Communication method, synchronization method and communication apparatus

Abstract

Provided in the present application are a communication method, a synchronization method and a communication apparatus. The communication method comprises: a terminal receives first information, the first information being used for instructing a terminal to hand over to a first cell, and the first information comprising multiple pieces of ephemeris-related information corresponding to the first cell; the terminal determines to hand over to the first cell and determines first ephemeris-related information corresponding to the first cell, the first ephemeris-related information being one among the multiple pieces of ephemeris-related information; and, according to the first ephemeris-related information, the terminal accesses the first cell. The communication method provided by the present application enables terminals to use during the coverage periods of satellites ephemeris-related information of corresponding satellites to perform conditional handovers, thus effectively reducing signaling overheads.

Description

A communication method, a synchronization method and a communication device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on November 3, 2023, with application number 202311465735.7 and invention name “A communication method, synchronization method and communication device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and more specifically, to a communication method, a synchronization method, and a communication device. Background Art

[0003] In non-terrestrial network (NTN) systems, satellite networks can provide coverage in areas difficult to reach by terrestrial networks and enhance the reliability of mobile communications. Satellite cells can cover very large areas. For example, in a ground stationary cell scenario, a satellite adjusts its beam to maintain consistent coverage for a period of time. When service becomes unavailable, the next satellite takes over. In this scenario, the ground base station remains unchanged, only the serving satellite changes. Terminals only need to resynchronize downlink and uplink with the new satellite upon its arrival. This process does not require the base station to send an L3 handover command, thereby reducing signaling overhead.

[0004] However, due to the mobility of terminals, terminals at the edge of a cell's coverage may move out of coverage. Alternatively, due to inconsistencies in the coverage of new and old satellites, the new satellite's coverage is smaller than that of the current serving satellite, and terminals at the cell's edge may no longer be within the coverage of the new satellite. To improve the robustness of handovers, the network must configure conditional handover configuration information for the terminal, enabling it to switch from the current cell to the target cell. However, changes in the satellites of candidate target cells require updating the conditional handover configuration information. This requires the network to continuously update the conditional handover configuration information, resulting in high signaling overhead. Therefore, reducing the overhead of conditional handover configuration has become a pressing issue.

[0005] Summary of the Invention

[0006] The present application provides a communication method, a synchronization method, and a communication device, which can reduce the signaling overhead of a terminal when performing conditional switching.

[0007] In a first aspect, a communication method is provided, including: a terminal receives first information, the first information being used to instruct the terminal to switch to a first cell, the first information including multiple sets of ephemeris-related information corresponding to the first cell; the terminal determines to switch to the first cell and first ephemeris-related information corresponding to the first cell, wherein the first ephemeris-related information is one of the multiple sets of ephemeris-related information; and the terminal accesses the first cell based on the first ephemeris-related information.

[0008] In the embodiment of the present application, the CHO configuration information carries the same switching configuration information and ephemeris-related information of multiple satellites, so that when the satellite of the target cell to be accessed by the terminal changes, the source base station does not need to send the changed CHO configuration information to the terminal. The terminal only needs to enable the ephemeris-related information of the corresponding satellite during the time period covered by the satellite for conditional switching, which effectively saves signaling overhead.

[0009] In combination with the first aspect, in certain implementations of the first aspect, the first information also includes activation times corresponding to the multiple sets of ephemeris-related information respectively; the terminal determines that the first ephemeris-related information corresponding to the first cell includes: the first activation time corresponding to the first ephemeris-related information is equal to or later than the time when the terminal determines to switch to the first cell.

[0010] In the embodiment of the present application, different ephemeris-related information is enabled at different times by using the enabling time corresponding to the ephemeris-related information carried in the CHO configuration information, thereby effectively saving signaling overhead.

[0011] In combination with the first aspect, in some implementations of the first aspect, the first information further includes multiple physical cell identifiers, the physical cell identifiers correspond one-to-one to the ephemeris-related information, and the terminal determines the first physical cell identifier corresponding to the first cell.

[0012] In combination with the first aspect, in certain implementations of the first aspect, the first information is conditional switching configuration information of the first cell, and the conditional switching configuration information includes an execution condition for the terminal to switch to the first cell.

[0013] In combination with the first aspect, in some implementations of the first aspect, when an execution condition of the first cell is met, the terminal does not access the first cell.

[0014] The communication method provided in the embodiment of the present application, based on the satisfaction of the execution conditions of the conditional switching, further determines whether the terminal executes the conditional switching of the target cell. This can alleviate communication problems caused by insufficient time for the terminal to access the target cell or too long waiting time, improve the terminal switching efficiency, and shorten the service interruption time.

[0015] In conjunction with the first aspect, in certain implementations of the first aspect, the first information further includes a first out-of-service time corresponding to the first ephemeris-related information;

[0016] When the execution condition is met and the time interval between the current moment and the first service outage time is less than a first threshold, the terminal does not access the first cell; or

[0017] When the execution condition is met and the time interval between the current moment and the first service outage time is greater than or equal to a first threshold, the terminal accesses the first cell.

[0018] In combination with the first aspect, in certain implementations of the first aspect, the first information also includes a second service stop time of the terminal's ephemeris-related information in the current cell; when the execution condition is met and the time interval between the current moment and the second service stop time exceeds a second threshold, the terminal does not access the first cell; or when the execution condition is met and the time interval between the current moment and the second service stop time is less than or equal to the second threshold, the terminal accesses the first cell.

[0019] In combination with the first aspect, in certain implementations of the first aspect, the first information also includes a second service stop time of the terminal's ephemeris-related information in the current cell; when the execution condition is met and the interval between the second service stop time and the first activation time exceeds a third threshold, the terminal does not access the first cell; or when the execution condition is met and the interval between the second service stop time and the first activation time is less than or equal to the third threshold, the terminal accesses the first cell.

[0020] In combination with the first aspect, in certain implementations of the first aspect, when the execution condition is met and the interval between the current moment and the first activation time exceeds a fourth threshold, the terminal does not access the first cell; or when the execution condition is met and the interval between the current moment and the first activation time is less than or equal to the fourth threshold, the terminal accesses the first cell.

[0021] The communication method provided in the embodiment of the present application, based on the satisfaction of the execution conditions of the conditional switching, further determines whether the terminal executes the conditional switching of the target cell. This can alleviate communication problems caused by insufficient time for the terminal to access the target cell or too long waiting time, improve the terminal switching efficiency, and shorten the service interruption time.

[0022] With reference to the first aspect, in certain implementations of the first aspect, the terminal initiates determination of the execution condition after the first activation time.

[0023] In a second aspect, a communication method is provided, including: a terminal receives first information, the first information being used to instruct the terminal to switch to a first cell, the first information including an execution condition for the terminal to switch to the first cell; the first information also including first ephemeris-related information corresponding to the first cell; the terminal determines that the execution condition is met, and the terminal determines whether to access the first cell based on the first information.

[0024] The communication method provided in the embodiment of the present application, based on the satisfaction of the execution conditions of the conditional switching, further determines whether the terminal executes the conditional switching of the target cell. This can alleviate communication problems caused by insufficient time for the terminal to access the target cell or too long waiting time, improve the terminal switching efficiency, and shorten the service interruption time.

[0025] In combination with the second aspect, in certain implementations of the second aspect, the first information also includes a first service outage time corresponding to the first ephemeris-related information; when the time interval between the current moment and the first service outage time is less than a first threshold, the terminal does not access the first cell; or when the time interval between the current moment and the first service outage time is greater than or equal to the first threshold, the terminal accesses the first cell.

[0026] In combination with the second aspect, in certain implementations of the second aspect, the first information also includes a second service stop time of the terminal's ephemeris-related information in the current cell; when the time interval between the current moment and the second service stop time exceeds a second threshold, the terminal does not access the first cell; or when the time interval between the current moment and the second service stop time is less than or equal to the second threshold, the terminal accesses the first cell.

[0027] In combination with the second aspect, in certain implementations of the second aspect, the first information also includes a first activation time corresponding to the first ephemeris-related information and a second service stop time of the ephemeris-related information of the terminal in the current cell; when the interval between the second service stop time and the first activation time exceeds a third threshold, the terminal does not access the first cell; or when the interval between the second service stop time and the first activation time is less than or equal to the third threshold, the terminal accesses the first cell.

[0028] In combination with the second aspect, in certain implementations of the second aspect, the first information also includes a first activation time corresponding to the first ephemeris-related information; when the interval between the current moment and the first activation time exceeds a fourth threshold, the terminal does not access the first cell; or when the interval between the current moment and the first activation time is less than or equal to the fourth threshold, the terminal accesses the first cell.

[0029] In a third aspect, a synchronization method is provided, including: a target base station sends second information, where the second information is used to identify a change in first information or resources configured for a terminal; the target base station receives a switching request information, where the switching request information is used to instruct the target base station to reconfigure the first information, and the target base station sends the reconfigured first information, where the reconfigured first information includes first ephemeris-related information and an effective time corresponding to the first cell, and the reconfigured first information is used to instruct the terminal to switch to the first cell and enable the first ephemeris-related information at the effective time.

[0030] In the embodiment of the present application, a CHO configuration information change is triggered by a target base station to generate CHO reconfiguration information. The CHO reconfiguration information includes ephemeris-related information of the changed satellite and the corresponding effective time, so that the terminal uses the CHO reconfiguration information and the changed satellite to cover the candidate target cell in synchronization, effectively improving the switching efficiency.

[0031] In combination with the third aspect, in certain implementations of the third aspect, the second information includes a cause value.

[0032] In a fourth aspect, a synchronization method is provided, including: a source base station sends a switching request message, wherein the switching request message is used to instruct the target base station to reconfigure the first information, and the reconfigured first information includes the first ephemeris-related information and the effective time corresponding to the first cell, and the source base station receives the reconfigured first information sent by the target base station, and the reconfigured first information is used to instruct the terminal to switch to the first cell and enable the first ephemeris-related information at the effective time.

[0033] In the embodiment of the present application, a source base station triggers a CHO configuration information change, instructing the target base station to generate CHO reconfiguration information. The CHO reconfiguration information includes ephemeris-related information of the changed satellite and the corresponding effective time, so that the terminal uses the CHO reconfiguration information and the changed satellite to cover the candidate target cell in synchronization, effectively improving the switching efficiency.

[0034] In combination with the fourth aspect, in some implementations of the fourth aspect, the switching request information includes a conditional switching trigger value, and the conditional switching trigger value is used to trigger a change in the first information or resource configured by the terminal.

[0035] In a fifth aspect, a synchronization method is provided, including: a terminal receives first reconfiguration information, the first reconfiguration information including first ephemeris-related information and an effective time corresponding to a first cell, the terminal switches to the first cell according to the reconfiguration first information and enables the first ephemeris-related information at the effective time.

[0036] In the sixth aspect, a communication device is provided, including a communication unit for receiving first information, wherein the first information is used to instruct a terminal to switch to a first cell, and the first information includes multiple sets of ephemeris-related information corresponding to the first cell; a processing unit for determining switching to the first cell and first ephemeris-related information corresponding to the first cell, wherein the first ephemeris-related information is one of the multiple sets of ephemeris-related information; the processing unit is also used to access the first cell based on the first ephemeris-related information.

[0037] In combination with the sixth aspect, in certain implementations of the sixth aspect, the first information also includes activation times corresponding to the multiple sets of ephemeris-related information; the processing unit determines that the first ephemeris-related information corresponding to the first cell includes: the first activation time corresponding to the first ephemeris-related information is equal to or less than the time determined by the processing unit to switch to the first cell.

[0038] In combination with the sixth aspect, in certain implementations of the sixth aspect, the first information also includes multiple physical cell identifiers, the physical cell identifiers correspond one-to-one to the ephemeris-related information, and the processing unit is further used to determine the first physical cell identifier corresponding to the first cell.

[0039] In combination with the sixth aspect, in certain implementations of the sixth aspect, the first information is conditional switching configuration information of the first cell, and the conditional switching configuration information includes the execution conditions for the terminal to switch to the first cell.

[0040] In combination with the sixth aspect, in certain implementations of the sixth aspect, when an execution condition of the first cell is met, the terminal does not access the first cell.

[0041] In combination with the sixth aspect, in certain implementations of the sixth aspect, the first information also includes a first service stop time corresponding to the first ephemeris-related information; when the execution condition is met and the time interval between the current moment and the first service stop time exceeds a first threshold, the terminal does not access the first cell; or when the execution condition is met and the time interval between the current moment and the first service stop time is less than or equal to the first threshold, the terminal accesses the first cell.

[0042] In combination with the sixth aspect, in certain implementations of the sixth aspect, the first information also includes a first service outage time corresponding to the first ephemeris related information; when the execution condition is met and the interval between the first service outage time and the first activation time exceeds a second threshold, the terminal does not access the first cell; or when the execution condition is met and the interval between the first service outage time and the first activation time is less than or equal to the second threshold, the terminal accesses the first cell.

[0043] In combination with the sixth aspect, in certain implementations of the sixth aspect, when the execution condition is met and the interval between the current moment and the first activation time exceeds a third threshold, the terminal does not access the first cell; or when the execution condition is met and the interval between the current moment and the first activation time is less than or equal to the third threshold, the terminal accesses the first cell.

[0044] In combination with the sixth aspect, in certain implementations of the sixth aspect, the processing unit is further configured to start determining the execution condition after the first enabling time.

[0045] In the seventh aspect, a communication device is provided, including a communication unit for receiving first information, wherein the first information is used to instruct a terminal to switch to a first cell, and the first information includes an execution condition for the terminal to switch to the first cell; a processing unit for determining that the execution condition is met, and the terminal determines not to access the first cell based on the first information.

[0046] In combination with the seventh aspect, in certain implementations of the seventh aspect, the first information also includes first ephemeris-related information corresponding to the first cell and a first service outage time corresponding to the first ephemeris-related information; when the time interval between the current moment and the first service outage time exceeds a first threshold, the terminal does not access the first cell.

[0047] In combination with the seventh aspect, in certain implementations of the seventh aspect, the first information also includes first ephemeris-related information corresponding to the first cell and a first activation time and a first service stop time corresponding to the first ephemeris-related information; when the interval between the first service stop time and the first activation time exceeds a second threshold, the terminal does not access the first cell.

[0048] In combination with the seventh aspect, in certain implementations of the seventh aspect, the first information also includes first ephemeris-related information corresponding to the first cell and a first activation time corresponding to the first ephemeris-related information; when the interval between the current moment and the first activation time exceeds a third threshold, the terminal does not access the first cell.

[0049] In the eighth aspect, a communication device is provided, including: a communication unit for sending second information, wherein the second information is used to identify a change in the first information or resource configured for the terminal; the communication unit is also used to receive a switching request information, wherein the switching request information is used to instruct the target base station to reconfigure the first information; the communication unit is also used to send the reconfigured first information, wherein the reconfigured first information includes the first ephemeris-related information and the effective time corresponding to the first cell; and a processing unit for instructing the terminal to switch to the first cell and enable the first ephemeris-related information at the effective time.

[0050] In combination with the eighth aspect, in certain implementations of the eighth aspect, the second information includes a cause value.

[0051] In the ninth aspect, a communication device is provided, including: a communication unit for sending a switching request information, wherein the switching request information is used to instruct the target base station to reconfigure the first information, and the reconfigured first information includes the first ephemeris-related information and the effective time corresponding to the first cell; the communication unit is also used to receive the reconfigured first information sent by the target base station; a processing unit is used to instruct the terminal to switch to the first cell and enable the first ephemeris-related information at the effective time.

[0052] In combination with the ninth aspect, in certain implementations of the ninth aspect, the switching request information includes a conditional switching trigger value, and the conditional switching trigger value is used to trigger a change in the first information or resource configured by the terminal.

[0053] In the tenth aspect, a communication device is provided, including: a communication unit for receiving first reconfiguration information, the first reconfiguration information including first ephemeris-related information and effective time corresponding to the first cell; a processing unit for switching to the first cell according to the reconfiguration first information and enabling the first ephemeris-related information at the effective time.

[0054] In the eleventh aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is run on a computer, the computer is caused to execute the method as described in the first aspect and any one of the implementation methods of the first aspect, or the computer is caused to execute the method as described in the second aspect and any one of the implementation methods of the second aspect.

[0055] In the twelfth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is run on a computer, the computer is caused to execute the method as described in the third aspect and any one of the implementations of the third aspect, or the computer is caused to execute the method as described in the fourth aspect and any one of the implementations of the fourth aspect, or the computer is caused to execute the method as described in the fifth aspect.

[0056] In the thirteenth aspect, a computer program product is provided, wherein the computer program product includes a method for executing the method as described in the first aspect and any one of the implementation methods of the first aspect, or the computer program product includes a method for executing the method as described in the second aspect and any one of the implementation methods of the second aspect.

[0057] In the fourteenth aspect, a computer program product is provided, wherein the computer program product includes a method for executing the method as described in the third aspect and any one of the implementation methods of the third aspect, or the computer program product includes a method for executing the method as described in the fourth aspect and any one of the implementation methods of the fourth aspect, or the computer program product includes a method for executing the method as described in the fifth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0059] FIG2 is a schematic diagram of a communication method provided in an embodiment of the present application.

[0060] FIG3 is a schematic diagram of a communication method provided in an embodiment of the present application.

[0061] FIG4 is a schematic diagram of a communication method provided in an embodiment of the present application.

[0062] FIG5 is a schematic diagram of a communication method provided in an embodiment of the present application.

[0063] FIG6 is a schematic diagram of a communication method provided in an embodiment of the present application.

[0064] FIG7 is a schematic diagram of a synchronization method provided in an embodiment of the present application.

[0065] FIG8 is a schematic diagram of a synchronization method provided in an embodiment of the present application.

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

[0067] FIG10 is a schematic diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0068] The technical solution in this application will be described below with reference to the accompanying drawings.

[0069] Communications achieved with the help of non-terrestrial network equipment in a non-terrestrial network (NTN) are called non-terrestrial communications. NTN systems can include satellite systems, high altitude platform station (HAPS) communication systems, and other aerial network equipment. NTN has the advantages of wide coverage, long communication distance, high reliability, high flexibility, and high throughput. It is not affected by geographical environment, climatic conditions, and natural disasters, and has been widely used in various fields. Introducing NTN communications into mobile network communications, such as fifth-generation (5G) communications, can improve user experience. On the one hand, satellite networks can provide communication services to areas that are difficult for terrestrial networks to cover, such as oceans, forests, deserts, or remote areas. On the other hand, satellite networks can enhance the reliability of mobile communications, such as providing more stable communication services for users in high-speed mobile scenarios such as trains and airplanes. In addition, satellite networks can also provide more data transmission resources and support the connection of a larger number of terminal devices.

[0070] Generally speaking, the higher the satellite's orbit, the larger its coverage area, but the longer the communication delay. Based on the orbital altitude, satellites can be divided into:

[0071] (1) Low Earth Orbit (LEO): orbit altitude is 160 to 2000 km;

[0072] (2) Medium Earth Orbit (MEO): orbital altitude is 2000 to 35786 km;

[0073] (3) Geostationary Orbit (GEO): orbital altitude is 35,786 km;

[0074] Among them, GEO is a synchronous earth satellite orbit, and the satellites operating in this orbit are stationary relative to the ground; LEO and MEO are collectively referred to as non-geostationary orbits (NGSO), and the satellites operating in such orbits move at high speed relative to the ground.

[0075] NGSOs are further categorized into Earth Moving Cells and Earth Fixed Cells, depending on whether the satellite's beam moves with it. In Earth Moving Cells, the cell moves relative to the ground, and the satellite's beam follows its movement. In Earth Fixed Cells or Quasi-Earth Fixed Cells, the cell remains stationary relative to the ground for a specified period of time, and the satellite antenna uses its beamforming capabilities to direct the beam to a fixed area on the ground for a specified period of time.

[0076] Satellites can generally be divided into two categories based on their operating mode. The first is transparent forwarding, in which satellites relay cell information from ground network equipment (such as base stations). Satellites perform wireless frequency filtering, frequency conversion, and amplification. In other words, satellites primarily act as L1 relays, regenerating physical layer signals and lack any higher protocol layer functionality.

[0077] The second form is regenerative, where the satellite has the processing capabilities of a base station. Regenerative satellites can be categorized as: regenerative satellites without inter-satellite links (ISLs) between satellites; regenerative satellites with ISLs, where there are interfaces for direct data exchange between satellites (Xn ports); and regenerative satellites with the DU processing capabilities of a base station, in which case the satellite acts as a DU.

[0078] The embodiments of the present application can be used in transparent transmission satellite architecture and regenerative satellite architecture, and can also be used in Earth Moving Cell (earth moving cell) and Quasi-Earth Fixed Cell (quasi-stationary cell) scenarios.

[0079] The terminal in the embodiments of the present application, also referred to as user equipment (UE), mobile station (MS), mobile terminal (MT), etc., refers to a device that provides voice and / or data connectivity to a user. For example, a handheld device or vehicle-mounted device with wireless connection function. Currently, some examples of terminals include: mobile phones, tablet computers, laptop computers, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, etc.

[0080] The base station in the embodiment of the present application, also referred to as the access network device, refers to a radio access network (RAN) node (or device) that connects a terminal to a wireless network. Currently, some examples of RAN nodes are: evolved Node B (gNB), transmission reception point (TRP), evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved NodeB, or home Node B, HNB), base band unit (BBU), or wireless fidelity (Wifi) access point (AP). In addition, in a network structure, the access network device may include a centralized unit (CU) node, a distributed unit (DU) node, or a RAN device including a CU node and a DU node. RAN equipment, including CU and DU nodes, splits the protocol layers of the gNB in ​​the NR system. Some protocol layer functions are centrally controlled by the CU, while some or all of the remaining protocol layer functions are distributed in the DU, which is centrally controlled by the CU. Furthermore, the centralized unit (CU) is further divided into the control plane (CU-CP) and the user plane (CU-UP). The CU-CP is responsible for control plane functions, primarily including RRC and the control plane's counterpart, PDCP (PDCP-C). PDCP-C is responsible for control plane data encryption, integrity protection, and data transmission. The CU-UP is responsible for user plane functions, primarily including SDAP and the user plane's counterpart, PDCP (PDCP-U). SDAP is responsible for processing core network data and mapping flows to bearers. PDCP-U is responsible for data plane encryption, integrity protection, header compression, sequence number maintenance, and data transmission. The CU-CP and CU-UP are connected via the E1 interface. The CU-CP represents the gNB's connection to the core network via the NG interface. The control plane connects to the DU via the F1 interface, F1-C. The CU-UP is connected to the DU via the F1 interface user plane, i.e., F1-U. Alternatively, the PDCP-C is also located in the CU-UP.

[0081] The core network device in the embodiment of the present application refers to the device in the core network (CN) that provides service support for the terminal. At present, some examples of core network devices are: access and mobility management function (AMF) entity, session management function (SMF) entity, user plane function (UPF) entity, etc., which are not listed here one by one. Among them, the AMF entity can be responsible for the access management and mobility management of the terminal; the SMF entity can be responsible for session management, such as user session establishment, etc.; the UPF entity can be a functional entity of the user plane, mainly responsible for connecting to the external network. It should be noted that the entity in this application can also be referred to as a network element or a functional entity. For example, the AMF entity can also be referred to as an AMF network element or an AMF functional entity. For another example, the SMF entity can also be referred to as an SMF network element or an SMF functional entity, etc.

[0082] In addition, in order to facilitate understanding of the embodiments of the present application, the following explanations are made.

[0083] First, in this application, "used to indicate" can include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used to indicate A, it can include that the indication information directly indicates A or indirectly indicates A, but it does not mean that the indication information must include A.

[0084] The information indicated by the indication information is referred to as the pending indication information. In specific implementations, there are many ways to indicate the pending indication information. The pending indication information can be sent as a whole or divided into multiple sub-information and sent separately. The transmission period and / or timing of these sub-information can be the same or different. This application does not limit the specific transmission method.

[0085] Second, "at least one" shown in the present application refers to one or more, and "a plurality of" refers to two or more. In addition, in the embodiments of the present application, "first", "second" and various digital numbers (for example, "#1", "#2", etc.) are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of each process below does not mean the order of execution. The execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. It should be understood that the objects described in this way can be interchanged where appropriate, so that solutions other than the embodiments of the present application can be described. In addition, in the embodiments of the present application, words such as "201", "202" are only for the convenience of description and are not used to limit the order of execution of steps.

[0086] Third, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0087] Fourth, the term "storage" used in the embodiments of this application may refer to storage in one or more memories. The one or more memories may be provided separately or integrated into an encoder or decoder, a processor, or a communication device. The one or more memories may also be provided in part separately and in part integrated into a decoder, a processor, or a communication device. The memory may be any type of storage medium, and this application is not limited thereto.

[0088] Fifth, the term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0089] To facilitate understanding of the embodiments of the present application, a brief description of the basic concepts involved in the present application is first given.

[0090] 1. Traditional switching

[0091] Due to the movement of the UE, the signal quality of the network currently accessed by the UE may deteriorate, and it is necessary to switch to a cell with better signal quality to obtain service. In the traditional handover process, the UE's handover is controlled by the network equipment, that is, the network equipment instructs the UE which cell to switch to and how to switch by sending a handover message. As shown in Figure 1, after receiving the handover message, the UE accesses the target cell based on the content contained in the handover message. Therefore, the network side needs to obtain the target cell identifier. The specific handover steps are described as follows:

[0092] Step 1: The source base station sends an RRC reconfiguration message to the connected UE, instructing the UE to perform measurement, which includes parameters such as measurement object, report configuration, and measurement identifier.

[0093] Step 2: The UE measures the cell according to the RRC reconfiguration message and generates reports to report various events to the source base station.

[0094] Step 3: After receiving the report from the UE, the source base station makes a decision. If the decision result is a handover, the source base station sends a handover request message to the target base station.

[0095] Step 4: The target base station determines whether to allow the UE to switch in. If the decision is yes, it sends a handover confirmation message to the source base station, which includes parameters such as the new C-RNTI and target base station security-related algorithms.

[0096] Step 5: After receiving the handover confirmation message from the target base station, the source base station sends an RRC reconfiguration message (handover command) to the UE, which contains the content from the handover confirmation message in step 4. Specifically, the handover command in the NR system contains relevant information about the target cell and relevant configuration parameters required for the UE to access the target cell, for example, target cell information (such as the PCI of the target cell and the frequency information corresponding to the target cell), the C-RNTI allocated by the target cell to the UE, and the RACH resource information required to access the target cell (such as dedicated RACH resources and / or common RACH resources).

[0097] Step 6: The UE initiates random access to the target base station according to the handover command. In the existing handover process, the UE will disconnect from the source base station, and the UE will experience a brief interruption in sending and receiving data before successfully accessing the target base station.

[0098] Step 7: The UE sends an RRC reconfiguration completion message to the target base station.

[0099] 2. Conditional Handoff (CHO)

[0100] In terrestrial networks (TNs), user mobility can cause the signal quality of the current serving cell to deteriorate, necessitating a handoff to a neighboring cell with better signal quality. Unlike terrestrial networks, satellite cells cover very large areas (with a coverage radius of tens to hundreds of kilometers), and users generally remain within the satellite's cell coverage area after moving. Furthermore, the high-speed movement of NGSOs relative to the ground means that the satellite's coverage of a given area on the ground is short-lived, leading users to frequently change serving cells. Therefore, unlike terrestrial networks, satellite mobility is the primary cause of user handoffs.

[0101] Therefore, for Earth Fixed Cell or Quasi-Earth Fixed Cell, the satellite can stare at the ground for a period of time. When the satellite is about to move out of the UE's line of sight, all UEs in the cell must switch to the next satellite. For Earth Moving Cell, the cell moves with the satellite, and UEs are constantly switching in and out as the satellite sweeps across the ground. For NGSO, the high-speed movement of the satellite leads to frequent user handoffs. For Earth Moving Cell, frequent large-scale user handoffs incur significant signaling overhead. For Earth Fixed Cell or Quasi-Earth Fixed Cell, the simultaneous large-scale handoffs of users can lead to signaling storms and congestion. Therefore, addressing the signaling overhead caused by frequent user handoffs in NGSO is key to improving the communication efficiency of NTN systems.

[0102] In order to avoid the link quality of the source base station from further deteriorating, which leads to the inability to normally exchange signaling between the UE and the source base station, and thus the failure of the handover to be successfully executed, the existing technology proposes a conditional handover (CHO) mechanism. Specifically, the source base station sends CHO configuration information to the UE when the link quality with the UE is good. The configuration information includes CHO trigger conditions and information about candidate target cells (such as the CGI of the candidate target cell, or the PCI of the candidate target cell and the frequency information corresponding to the candidate target cell). After receiving the configuration information, the UE determines whether the candidate target cell meets the handover trigger conditions based on the configuration information, and uses a candidate target cell that meets the handover trigger conditions as the target cell; then, the UE initiates random access to the target cell. After the random access is successful, the UE sends an RRC reconfiguration completion message to the base station to which the target cell belongs (i.e., the target base station), notifying the target base station that the conditional handover is completed.

[0103] Step 1: The source base station configures the UE to perform neighboring cell measurement. The measurement configuration information may be delivered via an RRC reconfiguration message. The UE performs the measurement and reports the measurement result to the source base station.

[0104] Step 2: The source base station selects a candidate target cell according to the measurement result and sends a handover request to the candidate target cell.

[0105] Step 3: The candidate target base station sends a handover response message to the source base station. The handover response message carries the configuration information of the candidate target cell.

[0106] Step 4: The source base station sends the handover configuration information to the UE.

[0107] In step 5, upon receiving the handover configuration information, the UE begins evaluating the CHO execution conditions of candidate target cells while maintaining a connection to the source eNB. If at least one of the candidate CHO target cells meets the corresponding CHO execution conditions, the UE leaves the source eNB, switches to the target eNB, and then sends an RRC Reconfiguration Complete message to the target eNB to complete the RRC handover process. The UE releases the stored CHO configuration after successfully completing the RRC handover process.

[0108] In NTN ground stationary cell scenarios, satellites adjust their beams to maintain consistent coverage for a period of time. When the cell is no longer serviced or covered, the next satellite takes over. This allows the ground base station to remain unchanged, preserving the terminal's radio resource configuration before and after the satellite change. For example, the cell's physical cell identifier (PCI) remains unchanged, and no L3 signaling handover is required. The terminal only needs to resynchronize with the cell through the new satellite after the arrival of the new satellite (e.g., at the time the satellite stops serving the cell before the change, at the time the satellite starts serving the cell after the change, or at any time between the time the satellite starts serving the cell after the change and the time the satellite stops serving the cell before the change). The UE and base station maintain the radio resource configuration allocated to the terminal before the handover, thus resolving the signaling storm caused by handovers in this scenario. This method can be referred to as a handover solution that requires no L3 handover commands when the satellite changes but the cell identifier remains unchanged.

[0109] There are two handover scenarios for ground stationary cells: hard handover (no overlap between the front and rear satellite coverage) and soft handover (overlap between the front and rear satellite coverage).

[0110] Optionally, in the NTN ground stationary cell scenario, when switching the satellite serving or covering the cell, the cell's physical cell identifier (PCI) can change. Therefore, the terminal's wireless resource configuration information can remain unchanged before and after the satellite change. The terminal and base station only need to change the cell's physical cell identifier. In this satellite switching scenario, there is no need to introduce L3 signaling switching for the terminal. The terminal only needs to resynchronize with the cell through the new satellite after the new satellite arrives (for example, at the moment the satellite stops serving the cell before the change, or at the moment the satellite starts serving the cell after the change, or at any time between the moment the satellite starts serving the cell after the change and the moment the satellite stops serving the cell before the change). The UE and base station maintain the configuration of the wireless resources allocated to the terminal before the switch, but need to change the cell's physical cell identifier. This can also solve the signaling storm problem caused by switching in this scenario. This method can be called a switching solution where the satellite changes but the cell identifier changes without requiring an L3 switching command.

[0111] However, due to the mobility of UE, a UE at the edge of cell coverage may move out of the current satellite or the coverage of the current cell, or because the coverage of the new and old satellites is inconsistent, the coverage of the new satellite is smaller than that of the current serving satellite. Therefore, when using handover without L3 signaling (or satellite change, hereinafter handover without L3 signaling may also be referred to as satellite change), the UE at the edge of the cell is at risk of failing to access the target satellite.

[0112] To prevent handover failures for UEs at the cell edge due to UE mobility or inconsistent coverage between new and old satellites, the network can configure CHO for both UEs or only for UEs at the cell edge. For example, when the signal quality of the cell with PCI#1 deteriorates, the UE can autonomously switch to the cell corresponding to PCI#2, improving handover robustness.

[0113] To improve handover robustness, the network configures CHO for the UE. However, the ephemeris information of candidate target cells may need to be updated due to satellite changes. If the satellites of candidate target cells change, the network needs to update the CHO configuration information, for example, deleting the missing candidate target cells or configuring new ones, which can easily increase signaling overhead.

[0114] Therefore, an embodiment of the present application provides a communication method that can reduce the signaling overhead of a terminal when performing conditional switching.

[0115] FIG2 is a schematic flow chart of a communication method provided by the present application. The method includes the following steps:

[0116] S201: A source base station sends measurement configuration information to a terminal. The terminal performs measurement according to the measurement configuration information and reports the measurement result to the source base station.

[0117] Specifically, the measurement configuration information includes measurement object, report configuration, measurement ID, measurement configuration and measurement GAP configuration.

[0118] S202: The source base station selects a candidate target cell for the terminal according to the measurement report and sends a CHO request message to the candidate target cell. After receiving the CHO request message, the candidate target cell sends a CHO request response message to the source base station.

[0119] Exemplarily, after receiving the CHO request message, the candidate target cell performs access control. When the candidate target cell decides to accept the CHO request of the source base station, it sends a CHO request response message to the source base station. The CHO request response message includes configuration information for the terminal to access the candidate target cell.

[0120] Optionally, the candidate target cell may be one or more. For example, the source base station sends a CHO request to the first candidate target cell. After the first candidate target cell confirms acceptance, it sends a CHO request response message to the source base station. The CHO request response message includes the configuration information of the first candidate target cell. The source base station also sends a CHO request to the second candidate target cell. After the second candidate target cell confirms acceptance, it sends a CHO request response message to the source base station. The CHO request response message includes the configuration information of the second candidate target cell.

[0121] It should be noted that S201 is optional. In S202, the source base station may also select a candidate target cell for the terminal based on other information.

[0122] S203 , the source base station sends CHO configuration information to the terminal. The CHO configuration information is first information and is used to instruct the terminal to switch to a candidate target cell. The CHO configuration information includes multiple sets of ephemeris-related information corresponding to the candidate target cells, where the candidate target cells include the first cell.

[0123] Exemplarily, the source base station sends CHO configuration information to the terminal, where the CHO configuration information includes NTN configuration information, for example, serving cell configuration information (Serving Cell Config Common) carries non-terrestrial network configuration (ntn-config), and the non-terrestrial network configuration carries multiple sets of ephemeris-related information corresponding to the candidate target cell. The CHO configuration information also includes handover configuration information (for example, information carried by synchronization reconfiguration information Reconfiguration With Sync).

[0124] Optionally, the ephemeris-related information (or satellite-related information) includes at least one of the following: ephemeris information, reference time of ephemeris information (such as epochTime), uplink synchronization validity period, cell-level Koffset (scheduling time offset), Kmac, timing advance information, such as commonTA-related parameters, coverage stop time, and coverage start time.

[0125] EpochTime is used to indicate the epoch time of the NTN auxiliary information (or related information). When explicitly provided through the SIB or through dedicated signaling, epochTime is the start time of the DL subframe, indicated by the downlink frame number and subframe number of the auxiliary information. If the epochTime field is not carried, not configured, or does not exist, the epoch time is the end time of the SI window that schedules this SIB19.

[0126] Optionally, each set of ephemeris-related information corresponding to the candidate target cell includes a corresponding activation time, or the CHO configuration information further includes activation times corresponding to multiple sets of ephemeris-related information.

[0127] Optionally, the activation time may be a point in time, at which the UE activates the ephemeris. For example, the point in time may be a UTC time, or the activation time may be a time period, such as [t1, t2]. Alternatively, the activation time may be determined by the ephemeris validity period in the ephemeris-related information. Alternatively, the activation time may be a reference time or an offset value relative to the reference time. For example, the reference time may be the epoch time of the ephemeris information, or another example may be the time when the CHO configuration information is received. For example, when the activation time is a reference time or an offset value relative to the reference time, the offset values ​​of the activation times corresponding to the multiple sets of ephemeris-related information are different, the multiple ephemeris-related information correspond to different activation times, and the terminal activates the corresponding ephemeris information according to the activation times corresponding to the different moments or time periods. For example, when the activation time is Coordinated Universal Time (UTC), the multiple sets of ephemeris information correspond to different activation times, and the terminal activates the corresponding ephemeris information according to the activation times corresponding to the different moments or time periods.

[0128] Exemplarily, the first candidate target cell is one of multiple candidate target cells configured by the source base station for the terminal, the first satellite is the satellite currently providing coverage for the first candidate target cell, the second satellite is the next satellite to provide coverage for the first candidate target cell, and the second satellite provides coverage for the first candidate target cell later than the first satellite. Optionally, the CHO configuration information at this time may include ephemeris-related information of the first satellite, ephemeris-related information of the second satellite, and ephemeris-related information of other satellites that subsequently provide coverage for the first candidate target cell; or, the CHO configuration information at this time may include ephemeris-related information of the first satellite and the corresponding first activation time, ephemeris-related information of the second satellite and the corresponding second activation time, and ephemeris-related information of other satellites that subsequently provide coverage for the first candidate target cell and the corresponding activation time.

[0129] Optionally, the time periods during which the first satellite and the second satellite provide coverage for the first candidate target cell may not overlap, that is, after the first satellite's coverage of the first candidate target cell disappears, the second satellite provides coverage for the first candidate target cell after a first time interval Gap1, where Gap1 is greater than or equal to 0. Optionally, the time periods during which the first satellite and the second satellite provide coverage for the first candidate target cell may also overlap.

[0130] Optionally, when the first satellite and the second satellite provide coverage for the first candidate target cell, the physical cell identifier of the first candidate target cell remains unchanged. That is, when a handover occurs in the satellite corresponding to the first candidate target cell, the physical cell identifier of the first candidate target cell remains unchanged or changes, and the handover solution described above that does not require an L3 handover command can be used between the first candidate target cell and the terminal served by the first candidate target cell.

[0131] Optionally, when the first satellite and the second satellite provide coverage for the first candidate target cell, the physical cell identifier of the first candidate target cell may change. When the physical cell identifier of the candidate target cell changes, for example, in a soft handover scenario, a handover without an L3 command is performed. In this case, the CHO configuration information may also include multiple physical cell identifiers, such as PCIs. For example, the target cell is one of multiple candidate target cells configured by the source base station for the terminal, the first satellite is the satellite currently providing coverage for the target cell, the second satellite is the next satellite to provide coverage for the target cell, and the second satellite provides coverage for the first target cell later than the first satellite. Optionally, the first and second satellites overlap in the time of coverage of the target cell. In this case, the CHO configuration information includes at least one of the following: at least one candidate target cell handover configuration information (e.g., information carried by synchronization reconfiguration information ReconfigurationWithSync), and at least one ephemeris information for at least one candidate target cell. For example, the source base station configures M candidate target cells for the terminal, and each candidate target cell is configured with ephemeris information for N_m (m = 1, 2, 3, ..., M) satellites. N_m is greater than or equal to 1, and the value of N_m can be different. Each ephemeris information corresponds to an activation time. The physical cell identifiers corresponding to the M candidate cells. Each candidate target cell can correspond to K_m (m = 1, 2, 3, ..., M) physical cell identifiers, where N_m is greater than or equal to 1 and can have different values. Optionally, N_m and K_m can be the same, meaning the PCI must be changed each time a satellite is changed. Alternatively, N_m and K_m can be different, corresponding to scenarios where satellites are changed but the PCI is not updated.

[0132] Exemplarily, the CHO configuration information at this time includes at least one of the following: the ephemeris-related information of the first satellite and the corresponding first physical cell identifier, the ephemeris-related information of the second satellite and the corresponding second physical cell identifier, and the ephemeris-related information of other satellites that subsequently provide coverage for the first candidate target cell and the corresponding physical cell identifier; or the CHO configuration information at this time includes at least one of the following: the ephemeris-related information of the first satellite, the corresponding first activation time and the corresponding first physical cell identifier, the ephemeris-related information of the second satellite, the corresponding second activation time and the corresponding second physical cell identifier, and the ephemeris-related information of other satellites that subsequently provide coverage for the first target cell, the corresponding activation time and the corresponding physical cell identifier.

[0133] Optionally, the source cell in the source base station may broadcast the activation time corresponding to each set of ephemeris-related information corresponding to the candidate target cell in a broadcast message. In one embodiment, the CHO configuration carries multiple sets of ephemeris-related information. The broadcast message broadcasts at least one service stop time or service start time of the candidate target cell. The service stop time or service start time in the broadcast message corresponds one-to-one to the ephemeris-related information in the CHO configuration. In another embodiment, the CHO configuration carries multiple sets of ephemeris-related information. The broadcast message broadcasts a service stop time of the candidate target cell. When the terminal receives the CHO configuration, the terminal considers the first set of ephemeris-related information to be valid. When the broadcasted service stop time of the candidate target cell is reached, the terminal considers the second set of ephemeris-related information to be valid. The source cell in the source base station will also update the broadcast message, carrying the new service stop time of the candidate target cell, and the terminal re-acquires the service stop time of the candidate target cell. When the new service stop time is reached, the terminal considers the third set of ephemeris-related information to be valid, and the source cell re-selects the service stop time of the candidate target cell. And so on.

[0134] In the embodiment of the present application, the CHO configuration information sent by the source base station to the terminal carries the ephemeris-related information and activation time of multiple satellites. Therefore, when the satellite of the target cell to be accessed by the terminal changes, the source base station does not need to send the changed CHO configuration information to the terminal. In other words, the source base station does not need to continuously delete the disappeared candidate target cells or configure new candidate target cells. The terminal only needs to perform conditional switching according to the corresponding ephemeris-related information, which effectively saves signaling overhead.

[0135] S204: The terminal receives CHO configuration information.

[0136] The terminal determines to enable the corresponding ephemeris related information according to the CHO configuration information.

[0137] Optionally, the CHO configuration information may further include activation times corresponding to the multiple sets of ephemeris-related information. The terminal determines which satellite of the target cell to use for ephemeris-related information based on the activation times corresponding to the ephemeris-related information of the satellites carried in the CHO configuration information. Optionally, the activation time of the ephemeris-related information determined to be activated by the terminal may be equal to or later than the time when the terminal determines to switch to the target cell.

[0138] For example, the first satellite currently covers the target cell, and the activation time may be the time when the CHO configuration information is received; or when the first satellite ends its coverage of the target cell and the second satellite is about to cover the target cell, the activation time may be the offset time relative to the time when the CHO configuration information is received, or the start time when the second satellite covers the target cell, or the time within the first time interval Gap1 covered by the first satellite and the second satellite. The embodiments of the present application are not limited to this.

[0139] Exemplarily, the first satellite currently covers the target cell, and the terminal enables the ephemeris-related information of the first satellite at the first activation time according to the CHO configuration information; or when the first satellite ends its coverage of the target cell and the second satellite is about to cover the target cell, the terminal enables the ephemeris-related information of the second satellite at the second activation time according to the CHO configuration information.

[0140] Optionally, the UE determines whether to change satellites based on the target satellite's ephemeris validity period. This validity period is configured for the UE during CHO configuration. When determining the CHO configuration, the source base station configures the ephemeris-related information in the order in which the satellites cover the candidate target cells. The UE applies new ephemeris information in the order in which the current ephemeris expires. For example, if the ephemeris validity period for satellite 1 expires, the UE applies the ephemeris for satellite 2, and so on. In this case, the ephemeris validity period does not need to be displayed; the UE applies the ephemeris information in the order in which it is applied.

[0141] Optionally, the UE determines when to take effect new ephemeris information based on the time when the target satellite covers the target cell. For example, the satellite configuration information (such as ntn-config) carried in the CHO configuration information carries the start time of each satellite covering the target cell, such as t-start, or the time when the target cell stops being covered, such as t-service. The UE takes effect the ephemeris information of the corresponding satellite at the t-start corresponding to each satellite, or takes effect the ephemeris information of the next satellite when the t-service of each ephemeris information expires. Optionally, when the CHO configuration information is determined, the ephemeris information is configured in the order in which the satellites cover the neighboring cells.

[0142] Optionally, the terminal determines the effective ephemeris-related information based on the current time. For example, if the current time is after the activation time corresponding to ephemeris-related information #1 and before the activation time corresponding to ephemeris-related information #2, the terminal uses ephemeris-related information #1. For another example, if the current time is within the effective time corresponding to ephemeris-related information #1, the terminal uses ephemeris-related information #1.

[0143] At different times or time periods, the terminal uses the same CHO switching configuration and the ephemeris-related information corresponding to the activation time to access the target base station. For example, at time t1 or in the time period [t1, t2], the terminal uses the CHO switching configuration and the ephemeris-related information of the first satellite to access the target base station.

[0144] Optionally, when the physical cell identifier of the candidate target cell changes, for example, when a handover without an L3 command is performed in a soft handover scenario, and the first satellite currently covers the target cell, the terminal activates the ephemeris-related information and the first physical cell identifier of the first satellite at a first activation time according to the CHO configuration information; or when the first satellite ends coverage of the target cell and a second satellite is about to cover the target cell, the terminal activates the ephemeris-related information and the second physical cell identifier of the second satellite at a second activation time according to the CHO configuration information. At different times or time periods, the terminal accesses the target base station using the same CHO handover configuration, the PCI corresponding to the activation time, and the ephemeris-related information corresponding to the activation time.

[0145] S205: The terminal determines the CHO execution condition according to the CHO configuration information.

[0146] Specifically, the CHO execution conditions include time conditions and / or distance conditions. The time conditions include a first time window. If the current time is within the first time window, the time condition is satisfied. For example, if the first time window is [t1, t2], the terminal can execute CHO within [t1, t2].

[0147] Specifically, the distance condition includes a first distance threshold D1 and a second distance threshold D2. If the distance from the terminal to the target cell is less than the first distance threshold D1, and the distance from the terminal to the source cell is greater than the second distance threshold D2, the distance condition is met. Alternatively, the distance from the terminal to the target cell may be the distance from the terminal to a reference point of the target cell, and the distance from the terminal to the source cell may be the distance from the terminal to a reference point of the source cell. Alternatively, the first and second distance thresholds may be configured for the terminal by the network.

[0148] Optionally, the execution condition may also include a measurement event. When one or more of the time condition, distance condition, or measurement event are simultaneously met, the terminal satisfies the execution condition. For example, the terminal satisfies one of the following conditions: time condition, distance condition, measurement event, time condition and measurement event, or distance condition and measurement event. Optionally, any two or three of the time condition, distance condition, and measurement event are configured jointly. Conditional switching is executed when any of the two or three validation conditions are met.

[0149] S206: The terminal immediately performs a handover without L3 signaling in the source cell and performs downlink synchronization with the source cell through the target satellite of the source cell; or the terminal determines that the CHO execution condition of a candidate target cell is met, and the terminal accesses the candidate target cell.

[0150] Optionally, the first time can be time information (t-service) indicating when the source cell stops service, that is, the time information that stops covering the current area, or it can be the time when the next satellite broadcast by the source cell provides service to the source cell (t-start), or any time between the two.

[0151] Before S201, the communication method further includes: the source base station sending indication information of handover without L3 signaling to the terminal. The indication information of handover without L3 signaling is used to: when the terminal receives the indication information and the terminal supports the handover without L3 signaling capability, the terminal performs the handover without L3 signaling, and the indication information is used to instruct the terminal to perform the handover without L3 signaling.

[0152] Exemplarily, the indication information can be sent down in a system message, and the indication information can be a Boolean value, indicating the terminal through true or false; or the indication information indicates whether switching without L3 signaling is supported; or the indication information can be a physical cell identifier corresponding to the next satellite of the source cell, etc., and the physical cell identifier is used to implicitly indicate that the terminal can perform switching without L3 signaling, and switch to the PCI carried in the system message; or the indication information can also be represented by the indicated time information, and the indicated time information implicitly indicates that the terminal performs switching without L3 signaling.

[0153] Optionally, when some terminals or terminals at the edge of the cell are unable to perform downlink synchronization with the source cell through the next satellite of the source cell, the terminal determines the execution condition according to the CHO configuration information. When the execution condition is met, the terminal performs conditional switching on the target cell and accesses the target cell.

[0154] Optionally, when the terminal determines that the CHO execution conditions for a candidate target cell are met, the terminal device determines which ephemeris-related information corresponding to the candidate target cell to enable. The terminal then accesses the candidate target cell based on the ephemeris-related information. For a specific method for the terminal device to determine which ephemeris-related information corresponding to the candidate target cell to enable, refer to the method described in S204. Optionally, upon receiving the CHO configuration information in S204, the terminal device does not need to determine which ephemeris-related information corresponding to the candidate target cell to enable. Instead, when the execution conditions corresponding to the candidate target cell are met in S206, the terminal device determines which ephemeris-related information corresponding to the candidate target cell to enable.

[0155] In the embodiment of the present application, the CHO configuration information carries the same switching configuration information and ephemeris-related information of multiple satellites, so that when the satellite of the candidate target cell of the terminal changes, the source base station does not need to send the changed CHO configuration information to the terminal. That is, the source base station does not need to continuously delete the disappeared candidate target cells or configure new candidate target cells. The terminal only needs to enable the ephemeris-related information of the corresponding satellite during the time period covered by the satellite for conditional switching, which effectively saves signaling overhead.

[0156] When the target cell's execution conditions are met, according to the current protocol, the terminal will immediately adopt the target cell's configuration and access the candidate target cell. In scenarios where the target cell is an Earth Fixed Cell or Quasi-Earth Fixed Cell and the satellite is about to change, the target cell meets the CHO execution conditions and the target cell is about to change its satellite. If the terminal directly disconnects from the source cell, it may not be able to immediately access the candidate target cell (for example, if the service start time of the candidate target cell's new satellite has not yet arrived). This will cause the terminal's communication to be interrupted, affecting service performance.

[0157] Therefore, an embodiment of the present application also provides a communication method, which enables a terminal to successfully access a target base station where a target cell is located, thereby reducing the interruption time of communication services.

[0158] FIG3 is a schematic flow chart of a communication method provided by the present application, which includes the following steps:

[0159] S301: The terminal determines, based on the CHO configuration information sent by the source base station, whether the CHO execution condition corresponding to the candidate target cell is met.

[0160] When one or more of the time condition, distance condition, or measurement event are simultaneously met, the terminal satisfies the execution condition. For example, the terminal satisfies one or more of the following conditions: time condition, distance condition, and measurement event. The specific execution conditions and the determination of whether the execution conditions are met are described in S204 above and are not repeated here.

[0161] In this step, if the execution condition of the CHO corresponding to the candidate target cell is met, the candidate target cell is confirmed as the target cell.

[0162] Optionally, before S301 , execute S202 to S204 in FIG. 2 .

[0163] S302: The terminal obtains a first threshold.

[0164] Optionally, the CHO configuration information also includes first ephemeris-related information corresponding to the target cell and a corresponding first out-of-service time, or the source cell broadcasts the first out-of-service time in a broadcast message. The first out-of-service time is the time when the satellite corresponding to the first ephemeris-related information corresponding to the target cell stops serving the target cell. The time interval between the current time and the first out-of-service time is the remaining service time.

[0165] Optionally, the first out-of-service time may be read by the terminal through a system message SIB, such as SIB19. The SIB may be a SIB broadcast by the serving cell, or a SIB broadcast by a neighboring cell, or may be sent by the network side to the terminal when sending the CHO configuration information. This embodiment of the present application is not specifically limited. The remaining service time may also be calculated by the terminal based on ephemeris-related information and / or cell coverage information (e.g., cell reference position, cell radius, etc.).

[0166] The terminal obtains a first threshold. Optionally, the first threshold is at least sufficient to support the terminal completing random access. For example, the value of the first threshold is greater than the round-trip time (RTT) between the terminal and the target base station. Optionally, the first threshold can be preconfigured for the terminal by the network, or carried in CHO configuration information and sent to the terminal by the source base station, or the first threshold is a value agreed upon in a protocol. This embodiment of the present application is not specifically limited to this.

[0167] This application does not limit the order of S301 and S302.

[0168] S303: The terminal determines whether to access the target cell according to the first threshold.

[0169] Specifically, if the remaining service time of the target cell is greater than or equal to a first threshold, that is, the terminal has sufficient time to access the target cell, the terminal performs CHO on the target cell, and the terminal accesses the target cell. If the remaining service time is less than the first threshold, the terminal cannot successfully switch before the next satellite coverage of the target cell, or the terminal cannot successfully switch before the current satellite coverage of the target cell disappears, or the terminal cannot successfully switch before the current target cell disappears. Successful switching can also be considered as successful access to the target cell without performing CHO on the target cell.

[0170] Optionally, in this application, S301 and S303 may be the same step. That is, when the terminal determines whether the execution conditions of the CHO corresponding to the candidate target cell are met, it also needs to consider the content in S303. That is, when one or more of the time conditions, distance conditions, or measurement events corresponding to a candidate target cell are simultaneously met, and the remaining service time of the candidate target cell is greater than or equal to the first threshold, the terminal considers that the execution conditions of the CHO are met; otherwise, it is considered that they are not met.

[0171] FIG4 is a schematic flow chart of another communication method provided by the present application, which includes the following steps:

[0172] S401: The terminal determines, based on the CHO configuration information sent by the source base station, whether the CHO execution condition corresponding to the candidate target cell is met.

[0173] Optionally, please refer to the description in S301.

[0174] S402: The terminal obtains a second threshold.

[0175] Optionally, the CHO configuration information also includes the service stop time of the terminal's ephemeris-related information corresponding to the current source cell, or the time when the satellite corresponding to the current source cell stops providing services for the source cell, that is, the second service stop time, or the source cell broadcasts the second service stop time in a broadcast message.

[0176] S403: The terminal determines whether to access the target cell according to the second threshold.

[0177] Specifically, the first time interval is the time interval between the current moment and the second out-of-service time. If the first time interval is less than or equal to the second threshold, the terminal performs CHO handover to the target cell and accesses the target cell. If the first time interval is greater than the second threshold, that is, the terminal can continue to communicate in the source cell, the terminal does not perform CHO on the target cell. The terminal can continue to determine whether the execution conditions of the CHO corresponding to the candidate target cell are met and whether the first time interval is less than or equal to the second threshold. When the terminal executes the handover command without L3 signaling corresponding to the source cell, the terminal accesses the source cell through the new satellite of the source cell, and the terminal can retain the CHO configuration information of the candidate target cell.

[0178] Optionally, the second threshold may be pre-configured for the terminal by the network side, or carried in CHO configuration information and sent by the source base station to the terminal.

[0179] Optionally, in this application, S401 and S403 may be the same step. That is, when the terminal determines whether the execution conditions of the CHO corresponding to the candidate target cell are met, it also needs to consider the content of S403. That is, when one or more of the time conditions, distance conditions, or measurement events corresponding to a candidate target cell are simultaneously met, and the first time interval is less than or equal to the second threshold, the terminal considers that the execution conditions of the CHO are met; otherwise, it is considered that they are not met. Optionally, Figures 3 and 4 can be combined. That is, the terminal determines whether to access the target cell based on the first threshold and the second threshold.

[0180] FIG5 is a schematic flow chart of another communication method provided by the present application, which includes the following steps:

[0181] S501: The terminal determines that a CHO execution condition is met according to CHO configuration information sent by a source base station.

[0182] Optionally, please refer to the description in S301.

[0183] S502: The terminal obtains a third threshold.

[0184] Optionally, the CHO configuration information also includes a first activation time corresponding to the first ephemeris-related information corresponding to the target cell and a second out-of-service time corresponding to the target cell. Alternatively, the source cell broadcasts the first activation time or the second out-of-service time in a broadcast message. The first activation time may also be the time when the next satellite corresponding to the target cell begins providing service to the target cell. The second out-of-service time is the time when the current satellite corresponding to the target cell stops providing service to the target cell.

[0185] S503: The terminal determines whether to access the target cell according to the third threshold.

[0186] Specifically, the second time interval is the time interval between the first activation time and the second out-of-service time. If the second time interval is less than or equal to the third threshold, the terminal performs CHO handover to the target cell and accesses the target cell. If the second time interval is greater than the third threshold, the terminal can continue to communicate in the source cell and does not perform CHO on the target cell. The terminal can continue to determine whether the execution conditions of CHO corresponding to the candidate target cell are met and whether the second time interval is less than or equal to the third threshold. When the terminal executes the handover command without L3 signaling corresponding to the source cell, the terminal accesses the source cell via the new satellite of the source cell, and the terminal can retain the CHO configuration information of the candidate target cell.

[0187] Optionally, the third threshold may be pre-configured for the terminal by the network side, or carried in CHO configuration information and sent by the source base station to the terminal.

[0188] Optionally, in this application, S501 and S503 may be the same step. That is, when the terminal determines whether the execution conditions of the CHO corresponding to the candidate target cell are met, it also needs to consider the content of S503. That is, when one or more of the time conditions, distance conditions, or measurement events corresponding to a candidate target cell are simultaneously met, and the second interval is less than or equal to the third threshold, the terminal considers that the execution conditions of the CHO are met; otherwise, it is considered that they are not met.

[0189] FIG6 is a schematic flow chart of another communication method provided by the present application, which includes the following steps:

[0190] S601: The terminal determines that a CHO execution condition is met according to CHO configuration information sent by a source base station.

[0191] Optionally, please refer to the description in S301.

[0192] S602: The terminal obtains a fourth threshold.

[0193] Optionally, the CHO configuration information also includes information related to the first ephemeris corresponding to the target cell and the corresponding first activation time. Alternatively, the source cell broadcasts the first activation time in a broadcast message. The first activation time may also be the time when the next satellite corresponding to the target cell begins providing service to the target cell.

[0194] S603: The terminal determines whether to access the target cell according to the fourth threshold.

[0195] Specifically, the third time interval is the time interval between the current moment at which the terminal makes the determination and the first activation time. If the third time interval is less than or equal to the fourth threshold, the terminal performs CHO handover to the target cell and accesses the target cell. If the third time interval is greater than the fourth threshold, the terminal may continue to communicate in the source cell, and the terminal does not perform CHO on the target cell. The terminal may continue to determine whether the CHO execution conditions corresponding to the candidate target cell are met and whether the third time interval is less than or equal to the fourth threshold. When the terminal executes the L3 signaling-free handover command corresponding to the source cell, the terminal accesses the source cell via the source cell's new satellite, and the terminal may retain the CHO configuration information of the candidate target cell.

[0196] Optionally, the fourth threshold may be pre-configured for the terminal by the network side, or carried in CHO configuration information and sent by the source base station to the terminal.

[0197] Optionally, in this application, S601 and S603 may be the same step. That is, when the terminal determines whether the execution conditions of the CHO corresponding to the candidate target cell are met, it also needs to consider the content of S603. That is, when one or more of the time conditions, distance conditions, or measurement events corresponding to a candidate target cell are simultaneously met, and the third interval is less than or equal to the fourth threshold, the terminal considers that the execution conditions of the CHO are met; otherwise, it is considered that they are not met.

[0198] Optionally, S602 is optional, and S603 is replaced by the terminal determining whether to access the target cell based on the first activation time. When the terminal determines that the execution condition of CHO corresponding to the target cell is met and the current time reaches the first activation time or is after the first activation time, the terminal performs CHO switching to the target cell.

[0199] The communication method provided in the embodiment of the present application, based on the satisfaction of the execution conditions of the conditional switching, further determines whether the terminal executes the conditional switching of the target cell. This can alleviate communication problems caused by insufficient time for the terminal to access the target cell or too long waiting time, improve the terminal switching efficiency, and shorten the service interruption time.

[0200] When the satellite of the candidate target cell changes, the ephemeris-related information in the CHO configuration information needs to be changed. The source base station needs to update the CHO configuration information and send CHO reconfiguration information to the terminal. The CHO configuration information triggers the change before the satellite changes (i.e., before t-service). Therefore, it is necessary to consider the synchronization of the time when the terminal uses the CHO reconfiguration information and the time when the changed satellite covers the candidate target cell. If they are not synchronized, it will affect the switching efficiency. Therefore, the embodiment of the present application also provides a synchronization method so that the time when the terminal uses the CHO reconfiguration information is consistent with the time when the changed satellite covers the candidate target cell, that is, the terminal uses the CHO reconfiguration information and the time when the changed satellite covers the candidate target cell is synchronized.

[0201] Figure 7 is a schematic flow chart of a synchronization method provided by this application. The target base station triggers a CHO configuration information change before a satellite change. The target cell generates new CHO configuration information, which carries the ephemeris information of the changed satellite. The source base station sends the CHO reconfiguration information to the terminal when the changed satellite arrives.

[0202] Illustratively, the time when the first satellite starts covering the target cell is t1, and the time when the first satellite ends covering the target cell is t-service1; the time when the second satellite starts covering the target cell is t2, and the time when the second satellite ends covering the target cell is t-service2.

[0203] The target cell changes satellites before t-service1. At this time, the target base station triggers a CHO configuration information change. The configuration information carries the ephemeris information of the second satellite. Optionally, the configuration information can carry the time when the second satellite starts to cover the target cell, for example, t2. After the terminal receives the CHO reconfiguration information, the new CHO configuration information takes effect at t2. The specific signaling process can be:

[0204] S701: The target base station sends a CHO cancel (conditional Handover Cancel) message to the source base station.

[0205] Specifically, the CHO cancellation information carries a cause value, which indicates that the CHO configuration information or resources configured by the terminal have changed, or that the ephemeris-related information of the candidate target cell has changed. Optionally, the cause value may be cho-cpc-resources-tobechanged.

[0206] S702: The source base station receives the CHO cancellation information and sends a handover request (Handover request) information to the target base station.

[0207] Optionally, the handover request information may carry first indication information, instructing the target base station to change CHO configuration information.

[0208] S703: The target base station receives the handover request information and sends CHO reconfiguration information to the source base station.

[0209] The CHO reconfiguration information includes the ephemeris-related information of the changed satellite providing coverage for the target cell. Optionally, the CHO reconfiguration information also includes the effective time of the ephemeris-related information, or the effective time is included in the handover request confirmation message sent by the target base station to the source base station. The effective time is not included in the CHO reconfiguration information.

[0210] Specifically, after receiving the handover request information, the target base station generates CHO reconfiguration information (which may be an RRC reconfiguration message generated by the candidate target cell), and the CHO reconfiguration information may be carried in a handover request acknowledgment (HandoverRequestACK) message and sent to the source base station.

[0211] For example, the second satellite is a changed satellite, and the CHO reconfiguration information may carry ephemeris-related information of the second satellite. The CHO reconfiguration information may also carry the time when the second satellite begins to cover the target cell (i.e., effective time), for example, t2. After receiving the CHO reconfiguration information, the terminal generates new CHO configuration information at time t2.

[0212] S704: The source base station receives the CHO reconfiguration information and sends the CHO reconfiguration information to the terminal.

[0213] Specifically, the CHO configuration information may be carried in the RRC reconfiguration information and sent by the source base station to the terminal. After receiving the CHO reconfiguration information, the terminal takes effect at the effective time. The CHO reconfiguration information includes the ephemeris-related information of the changed satellite.

[0214] It should be noted that if the CHO configuration information does not carry an effective time, the effective time is carried in the handover request confirmation information. The source base station can send the CHO configuration information to the terminal when the changed satellite arrives (for example, at the effective time) or before (for example, to ensure that the terminal receives the CHO configuration information very soon before the effective time). Optionally, if the CHO configuration information carries an effective time, the time when the source base station sends the CHO configuration information can be unlimited. If the target base station triggers the generation of CHO reconfiguration information after the target cell satellite is changed, there is no need to consider the effective time, that is, the time when the terminal uses the CHO reconfiguration information is consistent with the time when the satellite covers the candidate target cell.

[0215] It should be noted that, before S701, the synchronization method further includes:

[0216] S7001: The source base station sends indication information of handover without L3 signaling and time information of taking effect of handover without L3 signaling, such as t-start, to the terminal. Optionally, the indication information may be sent in a system message.

[0217] S7002: The terminal initiates a connection and successfully connects to the source base station.

[0218] S7001 and S7002 are optional.

[0219] S7003: The source base station sends CHO configuration information to the terminal. Optionally, the source base station may send the CHO configuration information only to the terminal located at the cell edge.

[0220] S7004: The terminal receives CHO configuration information sent by the source base station.

[0221] It should be noted that, after S704, the synchronization method further includes the aforementioned step S206, which will not be described in detail here.

[0222] In an embodiment of the present application, a CHO configuration information change is triggered by a target base station to generate CHO reconfiguration information. The CHO reconfiguration information includes ephemeris-related information of the changed satellite and the corresponding effective time, so that the terminal uses the CHO reconfiguration information and the changed satellite to cover the candidate target cell in synchronization.

[0223] FIG8 is a schematic flow chart of another synchronization method provided by the present application, and the specific steps are as follows:

[0224] The source base station triggers a CHO configuration information change before the satellite changes, and the target cell generates new CHO configuration information. The CHO configuration information carries the ephemeris-related information of the changed satellite; the source base station sends the CHO reconfiguration information to the terminal when the changed satellite arrives.

[0225] Illustratively, the time when the first satellite starts covering the target cell is t1, and the time when the first satellite ends covering the target cell is t-service1; the time when the second satellite starts covering the target cell is t2, and the time when the second satellite ends covering the target cell is t-service2.

[0226] The target cell experiences a satellite change before t-service1. At this time, the source base station triggers a CHO configuration information change, requests the target base station to update the CHO configuration information, and indicates that the configuration information carries the ephemeris information of the second satellite. Optionally, the CHO reconfiguration information can carry the time when the second satellite begins to cover the target cell, for example, t2. After the terminal receives the CHO reconfiguration information, the new CHO configuration information takes effect at time t2. The specific signaling process can be:

[0227] S801: The source base station sends a handover request message to the target base station, where the handover request message includes indication information.

[0228] Optionally, when the target cell is about to replace the satellite, the source base station sends a handover request message to the target base station where the target cell is located. The handover request message includes a conditional handover trigger value (CHO trigger value). For example, the conditional handover trigger value may be CHO-replace.

[0229] Specifically, the handover request information also includes second indication information, which is used to instruct the target base station to change the CHO configuration information, and instruct the CHO reconfiguration information to carry the ephemeris-related information and effective time of the changed satellite providing coverage for the target cell.

[0230] S802: The target base station receives the handover request message and sends CHO reconfiguration information to the source base station. The CHO reconfiguration information includes ephemeris-related information of the changed satellite providing coverage for the target cell.

[0231] Optionally, the CHO reconfiguration information also includes the effective time of the ephemeris-related information, or the handover request confirmation information sent by the target base station to the source base station carries the effective time, which is not included in the CHO reconfiguration information.

[0232] Specifically, after receiving the handover request information, the target base station generates CHO reconfiguration information, and the CHO reconfiguration information may be carried in a handover request acknowledgment (Handover Request ACK) message and sent to the source base station.

[0233] Exemplarily, the second satellite is a changed satellite, and the CHO reconfiguration information may carry ephemeris-related information of the second satellite. The CHO reconfiguration information may also carry the time when the second satellite begins to cover the target cell, such as t2. After receiving the CHO reconfiguration information, the terminal generates new CHO configuration information at time t2.

[0234] S803: The source base station receives the CHO reconfiguration information and sends the CHO reconfiguration information to the terminal.

[0235] Specifically, the CHO configuration information may be carried in the RRC reconfiguration information and sent by the source base station to the terminal. After receiving the CHO reconfiguration information, the terminal takes effect at the effective time. The CHO reconfiguration information includes the ephemeris-related information of the changed satellite.

[0236] It should be noted that if the CHO configuration information does not carry an effective time, the effective time is carried in the handover request confirmation information. The source base station can send the CHO configuration information to the terminal when the changed satellite arrives (for example, at the effective time) or before (for example, to ensure that the terminal receives the CHO configuration information very soon before the effective time). Optionally, if the CHO configuration information carries an effective time, the time when the source base station sends the CHO configuration information can be unlimited. If the source base station triggers the generation of CHO reconfiguration information after the target cell satellite is changed, there is no need to consider the effective time, that is, the time when the terminal uses the CHO reconfiguration information is consistent with the time when the satellite covers the candidate target cell.

[0237] It should be noted that, before S801, the synchronization method further includes:

[0238] S8001. The source base station sends indication information of handover without L3 signaling and time information of taking effect of handover without L3 signaling, such as t-start, to the terminal. Optionally, the indication information may be sent in a system message.

[0239] S8002: The terminal initiates a connection and successfully connects to the source base station.

[0240] S8001 and S8002 are optional.

[0241] S8003: The source base station sends CHO configuration information to the terminal. Optionally, the source base station may send the CHO configuration information only to the terminal located at the cell edge.

[0242] S8004: The terminal receives CHO configuration information sent by the source base station.

[0243] It should be noted that, after S804, the synchronization method further includes the aforementioned step S206, which will not be described in detail here.

[0244] In an embodiment of the present application, a source base station triggers a CHO configuration information change, instructing a target base station to generate CHO reconfiguration information. The CHO reconfiguration information includes ephemeris-related information of the changed satellite and the corresponding effective time, so that the terminal uses the CHO reconfiguration information and the changed satellite to cover the candidate target cell in synchronization.

[0245] FIG9 shows a schematic diagram of a communication device provided in an embodiment of the present application.

[0246] In some embodiments, the device 1000 includes: a communication unit 1100, used to receive first information, the first information is used to instruct the terminal to switch to the first cell, the first information includes multiple sets of ephemeris-related information corresponding to the first cell; a processing unit 1200, used to determine switching to the first cell and first ephemeris-related information corresponding to the first cell, wherein the first ephemeris-related information is one of the multiple sets of ephemeris-related information; the processing unit 1200 is also used to access the first cell based on the first ephemeris-related information.

[0247] Optionally, the first information also includes activation times corresponding to multiple sets of ephemeris-related information; the processing unit 1200 determines that the first ephemeris-related information corresponding to the first cell includes: the first activation time corresponding to the first ephemeris-related information is equal to or less than the time determined by the processing unit 1200 to switch to the first cell.

[0248] Optionally, the first information further includes multiple physical cell identifiers, and the physical cell identifiers correspond to the ephemeris-related information one-to-one. The processing unit 1200 is further configured to determine a first physical cell identifier corresponding to the first cell.

[0249] Optionally, the first information is conditional switching configuration information of the first cell, and the conditional switching configuration information includes an execution condition for the terminal to switch to the first cell.

[0250] Optionally, when the execution condition of the first cell is met, the terminal does not access the first cell.

[0251] Optionally, the first information also includes a first service outage time corresponding to the first ephemeris related information; when the execution condition is met and the time interval between the current moment and the first service outage time exceeds a first threshold, the terminal does not access the first cell; or when the execution condition is met and the time interval between the current moment and the first service outage time is less than or equal to the first threshold, the terminal accesses the first cell.

[0252] Optionally, the first information also includes a first service outage time corresponding to the first ephemeris related information; when the execution condition is met and the interval between the first service outage time and the first activation time exceeds a second threshold, the terminal does not access the first cell; or when the execution condition is met and the interval between the first service outage time and the first activation time is less than or equal to the second threshold, the terminal accesses the first cell.

[0253] Optionally, when the execution condition is met and the interval between the current moment and the first activation time exceeds a third threshold, the terminal does not access the first cell; or when the execution condition is met and the interval between the current moment and the first activation time is less than or equal to the third threshold, the terminal accesses the first cell.

[0254] Optionally, the processing unit 1200 is further configured to start determining the execution condition after the first enabling time.

[0255] An embodiment of the present application also provides a communication device, including: a communication unit, used to receive first information, the first information is used to instruct the terminal to switch to the first cell, the first information includes the execution conditions for the terminal to switch to the first cell; a processing unit, used to determine that the execution conditions are met, and the terminal determines not to access the first cell based on the first information.

[0256] Optionally, the first information also includes first ephemeris-related information corresponding to the first cell and a first service outage time corresponding to the first ephemeris-related information; when the time interval between the current moment and the first service outage time exceeds a first threshold, the terminal does not access the first cell.

[0257] Optionally, the first information also includes first ephemeris-related information corresponding to the first cell and a first activation time and a first service stop time corresponding to the first ephemeris-related information; when the interval between the first service stop time and the first activation time exceeds a second threshold, the terminal does not access the first cell.

[0258] Optionally, the first information also includes first ephemeris-related information corresponding to the first cell and a first activation time corresponding to the first ephemeris-related information; when the interval between the current moment and the first activation time exceeds a third threshold, the terminal does not access the first cell.

[0259] An embodiment of the present application also provides a communication device, including: a communication unit, used to send second information, the second information is used to identify a change in first information or resources configured for a terminal; the communication unit is also used to receive switching request information, the switching request information is used to instruct the target base station to reconfigure the first information, the communication unit is also used to send the reconfigured first information, the reconfigured first information includes first ephemeris related information and an effective time corresponding to the first cell, and a processing unit, used to instruct the terminal to switch to the first cell and enable the first ephemeris related information at the effective time.

[0260] Optionally, the second information includes a cause value.

[0261] An embodiment of the present application also provides a communication device, including: a communication unit, used to send a switching request message, the switching request message is used to instruct the target base station to reconfigure the first information, and the reconfigured first information includes the first ephemeris related information and the effective time corresponding to the first cell; the communication unit is also used to receive the reconfigured first information sent by the target base station; a processing unit, used to instruct the terminal to switch to the first cell and enable the first ephemeris related information at the effective time.

[0262] Optionally, the handover request information includes a conditional handover trigger value, and the conditional handover trigger value is used to trigger a change in the first information or resource configured by the terminal.

[0263] An embodiment of the present application also provides a communication device, including: a communication unit, configured to receive first reconfiguration information, the first reconfiguration information including first ephemeris-related information and an effective time corresponding to a first cell; and a processing unit, configured to switch to the first cell according to the reconfigured first information and enable the first ephemeris-related information at the effective time.

[0264] Figure 10 is a schematic block diagram of a communication device 900 provided in an embodiment of the present application. As shown in the figure, the device 900 includes: at least one processor 920. The processor 920 is coupled to a memory and is configured to execute instructions stored in the memory to transmit and / or receive signals. Optionally, the device 900 also includes a memory 930 for storing instructions. Optionally, the device 900 also includes a transceiver 910, and the processor 920 controls the transceiver 910 to transmit and / or receive signals.

[0265] It should be understood that the processor 920 and memory 930 may be combined into a processing device, and the processor 920 is used to execute the program code stored in the memory 930 to implement the above functions. In specific implementations, the memory 930 may also be integrated into the processor 920 or independent of the processor 920.

[0266] It should also be understood that the transceiver 910 may include a transceiver (or receiver) and a transmitter (or transmitter). The transceiver may further include an antenna, and the number of antennas may be one or more. The transceiver 910 may also be a communication interface or interface circuit.

[0267] For example, the transceiver 910 in the apparatus 900 may correspond to the transceiver unit in the above-mentioned embodiment, and the processor 920 in the apparatus 900 may correspond to the processing unit in the above-mentioned embodiment. It should be understood that the specific process of each transceiver and processor executing the above-mentioned corresponding steps has been described in detail in the above-mentioned method embodiment, and for the sake of brevity, it will not be repeated here.

[0268] During implementation, each step of the above method can be completed by an integrated logic circuit of the hardware in the processor or by instructions in the form of software. The steps of 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, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it will not be described in detail here.

[0269] It should be noted that the processor in the embodiments of the present application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment can be completed by hardware integrated logic circuits in the processor or software instructions. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0270] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous-link DRAM (SLDRAM), and direct RAM-bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0271] According to the communication method provided in the embodiment of the present application, the present application also provides a computer program product, which stores computer program code. When the computer program code runs on a computer, the computer executes the communication method of the present application.

[0272] According to the communication method provided in the embodiment of the present application, the present application also provides a computer-readable medium, which stores a program code. When the program code runs on a computer, the computer executes the communication method of the present application.

[0273] According to the communication method provided in the embodiment of the present application, the present application also provides a system, which includes the aforementioned device or equipment.

[0274] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disc (SSD)).

[0275] The network-side devices in the above-mentioned various apparatus embodiments correspond to the network-side devices or terminal devices in the terminal devices and method embodiments, and the corresponding steps are performed by the corresponding modules or units. For example, the communication unit (transceiver) performs the steps of obtaining or sending in the method embodiments, and other steps except sending and obtaining can be performed by the processing unit (processor). The functions of the specific units can be referred to the corresponding method embodiments. Among them, there can be one or more processors.

[0276] As used in this specification, the terms "component," "module," "system," and the like are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. By way of illustration, both an application running on a computing device and a computing device can be a component. One or more components can reside in a process and / or an execution thread, and a component can be located on a computer and / or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component on a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0277] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0278] 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.

[0279] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0280] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0281] The units described 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 to achieve the purpose of this embodiment according to actual needs.

[0282] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0283] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0284] 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: include: The terminal receives first information, where the first information is used to instruct the terminal to switch to a first cell, and the first information includes multiple sets of ephemeris related information corresponding to the first cell; The terminal determines to switch to the first cell and first ephemeris related information corresponding to the first cell, wherein the first ephemeris related information is one of the multiple sets of ephemeris related information; The terminal accesses the first cell according to the first ephemeris related information.

2. The communication method according to claim 1, characterized in that: The first information also includes activation times corresponding to the multiple sets of ephemeris related information respectively; The terminal determines, that the first ephemeris-related information corresponds to the first cell, including: a first activation time corresponding to the first ephemeris-related information is equal to or later than a time when the terminal determines to switch to the first cell.

3. The communication method according to claim 1 or 2, characterized in that: The first information also includes a plurality of physical cell identifiers, and the physical cell identifiers correspond to the ephemeris related information one by one. The terminal determines a first physical cell identifier corresponding to the first cell.

4. The communication method according to claim 1 or 2, characterized in that: The first information is conditional switching configuration information of the first cell, and the conditional switching configuration information includes an execution condition for the terminal to switch to the first cell.

5. The communication method according to claim 4, characterized in that: When the execution condition of the first cell is met, the terminal does not access the first cell.

6. The communication method according to claim 4, characterized in that: The first information also includes a first service stop time corresponding to the first ephemeris related information; When the execution condition is met and the time interval between the current time and the first service outage time is less than a first threshold, the terminal does not access the first cell; or When the execution condition is met and the time interval between the current moment and the first service outage time is greater than or equal to a first threshold, the terminal accesses the first cell.

7. The communication method according to claim 4, characterized in that: The first information also includes a second out-of-service time of the ephemeris-related information of the terminal in the current cell; When the execution condition is met and the time interval between the current time and the second service outage time exceeds a second threshold, the terminal does not access the first cell; or When the execution condition is met and the time interval between the current moment and the second service outage time is less than or equal to a second threshold, the terminal accesses the first cell.

8. The communication method according to claim 4, characterized in that: The first information also includes a second out-of-service time of the ephemeris-related information of the terminal in the current cell; When the execution condition is met and the interval between the second service outage time and the first activation time exceeds a third threshold, the terminal does not access the first cell; or When the execution condition is met and the interval between the second service outage time and the first activation time is less than or equal to a third threshold, the terminal accesses the first cell.

9. The communication method according to claim 4, characterized in that: When the execution condition is met and the interval between the current time and the first activation time exceeds a fourth threshold, the terminal does not access the first cell; or When the execution condition is met and the interval between the current moment and the first activation time is less than or equal to a fourth threshold, the terminal accesses the first cell.

10. The communication method according to any one of claims 4 to 9, characterized in that: The terminal starts judging the execution condition after the first enabling time.

11. A communication method, characterized in that: include: The terminal receives first information, where the first information is used to instruct the terminal to switch to a first cell, and the first information includes an execution condition for the terminal to switch to the first cell; The first information also includes first ephemeris related information corresponding to the first cell; The terminal determines that the execution condition is met, and the terminal determines whether to access the first cell according to the first information.

12. The communication method according to claim 11, characterized in that: The first information also includes a first service stop time corresponding to the first ephemeris related information; When the time interval between the current moment and the first service outage time is less than a first threshold, the terminal does not access the first cell; Or when the time interval between the current moment and the first service outage time is greater than or equal to a first threshold, the terminal accesses the first cell.

13. The communication method according to claim 11, characterized in that: The first information also includes a second out-of-service time of the ephemeris-related information of the terminal in the current cell; When the time interval between the current moment and the second service outage time exceeds a second threshold, the terminal does not access the first cell; Or when the time interval between the current moment and the second service outage time is less than or equal to a second threshold, the terminal accesses the first cell.

14. The communication method according to claim 11, characterized in that: The first information further includes a first activation time corresponding to the first ephemeris related information and a second service stop time of the ephemeris related information of the terminal in the current cell; When the interval between the second out-of-service time and the first activation time exceeds a third threshold, the terminal does not access the first cell; or When the interval between the second out-of-service time and the first activation time is less than or equal to a third threshold, the terminal accesses the first cell.

15. The communication method according to claim 11, characterized in that: The first information also includes a first activation time corresponding to the first ephemeris related information; When the interval between the current time and the first activation time exceeds a fourth threshold, the terminal does not access the first cell; or When the interval between the current moment and the first activation time is less than or equal to a fourth threshold, the terminal accesses the first cell.

16. A synchronization method, characterized in that: include: The target base station sends second information, where the second information is used to identify that the first information or resource configured for the terminal has changed; The target base station receives handover request information, where the handover request information is used to instruct the target base station to reconfigure the first information. The target base station sends first reconfiguration information, where the first reconfiguration information includes first ephemeris related information and an effective time corresponding to the first cell, The reconfigured first information is used to instruct the terminal to switch to the first cell and enable the first ephemeris related information at the effective time.

17. The synchronization method according to claim 16, characterized in that: The second information includes a cause value.

18. A synchronization method, characterized in that: include: The source base station sends a handover request message, where the handover request message is used to instruct the target base station to reconfigure the first information, and the reconfigured first information includes first ephemeris related information and an effective time corresponding to the first cell. The source base station receives the first reconfiguration information sent by the target base station, The reconfigured first information is used to instruct the terminal to switch to the first cell and enable the first ephemeris related information at the effective time.

19. The synchronization method according to claim 18, characterized in that: The switching request information includes a conditional switching trigger value, and the conditional switching trigger value is used to trigger a change in the first information or resource configured by the terminal.

20. A synchronization method, characterized in that: include: The terminal receives the first reconfiguration information, where the first reconfiguration information includes first ephemeris related information and an effective time corresponding to the first cell. The terminal switches to the first cell according to the reconfigured first information and enables the first ephemeris related information at the effective time.

21. A communication device, characterized in that: Used to implement the communication method according to any one of claims 1 to 10, or used to implement the communication method according to any one of claims 11 to 15.

22. A communication device, characterized in that: Used to implement the synchronization method as described in claim 16 or 17, or used to implement the synchronization method as described in claim 18 or 19, or used to implement the synchronization method as described in claim 20.

23. A communication device, characterized in that: The invention comprises a processor and a memory, wherein the memory is used to store a computer program or instructions, and the processor is used to execute the computer program or instructions in the memory, so that the method described in any one of claims 1 to 10 is executed, or the method described in any one of claims 11 to 15 is executed.

24. A communication device, characterized in that: The method comprises a processor and a memory, wherein the memory is used to store a computer program or instructions, and the processor is used to execute the computer program or instructions in the memory, so that the method of claim 16 or 17 is executed, or the method of claim 18 or 19 is executed, or the method of claim 20 is executed.

25. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 10, or the computer is caused to execute the method according to any one of claims 11 to 15.

26. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed on a computer, enables the computer to execute the method according to claim 16 or 17, or enables the computer to execute the method according to claim 18 or 19, or enables the computer to execute the method according to claim 20.

27. A computer program product, characterized in that The computer program product comprises means for executing the method according to any one of claims 1 to 10 , or the computer program product comprises means for executing the method according to any one of claims 11 to 15 .

28. A computer program product, characterized in that The computer program product comprises means for executing the method according to claim 16 or 17, or the computer program product comprises means for executing the method according to claim 18 or 19, or the computer program product comprises means for executing the method according to claim 20.

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