longer be the cell with the best signal quality among the neighboring cells, causing the NB-IoT terminal device to access an inappropriate cell; or, the NB-IoT terminal device still sends a random access request to the target cell according to the determined TA, resulting in access failure; or, after the NB-IoT terminal device accesses the target cell, it is measured that the communication quality provided by the target cell is still poor, and cell switching is required, which introduces additional power consumption overhead.

[0074] To ensure the accuracy of mobility management performed by a terminal device, the present application provides a communication method, comprising: a terminal device receiving mobility management configuration information indicating a first parameter and a second parameter from a network device corresponding to a source cell, and performing mobility management according to the mobility management configuration information; the first parameter is a location-based mobility management parameter; the second parameter is a signal quality-based mobility management parameter. In this way, the terminal device can perform location-based mobility management or signal quality-based mobility management according to the indication of the mobility management configuration information, flexibly select a target cell for access, and increase the probability of accessing a suitable target cell.

[0075] The communication method provided in the embodiments of the present application is described below with reference to the accompanying drawings.

[0076] The technical solutions of the embodiments of the present application can be used in various communication systems, which may be a third generation partnership project (3GPP) communication system, such as a long term evolution (LTE) system, or a fifth generation (5G) mobile communication system, a new air interface system, a satellite communication system, a new air interface vehicle network (NR V2X) system, and can also be applied to a system of LTE and 5G hybrid networking, or a device-to-device (D2D) communication system, a machine-to-machine (M2M) communication system, the Internet of Things (IoT), and other next-generation communication systems, and may also be a non-3GPP communication system without limitation.

[0077] The technical solutions of the embodiments of the present application can be applied to various communication scenarios, for example, one or more of the following communication scenarios: enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), machine type communication (MTC), massive machine type communication (mMTC), D2D, V2X, and IoT communication scenarios. The technical solutions of the embodiments of the present application can also be applied to long-distance communication scenarios, such as satellite communication scenarios where the distance between a terminal device and a network device is constantly changing, or other long-distance communication scenarios, without limitation.

[0078] Figure 1 is a structural diagram of a communication system provided in an embodiment of the present application. As shown in Figure 1, the communication system may include a terminal device, a network device corresponding to a source cell, and a network device corresponding to a target cell. The terminal device in Figure 1 may be a communication device with a wireless communication function, such as a terminal device that cannot communicate and measure at the same time (for example, a terminal device of IoT). The network device corresponding to the source cell in Figure 1 is a communication device that provides services for the terminal device. The network device corresponding to the target cell is a communication device that replaces the network device corresponding to the source cell to provide services for the terminal device. The network device corresponding to the source cell can be referred to as a source communication device, and the network device corresponding to the target cell can be referred to as a target communication device.

[0079] It should be understood that the network device corresponding to the source cell in Figure 1 and the network device corresponding to the target cell may be the same or different. For example, when a cell handover occurs between different cells of the same network device, the network device corresponding to the source cell and the network device corresponding to the target cell are the same network device. When a cell handover occurs between cells of different network devices, the network device corresponding to the source cell and the network device corresponding to the target cell are different network devices. In the case where the network device corresponding to the source cell and the network device corresponding to the target cell are different network devices, a direct communication link may be established between the network device corresponding to the source cell and the network device corresponding to the target cell, or there may be no direct communication link, without limitation.

[0080] It is understood that FIG1 is merely a schematic diagram and does not limit the applicable scenarios of the technical solutions provided in this application. Those skilled in the art should understand that, in a specific implementation, the communication system shown in FIG1 may include fewer devices than shown in FIG1 , or the communication system shown in FIG1 may include other devices. The number of devices in the communication system shown in FIG1 may also be determined based on specific needs and is not limited. The devices in the system shown in FIG1 are described below.

[0081] In the present application, the communication system shown in Figure 1 can be a satellite communication system. For example, it can be the satellite communication system shown in Figure 2. As shown in Figure 2, the satellite communication system may include: a terminal, a source satellite base station, a target satellite base station, a ground station, a user plane processing unit, a control plane processing unit, a data network, an air interface, an Xn interface, and a next generation (NG) interface. Among them, the air interface includes various types of air interfaces (such as 5G air interfaces), and the control plane processing unit includes an access mobility management function and a session management function. As shown in Figure 2, the terminal is connected to the source satellite base station and the target satellite base station through the air interface, the source satellite base station is connected to the ground station through the NG interface, the ground station is connected to the user plane processing unit through the NG interface, and the ground station is connected to the control plane processing unit through the NG interface. At the same time, when there is an available wireless link between the source satellite base station and the target satellite base station, the source satellite base station and the target satellite base station can complete the signaling interaction and user data transmission between the base stations through the Xn interface.

[0082] In this application, a satellite base station is a base station deployed on a satellite. The type of base station deployed on the satellite is not limited. It can be a 5G base station, or a base station in a future evolved communication system, etc. This application takes a 5G base station as an example for illustration, where the satellite base station can be alternatively described as a 5G base station deployed on a satellite, or a satellite access network device, or a satellite access network device or a satellite communication device, etc., without limitation.

[0083] The terminal may be an IoT terminal, which can be divided into terminals that support both cell switching and cell reselection (for example, enhanced machine-type communication (eMTC) terminals) according to the terminal capabilities, or terminals that support cell reselection but not cell switching (for example, NB-IoT terminals). IoT terminal devices in satellite communications are terminal devices that support access to IoT services (for example, eMTC terminal devices and NB-IoT terminal devices).

[0084] The source satellite base station is the network device corresponding to the source satellite cell providing services to the terminal. The source satellite base station includes satellite cell 1 and satellite cell 2. Satellite cell 2 is the satellite cell providing services to the terminal and may also be referred to as the source satellite cell. Satellite cell 1 and satellite cell 2 are the areas covered by the source satellite base station. The source satellite base station can provide services to the terminal within both satellite cell 1 and satellite cell 2.

[0085] The target satellite base station is the network device corresponding to the target satellite cell that takes over service from the source satellite cell for the terminal. The target satellite base station includes satellite cell 3 and satellite cell 4, which are candidate target satellite cells that take over service from the source satellite cell for the terminal. Satellite cell 3 and satellite cell 4 represent the areas covered by the target satellite base station. The target satellite base station can provide service to the terminal within satellite cell 3 and satellite cell 4.

[0086] The terminal device involved in this application can be terminal equipment or a functional module / chip in the terminal equipment, or it can be user equipment (UE), mobile station (MS), or mobile terminal (MT), etc. Specifically, the terminal can be a mobile phone, tablet computer, or computer with wireless transceiver function, and can also be a virtual reality (VR) terminal, augmented reality (AR) terminal, wireless terminal in industrial control, wireless terminal in unmanned driving, wireless terminal in telemedicine, wireless terminal in smart grid, wireless terminal in smart city, smart home, vehicle-mounted terminal, etc.

[0087] The network device involved in the present application can be an access network device or a functional module / chip in the access network device. It is a device in the radio access network (RAN) that connects the terminal to the wireless network. The RAN can be connected to the core network (for example, it can be the core network of LTE or the core network of 5G). The access network device can be a satellite base station (or flying platform) in a non-terrestrial network (NTN) scenario, an evolutionary Node B (eNB or eNodeB) in LTE, or a base station in a 5G network or a future evolved public land mobile network (PLMN), a broadband network gateway (BNG), an aggregation switch or a non-3GPP access device; or the access network device in the embodiment of the present application can also be a wireless controller in a cloud radio access network (CRAN); or a transmission and reception point (TRP), or a device including a TRP, etc., which is not specifically limited in the embodiment of the present application. Optionally, the base station in the embodiment of the present application may include various forms of base stations, such as: macro base stations, micro base stations (also called small stations), relay stations, access points, etc., and the embodiment of the present application does not make specific limitations on this.

[0088] The network device in the embodiment of the present application can be mounted or deployed on a flight platform, such as a low-altitude flight platform, a high-altitude flight platform, or a satellite. When the network device is mounted on the flight platform, the network device moves synchronously with the flight platform.

[0089] Optionally, each device in Figure 1 (such as a terminal device, a network device corresponding to the source cell, and a device corresponding to the target cell) can also be referred to as a communication device, which can be a general device or a dedicated device. The embodiments of the present application do not make specific limitations on this.

[0090] Optionally, the related functions of each device in FIG1 of the present application can be implemented by a single device, or by multiple devices together, or by one or more functional modules within a single device, and the embodiments of the present application do not specifically limit this. It is understood that the above functions can be network elements in a hardware device, software functions running on dedicated hardware, or a combination of hardware and software, or virtualized functions instantiated on a platform (e.g., a cloud platform).

[0091] The following describes the communication method provided in the embodiments of the present application in conjunction with the communication system shown in Figure 1. The actions and terms involved in the following embodiments can be referenced to each other. The names of messages exchanged between devices in each embodiment or the names of parameters in the messages are only examples, and other names can also be used in specific implementations. For example, the word "corresponding" in the following embodiments can be replaced by "associating", and the word "sending" in the following embodiments can be replaced by "transmitting".

[0092] FIG3 is a flow chart of a communication method provided in an embodiment of the present application. As shown in FIG3 , the method may include steps S301 to S303:

[0093] S301: A network device obtains mobility management configuration information.

[0094] The network device may be a network device corresponding to a source cell of the terminal device.

[0095] The network device may actively obtain the mobility configuration information from a local location. For example, the network device periodically obtains the mobility configuration information from a local location.

[0096] The mobility management configuration information is used to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter, and the second parameter is a signal quality-based mobility management parameter. The location-based mobility management parameter may include, but is not limited to, a location threshold corresponding to a location-based handover condition, and the signal quality-based mobility management parameter may include, but is not limited to, a signal quality threshold corresponding to a signal quality-based handover condition.

[0097] The location threshold may include one location threshold or two different location thresholds, and the signal quality threshold may include one signal quality threshold or two different signal quality thresholds.

[0098] Exemplarily, in a case where the location threshold includes a location threshold and the signal quality threshold includes a signal quality threshold, the location-based switching condition may include but is not limited to the relative position between the terminal device and the source cell being greater than the location threshold, and / or the relative position between the terminal device and the target cell being less than or equal to the location threshold. The signal quality-based switching condition may include but is not limited to the signal quality of the source cell being less than the signal quality threshold, and / or the signal quality of the target cell being greater than or equal to the signal quality threshold.

[0099] Exemplarily, in the case where the location threshold includes two different location thresholds and the signal quality threshold includes two different signal quality thresholds, wherein one location threshold corresponds to the location threshold between the terminal device and the source cell, the other location threshold corresponds to the location threshold between the terminal device and the target cell, and the location threshold between the terminal device and the source cell is greater than the location threshold between the terminal device and the source cell. wherein one signal quality threshold corresponds to the signal quality threshold between the terminal device and the source cell, the other signal quality threshold corresponds to the signal quality threshold between the terminal device and the target cell, and the signal quality threshold between the terminal device and the source cell is less than the signal quality threshold between the terminal device and the source cell.

[0100] It should be understood that in the present application, when the mobility management is cell switching, the above-mentioned location-based switching condition can be replaced by a description of a location-based cell switching condition, and the location-based cell switching condition can be used to perform cell switching based on location. The above-mentioned signal quality-based switching condition can be replaced by a description of a signal quality-based cell switching condition, and the signal quality-based cell switching condition can be used to perform cell reselection based on signal quality. When the mobility management is cell reselection, the above-mentioned location-based switching condition can be replaced by a description of a location-based cell reselection measurement condition, and the location-based cell reselection measurement condition can be used to perform cell reselection based on location. The above-mentioned signal quality-based switching condition can be replaced by a description of a signal quality-based cell reselection measurement condition, and the signal quality-based cell reselection measurement condition can be used to perform cell reselection based on location.

[0101] Optionally, the mobility management configuration information may further include configuration information of a candidate target cell configured by the source cell for the terminal device, which can replace the source cell in providing services to the terminal device, such as location information of the candidate target cell, radio resource configuration parameters (e.g., reference signal) of the candidate target cell, etc. Specifically, the candidate target cell may include one or more. The process of the source cell configuring the candidate target cell for the terminal device can refer to the existing technology and will not be described in detail.

[0102] S302: The network device sends mobility management configuration information, and the terminal device receives the mobility management configuration information.

[0103] The network device may send the mobility management configuration information via a broadcast message or radio resource control (RRC) signaling.

[0104] The network device may proactively send the mobility management configuration information to the terminal device. For example, the network device may periodically send the mobility management configuration information to the terminal device. Alternatively, the network device may trigger the sending of the mobility management configuration information to the terminal device. For example, upon receiving a request message from the terminal device requesting the mobility management configuration information, the network device may send the mobility management configuration information to the terminal device.

[0105] It should be understood that when the terminal device performs cell reselection, the network device corresponding to the source cell will send mobility management configuration information to the terminal device before the terminal device disconnects from it, so that the terminal device can select the target cell to access based on the received mobility management configuration information in an idle state.

[0106] Optionally, after receiving the mobility management configuration information, the terminal device may store the mobility management configuration information locally. In this way, when performing mobility management, the terminal device can quickly obtain the mobility management configuration information and perform mobility management based on the mobility management configuration information.

[0107] S303: The terminal device performs mobility management according to the mobility management configuration information.

[0108] Optionally, the terminal device may obtain GNSS measurement information and perform mobility management according to the validity of the GNSS measurement information and the mobility management configuration information. The validity of the GNSS measurement information may include whether the GNSS measurement information is valid or invalid.

[0109] In the present application, the GNSS measurement information being valid means that the terminal device can achieve uplink synchronization through the GNSS measurement information.

[0110] In one example, the terminal device performs mobility management based on the first parameter when the GNSS measurement information is valid.

[0111] Optionally, the terminal device performing mobility management based on the first parameter may include:

[0112] The terminal device determines a target cell based on the location threshold, the location-based handover condition, the relative location between the terminal device and the source cell, and the relative location between the terminal device and the candidate target cell, and further sends a random access request to the target cell.

[0113] Specifically, the terminal device may determine whether the relationship between the relative position between the terminal device and the source cell and the position threshold satisfies the position-based switching condition. If the relative position between the terminal device and the source cell satisfies the position-based switching condition, the terminal device may determine whether the relationship between the relative position between the terminal device and the candidate target cell reference point and the position threshold satisfies the position-based switching condition, determine the target cell from the candidate target cell that satisfies the position-based switching condition, and send a random access request to the target cell. If the relative position between the terminal device and the source cell does not satisfy the position-based switching condition, mobility management is terminated or not performed.

[0114] In the present application, the relative position between the terminal device and the source cell can be determined based on the location information of the terminal device and the location information of the source cell reference point. The location information of the terminal device is used to indicate the location of the terminal device. The location information of the terminal device may include the location coordinates of the terminal device. The location information of the terminal device can be obtained based on the GNSS measurement information of the terminal device. For example, the GNSS measurement information of the terminal device is the location information of the terminal device. The location information of the source cell reference point is used to indicate the location of the source cell. The location information of the source cell reference point may include the location coordinates of the source cell reference point. The source cell reference point may be the cell center or other location point of the source cell, without limitation. Specifically, the terminal device may determine the difference between the location coordinates of the terminal device and the location coordinates of the source cell reference point as the relative position between the terminal device and the source cell, or calculate the Euclidean distance between the location coordinates of the terminal device and the location coordinates of the source cell reference point, and use the calculated Euclidean distance as the relative position between the terminal device and the source cell.

[0115] Similarly, in the present application, the relative position between the terminal device and the candidate target cell can be determined based on the location information of the terminal device and the location information of the candidate target cell reference point. The location information of the terminal device is used to indicate the location of the terminal device. The location information of the terminal device may include the location coordinates of the terminal device. The location information of the candidate target cell reference point is used to indicate the location of the candidate target cell. The location information of the candidate target cell reference point may include the location coordinates of the candidate target cell reference point. The candidate target cell reference point may be the cell center or other location point of the candidate target cell, without limitation. Specifically, the terminal device may determine the difference between the location coordinates of the terminal device and the location coordinates of the candidate target cell reference point as the relative position between the terminal device and the candidate target cell, or calculate the Euclidean distance between the location coordinates of the terminal device and the location coordinates of the candidate target cell reference point, and use the calculated Euclidean distance as the relative position between the terminal device and the candidate target cell.

[0116] For example, when the first parameter includes a location threshold, the terminal device determines whether the relative position between the terminal device and the source cell is greater than the location threshold based on its own location information (for example, GNSS measurement information) and the location information of the source cell reference point. When it is greater than the location threshold, the terminal device determines whether the relative position between the terminal device and the candidate target cell is less than or equal to the location threshold based on its own location information and the location information of the candidate target cell reference point. If there is at least one first candidate target cell among the candidate target cells, the relative position between the terminal device and the first candidate target cell is less than or equal to the location threshold, any first candidate target cell is selected from the at least one first candidate target cell as the target cell, and the terminal device sends a random access request to the target cell. If there is no candidate target cell among the candidate target cells whose relative position is less than or equal to the location threshold, the terminal device does not perform mobility management or further the terminal device is in an idle state.

[0117] For another example, when the first parameter includes location threshold 1 and location threshold 2, location threshold 1 is the location threshold between the terminal device and the source cell, and location threshold 2 is the location threshold between the terminal device and the target cell, the terminal device determines whether the relative position between the terminal device and the source cell is greater than location threshold 1 based on its own location information (for example, GNSS measurement information) and the location information of the source cell reference point. When it is greater than location threshold 1, the terminal device determines whether the relative position between the terminal device and the candidate target cell is less than or equal to location threshold 2 based on its own location information and the location information of the candidate target cell reference point. If there is at least one first candidate target cell among the candidate target cells, the relative position between the terminal device and the first candidate target cell is less than or equal to location threshold 2, any first candidate target cell is selected from the at least one first candidate target cell as the target cell, and the terminal device sends a random access request to the target cell. If there is no candidate target cell among the candidate target cells whose relative position is less than or equal to location threshold 2, the terminal device does not perform mobility management or the terminal device is further in an idle state.

[0118] Exemplarily, mobility management is cell switching, the terminal device is the terminal in Figure 2, the source cell is satellite cell 2 in Figure 2, and candidate target cells configured for the terminal by satellite cell 2 include satellite cell 3 and satellite cell 4, and the location thresholds include 800km and 500km. The terminal determines that the relative position between the terminal and satellite cell 2 is 850km greater than 800km based on GNSS measurement information and the location information of the satellite cell 2 reference point of the source satellite base station. The terminal determines that the relative position between the terminal and satellite cell 3 is 450km based on GNSS measurement information and the location information of the satellite cell 3 reference point of the target satellite base station. The terminal determines that the relative position between the terminal and satellite cell 4 is 550km based on GNSS measurement information and the location information of the satellite cell 4 reference point of the target satellite base station. Satellite cell 3 is the target cell, and the terminal sends a random access request to satellite cell 3, so that the terminal switches from satellite cell 2 to satellite cell 3.

[0119] In another example, when the GNSS measurement information is invalid and within the first time period, the accumulated TA of the source cell is obtained, and mobility management is performed based on the second parameter.

[0120] Optionally, the terminal device performing mobility management based on the second parameter may include:

[0121] The terminal device determines the target cell based on the signal quality threshold, the signal quality-based switching condition, the signal quality of the source cell measured by the terminal device, and the signal quality of the candidate target cell measured by the terminal device, and further sends a random access request to the target cell.

[0122] Specifically, the terminal device may determine whether the signal quality of the source cell satisfies the signal quality-based switching condition. If the signal quality of the source cell satisfies the signal quality-based switching condition, the terminal device may determine whether the signal quality of the candidate target cell satisfies the signal quality-based switching condition, determine the target cell from the candidate target cell that satisfies the signal quality-based switching condition, and send a random access request to the target cell. If the signal quality of the source cell does not satisfy the signal quality-based switching condition, mobility management is terminated or not performed.

[0123] In the present application, the signal quality of the source cell may be determined based on the reference signal receiving quality (RSRQ) of the source cell reference signal, where the RSRQ of the source cell reference signal is used to indicate the signal quality of the source cell. Alternatively, the signal quality of the source cell may be determined based on the reference signal receiving power (RSRP) of the source cell reference signal, where the RSRP of the source cell reference signal is used to indicate the signal quality of the source cell.

[0124] Similarly, in the present application, the signal quality of the candidate target cell can be determined based on the RSRQ of the candidate target cell reference signal, and the RSRQ of the candidate target cell reference signal is used to indicate the signal quality of the candidate target cell. Alternatively, the signal quality of the candidate target cell can be determined based on the RSRP of the candidate target cell reference signal, and the RSRP of the candidate target cell reference signal is used to indicate the signal quality of the candidate target cell.

[0125] For example, the second parameter includes a signal quality threshold. When the GNSS measurement information fails and the terminal device is within the first time period, the terminal device measures the signal quality of the source cell to determine whether the signal quality of the source cell is less than the signal quality threshold. When the signal quality is less than the signal quality threshold, the terminal device measures the signal quality of the candidate target cell to determine whether the signal quality of the candidate target cell is greater than or equal to the signal quality threshold. If there is at least one first candidate target cell among the candidate target cells, the signal quality of the first candidate target cell is greater than or equal to the signal quality threshold. Any first candidate target cell is selected from the at least one first candidate target cell as the target cell. The terminal device sends a random access request to the target cell according to the accumulated TA of the source cell within the first time period. If there is no candidate target cell among the candidate target cells whose signal quality is greater than or equal to the signal quality threshold, the terminal device does not perform mobility management or the terminal device is further in an idle state.

[0126] For another example, when the second parameter includes signal quality threshold 1 and signal quality threshold 2, signal quality 1 is the signal quality threshold corresponding to the signal quality of the source cell, and signal quality 2 is the signal quality threshold corresponding to the signal quality of the target cell, when the GNSS measurement information is invalid and within the first time period, the terminal device measures the signal quality of the source cell to determine whether the signal quality of the source cell is less than signal quality threshold 1. When it is less than signal quality threshold 1, the terminal device measures the signal quality of the candidate target cell to determine whether the signal quality of the candidate target cell is greater than or equal to signal quality threshold 2. If there is at least one first candidate target cell among the candidate target cells, and the signal quality of the first candidate target cell is greater than or equal to signal quality threshold 2, any first candidate target cell is selected from the at least one first candidate target cell as the target cell, and the terminal device sends a random access request to the target cell according to the accumulated TA of the source cell within the first time period; if there is no first candidate target cell among the candidate target cells whose signal quality is greater than or equal to signal quality threshold 2, the terminal device does not perform mobility management or the terminal device is further in an idle state.

[0127] In one possible design, the terminal device selects a first candidate target cell with the best signal quality from at least one first candidate target cell as the target cell, and sends a random access request to the first candidate target cell.

[0128] In an exemplary embodiment, mobility management is cell handover, the terminal device is the terminal in Figure 2, the source cell is satellite cell 2 in Figure 2, the candidate target cells configured by the source cell for the terminal include satellite cell 3 and satellite cell 4, and the signal quality thresholds include 6 dB and 10 dB. The terminal measures the signal quality of satellite cell 2 as 5 dB less than 6 dB, the terminal measures the signal quality of satellite cell 3 as 15 dB, and the terminal measures the signal quality of satellite cell 4 as 11 dB. The signal quality of satellite cell 3 and the signal quality of satellite cell 4 are both greater than 10 dB. Therefore, the terminal can send a random access request to satellite cell 3 or satellite cell 4 within a first duration based on the accumulated TA of the source cell.

[0129] The first duration is the effective duration of the TAC, or a portion of the effective duration of the TAC. Uplink transmission of the terminal device is effective during the first duration.

[0130] TAC is used to extend the interval between two adjacent GNSS measurements performed by the terminal device, so that when the GNSS measurement information becomes invalid, the terminal device does not need to re-execute the GNSS measurement immediately. Uplink transmission can still be performed within the valid duration of TAC or part of the valid duration of TAC, and GNSS measurement can be re-executed when the timer corresponding to TAC ends.

[0131] Optionally, the TAC can be carried in a random access response (RAR) or in a media access control control element (MAC CE). The timer corresponding to the TAC can also be called a time alignment timer (TAT). The running time of the TAT corresponds to the effective duration of the uplink transmission of the terminal device. At the same time, the running time of the TAT can also correspond to the validity period of the TAC. That is, during the operation of the TAT and / or within the validity period of the TAC, the terminal device can perform uplink transmission; when the TAT operation ends and / or outside the validity period of the TAC, the terminal device cannot perform uplink transmission.

[0132] For example, a TAC process diagram is shown in FIG4 . On the one hand, the validity period of the GNSS measurement information obtained by the terminal device in FIG4 is from time T0 to time T2. The terminal device receives the TAC sent by the corresponding network device of the serving cell for the first time at time T1. The running period of the TAT corresponding to the TAC is from time T1 to time T4, that is, the terminal device can perform uplink transmission from time T1 to time T4, and the time period from time T1 to time T4 corresponds to the validity period of the TAC received for the first time. The terminal device receives the TAC sent by the corresponding network device of the serving cell for the second time at time T3. The running period of the TAT corresponding to the TAC is from time T3 to time T5, that is, the terminal device can still perform uplink transmission from time T3 to time T5, and the time period from time T3 to time T5 corresponds to the validity period of the TAC received for the second time. On the other hand, the GNSS measurement information obtained by the terminal device in FIG4 becomes invalid at time T2, but through the two received TACs, the terminal device can still perform uplink transmission within the time period from time T2 to time T5.

[0133] TAC can be used to carry TA. In order to ensure that the uplink transmissions from different terminal devices in the same cell do not interfere with each other, the network device requires that the uplink signals from different terminal devices in the same subframe but different frequency domain resources arrive at the network device at a substantially aligned time. Therefore, the network device will configure different TAs for different terminal devices, so that the terminal device can send uplink data (for example, random access request) to the network device according to the TA to achieve uplink synchronization. In random access, the network device determines the TA by measuring the received random access (RA) preamble, and sends it to the terminal device through the TAC in the RAR. Although the terminal device completes the uplink synchronization in random access, the position of the terminal device may change over time, so that the network device providing services for it needs to continuously maintain the TA to maintain uplink synchronization. At this time, the maintained TA can be sent to the terminal device through the TAC in the MAC CE.

[0134] In this application, when the first duration is the validity duration of a TAC, the first duration may be the duration of the TAT corresponding to the TAC. When the TAT corresponding to the TAC is running, the TAC is valid; when the TAT corresponding to the TAC ends, the TAC becomes invalid. It is understood that when the TAC is valid, the terminal device can perform uplink transmission; when the TAC is invalid, the terminal device cannot perform uplink transmission.

[0135] In this application, if the first duration is a portion of the TAC's valid duration, the first duration may be the remaining duration of the TAT corresponding to the TAC. If the remaining duration of the TAT corresponding to the TAC is not zero, the TAC is valid; if the remaining duration of the TAT corresponding to the TAC is zero, the TAC is invalid.

[0136] In one possible design, the terminal device receives indication information, which is used to indicate that the terminal device can continue uplink transmission after the GNSS measurement information becomes invalid. Therefore, the terminal device receives the indication information corresponding to the terminal device being in the period when the GNSS measurement information becomes invalid and within the first time period. Specifically, when the GNSS measurement information is valid, the terminal device receives indication information indicating that the terminal device can perform uplink transmission after the GNSS measurement information becomes invalid. The terminal device can obtain the accumulated TA of the source cell when the GNSS measurement information becomes invalid and perform mobility management based on the second parameter.

[0137] Optionally, when the GNSS measurement information of the terminal device is invalid and within the first time period, if the remaining valid time of the TAC exceeds a certain threshold, the terminal device is triggered to obtain the accumulated TA of the source cell and perform mobility management based on the second parameter.

[0138] In this application, when the terminal device releases the radio resources configured by the source cell for it (for example, the RRC command sent by the source cell to the terminal device), it maintains its own accumulated TA of the source cell and the remaining duration of the TAT corresponding to the TAC of the source cell. Specifically, the terminal device receives the TA of the source cell carried in the TAC through the RAR or MAC CE, and at the same time, accumulates the TA of the source cell received each time, and maintains the remaining duration of the TAT corresponding to the TAC.

[0139] In the present application, when the GNSS measurement information is invalid and within the first time period, the terminal device sends a random access request to the target cell, which may include: obtaining the accumulated TA of the source cell and the remaining time of the TAT corresponding to the TAC of the source cell; further, sending a random access request to the target cell based on the accumulated TA of the source cell and the remaining time of the TAT corresponding to the TAC of the source cell.

[0140] Based on the communication method shown in Figure 3, a terminal device can perform mobility management according to the instructions of the mobility management configuration information during long-term connected communications. Specifically, when the GNSS measurement information is valid, the terminal device performs mobility management based on the location-based mobility management parameters. When the GNSS measurement information is invalid and within a first time period, the terminal device obtains the accumulated TA of the source cell and performs mobility management based on the signal quality-based mobility management parameters. The terminal device's uplink transmission is valid within the first time period. In this way, the terminal device can flexibly select the target cell to access, increasing the probability of accessing the appropriate target cell.

[0141] Optionally, after the terminal device sends a random access request to the target cell, the method shown in Figure 5 may also be included. Figure 5 is a flow chart of a communication method provided by an embodiment of the present application, as shown in Figure 5, which may include steps S501 to S503:

[0142] S501: The network device corresponding to the target cell receives a request message from the terminal device.

[0143] The request message is used to request the configuration of GNSS measurement. The request message can be carried in message 3 (MSG3) or RRC connection establishment request. MSG3 is the third message in the random access process.

[0144] S502: The network device corresponding to the target sends a first response message; the terminal device receives the first response message and performs GNSS measurement.

[0145] The first response message is used to trigger GNSS measurement. The first response message can be carried in downlink data, such as message 4 (MSG4). MSG4 is the fourth message in the random access process.

[0146] It is understandable that when the terminal device supports a feedback mechanism (e.g., hybrid automatic repeat request (HARQ)), after receiving a response message in the downlink data, the terminal device needs to send a confirmation message corresponding to the downlink data to the network device corresponding to the target cell to perform GNSS measurement. When the terminal device does not support the feedback mechanism, the terminal device performs GNSS measurement after receiving a response message in the downlink data.

[0147] S503: The terminal device sends indication information to the network device corresponding to the target cell on the uplink scheduling resources.

[0148] Specifically, the terminal device reports the time required to perform GNSS measurements to the network device corresponding to the target cell; after the time required to perform GNSS measurements, the terminal device receives uplink scheduling resources from the network device corresponding to the target cell; and sends indication information to the network device corresponding to the target cell on the uplink scheduling resources, indicating the validity period of the GNSS measurement information. The indication information can be carried in message 5 (MSG5), which is the fifth message in the random access process.

[0149] Based on the method shown in Figure 5, after accessing the target cell, the terminal device requests the target cell to configure GNSS measurement and performs GNSS measurement. It is not necessary to perform GNSS measurement before sending a random access request to the target cell. This ensures the timeliness of the neighboring cell measurement results and reduces the delay in the terminal device performing mobility management.

[0150] Optionally, the terminal device may send the remaining running time of the first timer to the network device corresponding to the target cell.

[0151] Specifically, when releasing the information configured by the source cell, the terminal device starts a first timer and sends the remaining running time of the first timer to the network device corresponding to the target cell. The running time of the first timer corresponds to the remaining valid time of the TAC.

[0152] When the terminal device sends the remaining duration of the first timer to the network device corresponding to the target cell, the terminal device may receive a second response message from the target cell network device, the second response message being equivalent to triggering GNSS measurement, or may receive a TAC from the target cell network device, or perform GNSS measurement when the first time arrives. The TAC is used to extend the duration of the terminal device's uplink transmission.

[0153] The terminal device may determine the first time according to the time when the remaining running time of the first timer is sent. For example, the protocol stipulates that the terminal device starts performing GNSS measurement 10 seconds after the time when the remaining running time of the first timer is sent.

[0154] In one possible design, when the terminal device sends the remaining duration of the first timer to the network device corresponding to the target cell, GNSS measurement is performed when the second time arrives. The terminal device can determine the second time based on the time when the confirmation feedback is received from the network device corresponding to the target cell. For example, the protocol stipulates that the terminal device starts performing GNSS measurement 5 seconds after receiving the confirmation feedback from the network device corresponding to the target cell.

[0155] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of interaction between various devices. It is understandable that various devices, such as terminal devices, network devices (for example, network devices corresponding to the source cell, network devices corresponding to the target cell), etc., in order to implement the above functions, include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily appreciate that, in conjunction with the algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in a hardware or computer software driven hardware manner depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0156] In the embodiment of the present application, the functional modules of the terminal device, network communication device, etc. can be grouped according to the above method examples. For example, each functional module can be grouped according to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the grouping of modules in the embodiment of the present application is schematic and is only a logical functional grouping. In actual implementation, there may be other grouping methods.

[0157] Figure 6 shows a structural diagram of a communication device 600, which can be used to perform the functions of the terminal device involved in the above embodiments. As an implementation method, the communication device 600 shown in Figure 6 includes: a transceiver unit 6001, a processing unit 6002;

[0158] The transceiver unit 6001 is used to receive mobility management configuration information; the mobility management configuration information is used to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; the second parameter is a signal quality-based mobility management parameter; for example, the transceiver unit 6001 can support the communication device 600 to execute S302.

[0159] The processing unit 6002 is configured to perform mobility management according to the mobility management configuration information. For example, the processing unit 6002 may support the communication device 600 to perform S303.

[0160] For the description of mobility management configuration information, first parameter, second parameter, and mobility management, reference may be made to that in the above method embodiment.

[0161] Specifically, all relevant contents of each step involved in the method embodiment shown in FIG3 can be referred to the functional description of the corresponding functional module, and will not be repeated here. The communication device 600 is used to perform the functions of the terminal device in the communication method shown in FIG3, and thus can achieve the same effect as the above-mentioned communication method.

[0162] FIG7 shows a structural diagram of a communication device 700, which can be used to perform the functions of the network device corresponding to the source cell involved in the above embodiments. As an implementation method, the communication device 700 shown in FIG7 includes: a processing unit 7001, a transceiver unit 7002;

[0163] Processing unit 7001 is configured to obtain mobility management configuration information; the mobility management configuration information is configured to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; and the second parameter is a signal quality-based mobility management parameter. For example, processing unit 7001 may be configured to support communication device 700 in executing S301.

[0164] The transceiver unit 7002 is configured to send mobility management configuration information. For example, the transceiver unit 7002 may be configured to support the communication device 700 in executing S302.

[0165] For the description of the mobility management configuration information, the first parameter, and the second parameter, reference may be made to that in the above method embodiment.

[0166] Specifically, all relevant content of each step involved in the method embodiment shown in Figure 3 can be referenced to the functional description of the corresponding functional module and will not be repeated here. Communication device 700 is used to perform the functions of the network device corresponding to the source cell in the communication method shown in Figure 3, thereby achieving the same effect as the above-mentioned communication method.

[0167] FIG8 shows a structural diagram of a communication device 800, which can be used to perform the functions of the network device corresponding to the target cell involved in the above embodiment. As an implementation method, the communication device 800 shown in FIG8 includes: a transceiver unit 8001;

[0168] The transceiver unit 8001 is configured to receive a request message for requesting configuration of GNSS measurement. For example, the transceiver unit 8001 may be configured to support the communication device 800 in executing S501.

[0169] The transceiver unit 8001 is further configured to send a first response message for triggering the execution of GNSS measurement. For example, the transceiver unit 8001 may be configured to support the communication device 800 in executing S502.

[0170] For the description of the request message for requesting the configuration of GNSS measurement and the response message for triggering the execution of GNSS measurement, reference may be made to the description in the above method embodiment.

[0171] Specifically, all relevant content of each step involved in the method embodiment shown in Figure 5 can be referenced to the functional description of the corresponding functional module and will not be repeated here. Communication device 800 is used to perform the functions of the network device corresponding to the target cell in the communication method shown in Figure 5, thereby achieving the same effect as the above-mentioned communication method.

[0172] The processing unit mentioned above can be a processing module, a processor, or a controller. It can implement or execute the various exemplary logical blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and so on. The transceiver unit can be a communication module, a transceiver circuit, or a communication interface. Any of the communication devices mentioned above can also include a storage unit for storing program code and data of any communication device. The storage unit can be a storage module or a memory. When the processing module is a processor, the communication module is a communication interface, and the storage module is a memory, the communication device 600, communication device 700, and communication device 800 involved in the embodiments of the present application can be the communication device 900 shown in Figure 9. For example, the terminal device, the network device corresponding to the source cell, and the network device corresponding to the target cell mentioned above can adopt the structure shown in Figure 9 or include the components shown in Figure 9. Figure 9 is a schematic diagram of the structure of a communication device 900 provided in an embodiment of the present application. As shown in Figure 9, the communication device 900 can include a processor 901, a communication circuit 902, and a communication interface 903.

[0173] Furthermore, the communication device 900 may further include a memory 904 , wherein the processor 901 , the memory 904 and the communication interface 903 may be connected via a communication line 902 .

[0174] The processor 901 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The processor 901 may also be other communication devices with processing capabilities, such as circuits, devices, or software modules.

[0175] The communication line 902 is used to transmit information between the components included in the communication device 900.

[0176] The communication interface 903 is used to communicate with other devices or other communication networks. The other communication network can be Ethernet, a radio access network (RAN), a wireless local area network (WLAN), etc. The communication interface 903 can be a radio frequency module, a transceiver, or any communication device capable of achieving communication. The embodiment of the present application is described using the communication interface 903 as an example of a radio frequency module, wherein the radio frequency module may include an antenna, a radio frequency circuit, etc., and the radio frequency circuit may include a radio frequency integrated chip, a power amplifier, etc.

[0177] The memory 904 is used to store instructions, where the instructions may be computer programs.

[0178] Among them, the memory 904 can be a read-only memory (ROM) or other types of static storage devices that can store static information and / or instructions, or a random access memory (RAM) or other types of dynamic storage devices that can store information and / or instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage, magnetic disk storage media or other magnetic storage devices, and optical disc storage includes compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.

[0179] It should be noted that the memory 904 can exist independently of the processor 901 or can be integrated with the processor 901. The memory 904 can be used to store instructions, program code, or some data. The memory 904 can be located within the communication device 900 or outside the communication device 900, without limitation. The processor 901 is configured to execute the instructions stored in the memory 904 to implement the random access procedure preamble transmission method provided in the following embodiments of the present application.

[0180] In one example, the processor 901 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 9 .

[0181] As an optional implementation, the communication device 900 includes multiple processors. For example, in addition to the processor 901 in FIG. 9 , it may also include a processor 907 .

[0182] As an optional implementation, the communication apparatus 900 further includes an output device 905 and an input device 906. The input device 906 is a keyboard, a mouse, a microphone, or a joystick, and the output device 905 is a display screen, a speaker, or other devices.

[0183] It should be noted that the communication device 900 may be a desktop computer, a portable computer, a network server, a mobile phone, a tablet computer, a wireless terminal, an embedded device, a chip system, or a device having a structure similar to that shown in FIG9 . Furthermore, the component structure shown in FIG9 does not limit the communication device. In addition to the components shown in FIG9 , the communication device may include more or fewer components than shown, or combine certain components, or arrange the components differently.

[0184] In the embodiment of the present application, the chip system can be composed of chips, or can include chips and other discrete devices.

[0185] The embodiments of the present application also provide a computer-readable storage medium. All or part of the processes in the above-mentioned method embodiments can be completed by a computer program to instruct the relevant hardware. The program can be stored in the above-mentioned computer-readable storage medium. When the program is executed, it can include the processes of the above-mentioned method embodiments. The computer-readable storage medium can be a terminal device of any of the above-mentioned embodiments, such as: an internal storage unit including a data transmission end and / or a data receiving end, such as a hard disk or memory of the terminal device. The above-mentioned computer-readable storage medium can also be an external storage device of the above-mentioned terminal device, such as a plug-in hard disk, a smart memory card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the above-mentioned terminal device. Furthermore, the above-mentioned computer-readable storage medium can also include both the internal storage unit of the above-mentioned terminal device and an external storage device. The above-mentioned computer-readable storage medium is used to store the above-mentioned computer program and other programs and data required by the above-mentioned terminal device. The above-mentioned computer-readable storage medium can also be used to temporarily store data that has been output or is to be output.

[0186] It should be understood that the collection, storage, use, processing, transmission, provision, and disclosure of user personal information involved in the technical solution of this application complies with relevant laws and regulations and does not violate public order and good morals. For example, in the technical solution of this application, the processing of user personal information is carried out with the user's authorization, and the same description is not repeated here.

[0187] It should be noted that the terms "first" and "second" in the specification, claims, and drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products, or devices.

[0188] It should be understood that in the present application, "at least one (item)" refers to one or more, "more than one" refers to two or more, "at least two (items)" refers to two or three and more than three, and "and / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0189] It should be understood that in the embodiments of the present application, "B corresponding to A" means that B is associated with A. For example, B can be determined based on A. It should also be understood that determining B based on A does not mean determining B based solely on A; B can also be determined based on A and / or other information. In addition, the "connection" in the embodiments of the present application refers to various connection methods, such as direct connection and indirect connection, to achieve communication between devices, and the embodiments of the present application do not impose any limitations on this.

[0190] Unless otherwise specified, the "transmission" (transmit / transmission) appearing in the embodiments of the present application refers to bidirectional transmission, including the actions of sending and / or receiving. Specifically, the "transmission" in the embodiments of the present application includes the sending of data, the receiving of data, or the sending of data and the receiving of data. In other words, the data transmission here includes uplink and / or downlink data transmission. Data may include channels and / or signals, uplink data transmission is uplink channel and / or uplink signal transmission, and downlink data transmission is downlink channel and / or downlink signal transmission. The "network" and "system" appearing in the embodiments of the present application express the same concept, and the communication system is the communication network.

[0191] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the grouping of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be grouped into different functional modules to complete all or part of the functions described above.

[0192] In the several embodiments provided in this application, it should be understood that the disclosed communication devices and methods can be implemented in other ways. For example, the communication device embodiments described above are merely illustrative. For example, the grouping of the modules or units is merely a logical functional grouping. In actual implementation, there may be other grouping methods, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0193] The units described as separate components may or may not be physically separate, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0194] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0195] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a device, such as a single-chip microcomputer, a chip, etc., or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media for storing program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0196] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: The method comprises: Receiving mobility management configuration information; the mobility management configuration information is used to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; the second parameter is a signal quality-based mobility management parameter; Mobility management is performed according to the mobility management configuration information.

2. The method according to claim 1, characterized in that The performing mobility management according to the mobility management configuration information includes: When the GNSS measurement information is valid, performing mobility management based on the first parameter; In the case where the GNSS measurement information is invalid and within a first time period, mobility management is performed based on the second parameter; and uplink transmission is valid within the first time period.

3. The method according to claim 2, characterized in that The performing mobility management based on the second parameter when the GNSS measurement information is invalid and within the first time period includes: Obtain the accumulated timing advance TA of the source cell; Mobility management is performed based on the accumulated timing advance TA of the source cell.

4. The method according to claim 2 or 3, characterized in that The first duration is the effective duration of the timing advance command TAC; or, The first duration is a portion of the valid duration of the timing advance command TAC.

5. The method according to any one of claims 1 to 4, characterized in that The method further comprises: Sending a request message to a network device corresponding to a target cell; the request message is used to request configuration of GNSS measurement; A first response message is received from a network device corresponding to the target cell; the first response message is used to trigger GNSS measurement.

6. The method according to claim 5, characterized in that The request message is carried in the message MSG3 or the radio resource control RRC connection establishment request.

7. The method according to claim 5, characterized in that The first response message is carried in downlink data.

8. The method according to claim 2 or 3, characterized in that The method further comprises: The information configured by the source cell for the terminal device in the terminal device is released, and a first timer is started; the running time of the first timer corresponds to the remaining valid time of the TAC.

9. The method according to claim 8, characterized in that The method further comprises: The remaining running time of the first timer is sent to a network device corresponding to the target cell.

10. The method according to claim 9, characterized in that The method further comprises: receiving a second response message from a network device corresponding to the target cell, where the second response message is used to trigger GNSS measurement; or, receiving a timing advance command TAC from a network device corresponding to the target cell, wherein the TAC is used to extend the duration of uplink transmission; or When a first time arrives, GNSS measurement is performed; the first time is determined according to the time when the remaining running time of the first timer is sent.

11. The method according to any one of claims 1 to 7, characterized in that: The method further comprises: reporting the time required to perform the GNSS measurement to a network device corresponding to the target cell; After a time required to perform the GNSS measurement, receiving uplink scheduling resources from a network device corresponding to the target cell; Indication information is sent to a network device corresponding to the target cell on the uplink scheduling resource, where the indication information is used to indicate a valid duration of GNSS measurement information.

12. The method according to claim 11, characterized in that The indication information is carried in message MSG5.

13. A communication method, characterized in that: The method comprises: Acquiring mobility management configuration information; the mobility management configuration information is used to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; the second parameter is a signal quality-based mobility management parameter; Sending the mobility management configuration information.

14. A communication method, characterized in that: The method comprises: Receive a request message; the request message is used to request configuration of GNSS measurement; Send a first response message; the first response message is used to trigger the execution of GNSS measurement.

15. The method according to claim 14, characterized in that The request message is carried in the message MSG 3 or the radio resource control RRC connection establishment request.

16. The method according to claim 15, characterized in that The first response message is carried in downlink data.

17. The method according to claim 14, characterized in that The method further comprises: receiving a remaining running time of a first timer; The running time of the first timer corresponds to the remaining valid time of the timing advance command TAC.

18. The method according to claim 17, characterized in that The method further comprises: sending a second response message, where the second response message is used to trigger execution of a GNSS measurement; or, A timing advance command (TAC) is sent, where the TAC is used to extend the duration of uplink transmission.

19. The method according to any one of claims 14 to 18, characterized in that: The method further comprises: the time required to receive the GNSS measurements from the terminal device; After a time required to perform the GNSS measurement, sending an uplink scheduling resource to the terminal device; Indication information is received from the terminal device on the uplink scheduling resource, where the indication information is used to indicate a valid duration of the GNSS measurement.

20. The method according to claim 19, characterized in that The indication information is carried in message MSG5.

21. A communication device, characterized in that: The communication device comprises: A transceiver unit, configured to receive mobility management configuration information; the mobility management configuration information is used to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; the second parameter is a signal quality-based mobility management parameter; A processing unit is configured to perform mobility management according to the mobility management configuration information.

22. A communication device, characterized in that: The communication device comprises: A processing unit, configured to obtain mobility management configuration information; the mobility management configuration information is used to indicate a first parameter and a second parameter; the first parameter is a location-based mobility management parameter; the second parameter is a signal quality-based mobility management parameter; The transceiver unit is configured to send the mobility management configuration information.

23. A communication device, characterized in that: The communication device comprises: A transceiver unit, configured to receive a request message for requesting configuration of a GNSS measurement; The transceiver unit is further configured to send a first response message; the first response message is used to trigger execution of GNSS measurement.

24. A communication device, characterized in that: The communication device includes a processor and a communication interface, and the processor and the communication interface are used to support the communication device to execute the communication method according to any one of claims 1 to 12, or to execute the method according to claim 13, or to execute the method according to any one of claims 14 to 20.

25. A communication system, characterized in that: The communication system includes the communication device according to claim 21, the communication device according to claim 22, and the communication device according to claim 23.

26. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, which, when executed on a computer, enable the computer to execute the method according to any one of claims 1 to 12, or enable the computer to execute the method according to claim 13, or enable the computer to execute the method according to any one of claims 14 to 20.

27. A computer program product, characterized in that The computer program product includes computer instructions, which, when executed on a computer, enable the computer to execute the method according to any one of claims 1 to 12, or enable the computer to execute the method according to claim 13, or enable the computer to execute the method according to any one of claims 14 to 20.

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