Communication method, apparatus and system

Abstract

The present application provides a communication method, apparatus and system, which can be suitable for NTN scenarios. In the method, when a user equipment encounters a connection failure, the user equipment records related information of a mobility process and reports same to a network device, such that the network device can optimize related parameters conveniently, and an interruption time delay caused by the connection failure can be reduced.

Description

Communication method, device and system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on March 29, 2024, with application number 202410389205.7 and application name “Communication Methods, Devices and Systems”, 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] To identify mobility-related anomalies such as radio link failure, handover failure, and radio link failure in the target cell, user equipment (UE) can record and report mobility-related anomaly parameters to the network device, namely, a radio link failure report (RLF report). The network device can then optimize the UE's mobility parameters based on the RLF report. However, the current RLF reporting mechanism does not support mobility scenarios in non-terrestrial networks (NTNs). Summary of the Invention

[0004] The present application provides a communication method, device, and system that can analyze failure causes in an NTN scenario, thereby adjusting NTN-related parameters to reduce the occurrence of mobility anomalies and improve user experience.

[0005] In a first aspect, a communication method is provided. The method may be executed by a terminal device, or may be executed by a component of the terminal device (e.g., a chip, circuit, or chip system), which is not limited in this application. For ease of understanding, this application is described using execution by a terminal device as an example.

[0006] The method includes: a terminal device receives first information from a network device, where the first information is used to indicate at least one first trigger condition that the terminal device needs to satisfy to trigger a conditional handover (CHO) to a target cell; the terminal device fails to connect during a mobility process in a non-terrestrial network (NTN) and records a first report, where the first report is used to indicate information about the terminal device during the mobility process in the NTN; and the terminal device sends the first report to the network device.

[0007] Illustratively, the first report may be an RLF report, or the first report may be other reports, which is not limited in this application.

[0008] In this method, when a connection failure occurs in an NTN scenario, the terminal device can report the cause of the connection failure to the network device through a first report, which facilitates the network device to optimize relevant parameters and reduce the interruption delay caused by the connection failure.

[0009] In combination with the first aspect, in certain implementations of the first aspect, the at least one first trigger condition includes a distance trigger condition, which is: the distance between the terminal device and the source cell reference point is greater than the first threshold value, and / or the distance between the terminal device and the target cell reference point is less than the second threshold value.

[0010] Specifically, the first report may include at least one of the following information:

[0011] The time measured when the distance between the terminal device and the source cell reference point is greater than the first threshold value; the time measured when the distance between the terminal device and the target cell reference point is less than the second threshold value; whether the distance between the terminal device and the source cell reference point is greater than the first threshold value or whether the distance between the terminal device and the target cell reference point is less than the second threshold value is satisfied first; the time interval between the time measured when the distance between the terminal device and the source cell reference point is greater than the first threshold value and the time measured when the distance between the terminal device and the target cell reference point is less than the second threshold value.

[0012] Through the above method, when the terminal device does not meet the distance trigger condition or the terminal device meets the distance trigger condition but does not meet other trigger conditions, it can report to the network device the satisfaction and / or non-satisfaction of the specific threshold values ​​involved in the distance trigger condition, so that the network device can adjust the threshold values ​​that are not met by the terminal device and reduce the number of connection failures.

[0013] In combination with the first aspect, in certain implementations of the first aspect, the at least one first trigger condition includes a time trigger condition, which is: the time measured by the terminal device is greater than a third threshold value and less than a fourth threshold value, and the fourth threshold value is the sum of the third threshold value and the duration, and the duration is the time when the terminal device can access the target cell.

[0014] Through the above method, when the terminal device triggers CHO to the target cell in the NTN, it needs to consider the distance dimension information and / or time dimension information, so that the terminal device can trigger CHO more reasonably and increase the probability of successful CHO of the terminal device.

[0015] In combination with the first aspect, in certain implementations of the first aspect, the at least one first trigger condition includes a radio resource management (RRM) measurement trigger condition, and the RRM measurement trigger condition is: the RRM measurement result of the source cell measured by the terminal device is less than the fifth threshold value, and / or, the RRM measurement result of the target cell measured by the terminal device is greater than the sixth threshold value, and / or, the difference between the RRM measurement result of the target cell measured by the terminal device and the RRM measurement result of the source cell is greater than the seventh threshold value.

[0016] Specifically, the first report may include at least one of the following information:

[0017] The time at which the terminal device measures when the RRM measurement result of the source cell is less than the fifth threshold value; the time at which the terminal device measures when the RRM measurement result of the target cell is greater than the sixth threshold value; whether the RRM measurement result of the source cell is less than the fifth threshold value or whether the RRM measurement result of the target cell is greater than the sixth threshold value is satisfied first; the time interval between the time at which the terminal device measures when the RRM measurement result of the source cell is less than the fifth threshold value and the time at which the terminal device measures when the RRM measurement result of the target cell is greater than the sixth threshold value.

[0018] Through the above method, when the terminal device does not meet the RRM measurement trigger condition or the terminal device meets the RRM measurement trigger condition but does not meet other trigger conditions, it can report to the network device the satisfaction and / or non-satisfaction of the specific threshold values ​​involved in the RRM measurement trigger condition, so that the network device can adjust the threshold value that is not met by the terminal device and reduce the number of connection failures.

[0019] In combination with the first aspect, in certain implementations of the first aspect, when the terminal device meets the above-mentioned distance trigger condition or the terminal device meets the above-mentioned time trigger condition, but does not meet the above-mentioned RRM measurement trigger condition, the first report also includes the wireless resource management RRM measurement result of the terminal device.

[0020] Through the above method, when the RRM measurement triggering condition is not met, the terminal device can report the RRM measurement result to the network device, so that the network device can set a more reasonable RRM threshold value for the target cell.

[0021] In conjunction with the first aspect, in certain implementations of the first aspect, when the terminal device meets the foregoing RRM measurement trigger condition but does not meet the foregoing distance trigger condition, the first report further includes at least one of the following information:

[0022] The distance between the terminal device and the reference point of the source cell; the distance between the terminal device and the reference point of the target cell.

[0023] Through the above method, when the distance trigger condition is not met, the terminal device can report the distance between the terminal device and the source cell reference point and / or the distance between the terminal device and the target cell reference point to the network device, so that the network device can set a more reasonable distance threshold value for the candidate cell.

[0024] In combination with the first aspect, in certain implementations of the first aspect, when the terminal device meets the above-mentioned RRM measurement trigger condition but does not meet the above-mentioned time trigger condition, the first report also includes the time of the terminal device measurement.

[0025] Through the above method, when the time trigger condition is not met, the terminal device can report the time measured by the terminal device to the network device, so that the network device can set a more reasonable time threshold value for the candidate cell.

[0026] Exemplarily, the connection failure includes a radio link failure of the source cell or a CHO failure of the terminal device or a handover failure within the first time period after a CHO success of the terminal device.

[0027] In a second aspect, a communication method is provided. The method can be executed by a network device, or can also be executed by a component of the network device (such as a chip, circuit, or chip system), which is not limited in this application. For ease of understanding, this application is described using the network device as an example.

[0028] The method includes: a network device sends first information to a terminal device, where the first information is used to indicate at least one first trigger condition that the terminal device needs to meet to trigger CHO to a target cell; the network device receives a first report from the terminal device, where the first report is recorded when the terminal device fails to connect during a mobility process in a non-terrestrial network (NTN), and the first report is used to indicate information about the terminal device during the mobility process in the NTN; and the network device adjusts mobility parameters based on the first report.

[0029] Illustratively, the first report may be an RLF report, or the first report may be other reports, which is not limited in this application.

[0030] In this method, when a connection failure occurs in an NTN scenario, the terminal device can report the cause of the connection failure to the network device through a first report, which facilitates the network device to optimize relevant parameters and reduce the interruption delay caused by the connection failure.

[0031] In combination with the second aspect, in certain implementations of the second aspect, the at least one first trigger condition mentioned above includes a distance trigger condition, which is: the distance between the terminal device and the source cell reference point is greater than the first threshold value, and / or the distance between the terminal device and the target cell reference point is less than the second threshold value.

[0032] Specifically, the first report may include at least one of the following information:

[0033] The time measured when the distance between the terminal device and the source cell reference point is greater than the first threshold value; the time measured when the distance between the terminal device and the target cell reference point is less than the second threshold value; whether the distance between the terminal device and the source cell reference point is greater than the first threshold value or whether the distance between the terminal device and the target cell reference point is less than the second threshold value is satisfied first; the time interval between the time measured when the distance between the terminal device and the source cell reference point is greater than the first threshold value and the time measured when the distance between the terminal device and the target cell reference point is less than the second threshold value.

[0034] Through the above method, when the terminal device does not meet the distance trigger condition or the terminal device meets the distance trigger condition but does not meet other trigger conditions, it can report to the network device the satisfaction and / or non-satisfaction of the specific threshold values ​​involved in the distance trigger condition, so that the network device can adjust the threshold values ​​that are not met by the terminal device and reduce the number of connection failures.

[0035] In combination with the second aspect, in certain implementations of the second aspect, the at least one first trigger condition includes a time trigger condition, which is: the time measured by the terminal device is greater than a third threshold value and less than a fourth threshold value, and the fourth threshold value is the sum of the third threshold value and the duration, and the duration is the time that the terminal device can access the target cell.

[0036] Through the above method, when the terminal device triggers CHO to the target cell in the NTN, it needs to consider the distance dimension information and / or time dimension information, so that the terminal device can trigger CHO more reasonably and increase the probability of successful CHO of the terminal device.

[0037] In combination with the second aspect, in certain implementations of the second aspect, the at least one first trigger condition includes a radio resource management (RRM) measurement trigger condition, and the RRM measurement trigger condition is: the RRM measurement result of the source cell measured by the terminal device is less than the fifth threshold value, and / or, the RRM measurement result of the target cell measured by the terminal device is greater than the sixth threshold value, and / or, the difference between the RRM measurement result of the target cell measured by the terminal device and the RRM measurement result of the source cell is greater than the seventh threshold value.

[0038] Specifically, the first report may include at least one of the following information:

[0039] The time at which the terminal device measures when the RRM measurement result of the source cell is less than the fifth threshold value; the time at which the terminal device measures when the RRM measurement result of the target cell is greater than the sixth threshold value; whether the RRM measurement result of the source cell is less than the fifth threshold value or whether the RRM measurement result of the target cell is greater than the sixth threshold value is satisfied first; the time interval between the time at which the terminal device measures when the RRM measurement result of the source cell is less than the fifth threshold value and the time at which the terminal device measures when the RRM measurement result of the target cell is greater than the sixth threshold value.

[0040] Through the above method, when the terminal device does not meet the RRM measurement trigger condition or the terminal device meets the RRM measurement trigger condition but does not meet other trigger conditions, it can report to the network device the satisfaction and / or non-satisfaction of the specific threshold values ​​involved in the RRM measurement trigger condition, so that the network device can adjust the threshold value that is not met by the terminal device and reduce the number of connection failures.

[0041] In combination with the second aspect, in certain implementations of the second aspect, when the terminal device meets the above-mentioned distance trigger condition or the terminal device meets the above-mentioned time trigger condition, but does not meet the above-mentioned RRM measurement trigger condition, the first report also includes the wireless resource management RRM measurement result of the terminal device.

[0042] Through the above method, when the RRM measurement triggering condition is not met, the terminal device can report the RRM measurement result to the network device, so that the network device can set a more reasonable RRM threshold value for the target cell.

[0043] In conjunction with the second aspect, in certain implementations of the second aspect, when the terminal device meets the foregoing RRM measurement trigger condition but does not meet the foregoing distance trigger condition, the first report further includes at least one of the following information:

[0044] The distance between the terminal device and the reference point of the source cell; the distance between the terminal device and the reference point of the target cell.

[0045] Through the above method, when the distance trigger condition is not met, the terminal device can report the distance between the terminal device and the source cell reference point and / or the distance between the terminal device and the target cell reference point to the network device, so that the network device can set a more reasonable distance threshold value for the candidate cell.

[0046] In combination with the second aspect, in certain implementations of the second aspect, when the terminal device meets the above-mentioned RRM measurement trigger condition but does not meet the above-mentioned time trigger condition, the first report also includes the time of the terminal device measurement.

[0047] Through the above method, when the time trigger condition is not met, the terminal device can report the time measured by the terminal device to the network device, so that the network device can set a more reasonable time threshold value for the candidate cell.

[0048] Exemplarily, the connection failure includes a radio link failure of the source cell or a CHO failure of the terminal device or a handover failure within the first time period after a CHO success of the terminal device.

[0049] In a third aspect, a communication device is provided, comprising: a transceiver module for receiving first information from a network device, the first information being used to indicate at least one first trigger condition that the communication device needs to satisfy to trigger CHO to a target cell; the communication device further comprising: a processing module for recording a first report when a connection fails during the mobility process of the NTN, the first report being used to indicate information of the communication device during the mobility process of the NTN; the transceiver module being further used to send the first report to the network device.

[0050] For the relevant explanation and description of the beneficial effects of the third aspect, please refer to the description of the first aspect.

[0051] In a fourth aspect, a communication device is provided, comprising: a transceiver module for sending first information to a terminal device, the first information being used to indicate at least one first trigger condition that the terminal device needs to satisfy to trigger CHO to a target cell; the transceiver module is also used to receive a first report from the terminal device, the first report being recorded when the terminal device fails to connect during a mobility process of the NTN, the first report being used to indicate information of the terminal device during the mobility process of the NTN; the communication device further comprising: a processing module for adjusting mobility parameters based on the first report.

[0052] For relevant explanations and descriptions of the beneficial effects of the fourth aspect, please refer to the description of the second aspect.

[0053] In a fifth aspect, the present application provides a communication device, comprising an interface circuit and a processor, wherein the interface circuit is used to implement the function of the transceiver module in the third aspect, and the processor is used to implement the function of the processing module in the third aspect.

[0054] In a sixth aspect, the present application provides a communication device, comprising an interface circuit and a processor, wherein the interface circuit is used to implement the function of the transceiver module in the fourth aspect, and the processor is used to implement the function of the processing module in the sixth aspect.

[0055] In the seventh aspect, the present application provides a computer-readable storage medium, which stores a program code for execution by a terminal device, and the program code includes a computer program or instruction for executing the method of the first aspect or any possible method in the first aspect or all possible methods in the first aspect.

[0056] In an eighth aspect, the present application provides a computer-readable storage medium storing a program code for execution by a network device, the program code comprising a computer program or instruction for executing the method of the second aspect or any possible manner in the second aspect or all possible manners in the second aspect.

[0057] In the ninth aspect, a computer program product storing computer-readable instructions is provided, which, when the computer-readable instructions are executed on a computer, enables the computer to execute the method of the first aspect or any possible method of the first aspect or all possible methods of the first aspect.

[0058] In the tenth aspect, a computer program product storing computer-readable instructions is provided, which, when the computer-readable instructions are executed on a computer, enables the computer to execute the method of the above-mentioned second aspect or any possible method of the second aspect or all possible methods of the second aspect.

[0059] In the eleventh aspect, a communication system is provided, which includes a device having the function of implementing the method of the above-mentioned first aspect or any possible manner in the first aspect or all possible manners in the first aspect, and a device having the function of implementing the method of the above-mentioned second aspect or any possible manner in the second aspect or all possible manners in the second aspect.

[0060] In the twelfth aspect, a processor is provided, which is coupled to a memory and is used to execute the method of the above-mentioned first aspect or any possible manner of the first aspect or all possible manners of the first aspect.

[0061] In a thirteenth aspect, a processor is provided, coupled to a memory, for executing the method of the second aspect or any possible manner of the second aspect or all possible manners of the second aspect.

[0062] In a fourteenth aspect, a chip system is provided, comprising a processor and a memory, wherein the processor is configured to execute a computer program or instruction stored in the memory, so that the chip system implements the method of any of the aforementioned first or second aspects, and any possible implementation of either aspect. The chip system may be composed of a chip alone, or may include a chip and other discrete components. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] FIG1 is a schematic diagram of an NTN network architecture 100 applicable to an embodiment of the present application.

[0064] FIG2 is a schematic diagram of another NTN network architecture 200 applicable to an embodiment of the present application.

[0065] FIG3 is a schematic diagram of yet another NTN network architecture 300 applicable to an embodiment of the present application.

[0066] FIG4 is a schematic diagram of an ORAN system applicable to an embodiment of the present application.

[0067] FIG5 is a schematic diagram of yet another NTN network architecture 400 applicable to an embodiment of the present application.

[0068] FIG6 is a schematic flow chart of a communication method 600 provided in an embodiment of the present application.

[0069] FIG7 shows a schematic block diagram of a communication device provided in an embodiment of the present application.

[0070] FIG8 shows a schematic structural diagram of a communication device provided in an embodiment of the present application.

[0071] FIG9 shows a schematic diagram of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0072] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0073] The technical solutions provided in this application can be applied to various communication systems, such as: fifth generation (5G) or new radio (NR) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, etc. The technical solutions provided in this application can also be applied to future communication systems, such as future mobile communication systems. The technical solutions provided in this application can also be applied to device to device (D2D) communication, vehicle-to-everything (V2X) communication, machine to machine (M2M) communication, machine type communication (MTC), and Internet of Things (IoT) communication systems or other communication systems.

[0074] The terminal devices in the embodiments of the present application include various devices with wireless communication functions, which can be used to connect people, objects, machines, etc. The terminal devices can be widely used in various scenarios, such as: cellular communication, D2D, V2X, peer to peer (P2P), M2M, MTC, IoT, virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery, etc. The terminal device can be a terminal in any of the above scenarios, such as an MTC terminal, an IoT terminal, etc. The terminal device may be user equipment (UE), terminal, fixed device, mobile station device or mobile device of the 3rd Generation Partnership Project (3GPP) standard, subscriber unit, handheld device, vehicle-mounted device, wearable device, cellular phone, smart phone, SIP phone, wireless data card, personal digital assistant (PDA), computer, tablet computer, notebook computer, wireless modem, handheld device, laptop computer, computer with wireless transceiver function, smart book, vehicle, satellite, global positioning system (GPS) device, target tracking device, aircraft (such as drone, helicopter, multi-copter, quadcopter, or airplane), ship, remote control device, smart home device, industrial equipment, or a device built into the above devices (such as a communication module, modem or chip in the above devices), or other processing devices connected to the wireless modem.

[0075] It should be understood that in some scenarios, a terminal device can also be used to act as a base station. For example, a terminal device can act as a scheduling entity that provides sidelink signals between terminal devices in scenarios such as V2X, D2D, or P2P.

[0076] In the embodiments of the present application, the device for implementing the function of the terminal device can be the terminal device, or it can be a device that can support the terminal device to implement the function, such as a chip system or chip, which can be installed in the terminal device. In the embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0077] The network device in the embodiment of the present application can be a device for communicating with a terminal device, and the network device can also be referred to as an access network device or a wireless access network device, such as a base station. The base station can broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master station, auxiliary station, multi-standard wireless (motor slide retainer, MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof. A base station can also refer to a communication module, a modem, or a chip used to be set in the aforementioned device or apparatus. A base station can also be a mobile switching center, a device that performs base station functions in D2D, V2X, and M2M communications, a network-side device in a future communication network, or a device that performs base station functions in a future communication system. A base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form used by the network equipment.

[0078] The network device in the embodiment of the present application may refer to a radio access network (RAN) node (or device) used to access a terminal device to a wireless network.

[0079] In one possible scenario, a RAN node can be a base station (BS), eNodeB, access point, transit router (TRP), gNB, a base station in a future mobile communication system, a base station in a future mobile communication system, or an access node in a Wi-Fi system. A RAN node can be a macro base station, a micro base station, an indoor station, a relay node, a donor node, or a radio controller in a cloud radio access network (CRAN) scenario. Alternatively, a RAN node can be a server, a wearable device, a vehicle, or an onboard device. For example, a roadside unit (RSU) in V2X technology.

[0080] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0081] In the embodiments of the present application, the device for implementing the function of the network device can be the network device, or it can be a device that can support the network device to implement the function, such as a chip system or chip, which can be installed in the network device. In the embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0082] The network equipment and terminal devices of the present application can be applied to non-terrestrial networks (NTNs). NTN communications have the advantages of wide coverage, long communication distance, high reliability, great flexibility, and high throughput. NTN communications are not affected by geographical environment, climatic conditions, and natural disasters, and have been widely used in aviation communications, maritime communications, military communications, and other fields. On the one hand, NTNs can provide communication services for areas that are difficult for terrestrial networks to cover (for example, oceans, forests, deserts, or remote areas). On the other hand, NTNs can enhance communication reliability, for example, providing more stable communication services for users in high-speed mobile scenarios such as trains and airplanes. On another hand, NTNs can also provide more data transmission resources and support a larger number of connections. Therefore, introducing NTNs into future communication systems can greatly improve user experience. The following description of NTN communications in this application uses satellite communications as an example of NTN communications, but can also be extended to other non-terrestrial network communications, such as high altitude platform station (HAPS) communications.

[0083] Generally speaking, the higher the satellite's orbit, the larger its coverage area, but the longer the communication delay. According to the satellite's orbital altitude, satellites can be divided into: (1) low earth orbit (LEO) satellites, the orbital altitude of LEO satellites is approximately 160 kilometers (km) to 2000 km; (2) medium earth orbit (MEO) satellites, the orbital altitude of MEO satellites is approximately 2000 km to 35786 km; (3) geostationary earth orbit (GEO), the orbital altitude of GEO satellites is approximately 35786 km. Among them, LEO satellites and MEO satellites are collectively referred to as non-geostationary satellite orbit (NGSO) satellites. Satellites operating in this orbit move at high speed relative to the ground. GEO satellites are synchronous earth satellite orbits, and satellites operating in this orbit are stationary relative to the ground. The communication delay of NGSO satellites is lower than that of GEO satellites, so many satellite communication providers choose NGSO satellites as their communication satellites.

[0084] NGSO satellites are further categorized as Earth Moving Cells and Earth Fixed Cells, depending on whether the satellite's beam moves with the satellite. For Earth Moving Cells, the cell served by the satellite moves relative to the ground, and the satellite's beam direction follows the satellite's movement. For Earth Fixed Cells, the cell served by the satellite remains fixed relative to the ground for a certain period of time, and the satellite antenna can use beamforming capabilities to direct the beam to a fixed area on the ground for a certain period of time.

[0085] The following briefly introduces the network architecture applicable to the embodiments of the present application.

[0086] Figure 1 is a schematic diagram of an architecture 100 of an NTN communication system applicable to an embodiment of the present application. The NTN communication system shown in Figure 1 includes network device #1, network device #2, a ground base station, a ground core network, and terminal devices. Network device #1 can be a satellite, such as a GEO satellite, MEO satellite, or LEO satellite, without limitation. Network device #2 can be a gateway (also known as a ground station, earth station, gateway, or gateway station) (NTN gateway), which can be used to connect network device #1 and the ground base station. One or more network devices #1 can be connected to one or more ground base stations through one or more network devices #2, without limitation. In Figure 1, the communication mode of network device #1 is transparent mode. That is, network device #1 acts as an analog RF repeater, performing wireless frequency conversion and amplification, and can transparently transmit or replicate signals between the ground base station and the terminal device. For example, a signal sent by a terminal device can be transparently transmitted through network device #1 and then forwarded to the ground base station by network device #2.

[0087] Figure 2 is a schematic diagram of an NTN communication system architecture 200 applicable to an embodiment of the present application. In Figure 2, the communication mode of network device #1 is regenerative mode, meaning that network device #1 can function as a wireless communication base station, regenerating signals received from the ground, and understanding and processing these signals. For example, network device #1 can be a base station mounted on an artificial satellite or high-altitude aircraft, such as an evolved base station (eNB), a 5G base station (gNB), or a base station (xNodeB) in a future communication system. Network device #2 can forward signaling between network device #1 (i.e., the base station) and the core network.

[0088] It should be noted that Figure 2 only shows one network device #1 and one network device #2. In actual use, an architecture with multiple network devices #1 and / or multiple network devices #2 may be adopted as needed. Each network device #1 can provide services to one or more terminal devices, each network device #2 can correspond to one or more network devices #1, and each network device #1 can correspond to one or more network devices #2. This embodiment of the application does not specifically limit this.

[0089] Figure 3 shows a schematic diagram of another NTN communication system architecture 300. Figure 3 uses two network devices #1 and two network devices #2 as an example. The communication mode of the two network devices #1 is regenerative mode, meaning that both network devices #1 can function as base stations for wireless communication. The difference from Figure 3 is that an inter-satellite link (ISL) exists between the two network devices #1. In this network architecture, different network devices #1 can communicate with each other and can also connect to the same terrestrial core network.

[0090] In another possible scenario, multiple RAN nodes collaborate to assist terminal devices in achieving wireless access, and different RAN nodes respectively implement part of the functions of the base station. For example, the RAN node can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be set separately, or they can be included in the same network element, such as a baseband unit (BBU). The CU and DU split the protocol layer of the base station, and the functions of some protocol layers are centrally controlled by the CU, while the functions of the remaining part or all of the protocol layers are distributed in the DU, and the DU is centrally controlled by the CU. The RU can be included in a radio frequency device or a radio frequency unit, such as an RRU, AAU or RRH.

[0091] In different systems, CU, DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an open access network (open RAN, ORAN) system, CU may also be called open CU (open CU, O-CU), DU may also be called open DU (open DU, O-DU), CU-CP may also be called open CU-CP (open CU-CP, O-CU-CP), CU-UP may also be called open CU-UP (open CU-UP, O-CU-UP), and RU may also be called open RU (open RU, O-RU). For example, Figure 4 is a schematic diagram of an ORAN system, and the ORAN system may include one or more O-CU, O-DU, O-RU, etc. For specific protocol layer functions, please refer to Table 1:

[0092] Table 1. Correspondence between RAN nodes in the ORAN system and their achievable protocol layer functions

[0093] Any of the CU (or CU-CP, CU-UP), DU, and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. In the ORAN system, any of the O-CU (or O-CU-CP, O-CU-UP), O-DU, and O-RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0094] It will be understood that the division of the protocol layer functions of the above-mentioned RAN nodes shown in Table 1 is merely an example and does not constitute a limitation on CU, DU, and RU.

[0095] Figure 5 shows a schematic diagram of another architecture 400 of the NTN communication system. Figure 5 differs from Figure 1 in that network device #1, acting as the DU of the base station, is separate from the CU of the ground base station and can understand, process, and regenerate signals from the ground, rather than simply transparently transmitting or replicating them, while the ground base station only acts as a CU. In this network architecture, the service link between the terminal device and network device #1 can transmit NR-Uu wireless interface signals, and the feeder link between network devices #1 and network devices #2 transmits satellite radio interface (SRI) signals, over which the F1 interface signals between the DU and CU are transmitted.

[0096] To facilitate understanding of the embodiments of the present application, the following briefly explains the terms involved in the embodiments of the present application.

[0097] 1. Traditional switching or basic switching

[0098] In mobile communication systems, the mobility management of connected terminal devices in traditional handover processes is controlled by network equipment. For example, the source base station instructs the terminal device to switch to a target cell and how to perform the handover by sending an RRC reconfiguration message (RRCReconfiguration) containing a handover command. Specifically, after receiving the RRC reconfiguration message containing the handover command, the terminal device immediately releases the source cell, stops uplink or downlink data transmission with the source cell, and accesses the target cell according to the content of the handover command. Therefore, the successful transmission of the handover message is a necessary condition for ensuring a successful handover under the traditional handover mechanism.

[0099] 2. Conditional Handover (CHO)

[0100] The CHO mechanism can improve the success rate of handover. For example, when the quality of the source link is good, the source base station sends an RRC reconfiguration message containing CHO configuration information to the terminal device. The CHO configuration information may include configuration information of one or more candidate cells, execution trigger conditions of one or more candidate cells (also called CHO trigger conditions), measurement configuration of one or more candidate cells, etc. After receiving the CHO configuration information, the terminal device will not immediately initiate a handover action to any candidate cell, but will continue to maintain connection and data transmission with the source base station. After the terminal device finds a candidate cell that meets the corresponding execution trigger conditions in one or more candidate cells, it can independently determine the target cell and further trigger the execution of CHO to the target cell.

[0101] 3. Dual Active Protocol Stack (DAPS) switching

[0102] The DAPS switching mechanism can reduce the switching interruption time. Among them, the switching interruption time is the period of time during which the terminal device cannot transmit data with any base station during the switching. For example, the source base station indicates the target cell to the terminal device through an RRC reconfiguration message containing a switching command. The terminal device accesses the target cell according to the content contained in the switching command. During the switching execution (or during access to the target cell), the terminal device will continue to transmit data with the source cell until the terminal device establishes a connection with the target cell for data transmission. Specifically, the terminal device can receive and send data with the source cell and the target cell at the same time in a short period of time:

[0103] The terminal device continues to receive downlink data from the source cell until the target cell instructs the terminal device to release the source cell;

[0104] The terminal device continues to send uplink user data to the source cell until it successfully randomly accesses the target cell.

[0105] DAPS handover places high demands on terminal device capabilities. From the terminal device's perspective, two protocol stacks are internally active during the DAPS handover process. One active protocol stack is used for transmitting and receiving user-plane data in the target cell; the other is used for transmitting and receiving user-plane data in the source cell. The source and target user-plane protocol stacks share a common PDCP entity, enabling both sides to share common reordering and deduplication functions.

[0106] 4. Radio link failure (RLF) report

[0107] The terminal device generally records an RLF report in the following two situations:

[0108] 1. The terminal device does not receive the handover command (for example, in a traditional handover or DAPS handover scenario), or in a CHO scenario, the terminal device receives CHO configuration information but does not trigger CHO execution, resulting in RLF.

[0109] 2. The terminal device performs a handover (such as a traditional handover, CHO or DAPS handover), but fails to access the target cell or an RLF occurs soon after accessing the target cell.

[0110] Currently, the RLF report covers traditional handover, CHO, and DAPS mobility scenarios, recording information about radio link failure or handover failure in these scenarios. However, it does not support NTN scenarios. In other words, in NTN scenarios, terminal devices do not report relevant information about handover failure or radio link failure.

[0111] In view of this, an embodiment of the present application proposes a communication method, which enables the terminal device to feedback RLF information to the network device in the NTN scenario, so that the network device can adjust the mobility parameters in a timely manner. Figure 6 is a schematic flow chart of a communication method 600 provided by an embodiment of the present application. In this embodiment, the terminal device and the network device are used as the execution subjects of the interaction diagram as an example to illustrate the method, but the present application does not limit the execution subjects of the interaction diagram. For example, the terminal device in Figure 6 can also be a chip, a chip system, or a processor that supports the method that can be implemented by the terminal device, and can also be a logic module or software that can implement all or part of the terminal device; the network device can also be a chip, a chip system, or a processor that supports the method that can be implemented by the network device, and can also be a logic module or software that can implement all or part of the network device.

[0112] The communication method 600 may include the following steps:

[0113] In step S610, the network device sends first information to the terminal device, where the first information is used to indicate at least one first triggering condition that needs to be satisfied for the terminal device to trigger CHO to the target cell.

[0114] The network device obtains the configuration information of one or more candidate cells from one or more candidate network devices. When the quality of the source link is good, the network device sends an RRC reconfiguration message containing CHO configuration information to the terminal device. The CHO configuration information may include the configuration information of one or more candidate cells, the execution trigger conditions of one or more candidate cells, the measurement configuration of one or more candidate cells, etc. The configuration information of one or more cells includes the configuration information that the terminal device should use when accessing the cell, such as uplink physical channel configuration, downlink physical channel configuration, etc. The execution trigger conditions of one or more candidate cells are used by the terminal device to evaluate whether CHO can be triggered to execute to the cell. When the execution trigger conditions of the cell are met, the terminal device triggers the execution of CHO to the cell. When the execution trigger conditions of the cell are not met, the terminal device does not trigger the execution of CHO to the cell.

[0115] Exemplarily, the execution triggering conditions of one or more candidate cells may correspond to the events in Table 2 below:

[0116] Table 2

[0117] Among them, Ms in Table 2 above represents the RRM measurement result of the source cell measured by the terminal device, Mn represents the RRM measurement result of the candidate cell measured by the terminal device, Ofs represents the frequency offset of the source cell, Ofn represents the frequency offset of the candidate cell, Ocs represents the cell offset of the source cell, Ocn represents the cell offset of the candidate cell, Off represents the offset of the RRM measurement result, M11 represents the distance between the terminal device and the source cell reference point (reference position) or the distance between the terminal device and the source cell mobile reference point (mobile reference position), M12 represents the distance between the terminal device and the candidate cell reference point (reference position) or the distance between the terminal device and the candidate cell mobile reference point (mobile reference position), Mt represents Indicates the time measured by the terminal device. TimeToTrigger indicates the duration during which the entry trigger condition or the exit trigger condition is continuously met. Hys for events A1, A2, A3, A4, A5, A6, B1, and B2 indicates the amplitude hysteresis of the RRM measurement result. Hys for events D1 and D2 indicates the amplitude hysteresis of the distance. Hys for the T1 event indicates the time hysteresis. Thresh1 and Thresh2 for events A1, A2, A3, A4, A5, A6, B1, and B2 indicate the RRM measurement thresholds. Thresh1 and Thresh2 for events D1 and D2 indicate the distance thresholds. Thresh1 for the T1 event indicates the time threshold. Generally speaking, each candidate cell has two execution trigger conditions. For example, one execution trigger condition can be an execution trigger condition corresponding to any one of the above-mentioned events A1, A2, A3, A4, A5, A6, B1, and B2, and the other execution trigger condition can be an execution trigger condition corresponding to any one of the events D1, D2 or T1.

[0118] Exemplarily, the measurement configuration of one or more candidate cells mainly includes at least one of the following information:

[0119] Based on the measurement capabilities of the terminal device, multiple parallel SSB-based measurement timing configurations (SMTCs) are configured for each cell (carrier) in one or more candidate cells. The SMTC indicates the timing location for initiating SSB measurements (SSB measurement period, SSB measurement duration, time offset, etc.); multiple SMTCs correspond to multiple measurement gaps (measurement gaps), which are the time periods when the terminal device leaves the current frequency point and measures on other frequencies; auxiliary information #1 provided in SIB19, which includes satellite ephemeris, common timing advance (TA) parameters, etc.; timing information and location information related to the serving cell. The timing information refers to the coordinated universal time (UTC) when the serving cell stops serving the current geographic area. In the earth fixed cell scenario, the location information refers to the reference position of the serving cell and the distance threshold between the terminal device and the reference position of the serving cell. In the earth moving cell scenario, the location information refers to the mobile reference position of the serving cell at the epoch time and the distance threshold between the mobile reference position of the serving cell.

[0120] Additionally, the measurement configuration of the one or more candidate cells may further include at least one of the following:

[0121] Measurement object, reporting configuration, trigger quantity, measurement identifier (measurement ID), etc. The measurement object refers to the object on which the terminal device performs RRM measurement, including SSB frequency, SSB subcarrier spacing, whitelist cells, blacklist cells, etc.; the reporting configuration refers to the standard for triggering the terminal device to report the measurement report and the format of the measurement report, etc. Each reporting configuration has a separate identifier (reportConfigId). The reporting configuration type can be divided into event-triggered reporting and periodic triggered reporting. Event-triggered reporting can be triggered by any of the events A1, A2, A3, A4, A5, A6, B1, and B2 in Table 2 above; the trigger quantity refers to the strategy for triggering event reporting; the measurement identifier can combine the measurement object and reporting configuration as a set.

[0122] After receiving the CHO configuration information, the terminal device will not immediately initiate a handover to any candidate cell, but will continue to maintain the connection and data transmission with the source cell provided by the source network device. After the terminal device finds a candidate cell that meets the corresponding execution trigger conditions among one or more candidate cells, it can independently determine the target cell and further trigger the CHO to the target cell.

[0123] Step S612: The terminal device fails to connect during the mobility process of the NTN and records a first report, where the first report is used to indicate information of the terminal device during the mobility process of the NTN.

[0124] Specifically, the terminal device triggers the execution of CHO to the target cell and needs to meet at least one first trigger condition of the target cell, including one or more of a distance trigger condition, a time trigger condition, and an RRM measurement trigger condition. The distance trigger condition is: the distance between the terminal device and the reference point of the source cell is greater than the first threshold value and / or the distance between the terminal device and the reference point of the target cell is less than the second threshold value. The distance trigger condition may correspond to the D1 and D2 events shown in Table 2 above. The time trigger condition is: the time measured by the terminal device is greater than the third threshold value and less than the fourth threshold value, wherein the fourth threshold value is the sum of the third threshold value and the duration, and the duration is the time when the terminal device can access the target cell. The time trigger condition may correspond to the T1 event shown in Table 2 above. Alternatively, the third threshold value may be set as the time when the target cell starts serving the geographical area where the terminal device is located, and the fourth threshold value may be set as the time when the target cell stops serving the geographical area where the terminal device is located. The RRM measurement trigger condition is: the RRM measurement result of the source cell measured by the terminal device is less than the fifth threshold value and / or the RRM measurement result of the target cell measured by the terminal device is greater than the sixth threshold value and / or the difference between the RRM measurement result of the target cell measured by the terminal device and the measurement result of the source cell is greater than the seventh threshold value. The RRM measurement trigger condition can correspond to any one of the events A1, A2, A3, A4, A5, A6, B1, and B2 shown in Table 2 above.

[0125] For example, the connection failure of the terminal device during the mobility process of the NTN is divided into the following situations:

[0126] The following situations 1 to 5: CHO is not triggered, and RLF occurs between the terminal device and the source cell.

[0127] Specifically, CHO not triggered means that the terminal device has not evaluated a candidate cell that meets the corresponding execution trigger condition, that is, the candidate cell does not meet its corresponding execution trigger condition; CHO triggered means that the terminal device has evaluated that there is a candidate cell that meets its corresponding execution trigger condition, and the candidate cell is the target cell to which the terminal device executes switching that meets the execution trigger condition, and the execution trigger condition corresponding to the target cell can be at least one of the above-mentioned first trigger conditions.

[0128] Case 1: The at least one first trigger condition includes the distance trigger condition, and the terminal device meets the distance trigger condition but fails to meet other trigger conditions, resulting in a connection failure. For example, the RRM measurement trigger condition is not met, or the terminal device fails to meet the distance trigger condition, resulting in a connection failure. In this case, the first report may include at least one of the following information:

[0129] 1) The time measured when the distance between the terminal device and the reference point of the source cell is greater than the above-mentioned first threshold value; illustratively, the above-mentioned distance trigger condition is: the distance between the terminal device and the reference point of the source cell is greater than the first threshold value, the terminal device meets the distance trigger condition at time T11, and the terminal device records the T11 time in the first report.

[0130] 2) The time measured when the distance between the terminal device and the target cell reference point is less than the above-mentioned second threshold value; illustratively, the above-mentioned distance trigger condition is: the distance between the terminal device and the target cell reference point is less than the second threshold value, the terminal device meets the distance trigger condition at time T12, and the terminal device records the T12 time in the first report.

[0131] 3) The time interval between the time measured when the distance between the terminal device and the source cell reference point is greater than the above-mentioned first threshold value and the time measured when the distance between the terminal device and the target cell reference point is less than the above-mentioned second threshold value. Exemplarily, the above-mentioned distance trigger condition is: the distance between the terminal device and the source cell reference point is greater than the first threshold value and the distance between the terminal device and the target cell reference point is less than the second threshold value, the terminal device satisfies the condition that the distance between the terminal device and the source cell reference point is greater than the first threshold value at time T11, and the terminal device satisfies the condition that the distance between the terminal device and the target cell reference point is less than the second threshold value at time T12, and the terminal device may record the time interval between time T11 and time T12 in the first report.

[0132] 4) Whether the distance between the terminal device and the source cell reference point is greater than the first threshold value or whether the distance between the terminal device and the target cell reference point is less than the second threshold value is satisfied first; illustratively, the above distance trigger condition is: the distance between the terminal device and the source cell reference point is greater than the first threshold value and the distance between the terminal device and the target cell reference point is less than the second threshold value, the terminal device satisfies the condition that the distance between the terminal device and the source cell reference point is greater than the first threshold value at time T11 and the terminal device satisfies the condition that the distance between the terminal device and the target cell reference point is less than the second threshold value at time T12 after time T11, the terminal device can record in the first report that the distance between the terminal device and the source cell reference point is greater than the above first threshold value first satisfied. Alternatively, the terminal device satisfies the condition that the distance between the terminal device and the source cell reference point is greater than the first threshold value at time T11 but the terminal device does not satisfy the condition that the distance between the terminal device and the target cell reference point is less than the second threshold value, the terminal device can record in the first report that the distance between the terminal device and the source cell reference point is greater than the above first threshold value first satisfied. Alternatively, if the terminal device satisfies the requirement that the distance between the terminal device and the target cell reference point is less than the second threshold value at time T12 but the terminal device does not satisfy the requirement that the distance between the terminal device and the source cell reference point is greater than the first threshold value, the terminal device may first record in the first report that the distance between the terminal device and the target cell reference point is less than the second threshold value.

[0133] Case 2: The at least one first trigger condition includes the RRM measurement trigger condition. The terminal device meets the RRM measurement trigger condition but fails to meet other trigger conditions, resulting in a connection failure. For example, the distance trigger condition or the time trigger condition is not met. Alternatively, the terminal device fails to meet the RRM measurement trigger condition, resulting in a connection failure. In this case, the first report may include at least one of the following information:

[0134] 1) The time at which the terminal device measures when the RRM measurement result of the source cell is less than the fifth threshold value; illustratively, the above-mentioned RRM measurement trigger condition is: the RRM measurement result of the source cell measured by the terminal device is less than the fifth threshold value, and the terminal device meets the RRM measurement trigger condition at time T21, and the terminal device records the T21 time in the first report.

[0135] 2) The time when the terminal device measures when the RRM measurement result of the target cell is greater than the above-mentioned sixth threshold value; illustratively, the above-mentioned RRM measurement trigger condition is: the RRM measurement result of the target cell measured by the terminal device is greater than the sixth threshold value, and the terminal device meets the RRM measurement trigger condition at time T22, and the terminal device records the T22 time in the first report.

[0136] 3) The time interval between the time measured by the terminal device when the RRM measurement result of the source cell is less than the above-mentioned fifth threshold value and the time measured by the terminal device when the RRM measurement result of the target cell is greater than the above-mentioned sixth threshold value; exemplarily, the above-mentioned RRM measurement trigger condition is: the RRM measurement result of the source cell measured by the terminal device is less than the fifth threshold value and the RRM measurement result of the target cell measured by the terminal device is greater than the sixth threshold value. The terminal device satisfies the RRM measurement result of the source cell measured by the terminal device is less than the fifth threshold value at time T21, and the terminal device satisfies the RRM measurement result of the target cell measured by the terminal device is greater than the sixth threshold value at time T22. The terminal device may record the time interval between time T21 and time T22 in the first report.

[0137] 4) Whether the RRM measurement result of the source cell is less than the above-mentioned fifth threshold value or whether the RRM measurement result of the target cell is greater than the above-mentioned sixth threshold value is satisfied first; illustratively, the above-mentioned RRM measurement trigger condition is: the RRM measurement result of the source cell measured by the terminal device is less than the fifth threshold value and the RRM measurement result of the target cell measured by the terminal device is greater than the sixth threshold value, the terminal device satisfies the RRM measurement result of the source cell measured by the terminal device at time T21 that is less than the fifth threshold value, and the terminal device satisfies the RRM measurement result of the target cell measured by the terminal device at time T22 after time T21 that is greater than the sixth threshold value, the terminal device can record in the first report that the RRM measurement result of the source cell is less than the fifth threshold value first. Alternatively, the terminal device satisfies the RRM measurement result of the source cell measured by the terminal device at time T21 that is less than the fifth threshold value, but the terminal device does not satisfy the RRM measurement result of the target cell measured by the terminal device that is greater than the sixth threshold value, the terminal device can record in the first report that the RRM measurement result of the source cell is less than the fifth threshold value first. Alternatively, if the terminal device satisfies the requirement that the RRM measurement result of the target cell measured by the terminal device is greater than the sixth threshold value at time T22, but the terminal device does not satisfy the requirement that the RRM measurement result of the source cell measured by the terminal device is less than the fifth threshold value, the terminal device can first record the requirement that the RRM measurement result of the target cell is greater than the sixth threshold value in the first report.

[0138] Case 3: The at least one first trigger condition includes the distance trigger condition and the RRM measurement trigger condition, or the at least one first trigger condition includes the time trigger condition and the RRM measurement trigger condition. The terminal device meets the distance trigger condition or the time trigger condition but does not meet the RRM measurement trigger condition. At this time, the first report also includes the RRM measurement result of the terminal device.

[0139] Specifically, the first report of situation three can also adaptively include one or more of the at least one information included in the first report of situation one, and the first report of situation three can also adaptively include one or more of the at least one information included in the first report of situation two.

[0140] It should be noted that the RRM measurement result when the terminal device meets the distance trigger condition or the time trigger condition may be: the RRM measurement result measured when the terminal device meets the distance trigger condition or the time trigger condition at the earliest, or the RRM measurement result measured when the terminal device meets the distance trigger condition or the time trigger condition at the latest, or multiple RRM measurement results during the period when the terminal device continuously meets the distance trigger condition or the time trigger condition or any one measurement result of the multiple RRM measurement results. This application does not limit this.

[0141] Case 4: The at least one first trigger condition includes the distance trigger condition and the RRM measurement trigger condition. The terminal device meets the RRM measurement trigger condition but does not meet the distance trigger condition. In this case, the first report also includes at least one of the following information:

[0142] The distance between the terminal device and the reference point of the source cell; the distance between the terminal device and the reference point of the target cell.

[0143] Specifically, the first report of situation four can also adaptively include one or more of the at least one information included in the first report of situation one, and the first report of situation three can also adaptively include one or more of the at least one information included in the first report of situation two.

[0144] It should be noted that when the terminal device meets the RRM measurement trigger condition, the distance between the terminal device and the source cell reference point and / or the distance between the terminal device and the target cell reference point can be: the distance between the terminal device and the source cell reference point and / or the distance between the terminal device and the target cell reference point measured when the terminal device meets the RRM measurement trigger condition at the earliest, or the distance between the terminal device and the source cell reference point and / or the distance between the terminal device and the target cell reference point measured when the terminal device meets the RRM measurement trigger condition at the latest, or the distance between the terminal device and the source cell reference point and / or the distance between the terminal device and the target cell reference point measured at any one of the distances between the terminal device and the source cell reference point and / or the distance between the terminal device and the target cell reference point measured multiple times during the period when the terminal device continues to meet the RRM measurement trigger condition, or the average value or median value of the distance between the terminal device and the source cell reference point and / or the distance between the terminal device and the target cell reference point measured multiple times during the period when the terminal device continues to meet the RRM measurement trigger condition, etc. This application does not limit this.

[0145] Case 5: The at least one first trigger condition includes the time trigger condition and the RRM measurement trigger condition. The terminal device meets the RRM measurement trigger condition but does not meet the time trigger condition. In this case, the first report also includes the time measured by the terminal device.

[0146] Specifically, the first report in case four may also adaptively include one or more of the at least one item of information included in the first report in case two above.

[0147] It should be noted that the time measured by the terminal device when the terminal device meets the RRM measurement trigger condition can be: the time measured when the terminal device meets the RRM measurement trigger condition at the earliest, or the time measured when the terminal device meets the RRM measurement trigger condition at the latest, or any one of the times measured multiple times during the period when the terminal device continuously meets the RRM measurement trigger condition, or the average value or median value of the times measured multiple times during the period when the terminal device continuously meets the RRM measurement trigger condition, etc. This application does not limit this.

[0148] Case 6: CHO is triggered, and a handover failure occurs between the terminal device and the target cell, or a handover fails within a first time period after a successful handover, and an RLF occurs between the terminal device and the target cell. The first time period is less than a threshold. In this case, the first report may include at least one of the following information:

[0149] 1) The first first trigger condition that is satisfied. Exemplarily, the at least one first trigger condition of the target cell includes the distance trigger condition and the RRM measurement trigger condition. If the terminal device first satisfies the distance trigger condition at time T1 and then satisfies the RRM measurement trigger condition at time T2 after time T1, the terminal device may record the distance trigger condition satisfied at time T1 in the first report.

[0150] 2) The time interval between the time when the terminal device satisfies the first trigger condition and the time when the terminal device satisfies the second first trigger condition. Exemplarily, the at least one first trigger condition of the target cell includes the distance trigger condition and the RRM measurement trigger condition. If the terminal device first satisfies the distance trigger condition at time T1 and the terminal device satisfies the RRM measurement trigger condition at time T2 after time T1, the terminal device may record the time interval between time T1 and time T2 in the first report.

[0151] Specifically, the first report of case 6 may also adaptively include one or more of the at least one item of information included in the first reports of cases 1 to 5 above.

[0152] Case 7: The terminal device is configured with the above CHO configuration information, but CHO is not necessarily executed.

[0153] After the terminal device receives the CHO configuration, CHO is not triggered, resulting in the terminal device not performing the switch, or the terminal device performs the switch. The switch performed by the terminal device can be CHO or traditional switch. When CHO is not triggered, the terminal device can receive a traditional switch command to perform traditional switch.

[0154] Specifically, the first report submitted in case seven may also adaptively include one or more of the at least one item of information included in the first reports in cases one to six above.

[0155] Exemplarily, the first report may be an RLF report, an SHR report, or other reports. The first report may also include at least one of the following information:

[0156] 1) Failed primary cell ID (failedPcellID): The cell ID of the terminal device that detects RLF, or the target cell ID of handover failure (HOF);

[0157] 2) Connection failure type (connectionFailureType): such as RLF or HOF;

[0158] 3) Primary cell identifier before connection failure (previousPCellId): the source cell identifier from which the terminal device last received a handover command;

[0159] 4) Reestablishment Cell Identifier (reestablishmentCellId): The cell identifier for the cell that initiates reestablishment after a connection failure.

[0160] 5) Connection failure time (timeConnFailure): The time from the last time the terminal device received the switching command to the time the connection failed;

[0161] 6) Time Since Failure (timeSinceFailure): The time from when the connection fails to when the connection fails is recorded. This generally refers to the time from when the connection fails to when the RLF-report is reported.

[0162] 7) RLF Cause (rlf-Cause): The reason for the radio link failure or the switching failure. For example, in the CHO scenario, the terminal device receives the CHO configuration information but does not trigger the execution of CHO, that is, the terminal device does not meet at least one of the above-mentioned first trigger conditions; or due to T310 timer timeout, T312 timer timeout, random access problem, beam recovery failure, channel listen before talk (LBT) failure, too many radio link control (RLC) retransmissions, etc.

[0163] Taking the T310 timer as an example, when the radio resource control (RRC) layer of the terminal device continuously receives downlink out-of-sync indications (out of sync) reported from the physical layer (PHY) of the terminal device equal to N310, timer T310 is started. During the operation of timer T310, if the terminal device detects that the radio link has recovered (i.e., the number of downlink in-sync indications (in sync) reported from the physical layer of the terminal device equals N311) or receives / executes an RRC reconfiguration message with synchronization function, timer T310 is stopped. Otherwise, the timer runs to timeout. Once the timeout occurs, the radio link is considered to have failed, and RRC reestablishment is initiated.

[0164] When the running time of timer T310 / T312 reaches a specific threshold A, the terminal device considers that the wireless link has failed. When the running time of timer T304 reaches a specific threshold B, the terminal device considers that the handover has failed.

[0165] The definitions of the three timers T304 / T310 / T312 are as follows:

[0166] Timer T304: The duration of timer T304 indicates the duration from the time the terminal device receives the RRC reconfiguration message to the time it successfully completes random access to the target cell. The terminal device starts timer T304 when it receives the RRC reconfiguration message and stops timer T304 when random access is completed.

[0167] Timer T310: The duration of timer T310 indicates the duration that the terminal device detects physical layer problems with the source cell. This problem typically occurs when the number of consecutive downlink out-of-sync indications exceeds a certain threshold. After timer T310 is started, if the radio link recovers during its operation, timer T310 is stopped.

[0168] T312 timer: Timer T312 is started during the operation of timer T310. The operation duration of timer T312 indicates the duration between the terminal device triggering a measurement report (usually) and the terminal device recovering synchronization with the source cell during the operation of timer T312.

[0169] Specifically, examples of the start time, stop time, and processing after expiration of the above three timers are shown in Table 3.

[0170] Table 3 Timer function

[0171] If a connection failure occurs in the terminal device (such as a radio link failure or a handover failure), the RLF report will be recorded. When the terminal device fails to connect again, the terminal device clears the previously recorded RLF report and records the latest RLF report. The RLF report reporting mechanism can be a delayed reporting mechanism. For example, the terminal device records the RLF report. When the terminal device accesses the network device, the network has a mechanism to request the terminal device to report the RLF report through a UE Information Request message. The terminal device sends the RLF report to the network device through a UE Information Response message, which is used by the network device to identify mobility process problems and optimize mobility parameters.

[0172] 8) Last handover type (lastHO Type): such as traditional handover, CHO or DAPS handover;

[0173] 9) Time since CHO reconfiguration (timeSinceCHOReconfig): generally refers to the time from the CHO reconfiguration command to the CHO handover failure or radio link failure.

[0174] 10) timeConnSourceDAPSFailure: the time when the last DAPS handover to the source cell radio link failed;

[0175] 11) CHO CellId: identification information of the candidate cell for CHO execution by the terminal device;

[0176] 12) Serving cell measurement result (measResultLastServCell): The reference signal measurement quantity available in the serving cell when the terminal device detects the connection failure. The reference signal can be SSB and / or CSI-RS, and the measurement quantity can be one or more of RSRP, RSSI, RSRQ, and SINR. When the connection failure is RLF, the serving cell of the terminal device is the cell where the RLF is detected; when the connection failure is a handover failure, the serving cell of the terminal device is the source cell of the handover failure;

[0177] 13) Neighboring cell measurement result (measResultLastNeighCell): The reference signal measurement quantity of the cell available in addition to the serving cell measured when the terminal device detects a connection failure. The reference signal can be SSB and / or CSI-RS, and the measurement quantity can be one or more of RSRP, RSSI, RSRQ, and SINR. In addition, it may also include the configuration information of one or more candidate cells for CHO, the execution trigger conditions of one or more candidate cells for CHO, the first first trigger condition satisfied by the terminal device, and the time interval between the time when the terminal device satisfies the first first trigger condition and the time when the terminal device satisfies the second first trigger condition;

[0178] 14) CHOCandidateCellList: identification information of other CHO candidate cells except the CHO candidate cells included in the above neighboring cell measurement results;

[0179] 15) RAInformationCommon: When HOF or RLF caused by random access problems or beam recovery failure, record information related to four-step random access and / or two-step random access, such as frequency information, time domain and frequency domain information of PRACH resources, subcarrier spacing, maximum number of msgA transmissions, RSRP of the downlink reference signal measured during four-step random access and / or two-step random access selection, random access attempt information including the beam number and the number of preambles sent on the beam, conflict detection indication, indication information of whether the RSRP threshold of four-step random access / two-step random access is reached, fallback indication information from two-step random access to four-step random access, amount of data to be transmitted for two-step random access, resource location of PUSCH for two-step random access, etc.

[0180] 16) C-RNTI: C-RNTI used by the terminal device in the serving cell.

[0181] Step S614: The terminal device sends a first report to the network device. Correspondingly, the network device receives the first report from the terminal device.

[0182] Step S616: The network device adjusts the mobility parameters according to the first report.

[0183] For example, the network device analyzes the first report and optimizes the mobility process and related parameters of the NTN accordingly, such as setting a more reasonable threshold value for the CHO trigger condition, preventing the terminal device from performing switching too early or too late, reducing the probability of switching failure or wireless link failure, and reducing the impact of data transmission interruption time on user experience.

[0184] In this method, when a connection failure occurs in an NTN scenario, the terminal device can report the cause of the connection failure to the network device through a first report. Furthermore, other relevant information of the mobility process can be reported in the first report to facilitate the network device to optimize relevant parameters and reduce the interruption delay caused by the connection failure.

[0185] It can be understood that some optional features in the embodiments of the present application may not depend on other features in some scenarios, and may also be combined with other features in some scenarios, without limitation.

[0186] It can also be understood that in the above method embodiments, the methods and operations implemented by the communication device can also be implemented by components (such as chips or circuits) that can be implemented by the communication device.

[0187] Corresponding to the methods provided in the above method embodiments, embodiments of the present application also provide corresponding apparatuses, which include modules for executing the corresponding methods in the above method embodiments. The modules may be software, hardware, or a combination of software and hardware. It is understood that the technical features described in the above method embodiments are also applicable to the following apparatus embodiments.

[0188] FIG7 is a schematic block diagram of a communication device 700 provided in an embodiment of the present application. The device 700 includes a transceiver unit 710. The transceiver unit 710 can be used to implement corresponding communication functions. The transceiver unit 710 can also be referred to as a communication interface or a communication unit.

[0189] Optionally, the apparatus 700 further includes a processing unit 720. The processing unit 720 may be configured to perform information processing.

[0190] Optionally, the device 700 also includes a storage unit, which can be used to store instructions and / or data. The processing unit 720 can read the instructions and / or data in the storage unit so that the device implements the actions of the communication device in the aforementioned method embodiments.

[0191] In one design, the apparatus 700 may be the terminal device in the aforementioned embodiment, or may be a component (e.g., a chip) of the terminal device. The apparatus 700 may implement steps or processes corresponding to those performed by the terminal device in the above method embodiment, wherein the transceiver unit 710 may be configured to perform the transceiver-related operations of the terminal device in the above method embodiment, and the processing unit 720 may be configured to perform the processing-related operations of the terminal device in the above method embodiment.

[0192] In a possible implementation, the transceiver unit 710 is configured to receive first information and may also be configured to send a first report.

[0193] In another possible implementation, the processing unit 720 is configured to record the first report.

[0194] The device 700 can implement the steps or processes executed by the terminal device in the method embodiment according to the embodiment of the present application. The device 700 may include a unit for executing the method executed by the terminal device in the embodiment shown in Figure 6.

[0195] In another design, the apparatus 700 may be the network device in the aforementioned embodiment, or a component (such as a chip) of the network device. The apparatus 700 may implement steps or processes corresponding to those performed by the network device in the above method embodiment, wherein the transceiver unit 1010 may be used to perform the transceiver-related operations of the network device in the above method embodiment, and the processing unit 720 may be used to perform the processing-related operations of the network device in the above method embodiment.

[0196] In a possible implementation, the transceiver unit 710 is configured to send the first information and receive the first report.

[0197] In another possible implementation, the processing unit 720 is configured to adjust the mobility parameter according to the first report.

[0198] The device 700 can implement the steps or processes executed by the network device in the method embodiment according to the embodiment of the present application. The device 700 may include a unit for executing the method executed by the network device in the embodiment shown in Figure 6.

[0199] A more detailed description of the device 700 can be directly obtained by referring to the relevant description in the above method embodiment, and will not be repeated here.

[0200] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0201] It should also be understood that the device 700 here is embodied in the form of a functional unit. The term "unit" here can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combined logic circuit and / or other suitable components that support the described functions. In an optional example, those skilled in the art will understand that the device 1000 can be specifically a communication device (such as a terminal device, or a network device) in the above-mentioned embodiment, and can be used to execute the various processes and / or steps corresponding to the communication device in the above-mentioned method embodiments. To avoid repetition, they will not be described here.

[0202] The apparatus 700 of each of the above-mentioned solutions has the function of implementing the corresponding steps performed by the communication device (such as a terminal device or a network device) in the above-mentioned method. The functions can be implemented by hardware, or the corresponding software can be implemented by hardware. The hardware or software includes one or more modules corresponding to the above-mentioned functions; for example, the transceiver unit can be replaced by a transceiver (for example, the sending unit in the transceiver unit can be replaced by a transmitter, and the receiving unit in the transceiver unit can be replaced by a receiver), and other units, such as the processing unit, can be replaced by a processor to respectively perform the sending and receiving operations and related processing operations in each method embodiment.

[0203] In addition, the transceiver unit 710 may also be a transceiver circuit (for example, may include a receiving circuit and a sending circuit), and the processing unit may be a processing circuit.

[0204] It should be noted that the apparatus in FIG7 may be the device in the aforementioned embodiment, or may be a chip or chip system, such as a system on chip (SoC). The transceiver unit may be an input / output circuit or a communication interface; the processing unit may be a processor, microprocessor, or integrated circuit integrated on the chip. This is not limited here.

[0205] Figure 8 is a schematic block diagram of a communication device 800 provided in an embodiment of the present application. The device 800 includes a processor 810, which is coupled to a memory 820. Optionally, the memory 820 is further included to store computer programs or instructions and / or data. The processor 810 is configured to execute the computer programs or instructions stored in the memory 820, or read the data stored in the memory 820, to perform the methods described in the above method embodiments.

[0206] Optionally, there are one or more processors 810 .

[0207] Optionally, there are one or more memories 820 .

[0208] Optionally, the memory 820 is integrated with the processor 810 or provided separately.

[0209] Optionally, as shown in Figure 8, the apparatus 800 further includes a transceiver 830, which is configured to receive and / or transmit signals. For example, the processor 810 is configured to control the transceiver 830 to receive and / or transmit signals.

[0210] As a solution, the device 800 is used to implement the operations performed by the communication device in the above various method embodiments.

[0211] For example, the processor 810 is configured to execute computer programs or instructions stored in the memory 820 to implement relevant operations of the terminal device or network device in each of the above method embodiments.

[0212] During implementation, each step of the above method can be completed by an integrated logic circuit of the hardware in the processor 810 or by instructions in the form of software. The method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 820, and the processor 810 reads the information in the memory 820 and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

[0213] It should be understood that in the embodiments of the present application, the processor may be one or more integrated circuits for executing relevant programs to execute the method embodiments of the present application.

[0214] A processor (e.g., processor 810) may include one or more processors and be implemented as a combination of computing devices. The processor may include one or more of the following: a microprocessor, a microcontroller, a digital signal processor (DSP), a digital signal processing device (DSPD), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device (PLD), gating logic, transistor logic, discrete hardware circuits, processing circuits, or other suitable hardware, firmware, and / or a combination of hardware and software to perform the various functions described in this disclosure. The processor may be a general-purpose processor or a special-purpose processor. For example, processor 810 may be a baseband processor or a central processing unit. A baseband processor may be used to process communication protocols and communication data. A central processing unit may be used to enable the device to execute software programs and process data in the software programs. In addition, a portion of the processor may also include non-volatile random access memory. For example, the processor may also store information about the device type.

[0215] In this application, the term "program" is used broadly to refer to software. Non-limiting examples of software include program code, program, subroutine, instruction, instruction set, code, code segment, software module, application, or software application. The program can be executed in a processor and / or computer to cause the device to perform the various functions and / or processes described in this application.

[0216] The memory (e.g., memory 820) can store data required by the processor (e.g., processor 810) when executing software. The memory can be implemented using any suitable storage technology. For example, the memory can be any available storage medium that can be accessed by the processor and / or computer. Non-limiting examples of storage media include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM), static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM), removable media, optical disk storage, magnetic disk storage media, magnetic storage devices, flash memory, registers, state memory, remotely mounted storage, local or remote memory components, or any other medium capable of carrying or storing software, data, or information and accessible by a processor / computer. It should be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0217] The memory (e.g., memory 820) and the processor (e.g., processor 810) may be provided separately or integrated together. The memory may be used to connect to the processor so that the processor can read information from the memory and store and / or write information in the memory. The memory may be integrated into the processor. The memory and the processor may be provided in an integrated circuit (e.g., the integrated circuit may be provided in a UE or other network node).

[0218] 9 is a schematic block diagram of a chip system 900 provided in an embodiment of the present application. The chip system 900 (or also referred to as a processing system) includes a logic circuit 910 and an input / output interface 920.

[0219] The logic circuit 910 may be a processing circuit in the chip system 900. The logic circuit 910 may be coupled to a storage unit and call instructions in the storage unit so that the chip system 900 can implement the methods and functions of the various embodiments of the present application. The input / output interface 920 may be an input / output circuit in the chip system 900, outputting information processed by the chip system 900 or inputting data or signaling information to be processed into the chip system 900 for processing.

[0220] As a solution, the chip system 900 is used to implement the operations performed by the communication device in the above various method embodiments.

[0221] For example, the logic circuit 910 is used to implement the processing-related operations performed by the terminal device in the above method embodiments, such as the processing-related operations performed by the terminal device in the embodiment shown in Figure 9; the input / output interface 920 is used to implement the sending and / or receiving-related operations performed by the terminal device in the above method embodiments, such as the sending and / or receiving-related operations performed by the terminal device in the embodiment shown in Figure 6.

[0222] For another example, the logic circuit 910 is used to implement the processing-related operations performed by the network device in the above method embodiments, such as the processing-related operations performed by the network device in the embodiment shown in Figure 6; the input / output interface 920 is used to implement the sending and / or receiving-related operations performed by the network device in the above method embodiments, such as the sending and / or receiving-related operations performed by the network device in the embodiment shown in Figure 6.

[0223] An embodiment of the present application further provides a computer-readable storage medium storing computer instructions for implementing the methods executed by a communication device (such as a terminal device or a network device) in the above-mentioned method embodiments.

[0224] An embodiment of the present application further provides a computer program product comprising instructions, which, when executed by a computer, implement the methods performed by a communication device (such as a terminal device or a network device) in the above-mentioned method embodiments.

[0225] An embodiment of the present application also provides a communication system, which includes the terminal device and network device in the above embodiments.

[0226] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0227] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the above-mentioned units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, 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 interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0228] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to implement the solutions provided in this application.

[0229] In addition, each functional unit in each embodiment of the present application may be integrated into one unit, each unit may exist physically separately, or two or more units may be integrated into one unit.

[0230] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0231] When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instruction can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instruction can be transmitted from a website, computer, server or data center to another website, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). About computer-readable storage medium, reference can be made to the above description.

[0232] 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 this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: The method comprises: receiving first information from a network device, where the first information is used to indicate at least one first triggering condition that needs to be satisfied for the terminal device to trigger conditional handover (CHO) to a target cell; During a mobility process of a non-terrestrial network (NTN), a connection fails and a first report is recorded, where the first report is used to indicate information of the terminal device during the mobility process of the NTN; The first report is sent to the network device.

2. The method according to claim 1, characterized in that The at least one first trigger condition includes a distance trigger condition, wherein the distance trigger condition is: the distance between the terminal device and the source cell reference point is greater than a first threshold value, and / or the distance between the terminal device and the target cell reference point is less than a second threshold value, The first report includes at least one of the following information: The time measured when the distance between the terminal device and the source cell reference point is greater than the first threshold; The time measured when the distance between the terminal device and the target cell reference point is less than the second threshold; whether the distance between the terminal device and the source cell reference point is greater than the first threshold value or whether the distance between the terminal device and the target cell reference point is less than the second threshold value is satisfied first; The time interval between the time measured when the distance between the terminal device and the source cell reference point is greater than the first threshold value and the time measured when the distance between the terminal device and the target cell reference point is less than the second threshold value.

3. The method according to claim 1 or 2, characterized in that The at least one first trigger condition includes a time trigger condition, and the time trigger condition is: the time measured by the terminal device is greater than a third threshold value and less than a fourth threshold value, the fourth threshold value is the sum of the third threshold value and the duration, and the duration is the time when the terminal device can access the target cell.

4. The method according to any one of claims 1 to 3, characterized in that The at least one first trigger condition includes a radio resource management RRM measurement trigger condition, where the RRM measurement trigger condition is: an RRM measurement result of the source cell measured by the terminal device is less than a fifth threshold value, and / or, an RRM measurement result of the target cell measured by the terminal device is greater than a sixth threshold value, and / or, a difference between the RRM measurement result of the target cell measured by the terminal device and the RRM measurement result of the source cell is greater than a seventh threshold value, The first report includes at least one of the following information: The time measured by the terminal device when the RRM measurement result of the source cell is less than the fifth threshold; The time measured by the terminal device when the RRM measurement result of the target cell is greater than the sixth threshold; whether the RRM measurement result of the source cell is less than the fifth threshold value or whether the RRM measurement result of the target cell is greater than the sixth threshold value; The time interval between the time measured by the terminal equipment when the RRM measurement result of the source cell is less than the fifth threshold value and the time measured by the terminal equipment when the RRM measurement result of the target cell is greater than the sixth threshold value.

5. The method according to any one of claims 2 to 4, characterized in that When the terminal device meets the distance trigger condition or the terminal device meets the time trigger condition but does not meet the RRM measurement trigger condition, the first report also includes the radio resource management RRM measurement result of the terminal device.

6. The method according to any one of claims 2 to 4, characterized in that When the terminal device meets the RRM measurement trigger condition but does not meet the distance trigger condition, the first report further includes at least one of the following information: The distance between the terminal device and the source cell reference point; The distance between the terminal device and the target cell reference point.

7. The method according to claim 3 or 4, characterized in that When the terminal device meets the RRM measurement trigger condition but does not meet the time trigger condition, the first report also includes the time of measurement by the terminal device.

8. The method according to any one of claims 1 to 7, characterized in that The connection failure includes a radio link failure of the source cell or a CHO failure of the terminal device or a handover failure within the first time period after a CHO success of the terminal device.

9. A communication method, characterized in that: The method comprises: Sending first information to a terminal device, where the first information is used to indicate at least one first trigger condition that the terminal device needs to meet to trigger conditional handover (CHO) to a target cell; receiving a first report from the terminal device, where the first report is recorded when the terminal device fails to connect during a mobility process of the non-terrestrial network (NTN), and the first report is used to indicate information about the terminal device during the mobility process of the non-terrestrial network (NTN); A mobility parameter is adjusted based on the first report.

10. The method according to claim 9, characterized in that The at least one first trigger condition includes a distance trigger condition, wherein the distance trigger condition is: the distance between the terminal device and the source cell reference point is greater than a first threshold value, and / or the distance between the terminal device and the target cell reference point is less than a second threshold value, The first report includes at least one of the following information: The time measured when the distance between the terminal device and the source cell reference point is greater than the first threshold; The time measured when the distance between the terminal device and the target cell reference point is less than the second threshold; whether the distance between the terminal device and the source cell reference point is greater than the first threshold value or whether the distance between the terminal device and the target cell reference point is less than the second threshold value is satisfied first; The time interval between the time measured when the distance between the terminal device and the source cell reference point is greater than the first threshold value and the time measured when the distance between the terminal device and the target cell reference point is less than the second threshold value.

11. The method according to claim 9 or 10, characterized in that The at least one first trigger condition includes a time trigger condition, and the time trigger condition is: the time measured by the terminal device is greater than a third threshold value and less than a fourth threshold value, the fourth threshold value is the sum of the third threshold value and the duration, and the duration is the time when the terminal device can access the target cell.

12. The method according to any one of claims 9 to 11, characterized in that The at least one first trigger condition includes a radio resource management RRM measurement trigger condition, where the RRM measurement trigger condition is: an RRM measurement result of the source cell measured by the terminal device is less than a fifth threshold value, and / or, an RRM measurement result of the target cell measured by the terminal device is greater than a sixth threshold value, and / or, a difference between the RRM measurement result of the target cell measured by the terminal device and the RRM measurement result of the source cell is greater than a seventh threshold value, The first report includes at least one of the following information: The time measured by the terminal device when the RRM measurement result of the source cell is less than the fifth threshold; The time measured by the terminal device when the RRM measurement result of the target cell is greater than the sixth threshold; whether the RRM measurement result of the source cell is less than the fifth threshold value or whether the RRM measurement result of the target cell is greater than the sixth threshold value; The time interval between the time measured by the terminal equipment when the RRM measurement result of the source cell is less than the fifth threshold value and the time measured by the terminal equipment when the RRM measurement result of the target cell is greater than the sixth threshold value.

13. The method according to any one of claims 10 to 12, characterized in that When the terminal device meets the distance trigger condition or the terminal device meets the time trigger condition but does not meet the RRM measurement trigger condition, the first report further includes at least one of the following information: The RRM measurement result of the terminal device.

14. The method according to any one of claims 10 to 12, characterized in that When the terminal device meets the RRM measurement trigger condition but does not meet the distance trigger condition, the first report further includes at least one of the following information: The distance between the terminal device and the source cell reference point; The distance between the terminal device and the target cell reference point.

15. The method according to claim 11 or 12, characterized in that When the terminal device meets the RRM measurement trigger condition but does not meet the time trigger condition, the first report also includes the time of measurement by the terminal device.

16. The method according to any one of claims 1 to 7, characterized in that The connection failure includes a radio link failure of the source cell or a CHO failure of the terminal device or a handover failure within the first time period after a CHO success of the terminal device.

17. A communication device, characterized in that: Comprising means for executing the method according to any one of claims 1 to 8.

18. A communication device, characterized in that: Comprising means for performing the method as claimed in any one of claims 9 to 16.

19. A communication system, characterized in that: Comprising the communication device according to claim 17 and the communication device according to claim 18.

20. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 16.

21. A computer program product, characterized in that The computer program product comprises instructions for performing the method of any one of claims 1 to 16.

22. A chip system, characterized in that: The chip system comprises a processor and a memory, wherein the processor is used to execute a computer program or instruction stored in the memory, so that the chip system performs the method as claimed in any one of claims 1 to 16.

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