Communication method, synchronization method and communication device

Abstract

Provided are a communication method, a synchronization method and a communication device, the communication method comprising: a terminal receiving first information, the first information being used for instructing the terminal to switch to a first cell, the first information comprising 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, and the first ephemeris related information is one of the multiple sets of ephemeris related information; and the terminal accesses the first cell according to the first ephemeris related information. According to the communication method provided by the invention, the terminal can start the ephemeris related information of the corresponding satellite in the time period covered by the satellite to carry out condition switching, so that the signaling overhead is effectively saved.

Description

Technical Field

[0001] 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

[0002] In the non-terrestrial network (NTN) system, the satellite network can provide coverage for areas that are difficult to cover with the ground network, and can also enhance the reliability of mobile communications. The satellite cell coverage area is very large. For example, in the ground static cell scenario, the satellite will adjust its beam so that the area covered by the beam remains unchanged for a period of time, and then when the service cannot be provided, the next satellite will provide coverage. In this scenario, the ground base station remains unchanged, but the service satellite has changed. The terminal only needs to resynchronize with the new satellite for downlink and uplink after the new satellite arrives. This process does not require the base station to send an L3 switching command, thereby reducing signaling overhead.

[0003] However, due to the mobility of the terminal, the terminal at the edge of the cell coverage may move out of the coverage range, or due to the inconsistency of the coverage range of the new and old satellites, the coverage range of the new satellite is smaller than the coverage range of the current service satellite, and the terminal at the edge of the cell may not be within the coverage range of the new satellite. In order to improve the robustness of the switching, the network needs to configure conditional switching configuration information for the terminal so that the terminal can switch from the current cell to the target cell. However, the change of the satellite of the candidate target cell will cause the conditional switching configuration information to be updated, and the network side needs to continuously update the conditional switching configuration information, resulting in a large signaling overhead. Therefore, how to reduce the overhead of the conditional switching configuration has become a problem that needs to be solved urgently. Summary of the invention

[0004] 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.

[0005] 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 according to the first ephemeris-related information.

[0006] The embodiment of the present application carries the same switching configuration information and ephemeris-related information of multiple satellites through CHO configuration information, 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.

[0007] 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.

[0008] The embodiment of the present application enables different ephemeris-related information at different times through the activation time corresponding to the ephemeris-related information carried in the CHO configuration information, thereby effectively saving signaling overhead.

[0009] 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 a first physical cell identifier corresponding to the first cell.

[0010] 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.

[0011] 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.

[0012] The communication method provided in the embodiment of the present application can alleviate communication problems caused by insufficient time for the terminal to access the target cell or too long waiting time by further judging whether the terminal executes conditional switching to the target cell based on the satisfaction of the execution conditions of the conditional switching, thereby improving the terminal switching efficiency and shortening the service interruption time.

[0013] In combination with the first aspect, in some implementations of the first aspect, the first information further includes a first service outage time corresponding to the first ephemeris related information;

[0014] 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

[0015] 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.

[0016] 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.

[0017] 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 in the ephemeris-related information of 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.

[0018] 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.

[0019] The communication method provided in the embodiment of the present application can alleviate communication problems caused by insufficient time for the terminal to access the target cell or too long waiting time by further judging whether the terminal executes conditional switching to the target cell based on the satisfaction of the execution conditions of the conditional switching, thereby improving the terminal switching efficiency and shortening the service interruption time.

[0020] In combination with the first aspect, in some implementations of the first aspect, the terminal starts determining the execution condition after the first enabling time.

[0021] In a second aspect, a communication method is provided, including: a terminal receives first information, the first information is used to instruct the terminal to switch to a first cell, 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 based on the first information.

[0022] The communication method provided in the embodiment of the present application can alleviate communication problems caused by insufficient time for the terminal to access the target cell or too long waiting time by further judging whether the terminal executes conditional switching to the target cell based on the satisfaction of the execution conditions of the conditional switching, thereby improving the terminal switching efficiency and shortening the service interruption time.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] According to a third aspect, a synchronization method is provided, including: a target base station sends second information, wherein the second information is used to identify that first information or resources configured for a terminal have changed; the target base station receives a switching request information, wherein 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, wherein 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.

[0028] In the embodiment of the present application, a CHO configuration information change is triggered by a target base station to generate CHO reconfiguration information, wherein 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 synchronously, thereby effectively improving the switching efficiency.

[0029] In combination with the third aspect, in certain implementations of the third aspect, the second information includes a cause value.

[0030] 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 a target base station to reconfigure first information, and the reconfigured first information includes first ephemeris-related information and an effective time corresponding to a 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 a terminal to switch to the first cell and enable the first ephemeris-related information at the effective time.

[0031] In the 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, wherein the CHO reconfiguration information includes ephemeris-related information of the changed satellite and a corresponding effective time, so that the terminal uses the CHO reconfiguration information and the changed satellite to cover the candidate target cell synchronously, thereby effectively improving the switching efficiency.

[0032] 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.

[0033] 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.

[0034] In a sixth aspect, a communication device is provided, comprising 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; and the processing unit is also used to access the first cell based on the first ephemeris-related information.

[0035] 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 respectively; 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.

[0036] 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 a first physical cell identifier corresponding to the first cell.

[0037] 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.

[0038] 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.

[0039] In combination with the sixth aspect, in certain implementation methods 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 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.

[0040] In combination with the sixth aspect, in certain implementation methods 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.

[0041] 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.

[0042] In combination with the sixth aspect, in certain implementations of the sixth aspect, the processing unit is further used to start determining the execution condition after the first enabling time.

[0043] 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; and 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.

[0044] In combination with the seventh aspect, in certain implementation methods 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.

[0045] In combination with the seventh aspect, in certain implementation methods 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.

[0046] In combination with the seventh aspect, in certain implementation methods 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.

[0047] In the eighth aspect, a communication device is provided, including: a communication unit, used to send second information, wherein the second information is used to identify that the first information or resources configured for the terminal have changed; the communication unit is also used to receive switching request information, wherein the switching request information is used to instruct the target base station to reconfigure the first information, and the communication unit is also used to send the reconfigured first information, wherein the reconfigured first information includes first ephemeris related information and an effective time corresponding to the first cell, and 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.

[0048] In combination with the eighth aspect, in certain implementations of the eighth aspect, the second information includes a cause value.

[0049] In the ninth aspect, a communication device is provided, including: a communication unit, used to send 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, used to instruct the terminal to switch to the first cell and enable the first ephemeris related information at the effective time.

[0050] 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.

[0051] In the tenth aspect, a communication device is provided, including: a communication unit, used to receive first reconfiguration information, the first reconfiguration information including first ephemeris related information and effective time corresponding to a first cell; a processing unit, used to switch to the first cell according to the reconfiguration first information and enable the first ephemeris related information at the effective time.

[0052] 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 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 described in the second aspect and any one of the implementation methods of the second aspect.

[0053] 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 executes the method as described in the third aspect and any one of the implementations of the third aspect, or the computer executes the method as described in the fourth aspect and any one of the implementations of the fourth aspect, or the computer executes the method as described in the fifth aspect.

[0054] In the thirteenth aspect, a computer program product is provided, characterized in that 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.

[0055] In the fourteenth aspect, a computer program product is provided, characterized in that 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

[0056] Figure 1 It is a schematic diagram of a communication method provided in an embodiment of the present application.

[0057] Figure 2 It is a schematic diagram of a communication method provided in an embodiment of the present application.

[0058] Figure 3 It is a schematic diagram of a communication method provided in an embodiment of the present application.

[0059] Figure 4 It is a schematic diagram of a communication method provided in an embodiment of the present application.

[0060] Figure 5 It is a schematic diagram of a communication method provided in an embodiment of the present application.

[0061] Figure 6 It is a schematic diagram of a communication method provided in an embodiment of the present application.

[0062] Figure 7 It is a schematic diagram of a synchronization method provided in an embodiment of the present application.

[0063] Figure 8 It is a schematic diagram of a synchronization method provided in an embodiment of the present application.

[0064] Fig. 9It is a schematic diagram of a communication device provided in an embodiment of the present application.

[0065] Fig.10 It is a schematic diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0066] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0067] The communication achieved with the help of non-terrestrial network equipment in non-terrestrial network (NTN) is called non-terrestrial communication. NTN system can include satellite system, high altitude platform station (HAPS) communication system 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 communication into mobile network communication, such as the fifth generation (5th-Generation, 5G) communication, can improve user experience. On the one hand, satellite network can provide communication services for areas that are difficult to cover by terrestrial network, such as oceans, forests, deserts or remote areas; on the other hand, satellite network can enhance the reliability of mobile communication, such as providing more stable communication services for users in high-speed mobile scenarios such as trains and airplanes; in addition, satellite network can also provide more data transmission resources and support the connection of a larger number of terminal devices.

[0068] Generally speaking, the higher the satellite's orbit, the larger its coverage area, but the longer the communication delay. According to the orbital altitude, satellites can be divided into:

[0069] (1) Low Earth Orbit (LEO): orbit altitude is 160 to 2 000 km;

[0070] (2) Medium orbit (MEO): orbit altitude is 2000~35786km;

[0071] (3) Geostationary orbit (GEO): orbit altitude is 35 786 km;

[0072] 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.

[0073] For NGSO, depending on whether the satellite beam moves with the satellite, it can be further divided into Earth Moving Cell and Earth Fixed Cell. For Earth Moving Cell, the cell moves relative to the ground, and the satellite beam points to follow the satellite movement; for Earth Fixed Cell or Quasi-Earth Fixed Cell, the cell is fixed relative to the ground for a certain period of time, and the satellite antenna can use its beamforming capability to point the beam to a certain area fixed on the ground for a certain period of time.

[0074] Satellites can be generally divided into two categories according to their working modes. The first form is transparent forwarding, where the satellite forwards the cell information of ground network equipment (such as base stations). The role of the satellite is wireless frequency filtering, frequency conversion and amplification, that is, the satellite mainly acts as an L1 relay to regenerate the physical layer signal and does not have other higher protocol layers.

[0075] The second form is the regenerative form, where the satellite has the processing function of a base station. In the regenerative working mode, it can be divided into regenerative satellites without inter-satellite links, that is, there is no inter-satellite link (ISL) between satellites; regenerative satellites with inter-satellite links, that is, there is an interface between satellites to directly exchange data, where the inter-satellite link is the Xn port; regenerative satellites with the DU processing function of a base station, in which the satellite acts as a DU.

[0076] 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 mobile cell) and Quasi-Earth Fixed Cell (quasi-stationary cell) scenarios.

[0077] The terminal in the embodiment 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 with a wireless connection function, a vehicle-mounted device, etc. At present, some examples of terminals are: mobile phones, tablet computers, laptop computers, PDAs, mobile internet devices (MID), 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.

[0078] 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. At present, some examples of RAN nodes are: a further evolved Node B (gNB), a transmission reception point (TRP), an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., home evolved NodeB, or home Node B, HNB), a base band unit (BBU), or a wireless fidelity (Wifi) access point (AP), etc. 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. The RAN equipment including CU nodes and DU nodes splits the protocol layer of gNB in ​​the NR system, puts some functions of the protocol layer in the CU for centralized control, and distributes some or all functions of the protocol layer in the DU, which is centrally controlled by the CU. Furthermore, the centralized unit CU can also be divided into the control plane (CU-CP) and the user plane (CU-UP). Among them, CU-CP is responsible for the control plane function, mainly including RRC and PDCP corresponding to the control plane, namely PDCP-C. PDCP-C is mainly responsible for encryption and decryption, integrity protection, data transmission, etc. of the control plane data. CU-UP is responsible for the user plane function, mainly including SDAP and PDCP corresponding to the user plane, namely PDCP-U. Among them, SDAP is mainly responsible for processing the data of the core network and mapping the flow to the bearer. PDCP-U is mainly responsible for encryption and decryption, integrity protection, header compression, sequence number maintenance, data transmission, etc. of the data plane. Among them, CU-CP and CU-UP are connected through the E1 interface. CU-CP represents the connection between gNB and the core network through the NG interface. The control plane, namely F1-C, is connected to DU through the F1 interface. CU-UP is connected to DU via F1 interface user plane, i.e. F1-U. Of course, another possible implementation is that PDCP-C is also in CU-UP.

[0079] The core network device in the embodiment of the present application refers to the device in the core network (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.

[0080] In addition, in order to facilitate understanding of the embodiments of the present application, the following points are explained.

[0081] First, in this application, "used for indication" may include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used for indicating A, it may include that the indication information directly indicates A or indirectly indicates A, but it does not mean that A must be included in the indication information.

[0082] The information indicated by the indication information is called the information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated. The information to be indicated can be sent as a whole, or divided into multiple sub-information and sent separately, and the sending period and / or sending time of these sub-information can be the same or different. The specific sending method is not limited in this application.

[0083] Second, "at least one" shown in the present application refers to one or more, and "multiple" 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, and 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 in appropriate circumstances, so that the schemes other than the embodiments of the present application can be described. In addition, in the embodiments of the present application, the words "201", "202" and the like are only for the convenience of description, and the order of execution steps is not limited.

[0084] Third, in this application, the words "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a specific way.

[0085] Fourth, the "storage" involved in the embodiments of the present application may refer to storage in one or more memories. The one or more memories may be separately set or integrated in an encoder or decoder, a processor, or a communication device. The one or more memories may also be partially separately set and partially integrated in a decoder, a processor, or a communication device. The type of memory may be any form of storage medium, which is not limited by the present application.

[0086] Fifth, the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0087] To facilitate understanding of the embodiments of the present application, the basic concepts involved in the present application are first briefly explained.

[0088] 1. Traditional switching

[0089] Due to the movement of the UE, the signal quality of the network currently accessed by the UE may deteriorate, and the UE needs 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 device, that is, the network device sends a handover message to instruct the UE which cell to switch to and how to switch. Figure 1 As shown, after receiving the handover message, the UE accesses the target cell according to 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:

[0090] 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.

[0091] 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.

[0092] Step 3: After receiving the report reported by the UE, the source base station makes a decision, and the decision result is that the source base station sends a handover request message to the target base station during handover.

[0093] Step 4: The target base station determines whether to allow the UE to switch in. If the decision result 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.

[0094] Step 5: After receiving the handover confirmation message sent by 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 of step 4. Specifically, the handover command in the NR system contains relevant information of the target cell and relevant configuration parameters required for the UE to access the target cell, for example, target cell information (such as PCI of the target cell and frequency information corresponding to the target cell), C-RNTI allocated by the target cell to the UE, RACH resource information required to access the target cell (such as dedicated RACH resources and / or public RACH resources), etc.

[0095] 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 short interruption in sending and receiving data before successfully accessing the target base station.

[0096] Step 7: The UE sends an RRC reconfiguration completion message to the target base station.

[0097] 2. Conditional Switch (CHO)

[0098] In a terrestrial network (TN), the movement of users will cause the signal quality of the current service cell to deteriorate, and they need to switch to a neighboring cell with better signal quality. Unlike terrestrial networks, the cell coverage area of ​​satellites is very large (the coverage radius is tens to hundreds of kilometers), and users are generally still within the cell coverage area of ​​satellites after moving; in addition, the high-speed movement of NGSOs relative to the ground makes the satellite's coverage of a certain area on the ground very short, causing users to frequently change service cells. Therefore, unlike terrestrial networks, the mobility of satellites is the main reason for user switching.

[0099] Therefore, for Earth Fixed Cell or Quasi-Earth Fixed Cell, the satellite can stare at the ground for a while. When the satellite is about to move out of the UE's line of sight, all UEs in the cell need to 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 causes frequent user switching; for Earth Moving Cell, large-scale frequent user switching brings a lot of signaling overhead; for Earth Fixed Cell or Quasi-Earth Fixed Cell, large-scale simultaneous user switching will lead to signaling storms and cause signaling congestion. Therefore, solving the signaling overhead problem caused by frequent user switching under NGSO is the key to improving the communication efficiency of the NTN system.

[0100] In order to avoid the link quality of the source base station from further deteriorating, resulting in the inability to normally interact signaling between the UE and the source base station, which in turn causes the handover to fail to execute successfully, the prior art 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 condition based on the configuration information, and uses a candidate target cell that meets the handover trigger condition 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) to notify the target base station that the conditional handover is completed.

[0101] Step 1: The source base station configures the UE to perform neighboring cell measurement. The measurement configuration information may be sent via an RRC reconfiguration message. The UE performs the measurement and reports the measurement result to the source base station.

[0102] 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.

[0103] Step 3: The candidate target base station sends a handover response message to the source base station. The handover response message carries configuration information of the candidate target cell.

[0104] Step 4: The source base station sends the switching configuration information to the UE.

[0105] Step 5: Upon receiving the handover configuration information, the UE starts evaluating the CHO execution conditions of the candidate target cells while maintaining the connection with the source base station. If at least one of the CHO candidate target cells meets the corresponding CHO execution conditions, the UE leaves the source base station, switches to the target base station, and then sends an RRC reconfiguration complete message to the target base station to complete the RRC handover process. The UE releases the stored CHO configuration after successfully completing the RRC handover process.

[0106] In the NTN ground static cell scenario, the satellite will adjust its beam so that the area covered by the beam remains unchanged for a period of time. Then, when it is unable to provide service or coverage for the cell, the next satellite will provide coverage. In this scenario, the ground base station can remain unchanged, so the terminal's wireless resource configuration information can be kept unchanged before and after the satellite changes, for example, the cell's physical cell identifier PCI is not changed, and there is no need to introduce L3 signaling switching. The terminal only needs to re-synchronize with the cell through the new satellite after the new satellite arrives (for example, at the moment when the satellite stops serving the cell before the change, or at the moment when the satellite starts serving the cell after the change, or at any moment between the moment when the satellite starts serving the cell after the change and the moment when the satellite stops serving the cell before the change). The UE and the base station side keep the configuration of the wireless resources allocated to the terminal before the switch unchanged, which can solve the problem of signaling storm caused by switching in this scenario. This method can be called a switching solution without L3 switching command when the satellite changes but the cell identifier remains unchanged.

[0107] There are two handover scenarios for ground stationary cells: hard handover (no overlap between front and rear satellite coverage) and soft handover (overlap between front and rear satellite coverage).

[0108] Optionally, in the NTN ground stationary cell scenario, when switching to a satellite that provides services or coverage for the cell, the physical cell identifier PCI of the cell can be changed, so the terminal's wireless resource configuration information can be kept unchanged before and after the satellite is changed, and the terminal and the base station side only need to change the physical cell identifier of the cell. In this scenario of switching satellites, there is no need to introduce L3 signaling switching for the terminal. The terminal only needs to re-synchronize with the cell through the new satellite after the new satellite arrives (for example, at the moment when the satellite stops serving the cell before the change, or at the moment when the satellite starts serving the cell after the change, or at any moment between the moment when the satellite starts serving the cell after the change and the moment when the satellite stops serving the cell before the change). The UE and the base station side keep the configuration of the wireless resources allocated to the terminal before the switch unchanged, but the physical cell identifier of the cell needs to be changed, which can also solve the problem of signaling storm caused by switching in this scenario. This method can be called a switching solution in which the satellite changes but the cell identifier changes without the need for an L3 switching command.

[0109] However, due to the mobility of UE, the UE at the edge of the 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 are inconsistent, the coverage of the new satellite is smaller than the coverage of the current service satellite. The UE at the edge of the cell may not be within the coverage of the new satellite. Therefore, when using switching without L3 signaling (or satellite change, switching without L3 signaling can also be referred to as satellite change below), the UE at the edge of the cell is at risk of failing to access the target satellite.

[0110] In order to prevent the UE at the cell edge from failing to switch in a handover mode without L3 signaling due to the movement of the UE or the inconsistent coverage of the new and old satellites, the network can configure CHO for the UE at the same time, or only configure CHO for the UE 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 to improve the robustness of the handover.

[0111] In order to improve the robustness of handover, the network side will configure CHO for the UE, but the ephemeris-related information of the candidate target cell will need to be updated due to satellite changes. If the satellite of the candidate target cell changes, the network side needs to update the CHO configuration information, for example, delete the disappeared candidate target cell, or configure a new candidate target cell, which will easily lead to an increase in signaling overhead.

[0112] Therefore, an embodiment of the present application provides a communication method that can reduce the signaling overhead of a terminal when performing conditional switching.

[0113] Figure 2 This is a schematic flow chart of a communication method provided by the present application. It includes the following steps:

[0114] S201: The source base station sends measurement configuration information to the terminal. The terminal performs measurement according to the measurement configuration information and reports the measurement result to the source base station.

[0115] Specifically, the measurement configuration information includes measurement object, report configuration, measurement ID, measurement configuration and measurement GAP configuration.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] It should be noted that S201 is optional. In S202, the source base station may also select a candidate target cell for the terminal according to other information.

[0120] S203, the source base station sends CHO configuration information to the terminal, the CHO configuration information is first information, the CHO configuration information is used to instruct the terminal to switch to a candidate target cell, and the CHO configuration information includes multiple sets of ephemeris related information corresponding to the candidate target cells, wherein the candidate target cells include the first cell.

[0121] Exemplarily, the source base station sends CHO configuration information to the terminal, and the CHO configuration information includes NTN configuration information, such as the serving cell configuration information (Serving Cell Config Common) carrying the 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 switching configuration information (for example, information carried by the synchronous reconfiguration information Reconfiguration With Sync).

[0122] Optionally, the ephemeris-related information (or satellite-related information) includes at least one of the following: ephemeris information, reference time of the 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.

[0123] Among them, epochTime is used to indicate the epoch time of NTN auxiliary information (or related information). When explicitly provided through 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 or configured or does not exist, the epoch time is the end time of the SI window that schedules this SIB19.

[0124] Optionally, each set of ephemeris-related information corresponding to the candidate target cell includes a corresponding activation time, or the CHO configuration information also includes activation times corresponding to multiple sets of ephemeris-related information.

[0125] Optionally, the activation time may be a time point, and the UE activates the ephemeris at the corresponding time point. For example, the time point may be a UTC time, or the activation time may be a time period, such as [t1, t2]; or, the activation time may be determined by the ephemeris validity time in the ephemeris-related information; or 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, for another example, the reference time 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 one by one, and the terminal activates the corresponding ephemeris information according to the activation times corresponding to different moments or time periods. For example, when the activation time is the Universal Coordinated Time (UTC), the multiple sets of ephemeris information correspond to different activation times one by one, and the terminal activates the corresponding ephemeris information according to the activation times corresponding to different moments or time periods.

[0126] 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 providing 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 subsequent satellites that 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 subsequent satellites that provide coverage for the first candidate target cell and the corresponding activation time.

[0127] Optionally, the time period in 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, after a first time interval Gap1, the second satellite provides coverage for the first candidate target cell, where Gap1 is greater than or equal to 0. Optionally, the time period in which the first satellite and the second satellite provide coverage for the first candidate target cell may also overlap.

[0128] 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 the satellite corresponding to the first candidate target cell is switched, the physical cell identifier of the first candidate target cell remains unchanged or changes, and the first candidate target cell and the terminal served by the first candidate target cell can adopt the switching scheme without L3 switching command introduced above.

[0129] 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, a handover without an L3 command is performed in a soft handover scenario. At this time, the CHO configuration information may also include multiple physical cell identifiers, such as PCI. 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 that currently provides coverage for the target cell, the second satellite is the next satellite that provides coverage for the target cell, the second satellite provides coverage for the first target cell later than the first satellite, and optionally, the time when the first satellite and the second satellite cover the target cell overlaps. At this time, the CHO configuration information includes at least one of the following: at least one candidate target cell handover configuration information (for example, information carried by the synchronization reconfiguration information ReconfigurationWithSync), at least one ephemeris information of 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 of 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. Physical cell identifiers corresponding to M candidate cells, each candidate target cell can correspond to K_m (m = 1, 2, 3, ..., M) physical cell identifiers, N_m is greater than or equal to 1, and the value of N_m can be different. Optionally, the values ​​of N_m and K_m can be the same, that is, the PCI must be changed every time the satellite is changed, or the values ​​of N_m and K_m can be different, corresponding to the scenario where the satellite is changed but the PCI is not updated.

[0130] Exemplarily, the CHO configuration information at this time includes at least one of the following: ephemeris-related information of the first satellite and the corresponding first physical cell identifier, ephemeris-related information of the second satellite and the corresponding second physical cell identifier, and 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: ephemeris-related information of the first satellite, the corresponding first activation time and the corresponding first physical cell identifier, ephemeris-related information of the second satellite, the corresponding second activation time and the corresponding second physical cell identifier, and 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.

[0131] 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 the broadcast message. In one implementation, the CHO configuration carries multiple sets of ephemeris-related information. At least one service stop time or service start time of the candidate target cell is broadcast in the broadcast message. 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 implementation, the CHO configuration carries multiple sets of ephemeris-related information. A service stop time of the candidate target cell is broadcast in the broadcast message. When the terminal receives the CHO configuration, the terminal considers the first set of ephemeris-related information to be valid. When the service stop time of the candidate target cell broadcasted 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 arrives, 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.

[0132] 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, 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, 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 perform conditional switching according to the corresponding ephemeris-related information, which effectively saves signaling overhead.

[0133] S204: The terminal receives CHO configuration information.

[0134] The terminal determines to enable the corresponding ephemeris related information according to the CHO configuration information.

[0135] Optionally, the CHO configuration information may further include activation times corresponding to the multiple sets of ephemeris-related information, and the terminal determines the ephemeris-related information of which satellite of the target cell to use according to the activation time corresponding to the ephemeris-related information of the satellite 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.

[0136] Exemplarily, 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 an 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.

[0137] 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.

[0138] Optionally, the UE determines whether to change the satellite based on the effective time of the ephemeris of the target satellite. The effective time of the ephemeris is configured to the UE during CHO configuration. When the source base station determines the CHO configuration information, the ephemeris-related information is configured in the order in which the satellites cover the candidate target cells. The UE takes effect on the new ephemeris information in sequence after the current ephemeris information expires. For example, when the effective time of the ephemeris of satellite 1 expires, the UE takes effect on the ephemeris of satellite 2, and so on. At this time, there is no need to display the effective time of the indicated ephemeris information, and the UE takes effect on the ephemeris information in sequence.

[0139] 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.

[0140] Optionally, the terminal determines the effective ephemeris-related information according to the current time. For example, if the current time is after the activation time corresponding to the ephemeris-related information #1 and before the activation time corresponding to the ephemeris-related information #2, the terminal adopts the ephemeris-related information #1. For another example, if the current time is within the effective time corresponding to the ephemeris-related information #1, the terminal adopts the ephemeris-related information #1.

[0141] 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, the terminal uses the CHO switching configuration and the ephemeris-related information of the first satellite to access the target base station at time t1 or in the time period [t1, t2].

[0142] Optionally, 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, and the current first satellite covers the target cell, the terminal enables the ephemeris-related information and the first physical cell identifier 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, the second satellite is about to cover the target cell, and the terminal enables the ephemeris-related information and the second physical cell identifier of the second satellite at the second activation time according to the CHO configuration information. At different times or time periods, the terminal uses the same CHO handover configuration, the PCI corresponding to the activation time, and the ephemeris-related information corresponding to the activation time to access the target base station.

[0143] S205: The terminal determines the CHO execution condition according to the CHO configuration information.

[0144] Specifically, the CHO execution condition includes a time condition and / or a distance condition. The time condition includes a first time window. When the current time is within the range of 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].

[0145] Specifically, the distance condition includes a first distance threshold D1 and a second distance threshold D2. 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, that is, the distance condition is met. Optionally, 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. Optionally, the first distance threshold and the second distance threshold may be configured for the terminal by the network side.

[0146] Optionally, the execution condition may further include a measurement event. When one or more of the time condition, the distance condition, or the measurement event are met at the same time, the terminal satisfies the execution condition. For example, the terminal satisfies one of the following: the time condition, the distance condition, the measurement event, the time condition and the measurement event, the distance condition and the measurement event. Optionally, any two or three of the time condition, the distance condition, and the measurement event are jointly configured, and the conditional switching is performed when any of the two or three effective conditions are met.

[0147] S206, the terminal performs a signaling handover without L3 in the source cell at the first time, 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.

[0148] Optionally, the first time may be time information indicating when the source cell stops serving (t-service), that is, time information indicating when the coverage of the current area stops, or the time when the next satellite broadcast by the source cell provides service to the source cell (t-start), or any time in between.

[0149] Before S201, the communication method further includes: the source base station sends indication information of switching without L3 signaling to the terminal. The function of the indication information of switching without L3 signaling includes: when the terminal receives the indication information and the terminal supports the capability of switching without L3 signaling, the terminal performs switching without L3 signaling, and the indication information is used to instruct the terminal to perform switching without L3 signaling.

[0150] Exemplarily, the indication information can be sent in a system message, and the indication information can be a Boolean value, indicating the terminal by 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.

[0151] 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.

[0152] Optionally, when the terminal determines that the CHO execution condition of a candidate target cell is met, the terminal device determines which ephemeris-related information corresponding to the candidate target cell is enabled. Afterwards, the terminal accesses the candidate target cell according to the ephemeris-related information. For the specific method for the terminal device to determine which ephemeris-related information corresponding to the candidate target cell is enabled, refer to the method described in S204. Optionally, when the terminal receives the CHO configuration information in S204, it does not need to determine which ephemeris-related information corresponding to the candidate target cell is enabled, but when the execution condition corresponding to the candidate target cell is met in S206, the terminal device determines which ephemeris-related information corresponding to the candidate target cell is enabled.

[0153] The embodiment of the present application carries the same switching configuration information and ephemeris-related information of multiple satellites through CHO configuration information, 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.

[0154] When the execution conditions of the target cell are met, according to the current protocol, the terminal will immediately adopt the configuration of the target cell and access the candidate target cell. In the scenario where the target cell is an Earth Fixed Cell or Quasi-Earth Fixed Cell and the satellite will change, the target cell meets the CHO execution conditions, and the target cell is about to change the satellite. At this time, if the connection with the source cell is directly disconnected, the terminal may not be able to access the candidate target cell immediately (for example, the service start time of the new satellite of the candidate target cell has not arrived yet), and the terminal's communication will be interrupted, affecting service performance.

[0155] Therefore, an embodiment of the present application also provides a communication method, so that a terminal can successfully access a target base station where a target cell is located, thereby reducing the interruption time of communication services.

[0156] Figure 3 This is a schematic flow chart of a communication method provided by the present application. It includes the following steps:

[0157] S301: The terminal determines, according to the CHO configuration information sent by the source base station, whether the execution condition of the CHO corresponding to the candidate target cell is satisfied.

[0158] When one or more of the time condition, distance condition or measurement event are met at the same time, the terminal meets the execution condition, for example, the terminal meets one or more of the following conditions: time condition, distance condition, measurement event. The specific execution condition and the judgment of whether the execution condition is met have been described in the above S204 and will not be repeated here.

[0159] 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.

[0160] Optional. Before S301, execute Figure 2 S202~S204.

[0161] S302: The terminal obtains a first threshold.

[0162] Optionally, the CHO configuration information also includes first ephemeris-related information corresponding to the target cell and a corresponding first service stop time, or the source cell broadcasts the first service stop time in a broadcast message. The first service stop 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 moment and the first service stop time is the remaining service time.

[0163] Optionally, the first out-of-service time may be read by the terminal through a system message SIB, such as SIB19, which may be a SIB broadcast by the serving cell, or may be a SIB broadcast by a neighboring cell, or may be sent by the network side to the terminal when sending CHO configuration information, which is not specifically limited in the embodiment of the present application. 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.).

[0164] The terminal obtains a first threshold. Optionally, the first threshold can at least support the terminal to complete random access, for example, the value of the first threshold is greater than the round-trip time RTT from the terminal to the target base station. Optionally, the first threshold can be pre-configured for the terminal by the network side, or carried in the CHO configuration information and sent to the terminal by the source base station, or the first threshold is a value agreed upon by the protocol. This embodiment of the present application is not specifically limited to this.

[0165] This application does not limit the order of S301 and S302.

[0166] S303: The terminal determines whether to access the target cell according to the first threshold.

[0167] Specifically, the remaining service time of the target cell is greater than or equal to the first threshold, that is, the terminal has enough time to access the target cell, the terminal performs CHO on the target cell, and the terminal accesses the target cell. When 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 said to be successful access to the target cell without performing CHO on the target cell.

[0168] Optionally, in the present application, S301 and S303 may be the same step. That is, when the terminal determines whether the execution condition of the CHO corresponding to the candidate target cell is met, it also needs to consider the content in S303. That is, when one or more of the time condition, distance condition or measurement event corresponding to a candidate target cell is met at the same time, 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 condition of the CHO is met, otherwise it is considered that it is not met.

[0169] Figure 4 It is a schematic flow chart of another communication method provided by the present application. It includes the following steps:

[0170] S401, the terminal determines, according to the CHO configuration information sent by the source base station, that the execution condition of the CHO corresponding to the candidate target cell is satisfied.

[0171] Optionally, please refer to the description in S301.

[0172] S402: The terminal obtains a second threshold.

[0173] 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, i.e., the second service stop time, or the source cell broadcasts the second service stop time in a broadcast message.

[0174] S403: The terminal determines whether to access the target cell according to the second threshold.

[0175] Specifically, the first time interval is the time interval between the current moment and the second service outage time. The first time interval is less than or equal to the second threshold. The terminal executes CHO switching to the target cell and the terminal accesses the target cell. The first time interval is greater than the second threshold, that is, the terminal can continue to communicate in the source cell, and the terminal does not execute CHO for the target cell. The terminal can continue to determine whether the execution condition of the CHO corresponding to the candidate target cell is met and whether the first time interval is less than or equal to the second threshold. When the terminal executes the switching 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.

[0176] Optionally, the second threshold may be preconfigured by the network side for the terminal, or carried in CHO configuration information and sent by the source base station to the terminal.

[0177] Optionally, in this application, S401 and S403 can be the same step. That is, when the terminal determines whether the execution condition of the CHO corresponding to the candidate target cell is met, it also needs to consider the content in S403. That is, when one or more of the time condition, distance condition or measurement event corresponding to a candidate target cell is met at the same time, and the first time interval is less than or equal to the second threshold, the terminal considers that the execution condition of the CHO is met, otherwise it is considered that it is not met. Optionally, Figure 3 and Figure 4 They can be combined. That is, the terminal determines whether to access the target cell based on the first threshold and the second threshold.

[0178] Figure 5 It is a schematic flow chart of another communication method provided by the present application. It includes the following steps:

[0179] S501: The terminal determines that a CHO execution condition is met according to CHO configuration information sent by a source base station.

[0180] Optionally, please refer to the description in S301.

[0181] S502: The terminal obtains a third threshold.

[0182] 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 service stop time corresponding to the target cell. Alternatively, the source cell broadcasts the first activation time or the second service stop time in a broadcast message. The first activation time may also be referred to as the time when the next satellite corresponding to the target cell starts to provide services for the target cell. The second service stop time is the time when the current satellite corresponding to the target cell stops providing services for the target cell.

[0183] S503: The terminal determines whether to access the target cell according to the third threshold.

[0184] Specifically, the second time interval is the time interval between the first activation time and the second service stop time, the second time interval is less than or equal to the third threshold, the terminal performs CHO switching to the target cell, and the terminal accesses the target cell. The second time interval is greater than the third threshold, the terminal can continue to communicate in the source cell, and the terminal does not perform CHO on the target cell. The terminal can continue to determine whether the execution condition of the CHO corresponding to the candidate target cell is 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 through the new satellite of the source cell, and the terminal can retain the CHO configuration information of the candidate target cell.

[0185] Optionally, the third threshold may be pre-configured by the network side for the terminal, or carried in CHO configuration information and sent by the source base station to the terminal.

[0186] Optionally, in the present application, S501 and S503 may be the same step. That is, when the terminal determines whether the execution condition of the CHO corresponding to the candidate target cell is met, it also needs to consider the content in S503. That is, when one or more of the time condition, distance condition or measurement event corresponding to a candidate target cell is met at the same time, and the second interval is less than or equal to the third threshold, the terminal considers that the execution condition of the CHO is met, otherwise it is considered that it is not met.

[0187] Figure 6 It is a schematic flow chart of another communication method provided by the present application. It includes the following steps:

[0188] S601: The terminal determines that a CHO execution condition is met according to CHO configuration information sent by a source base station.

[0189] Optionally, please refer to the description in S301.

[0190] S602: The terminal obtains a fourth threshold.

[0191] Optionally, the CHO configuration information also includes first ephemeris related information corresponding to the target cell and a corresponding first activation time. Alternatively, the source cell broadcasts the first activation time in a broadcast message. The first activation time may also be referred to as the time when the next satellite corresponding to the target cell starts to provide services for the target cell.

[0192] S603: The terminal determines whether to access the target cell according to the fourth threshold.

[0193] Specifically, the third time interval is the time interval between the current moment when the terminal makes a judgment and the first activation time. If the third time interval is less than or equal to the fourth threshold, the terminal executes CHO switching to the target cell, and the terminal accesses the target cell. If the third time interval is greater than the fourth threshold, the terminal can continue to communicate in the source cell, and the terminal does not execute CHO for the target cell. The terminal can continue to judge whether the execution condition of the CHO corresponding to the candidate target cell is met and whether the third time interval is less than or equal to the fourth 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.

[0194] Optionally, the fourth threshold may be pre-configured by the network side for the terminal, or carried in CHO configuration information and sent by the source base station to the terminal.

[0195] Optionally, in the present application, S601 and S603 may be the same step. That is, when the terminal determines whether the execution condition of the CHO corresponding to the candidate target cell is met, it also needs to consider the content in S603. That is, when one or more of the time condition, distance condition or measurement event corresponding to a candidate target cell is met at the same time, and the third interval is less than or equal to the fourth threshold, the terminal considers that the execution condition of the CHO is met, otherwise it is considered that it is not met.

[0196] Optionally, S602 is optional, and S603 is replaced by the terminal judging whether to access the target cell according to the first activation time. When the terminal judges that the execution condition of CHO corresponding to the target cell is satisfied 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.

[0197] The communication method provided in the embodiment of the present application can alleviate communication problems caused by insufficient time for the terminal to access the target cell or too long waiting time by further judging whether the terminal executes conditional switching to the target cell based on the satisfaction of the execution conditions of the conditional switching, thereby improving the terminal switching efficiency and shortening the service interruption time.

[0198] 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 between 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, an 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 changed satellite covers the candidate target cell synchronously.

[0199] Figure 7 This is a schematic flow chart of a synchronization method provided by the present application. The target base station triggers a CHO configuration information change before the satellite changes, and the target cell generates new CHO configuration information, which 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.

[0200] Exemplarily, the time when the first satellite starts to cover the target cell is t1, and the time when the first satellite ends to cover the target cell is t-service1; the time when the second satellite starts to cover the target cell is t2, and the time when the second satellite ends to cover the target cell is t-service2.

[0201] The target cell has a satellite change before t-service1. At this time, the target base station triggers a CHO configuration information change, and the configuration information carries the ephemeris-related 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:

[0202] S701: The target base station sends a CHO cancel (conditional Handover Cancel) message to the source base station.

[0203] Specifically, the CHO cancellation information carries a cause value, and the cause value indicates that the CHO configuration information or resources configured by the terminal have changed, or the ephemeris-related information of the candidate target cell has changed. Optionally, the cause value may be cho-cpc-resources-tobechanged.

[0204] S702, the source base station receives the CHO cancellation information and sends a handover request (Handover request) information to the target base station.

[0205] Optionally, the handover request information may carry first indication information, instructing the target base station to change the CHO configuration information.

[0206] S703: The target base station receives the handover request information and sends CHO reconfiguration information to the source base station.

[0207] 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 carried in the handover request confirmation information sent by the target base station to the source base station, and the effective time is not included in the CHO reconfiguration information.

[0208] 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) information and sent to the source base station.

[0209] 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 starts to cover the target cell (ie, the effective time), for example, t2. After receiving the CHO reconfiguration information, the terminal generates new CHO configuration information at time t2.

[0210] S704: The source base station receives the CHO reconfiguration information and sends the CHO reconfiguration information to the terminal.

[0211] 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.

[0212] It should be noted that if the CHO configuration information does not carry the 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, 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 the effective time, the time when the source base station sends the CHO configuration information may not be restricted. 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.

[0213] It should be noted that, before S701, the synchronization method further includes:

[0214] S7001, the source base station sends indication information of switching without L3 signaling and time information of taking effect of switching without L3 signaling, such as t-start, to the terminal. Optionally, the indication information can be sent in a system message.

[0215] S7002, the terminal initiates a connection and successfully accesses the source base station.

[0216] Among them, S7001 and S7002 are optional.

[0217] 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 edge of the cell.

[0218] S7004: The terminal receives CHO configuration information sent by the source base station.

[0219] It should be noted that, after S704, the synchronization method further includes the aforementioned step S206, which will not be described in detail here.

[0220] In the embodiment of the present application, a CHO configuration information change is triggered by a target base station to generate CHO reconfiguration information, wherein 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 synchronously.

[0221] Figure 8 This is a schematic flow chart of another synchronization method provided by the present application, and the specific steps are as follows:

[0222] 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.

[0223] Exemplarily, the time when the first satellite starts to cover the target cell is t1, and the time when the first satellite ends to cover the target cell is t-service1; the time when the second satellite starts to cover the target cell is t2, and the time when the second satellite ends to cover the target cell is t-service2.

[0224] The target cell has a satellite change before t-service1. At this time, the source base station triggers the CHO configuration information change, requests the target base station to update the CHO configuration information, and indicates that the configuration information carries the ephemeris-related information of the second satellite. Optionally, the CHO reconfiguration 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 time t2. The specific signaling process can be:

[0225] S801, the source base station sends a handover request message to the target base station, where the handover request message includes indication information.

[0226] Optionally, when the target cell is about to replace the satellite, the source base station sends a switching request message to the target base station where the target cell is located, and the switching request message includes a conditional switching trigger value (CHO trigger value), for example, the conditional switching trigger value may be CHO-replace.

[0227] Specifically, the switching request information also includes second indication information, and the second indication information is used to instruct the target base station to change the CHO configuration information, and to indicate that the CHO reconfiguration information carries the ephemeris-related information and effective time of the changed satellite providing coverage for the target cell.

[0228] 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 that provides coverage for the target cell.

[0229] 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, and the effective time is not included in the CHO reconfiguration information.

[0230] 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) information and sent to the source base station.

[0231] 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 starts to cover the target cell, such as t2. After receiving the CHO reconfiguration information, the terminal generates new CHO configuration information at time t2.

[0232] S803: The source base station receives CHO reconfiguration information and sends the CHO reconfiguration information to the terminal.

[0233] 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.

[0234] It should be noted that if the CHO configuration information does not carry the 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, 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 the effective time, the time when the source base station sends the CHO configuration information may not be restricted. 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.

[0235] It should be noted that, before S801, the synchronization method further includes:

[0236] S8001, the source base station sends indication information of switching without L3 signaling and time information of taking effect of switching without L3 signaling, such as t-start, to the terminal. Optionally, the indication information can be sent in a system message.

[0237] S8002, the terminal initiates a connection and successfully accesses the source base station.

[0238] Among them, S8001 and S8002 are optional.

[0239] 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 edge of the cell.

[0240] S8004. The terminal receives CHO configuration information sent by the source base station.

[0241] It should be noted that, after S804, the synchronization method further includes the aforementioned step S206, which will not be described in detail here.

[0242] In the 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, wherein the CHO reconfiguration information includes ephemeris-related information of the changed satellite and a corresponding effective time, so that the terminal uses the CHO reconfiguration information and the changed satellite to cover the candidate target cell synchronously.

[0243] Fig. 9 A schematic diagram of a communication device provided in an embodiment of the present application is shown.

[0244] 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.

[0245] 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.

[0246] Optionally, the first information further includes multiple physical cell identifiers, and the physical cell identifiers correspond to the ephemeris-related information one by one. The processing unit 1200 is further configured to determine a first physical cell identifier corresponding to the first cell.

[0247] Optionally, the first information is conditional switching configuration information of the first cell, and the conditional switching configuration information includes execution conditions for the terminal to switch to the first cell.

[0248] Optionally, when the execution condition of the first cell is met, the terminal does not access the first cell.

[0249] 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.

[0250] 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.

[0251] 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.

[0252] Optionally, the processing unit 1200 is further configured to start determining the execution condition after the first enabling time.

[0253] 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 a terminal to switch to a first cell, the first information includes an execution condition for the terminal to switch to the first cell; a processing unit, used to determine that the execution condition is met, and the terminal determines not to access the first cell based on the first information.

[0254] 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.

[0255] 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.

[0256] 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.

[0257] 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 that the first information or resources configured for the terminal have changed; 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 effective time corresponding to the first cell, and 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.

[0258] Optionally, the second information includes a reason value.

[0259] 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.

[0260] Optionally, 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.

[0261] An embodiment of the present application also provides a communication device, including: a communication unit, used to receive first reconfiguration information, the first reconfiguration information including first ephemeris related information and an effective time corresponding to a first cell; a processing unit, used to switch to the first cell according to the reconfiguration first information and enable the first ephemeris related information at the effective time.

[0262] Fig.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 the memory and is used to execute instructions stored in the memory to send signals 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 send signals and / or receive signals.

[0263] It should be understood that the processor 920 and the memory 930 may be combined into one 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 implementation, the memory 930 may also be integrated into the processor 920 or independent of the processor 920.

[0264] 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 an interface circuit.

[0265] For example, the transceiver 910 in the device 900 may correspond to the transceiver unit in the above embodiment, and the processor 920 in the device 900 may correspond to the processing unit in the above embodiment. It should be understood that the specific process of each transceiver processor executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0266] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software modules in a processor for execution. 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 a 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 is not described in detail here.

[0267] It should be noted that the processor in the embodiment of the present application can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiment can be completed by the hardware integrated logic circuit or software instructions in the processor. The above processor can be a general processor, a digital signal processor (digital signal processor, DSP), an application-specific integrated circuit (application-specific integrated circuit, ASIC), a field-programmable gate array (field-programmable gate array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to perform, or the hardware and software modules in the decoding processor can be combined to perform. The software module can be located in a mature storage medium in the field 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 combination with its hardware.

[0268] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can 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 can 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 SDRAM (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.

[0269] According to the communication method provided in the embodiment of the present application, the present application also provides a computer program product, on which a computer program code is stored. When the computer program code is run on a computer, the computer executes the communication method of the present application.

[0270] 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.

[0271] 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.

[0272] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer 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 a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. 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. 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)).

[0273] The network side device in each of the above-mentioned apparatus embodiments corresponds to the network side device or terminal device in the terminal device and method embodiments, and the corresponding modules or units perform the corresponding steps. For example, the communication unit (transceiver) performs the steps of obtaining or sending in the method embodiment, and other steps except sending and obtaining can be performed by the processing unit (processor). The functions of the specific units can refer to the corresponding method embodiments. Among them, the processor can be one or more.

[0274] The terms "component", "module", "system", etc. used in this specification 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 applications running on a computing device and a computing device can be components. One or more components may reside in a process and / or an execution thread, and a component may be located on a computer and / or distributed between two or more computers. In addition, these components may be executed from various computer-readable media having various data structures stored thereon. Components may, for example, communicate through local and / or remote processes according to signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system and / or a network, such as the Internet interacting with other systems through signals).

[0275] 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.

[0276] Those of ordinary skill 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 to be beyond the scope of this application.

[0277] Those skilled in the art can 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.

[0278] In the several embodiments provided in the present 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 only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, 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.

[0279] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0280] 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.

[0281] 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 can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods 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.

[0282] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope 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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