Communication method and apparatus

Abstract

A communication method and apparatus. A terminal receives first information. The terminal determines, on the basis of the first information, that the terminal cannot communicate with a network device. The terminal outputs prompt information, the prompt information being used for providing a prompt of aligning the terminal with a satellite. In embodiments of the present application, if a terminal determines that the terminal cannot communicate with a network, the terminal may output prompt information to provide a prompt of aligning the terminal with a satellite, for example, a user may align the terminal with the satellite on the basis of the prompt information. Upon alignment of the terminal with the satellite, the terminal may restore communication with the network. Therefore, the embodiments of the present application enable the terminal to restore communication with the network.

Description

A communication method and apparatus

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202411312087.6, filed on September 19, 2024, and entitled “A communication method and apparatus”, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of communication technology, and in particular to a communication method and apparatus. BACKGROUND

[0004] In satellite communication technology, a user equipment (UE) can not receive a paging message from a network due to no alignment with a satellite. To this end, an alert technology is proposed for enhanced paging. For example, the network can search for the UE by sending an alert signal. The core of the alert technology is to reduce the coding rate of the alert signal to improve the coverage range of the alert signal, so that the alert signal can be received by the UE.

[0005] For the UE, when the signal is poor, the UE can communicate with the network by receiving the alert signal. However, in some cases, the UE can no longer receive the alert signal, and thus the UE will be unable to communicate with the network. SUMMARY

[0006] Embodiments of the present application provide a communication method and apparatus for enabling a terminal to resume communication with a network.

[0007] In a first aspect, a first communication method is provided, which can be applied to a first apparatus. The first apparatus is, for example, a terminal-side apparatus, which is also referred to as a terminal apparatus or a terminal. The terminal apparatus is, for example, a terminal device, or another device including a terminal device function, or a circuit, or a chip system (or a chip, such as a modem chip, also referred to as a baseband chip, or a system on chip (SoC) chip or a system in package (SIP) chip containing a modem core) or another functional module capable of realizing the function of a terminal device, which is, for example, arranged in a terminal device. The method comprises: receiving first information; determining that the terminal is unable to communicate with a network device according to the first information; and outputting prompt information, the prompt information being used to prompt the terminal to align with a satellite.

[0008] In the embodiments of the present application, if the terminal determines that it cannot communicate with the network, the terminal can output prompt information to prompt the terminal to be aligned with the satellite, for example, a user can align the terminal with the satellite according to the prompt information. After the terminal is aligned with the satellite, the terminal can resume communication with the network. It can be seen that the embodiments of the present application enable the terminal and the network to resume communication.

[0009] In an optional implementation, determining that the terminal cannot communicate with the network device according to the first information comprises: determining that configuration information of an alarm signal is changed according to the first information, the alarm signal being used to prompt the terminal that there is service arrival. If the configuration information of the alarm signal is changed, the terminal can not receive the changed alarm information (for example, the terminal does not know the changed configuration information), and thus the terminal can not communicate with the network.

[0010] In an optional implementation, determining that the configuration information of the alarm signal is changed according to the first information comprises: determining that the configuration information of the alarm signal is changed according to the first information and stored second information, the first information comprising first configuration information of the alarm signal, and the second information being used to indicate second configuration information of the alarm signal, the first configuration information being different from the second configuration information. The terminal has stored the second information, and the second information can indicate the second configuration information of the alarm signal. In addition, the terminal also receives the first information, and the first information indicates the second configuration information of the alarm signal. If the first configuration information is different from the second configuration information, or if the indication of the first information is different from the indication of the second information, it indicates that the configuration information of the alarm signal is changed.

[0011] In an optional implementation, the method further comprises: receiving system information, the system information comprising the second information. The second information can be sent through system information, or can be sent through other broadcast messages or unicast messages.

[0012] In an optional implementation, the first information is used to indicate that the configuration information of the alarm signal is changed. The first information can not indicate specific configuration information, but indicate that the configuration information of the alarm signal is changed. Then the terminal can determine that the configuration information of the alarm signal is changed according to the first information, without referring to other information, and the implementation of the terminal can be simplified.

[0013] In an optional implementation, the first information is comprised in a first alarm signal. The first information is sent through an alarm signal (for example, the first alarm signal), or can be sent through other broadcast messages or unicast messages.

[0014] In an optional implementation, the first information is used to configure a periodic TAU timer and an implicit detach timer, the periodic TAU timer is used for the terminal to perform a periodic tracking area update, and the implicit detach timer is used for the network device to deregister the terminal; or, the first information is used to configure a first timer, and the first timer is used to determine a time at which the network device deregisters the terminal. The periodic TAU timer and the implicit detach timer, or the first timer, can indicate the time at which the network device deregisters the terminal, and thus the terminal can output the prompt information according to the periodic TAU timer and the implicit detach timer, or output the prompt information according to the first timer, so as to timely prompt the user to aim at the satellite. For example, the terminal can output the prompt information when or before the network device deregisters the terminal, so that the terminal can timely contact the network device and reduce the probability that the terminal cannot communicate with the network device.

[0015] In an optional implementation, the method further includes: starting the implicit detach timer when the periodic TAU timer times out for the Nth time in succession, N being a positive integer; and outputting the prompt information, including: outputting the prompt information when or before the implicit detach timer times out. The network device can also maintain the periodic TAU timer and the detach timer, for example, the network device can start the implicit detach timer when the periodic TAU timer times out for the Nth time in succession, so that the terminal and the network device can have the same execution mechanism, and thus the terminal and the network device can have consistent cognition of the time of deregistration. Thus, the terminal can output the prompt information when or before the implicit detach timer times out, which is equivalent to outputting the prompt information when or before the terminal is deregistered, so that the terminal can timely contact the network device and reduce the probability that the terminal cannot communicate with the network device.

[0016] In an optional implementation, the first information is also used to configure the N. The N can be configured by the first information or predefined by a protocol, etc.

[0017] In an optional implementation, outputting the prompt information includes: outputting the prompt information when or before the first timer times out. The terminal can output the prompt information when or before the terminal is deregistered, so that the terminal can timely contact the network device and reduce the probability that the terminal cannot communicate with the network device.

[0018] In an optional implementation, the first information indicates a first geographical location, the first geographical location corresponds to a first TAL, the first TAL is a TAL corresponding to the terminal, and determining that the terminal cannot communicate with the network device according to the first information comprises: determining that the terminal moves out of the first geographical location. If the terminal moves out of the first geographical location, it indicates that the terminal moves out of the first TAL. If the terminal moves out of the first TAL, the terminal cannot receive an alarm signal for searching the terminal sent by the network device in the first TAL. Since the network device does not know the new TAL where the terminal is located, the network device also does not send the alarm signal for searching the terminal in the new TAL, so the terminal cannot receive the alarm signal for searching the terminal, which is also regarded as that the terminal cannot communicate with the network device.

[0019] In an optional implementation, the method further comprises: receiving a first synchronization signal; the first information indicates a first TAL or a synchronization signal corresponding to the first TAL, the first TAL is a TAL corresponding to the terminal, and determining that the terminal cannot communicate with the network device according to the first information comprises: determining that the first synchronization signal does not belong to the synchronization signal corresponding to the first TAL. The terminal can determine whether it cannot communicate with the network device or whether it moves out of the first TAL according to the received first synchronization signal.

[0020] In an optional implementation, determining that the first synchronization signal does not belong to the synchronization signal corresponding to the first TAL comprises: determining that a sequence corresponding to the first synchronization signal does not belong to a sequence of the synchronization signal corresponding to the first TAL; or, determining that a TA corresponding to the first synchronization signal does not belong to a TA included in the first TAL. Two optional ways for the terminal to determine whether the first synchronization signal belongs to the synchronization signal corresponding to the first TAL are given. In addition, the terminal can also determine whether the first synchronization signal belongs to the synchronization signal corresponding to the first TAL through other ways.

[0021] In an optional implementation, the method further comprises: camping on a first cell; and performing tracking area update. After camping on the first cell (for example, the terminal can camp on the first cell after pointing to the satellite), the terminal can perform TAU or LAU or registration request, so that the network device knows the location change of the terminal.

[0022] In a second aspect, a second communication method is provided, which can be applied to a second device. The second device is, for example, a network side device, which is also referred to as a network device. The network device is, for example, a network equipment, or other equipment including the function of the network equipment, or a circuit, or a chip system (or chip) or other functional module capable of implementing the function of the network equipment, which is, for example, arranged in the network equipment. The network equipment can be a non-ORAN architecture or an ORAN architecture; or the network equipment can be a CU, a DU or a RU under the ORAN architecture. The network equipment is, for example, located on the ground, or the network equipment is, for example, a satellite, or is located on a satellite. The method comprises: sending first information, the first information being used to determine that a terminal cannot communicate with a network device.

[0023] In an optional implementation, the first information is used to determine that configuration information of an alarm signal is changed, the alarm signal being used to prompt that the terminal has arrived traffic.

[0024] In an optional implementation, the first information is used to determine that configuration information of an alarm signal is changed, comprising: the first information and second information are used to determine that the configuration information of the alarm signal is changed, the first information comprising first configuration information of the alarm signal, the second information being used to indicate second configuration information of the alarm signal, the first configuration information being different from the second configuration information; or, the first information is used to indicate that the configuration information of the alarm signal is changed.

[0025] In an optional implementation, the method further comprises: sending information, the system information comprising the second information.

[0026] In an optional implementation, the first information is included in a first alarm signal.

[0027] In an optional implementation, the first information is used to configure a periodic TAU timer and an implicit detach timer, the periodic TAU timer being used for the terminal to perform a periodic tracking area update, the implicit detach timer being used for the network device to deregister the terminal; or, the first information is used to configure a first timer, the first timer being used to determine a time for the network device to deregister the terminal.

[0028] In an optional implementation, the first information is further used to configure N, wherein the implicit detach timer is started when the periodic location update timer times out for the Nth time in succession, N being a positive integer.

[0029] In an alternative implementation, the timing duration of the first timer is determined according to the timing duration of the periodic location update timer and the timing duration of the implicit detach timer.

[0030] In an alternative implementation, the first information is used to indicate a correspondence between a first TAL and a first geographical location, the first TAL being a TAL corresponding to the terminal; or, the first information is used to configure a synchronization signal corresponding to a first TAL, the first TAL being a TAL corresponding to the terminal; or, the first information is used to configure a first TAL, the first TAL being a TAL corresponding to the terminal.

[0031] As to the technical effects brought by the second aspect or the various alternative implementations of the second aspect, reference can be made to the introduction of the technical effects of the first aspect or the corresponding implementation.

[0032] In a third aspect, a device is provided. The device can be the terminal-side device of the first aspect. The device has the functions of the terminal-side device. For example, the device has the functions of the first aspect, for example, the device includes modules or units or means corresponding to the operations involved in the first aspect, which can be implemented by software, or by hardware, or by a combination of software and hardware. The device is, for example, a terminal device, or another device including the functions of a terminal device, or a chip system (or a chip or a circuit) or another functional module, which can implement the functions of a terminal device, and is, for example, arranged in a terminal device. In an alternative implementation, the device includes a baseband device and a radio frequency device. In another alternative implementation, the device includes a processing unit (sometimes also referred to as a processing module) and a transceiving unit (sometimes also referred to as a transceiving module). The transceiving unit can implement a transmitting function and a receiving function. When the transceiving unit implements a transmitting function, it can be referred to as a transmitting unit (sometimes also referred to as a transmitting module). When the transceiving unit implements a receiving function, it can be referred to as a receiving unit (sometimes also referred to as a receiving module). The transmitting unit and the receiving unit can be the same functional module, which is referred to as a transceiving unit and can implement a transmitting function and a receiving function. Alternatively, the transmitting unit and the receiving unit can be different functional modules, and the transceiving unit is a general term for these functional modules.

[0033] In an alternative implementation, the transceiving unit (or the receiving unit) is configured to receive the first information; the processing unit is configured to determine, according to the first information, that the terminal is unable to communicate with the network device; and the processing unit is further configured to output prompt information, the prompt information being used to prompt the terminal to be aligned with a satellite.

[0034] In an alternative implementation, the apparatus further includes a storage unit (also referred to as a storage module), and the processing unit is configured to be coupled with the storage unit and execute programs or instructions in the storage unit to enable the apparatus to perform the functions of the network-side apparatus according to the second aspect.

[0035] In a fourth aspect, an apparatus is provided. The apparatus can be the network-side apparatus according to the second aspect. The apparatus has the functions of the network-side apparatus. For example, the apparatus has the functions of the second aspect, e.g., the apparatus includes modules or units or means for performing the operations of the second aspect. The modules or units or means can be implemented in software, hardware, or a combination of software and hardware. The apparatus can be a network device, or another device having the functions of a network device, or a chip system (or chip or circuit) or another functional module that has the functions of a network device, e.g., implemented in a network device. In an alternative implementation, the apparatus includes a baseband apparatus and a radio frequency apparatus. In another alternative implementation, the apparatus includes a processing unit (also referred to as a processing module) and a transceiver unit (also referred to as a transceiver module). The transceiver unit can be implemented as described in the third aspect.

[0036] In an alternative implementation, the transceiver unit (or the sending unit) is configured to send first information, where the first information is used to determine that the terminal is unable to communicate with the network device.

[0037] In an alternative implementation, the apparatus further includes a storage unit (also referred to as a storage module), and the processing unit is configured to be coupled with the storage unit and execute programs or instructions in the storage unit to enable the apparatus to perform the functions of the network-side apparatus according to the second aspect.

[0038] In a fifth aspect, an apparatus is provided, which includes a memory and one or more processors. The memory is configured to store part or all of the computer programs or instructions for implementing the functions of the first aspect. The one or more processors are configured to execute the computer programs or instructions, which when executed cause the apparatus to implement the method in any possible design or implementation of the first aspect.

[0039] In a possible design, the apparatus can further include an interface circuit, where the processor is configured to communicate with other apparatuses or components through the interface circuit.

[0040] In a possible design, the apparatus can further include the memory.

[0041] The apparatus can be a terminal, or a communication module in a terminal, or a chip responsible for communication function in a terminal, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip containing a modem module.

[0042] In a sixth aspect, an apparatus is provided, which includes a memory and one or more processors. The memory is configured to store part or all of the computer program or instructions necessary to implement the functions involved in the second aspect above. The one or more processors are configured to execute the computer program or instructions, which, when executed, cause the apparatus to implement the method in any possible design or implementation manner of the second aspect above.

[0043] In a possible design, the apparatus can further include an interface circuit, and the processor is configured to communicate with other apparatuses or components through the interface circuit.

[0044] In a possible design, the apparatus can further include the memory.

[0045] The apparatus can be a network device, or a communication module in a network device, or a chip responsible for communication function in a network device, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip containing a modem module.

[0046] In a seventh aspect, a communication system is provided, which includes a network device. The network device is configured to perform the method performed by the network-side apparatus in the second aspect above. For example, the network-side apparatus can be implemented by the apparatus in the fourth aspect or the sixth aspect.

[0047] Optionally, the communication system further includes a terminal device. The terminal device is configured to perform the method performed by the terminal-side apparatus in the first aspect above. For example, the terminal device can be implemented by the apparatus in the third aspect or the fifth aspect.

[0048] In an eighth aspect, a computer-readable storage medium is provided, which is configured to store computer programs or instructions. When the computer programs or instructions are run, the method performed by the network-side apparatus or the terminal-side apparatus in the aspects above is implemented.

[0049] In a ninth aspect, a computer program product containing instructions is provided. When the computer programs or instructions are run on a computer, the method in the aspects above is implemented.

[0050] In a tenth aspect, a chip system is provided, which includes a processor and an interface. The processor is configured to call and run instructions from the interface, so that the chip system implements the method in the aspects above. BRIEF DESCRIPTION OF DRAWINGS

[0051] FIG. 1A is a schematic diagram of an access network device structure under an ORAN architecture;

[0052] FIG. 1B is a schematic diagram of a structure of a RAN chip;

[0053] FIGS. 2, 3A-3C are schematic diagrams of several application scenarios of embodiments of the present application;

[0054] FIG. 4 is a flowchart of a communication method provided by an embodiment of the present application;

[0055] FIGS. 5-8 are flowcharts of several optional implementation manners of the UE determining whether to move out of the first TAL in embodiments of the present application;

[0056] FIG. 9 is a flowchart of another communication method provided by an embodiment of the present application;

[0057] FIG. 10 is a schematic diagram of an apparatus provided by an embodiment of the present application;

[0058] FIG. 11 is a schematic diagram of another apparatus provided by an embodiment of the present application. DETAILED DESCRIPTION

[0059] To make the purposes, technical solutions and advantages of embodiments of the present application clearer, the following will further describe the embodiments of the present application in conjunction with the drawings.

[0060] In embodiments of the present application, the number of a noun, unless otherwise specified, represents "a singular noun or a plural noun", that is, "one or more". "At least one" means one or more, and "multiple" means two or more. "And / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following cases: A exists alone, A and B exist together, B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects. For example, A / B means A or B. "At least one of the following" or similar expressions means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b, or c means a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0061] The ordinal numbers "first", "second", and the like mentioned in embodiments of the present application are used to distinguish multiple objects, and are not used to limit the size, content, order, time sequence, priority, or importance of the multiple objects. In addition, the numbering of steps in each embodiment introduced in the present application is only used to distinguish different steps, and is not used to limit the order of the steps.

[0062] Hereinafter, some terms or concepts in the embodiments of the present application are explained and described to facilitate the understanding of those skilled in the art.

[0063] In the embodiments of the present application, the terminal device is a device with wireless transceiving function, which can be a fixed device, a mobile device, a handheld device (such as a mobile phone), a wearable device, a vehicle-mounted device, or a wireless device (such as a communication module, a modem, or a chip system, etc.) built in the above devices. The terminal device is used to connect people, things, machines, etc., and can be widely used in various scenarios, such as, but not limited to, the following scenarios: satellite communication scenarios, sensing scenarios, cellular communication, device-to-device communication (D2D), vehicle-to-everything (V2X), machine-to-machine / machine-type communication (M2M / MTC), internet of things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, unmanned aerial vehicle, robot, indoor commercial scenarios (such as mobile phone screen projection, file sharing, mobile phone video transmission to VR glasses), etc. When the terminal device is applied to V2X, it can also be referred to as a V2X device, such as a smart car, a digital car, an unmanned car, a self-driving car, a pure EV, a hybrid electric vehicle (HEV), a range extended EV (REEV), a plug-in HEV (PHEV), a new energy vehicle, a road site unit (RSU), etc. The terminal device can also be a device in D2D communication, such as a water meter, a power meter, etc.

[0064] In addition, in the embodiments of the present application, the terminal device can also be a terminal device in an internet of things (IoT) system. The IoT is an important part of future information technology development, and its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-object interconnection.

[0065] As introduced above, various terminal devices can be considered as on-board terminal devices if they are located on a vehicle (e.g., placed in or installed in a vehicle), and the on-board terminal device is also referred to as an on-board unit (OBU). The terminal device of the present application can also be an on-board module, an on-board module group, an on-board component, an on-board chip or an on-board unit built in a vehicle as one or more components or units, and the vehicle can implement the method of the present application through the built-in on-board module, on-board module group, on-board component, on-board chip or on-board unit.

[0066] The terminal device can also be referred to as a UE, a terminal, an access station, a UE station, a remote station, a wireless communication device, or a user device, etc.

[0067] In the embodiments of the present application, the device for implementing the function of the terminal device can be a terminal device, which can be a terminal device or a device capable of supporting the terminal device to implement the function, such as a chip system, and the device can be installed in the terminal device. In the technical solutions provided in the embodiments of the present application, the device for implementing the function of the terminal device is taken as an example of a terminal device to describe the technical solutions provided in the embodiments of the present application.

[0068] The network device in the embodiments of the present application, for example, includes an access network device (or an access network network element) and / or a core network device (or a core network network element). The access network device is a device with wireless transceiving function, used for communicating with the terminal device. The access network device includes but is not limited to a base station (a base transceiver station (BTS), a Node B, an evolved Node B (eNodeB) / eNB, or a next generation Node B (gNodeB) / gNB), a transmission reception point (TRP), a base station evolved in the future of the 3rd generation partnership project (3GPP), an access node in a wireless fidelity (Wi-Fi) system, a wireless relay node, a wireless backhaul node, and the like. The base station can be a macro base station, a micro base station, a pico base station, a small station, a relay station, and the like. A plurality of base stations can support a network of the same access technology or a network of different access technologies. A base station can include one or more co-sited or non-co-sited transmission reception points. The access network device can also be a wireless controller, a centralized unit (CU), and / or a distributed unit (DU) in a cloud radio access network (CRAN) scenario. The access network device can also be a server and the like. For example, the network device in the V2X technology can be a road side unit (RSU). The access network device is described below by taking a base station as an example. The base station can communicate with the terminal device or communicate with the terminal device through a relay station. The terminal device can communicate with a plurality of base stations in different access technologies. The core network device is used to implement mobile management, data processing, session management, policy and charging, and the like. The names of devices implementing core network functions in systems of different access technologies can be different, and the embodiments of the present application do not limit this.Taking a 5th generation (5G) system as an example, the core network device includes, for example, an access and mobility management function (AMF), a session management function (SMF), a policy control function (PCF), a user plane function (UPF), and the like.

[0069] In the CU-DU architecture, or in an open RAN (ORAN) system, the access network device can include one or more of a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), and the like. The CU and the DU can be separately arranged, or can be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). For a structure of the access network device, refer to FIG. 1A. The core network device and the access network device can communicate through a backhaul link; the CU and the DU in the access network device can communicate through a middlehaul link, and the DU and the RU can communicate through a front-haul link.

[0070] Alternatively, another structure of the access network device can refer to FIG. 1B, which takes the example of the access network device being implemented by a chip, for example, referred to as a RAN chip. The RAN chip can include a CU, a DU, and a RU. The CU can perform L2 functions, L3 functions, and the like. The DU can perform L1 functions, part of L2 functions, and the like. The RU can perform calculation of L1 and radio frequency (RF) digital part functions, and the like. The CU communicates with the core network device through a backhaul interface, which carries traffic between the CU and the core network device. The CU can include a central processing unit (CPU) of an X86 architecture or an ARM architecture, and an accelerator including a field programmable gate array (FPGA), a graphics processing unit (GPU), or other accelerators, and the like. The CPU and the FPGA, GPU, or other accelerators can communicate through a peripheral component interconnect express (PCIe) interface.

[0071] The CU communicates with the DU through a midhaul interface, which carries traffic between the CU and the DU. The DU can include a CPU of an X86 architecture or an ARM architecture, and an accelerator including an FPGA, a GPU, or other accelerators, and the like. The CPU and the FPGA, GPU, or other accelerators can communicate through a PCIe interface.

[0072] The DU communicates with the RU through a fronthaul interface, which carries traffic between the DU and the RU. If the access network device adopts an integrated DU, the integrated DU can include the functions of the DU and the RU described above, and the RAN can no longer separately include the RU. The RU can include a RAN fronthaul processing unit (RAN FH processing unit), a digital processing unit, and a radio frequency processing unit (RF processing unit). The RAN FH processing unit is implemented by, for example, an FPGA or an application specific integrated circuit (ASIC). The digital processing unit is implemented by, for example, an FPGA or an ASIC.

[0073] The RU can be connected with an antenna to communicate with the UE through the antenna.

[0074] The CU (or CU-CP and CU-UP), DU or RU can also have different names in different systems, but those skilled in the art can understand their meanings. For example, in an ORAN system, the CU can also be referred to as an open CU (O-CU), the DU can also be referred to as an open DU (O-DU), the CU-CP can also be referred to as an open CU-CP (O-CU-CP), the CU-UP can also be referred to as an open CU-UP (O-CU-UP), and the RU can also be referred to as an open RU (O-RU). For the convenience of description, the CU, CU-CP, CU-UP, DU and RU are taken as examples for description in the embodiments of the present application. Any one of the CU (or CU-CP, CU-UP), DU and RU in the embodiments of the present application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0075] The CU and the DU can be configured according to the protocol layer functions of the wireless network they implement. For example, the CU is configured to implement the functions of the packet data convergence protocol (PDCP) layer and the protocol layers above the PDCP layer (such as the radio resource control (RRC) layer and / or the service data adaption protocol (SDAP) layer, etc.); the DU is configured to implement the functions of the protocol layers below the PDCP layer (such as one or more of the radio link control (RLC) layer, the media access control (MAC) layer, or the physical (PHY) layer). For another example, the CU is configured to implement the functions of the PDCP layer and the protocol layers above the PDCP layer (such as the RRC layer and / or the SDAP layer), and the DU is configured to implement the functions of the protocol layers below the PDCP layer (such as one or more of the RLC layer, the MAC layer, or the PHY layer).

[0076] The configuration of the above CU and DU is merely an example, and the CU and DU can be configured to have functions as needed. For example, the CU or the DU can be configured to have more protocol layer functions, or the CU or the DU can be configured to have partial processing functions of the protocol layer. For example, partial functions of the RLC layer and functions of protocol layers above the RLC layer are arranged in the CU, and the remaining functions of the RLC layer and functions of protocol layers below the RLC layer are arranged in the DU. For another example, the functions of the CU or the DU can be divided according to a service type or other system requirements, for example, according to a delay requirement. Functions that require a processing time to meet a relatively low delay requirement are arranged in the DU, and functions that do not require the processing time to meet the delay requirement are arranged in the CU.

[0077] The DU and the RU can cooperate to jointly implement the functions of the PHY layer. One DU can be connected to one or more RUs. The functions of the DU and the RU can be configured in multiple ways according to design. For example, the DU is configured to implement baseband functions, and the RU is configured to implement intermediate radio frequency functions. For another example, the DU is configured to implement high-layer functions in the PHY layer, and the RU is configured to implement low-layer functions in the PHY layer or implement the low-layer functions and radio frequency functions. The high-layer functions in the PHY layer can include a part of functions of the PHY layer that are closer to the MAC layer, and the low-layer functions in the PHY layer can include another part of functions of the PHY layer that are closer to the intermediate radio frequency side.

[0078] In the embodiments of the present application, the device for implementing the function of the network device can be referred to as a network device, which can be a network element or a network device, or a device capable of supporting the network device or the network element to implement the function, such as a chip system, which can be installed in the network device. In the technical solutions provided in the embodiments of the present application, the device for implementing the function of the network device is taken as an example (for example, the device for implementing the function of the access network device is the access network device, and the device for implementing the function of the core network device is the core network device), and the technical solutions provided in the embodiments of the present application are described.

[0079] The technical features related to the embodiments of the present application are described below.

[0080] In satellite communication technology, a UE can not receive a paging message from a network due to no alignment with a satellite. Taking a calling service (a service initiated by a UE) as an example. Due to the calling service, the UE initiates a process of establishing a connection with the network after guiding a user to align the UE with a satellite. After establishing the connection with the network, the UE and the network can perform uplink and downlink data transmission. For a called UE, for example, a UE called by a calling user or a UE with information to be transmitted by the network, because the UE does not know when the network will call the UE, the UE may not be aligned with a satellite. This leads to that the UE cannot receive a paging message from the network, and cannot establish a connection with the network.

[0081] To this end, an embodiment of the present application proposes a technology of notifying a UE, which can be understood as a technology of enhancing paging, or a technology of informing a UE after a service is missed (for example, after paging fails), which can be referred to as an alert technology, or can have other names, such as a resilient notification, and the other names and "alert" can be replaced with each other, which is not limited herein. For example, the network can find a UE through an alert service or a resilient notification service. The service can notify the UE by sending an alert message or a resilient notification. Hereinafter, the name is taken as an example of alert. The alert message can carry an identifier of the UE, so as to find a specific UE; the UE can determine whether the message is for the UE according to the identifier in the alert message. Alternatively, the alert message can not carry the identifier of the UE, and the alert message can not be used to find a specific UE; however, in order for all UEs to receive the alert message, the alert message can be similar to system information. In order to ensure that the network can notify the UE, the UE needs to keep synchronization with the network to receive the alert message, and therefore the network needs to provide a synchronization signal for the UE to receive the alert message. In the embodiment of the present application, the synchronization signal for the UE to receive the alert message and the alert message (or, the "alert message" can be replaced with "a signal carrying the alert message". Hereinafter, the "alert message" is taken as an example) are collectively referred to as an alert signal, that is, the alert signal can refer to the synchronization signal for the UE to receive the alert message, or refer to the alert message, or refer to both signals.

[0082] The alert technology can improve the coverage of the alert signal. For example, by reducing the coding rate of the alert signal, or by repeatedly transmitting the alert signal or increasing the transmission power of the alert signal, etc., so that the alert signal can be received by the UE. For the UE, when the signal is poor (for example, the UE cannot normally receive services, such as cannot normally receive normal paging), the UE can receive information from the network by receiving the alert signal. But in some cases, the UE may no longer be able to receive the alert signal, for example, cannot receive the synchronization signal for synchronization with the network, and / or cannot receive the alert message, then the UE will not be able to communicate with the network.

[0083] In view of this, in the embodiments of the present application, if the UE determines that it cannot communicate with the network, the UE can output prompt information to prompt the UE to be aligned with the satellite, for example, the user can align the UE with the satellite according to the prompt information. After aligning the UE with the satellite, the UE can restore communication with the network. It can be seen that the embodiments of the present application enable the UE and the network to restore communication.

[0084] The communication method provided by the embodiments of the present application can be applied to a fourth generation (4th generation, 4G) communication system, such as a long term evolution (long term evolution, LTE) communication system, and can also be applied to a fifth generation (5th generation, 5G) communication system, such as a 5G new radio (new radio, NR) communication system, or to various communication systems evolved after 5G, such as a future communication system. The method provided by the embodiments of the present application can also be applied to a bluetooth system, a wireless fidelity (wireless fidelity, Wifi) system, a long range radio (long range radio, LoRa) system or a vehicle networking system. The method provided by the embodiments of the present application can also be applied to a terrestrial network (terrestrial network, TN), for example, to a scenario where the UE is in weak coverage in the terrestrial network; or, the method provided by the embodiments of the present application can also be applied to a non-terrestrial network (non-terrestrial network, NTN), such as a satellite communication system, for example, can be applied to a transparent satellite architecture, a backhaul satellite architecture or a regenerative satellite architecture, etc., without limitation.

[0085] Please refer to FIG. 2 for a schematic diagram of an application scenario of an embodiment of the present application. FIG. 2 includes a first device and a second device. The second device can send an alert signal, and the first device can receive the alert signal. The first device is, for example, a UE, and the second device is, for example, a network device (such as an access network device, a core network device, an RSU, or a control node). Alternatively, the first device and the second device are two different UEs. Alternatively, the first device and the second device can be two different network devices, for example, the first device is an RSU or a control node, and the second device is an access network device or a core network device.

[0086] Please refer to FIGS. 3A-3B for schematic diagrams of several network architectures of an NTN, which are also schematic diagrams of several application scenarios of an embodiment of the present application. For an architecture in which a UE is connected to a ground access network through a satellite, it can be referred to as a transparent satellite architecture (for example, FIG. 3A). For an architecture in which an access network device is arranged on a satellite (or the satellite has the function of an access network device), it can be referred to as a regenerative satellite architecture or a regenerative star architecture (for example, FIG. 3B). For an architecture in which a UE is connected to a ground access network and then connected to a ground network through a satellite, it can be referred to as a satellite backhaul architecture (for example, FIG. 3C).

[0087] In FIG. 3A, network elements (such as access network devices and / or core network devices) for transmitting services are all located on the ground. A UE accesses a network by accessing an access network device on the ground through a satellite, and the satellite has a transparent function.

[0088] In FIG. 3B, an access network device is arranged on a satellite, or a bottom layer processing module of an access network element is arranged on the satellite, or the satellite has part or all of the functions of an access network device. In addition to the access network device, other network elements (such as core network devices) for transmitting services are located on the ground. Alternatively, part or all of the network elements in the core network can also be arranged on the satellite, or the satellite can have the functions of part or all of the network elements in the core network.

[0089] In FIG. 3C, an access network device is located on the ground. A UE communicates with a satellite through an access network on the ground and then connects to a ground network through the satellite.

[0090] Optionally, the satellite in FIG. 3A, FIG. 3B, or FIG. 3C can also be replaced by a drone or a high-altitude aircraft, or other aerial devices.

[0091] It is mentioned above that, in some cases, a UE can not be able to receive an alert signal, for example, including being unable to receive a synchronization signal for receiving an alert message and / or being unable to receive an alert message. Several scenarios in which a UE cannot receive an alert signal are introduced as follows.

[0092] Scenario 1: UE receives an alert signal, which indicates that the resource of the subsequent alert signal changes. For example, the resource location of the subsequent received alert message changes. Since the UE does not know the changed resource location, the UE can no longer receive the alert signal. For example, the UE can switch the state of the UE to a no service state. In the no service state, the UE cannot receive the alert signal.

[0093] Scenario 2: Generally, the UE needs to contact the network periodically, for example, the UE can perform a periodic tracking area update (TAU) during the running of a periodic TAU timer, so that the network can know that the UE is still in the current tracking area (TA). However, if the UE is not on the satellite, the link budget can not support the UE to initiate communication to the network. Then when the periodic TAU timer expires, the UE cannot perform TAU. If the UE does not perform TAU for multiple times, the network can deregister the UE. If the UE is deregistered, the network will no longer search for the UE through the alert signal. Even if the UE is still monitoring the alert signal, the network will not send the alert signal to the UE.

[0094] Scenario 3: Generally, the UE can obtain the tracking area code (TAC) corresponding to the cell in which the UE resides by receiving the system information sent by the network. If the TAC corresponding to the cell in which the UE resides indicates that the cell does not belong to the tracking area list (TA list) configured for the UE by the network, it means that the UE has moved out of the TA list. The UE needs to perform TAU, so that the network knows that the UE has moved out of the original TA list, and can configure a new TA list for the UE. After the new TA list is configured, if the network needs to search for the UE, the network can send a signal in the area corresponding to the new TA list. However, if the UE can only receive the alert signal and cannot receive other signals from the network, it leads to that the UE cannot know whether it has moved out of the original TA list. Therefore, even if the UE has moved out of the original TA list, the UE will not initiate TAU. If the UE has moved out of the original TA list, the UE cannot receive the alert signal for searching for the UE in the area corresponding to the new TA list; and the UE also cannot receive the alert signal for searching for the UE sent by the network in the area corresponding to the original TA list.

[0095] In the above scenarios, the UE can face the problem of not being able to receive the alert signal, resulting in the UE being unable to communicate with the network. Embodiments of the present application can solve the problems described in the above scenarios.

[0096] The above relates to several states of the UE. The following describes the states of the UE in embodiments of the present application. In embodiments of the present application, the UE can have a plurality of different states, and at a certain moment the UE is in one of the states. For example, the states of the UE include a camped normally state, a camped on any cell state, and an any cell selection state. In addition, embodiments of the present application introduce a state, for example, referred to as a camped on alert (resilient) state, or can have other names. Hereinafter, the name is taken as an example.

[0097] The camped normally state can be applicable to a UE in a radio resource control (RRC) idle state or an RRC inactive state. The UE in the camped normally state can camp on a suitable cell. The UE can obtain normal service on the suitable cell, and therefore the normal service corresponds to the camped normally state. The public land mobile network (PLMN) to which the suitable cell belongs can be a PLMN that the UE can select or a PLMN that the UE registers, or a PLMN on an equivalent PLMN list. In addition, the UE satisfies the cell selection condition of the suitable cell. It can be understood that the signal quality of the suitable cell is good enough to satisfy the threshold configured in the system information.

[0098] When the UE cannot find a suitable cell, the UE can search for an acceptable cell. The UE stays in the acceptable cell for a generally short time, and the UE can obtain limited service in the acceptable cell, such as initiating an emergency call or receiving an emergency broadcast (earthquake and tsunami warning system (ETWS) and commercial mobile alert system (CMAS), etc. The state of the UE staying in the acceptable cell can be a camped on any cell state, and thus the limited service corresponds to the camped on any cell state. The camped on any cell state can be applicable to the UE in the RRC idle state. The acceptable cell only needs to meet the condition that the UE can stay in the acceptable cell, and does not need to be limited to the PLMN to which the acceptable cell belongs.

[0099] When the UE cannot stay in either a suitable cell or an acceptable cell, the UE is in an any cell selection state. In the any cell selection state, the UE can continuously search for a suitable cell or an acceptable cell.

[0100] Embodiments of the present application also introduce a camped on alert (resilient) state, which corresponds to the UE obtaining an alert service or a resilient service. For example, in the camped on alert (resilient) state, the UE can receive an alert signal. Optionally, the camped on alert (resilient) state can also be referred to as an alert state, or can have another name, which is not limited.

[0101] The method provided by the embodiments of the present application is described below with reference to the drawings. In various embodiments of the present application, the alert signal can also be referred to as a robust notification signal, or can also be referred to as a resilient notification, or can also have other names, and the alert signal is taken as an example herein. The alert signal can be sent in a broadcast manner. The alert signal has a function similar to paging, and can be used to transmit information to a specific UE, for example, the alert signal can be used to page the UE, or can be used to prompt the UE that there is service arrival, or can be used to indicate that the UE has missed service (for example, a called service), or can be used to indicate information of a missed called service, or can be used to prompt the UE to change an environment in which the UE is located, or can be used to prompt the UE to be aligned with a satellite, or can be used to prompt the UE to move to a line of sight (LoS) path between the UE and the satellite, or can be used to prompt the UE to improve channel quality of the UE, and the like. Optionally, coverage enhancement can be set for the alert signal, for example, the alert signal can satisfy one or more of the following: a lower coding rate, can be sent multiple times, or is sent using higher power. By satisfying one or more of the above, the UE can improve a reception success rate of the alert signal. After receiving the alert signal, the UE can enter an RRC connected state, or can output prompt information to prompt a user to change the environment in which the UE is located, or to prompt the user to align the UE with the satellite, or to prompt the user to move the UE to the LoS path between the UE and the satellite, or to prompt the user to improve the channel quality of the UE, or to remind the user of service calling, or to remind the user of a missed called service, and the like.

[0102] For example, a network device (for example, a core network device and / or an access network device) can no longer send a paging message, but instead uses the alert signal to replace the paging message. For example, when the network device wants to page the UE, the UE can be paged by sending the alert signal. Alternatively, the paging message can still be sent, and if the paging message sent by the network device (for example, a core network device and / or an access network device) does not receive a response from the UE, the network device (for example, a core network device and / or an access network device) can send the alert signal, and because the alert signal is subjected to coverage enhancement processing, the UE has a relatively high reception success rate for the alert signal. The alert signal can implement a paging function, or the alert signal can be used to notify the UE of a missed page or a missed called service or a missed called service. Alternatively, the alert signal can also be sent in other scenarios, and the embodiments of the present application do not limit this.

[0103] The optional steps are indicated by dashed lines in the drawings corresponding to various embodiments of the present application. The various embodiments herein can be applied to the network architecture shown in any one of FIG. 2, FIG. 3A-FIG. 3C. For example, the UE described in the various embodiments herein can be the first device shown in FIG. 2, and the network device described in the various embodiments herein can be the second device shown in FIG. 2. It can be understood that the various embodiments herein are taken as an example that the first device is the UE and the second device is the network device, but are not limited thereto. For another example, the UE described in the various embodiments herein can be the UE or the functional module in the UE shown in any one of FIG. 3A-FIG. 3C, and the network device described in the various embodiments herein can be the access network device or the functional module in the access network device shown in any one of FIG. 3A-FIG. 3C.

[0104] The present embodiment provides a communication method, please refer to FIG. 4, which is a flowchart of the method.

[0105] S401, the network device sends first information. Correspondingly, the UE receives the first information.

[0106] S402, the UE determines that the UE cannot communicate with the network device according to the first information.

[0107] S403, the UE outputs prompt information. The prompt information can prompt the UE to be aligned with the satellite. Wherein, S403 is an optional step.

[0108] In the following introduction process, S401-S403 will be introduced uniformly.

[0109] The first information can have various implementation manners, and correspondingly, the UE can also determine that the UE cannot communicate with the network in different ways, which will be introduced as follows.

[0110] 1. The first optional implementation manner of the UE determining that the UE cannot communicate with the network.

[0111] In this way, the UE determining, according to the first information, that the UE is unable to communicate with the network device can include that the UE is in an alert state (i.e., at this time the UE is unable to receive normal system information from the serving cell), and the UE determining, according to the first information, that configuration information of the alert signal changes. The normal system information can be, for example, system information that the UE can receive in a camped normally state or a camped on any cell state or an any cell selection state. The configuration information of the alert signal can be used to configure time domain resources and / or frequency domain resources of the alert signal, etc. If the configuration information of the alert signal changes, it indicates that the UE is unable to receive the alert signal at the original resource location, for example, including that the UE is unable to acquire a synchronization signal for receiving the alert message at the original resource location, or is unable to acquire the alert message at the original resource location. The UE determines, according to the first information, that the configuration information of the alert signal changes, but can not be able to determine the changed resource location, so the UE is unable to receive the alert signal at the changed resource location. It can be seen that if the configuration information of the alert signal changes, it can cause the UE to be unable to successfully receive the alert signal. Since the UE is in the alert state, it is unable to receive other normal services (for example, unable to receive a synchronization signal of the serving cell, such as a synchronization signal and PBCH block (SSB), unable to receive cell system information, unable to monitor a paging channel, etc.), which can also be regarded as the UE being unable to communicate with the network device.

[0112] The UE determining, according to the first information, that the configuration information of the alert signal changes can have different determination manners. As an optional implementation manner of the UE determining, according to the first information, that the configuration information of the alert signal changes, the UE can determine, according to the first information and stored second information, that the configuration information of the alert signal changes. For example, the first information can include or indicate first configuration information of the alert signal, and the second information can include or indicate second configuration information of the alert signal. If the first configuration information is the same as or is the same kind of configuration information as the second configuration information, it indicates that the configuration information of the alert signal does not change; or if the first configuration information is different from the second configuration information, it indicates that the configuration information of the alert signal changes.

[0113] Optionally, the second information is included in system information (SI), for example. Before S402, the UE can receive system information from the network device, which can include the second information. The second information is also referred to as configuration indication information of the alert signal, or value tag information of the alert signal, for example, or can also have other names. The second information occupies one or more bits, for example. Taking the case where the second information occupies one bit as an example. For example, when the configuration information of the alert signal is configuration information 1, the value of the bit is “0”; when the configuration information of the alert signal is configuration information 2, the value of the bit is “1”.

[0114] Optionally, the system information can also include or indicate the configuration information of the alert signal. For example, the system information can include or indicate at least one configuration information of the alert signal that the UE needs to monitor in the current cell or in the current TA or in a TA list (TAL). Each configuration information therein can be used to configure a set of time domain resources and / or frequency domain resources, and for each configuration information, the UE can monitor the alert signal according to the resources configured by the configuration information. The UE can monitor the alert signal using the resources configured by one of the configuration information, and the specific configuration information used can be indicated by the system information, for example, the system information indicates the UE to use the second configuration information in the at least one configuration information through the second information. Alternatively, the specific configuration information used can also be indicated by the alert signal, for example, the alert signal includes third information, which can indicate the UE to use the second configuration information in the at least one configuration information.

[0115] For another example, in a geostationary orbit (GEO) mobile radio (GMR) satellite system, the alert signal can be sent through a basic alerting channel (BACH). Therefore, optionally, the configuration information of the alert signal includes BACH configuration information, which can configure the time domain resources and / or frequency domain resources of the BACH. After the UE learns the BACH configuration information, it can monitor the BACH channel according to the BACH configuration information, so as to receive the alert signal.

[0116] If the UE receives the first information, the first information indicates the configuration information (e.g., the first configuration information) of the alert signal, the UE can compare the first information with the second information. If the configuration information (e.g., the first configuration information) indicated by the first information is different from the configuration information (e.g., the second configuration information) indicated by the second information, it means that the configuration information of the alert signal has changed. For example, the first information occupies the same number of bits as the second information, and optionally, if the value of the first information is the same as the value of the second information, it means that the configuration information of the alert signal has not changed; or if the value of the first information is different from the value of the second information, it means that the configuration information of the alert signal has changed. For example, the first information occupies one bit, and the second information occupies one bit. For example, the value of the first information and the value of the second information are both "0" or both "1", which means that the configuration information of the alert signal has not changed; for example, the value of the first information is "0", and the value of the second information is "1", which means that the configuration information of the alert signal has changed; for example, the value of the first information is "1", and the value of the second information is "0", which also means that the configuration information of the alert signal has changed. As can be seen, the UE can determine whether the configuration information of the alert signal has changed by the value of the first information and the value of the second information.

[0117] As another optional embodiment of the UE determining that the configuration information of the alert signal has changed according to the first information, the UE can determine that the configuration information of the alert signal has changed according to the indication of the first information. For example, the first information indicates that the configuration information of the alert signal has changed. The first information can occupy one or more bits, and for example, the first information occupies one bit. If the value of the bit is "1", it means that the configuration information of the alert signal has changed; if the value of the bit is "0", it means that the configuration information of the alert signal has not changed. Thus, the UE can determine whether the configuration information of the alert signal has changed according to the indication of the first information, without the aid of other information, which can simplify the processing process of the UE.

[0118] Optionally, the first information can be included in the alert signal, for example, the first information is included in a synchronization signal for receiving the alert signal, or is included in the alert message. The alert signal including the first information is referred to as a first alert signal for example. The first information can also be referred to as change indication information, or SI change indication information, or can also have other names. For example, in S401, the UE is in the camped on alert (resilient) state, and the UE can detect the alert signal. For example, the UE can detect the alert signal according to the configuration information (for example, the second configuration information) of the alert signal configured by the system information. In the embodiment of the present application, the alert signal can include a synchronization signal for receiving the alert message and / or the alert message. After detecting the first alert signal, the UE can determine whether the configuration information of the alert signal has changed according to the first information included in the first alert signal.

[0119] Wherein, the UE can enter the camped on alert (resilient) state when the quality of the synchronization signal is less than a first threshold, or can enter the camped on alert (resilient) state in other cases, which is not limited. The synchronization signal is, for example, SSB in the NR system, or frequency correction channel (FCCH) in the satellite system. For example, in the NR system, if the UE cannot receive the SSB, or although it can receive the SSB, but the signal quality of the SSB is less than the first threshold, the UE can enter the camped on alert (resilient) state. After entering the camped on alert (resilient) state, the UE can no longer perform normal services, for example, the normal services include one or more of the following: receiving the SSB of the serving cell, receiving the system information of the serving cell, or monitoring the paging channel, etc. In the GMR satellite system, whether the UE is in the camped on alert (resilient) state or not, the FCCH can be received. For example, when the UE is not in the camped on alert (resilient) state, if the signal quality of the FCCH is less than the first threshold, the UE can enter the camped on alert (resilient) state.

[0120] According to the first information, it is determined whether the configuration information of the alert signal is changed. The step is performed by, for example, the RRC layer of the UE. If the RRC layer determines that the configuration information of the alert signal is changed, the RRC layer can submit indication information to an upper layer of the UE to indicate that the configuration information of the alert signal is changed. The upper layer is, for example, a non-access stratum (NAS) layer or an application layer of the UE.

[0121] If the UE determines that the configuration information of the alert signal is changed, the UE can output prompt information. For example, the UE can output the prompt information by means of a ring and / or a user interface (UI), which prompts the user to align the UE with the satellite. If the user aligns the UE with the satellite, the channel condition between the UE and the network device can be improved. Optionally, the UE can enter a camped normally state and communicate with the network device normally.

[0122] 2. A second optional implementation in which the UE determines that the UE cannot communicate with the network.

[0123] In this way, the UE determines that the UE cannot communicate with the network device according to the first information, which can include that the UE is in an alert state, i.e., the UE does not perform normal services at this time, for example, the UE cannot receive normal system information from the serving cell, the UE determines that the UE is deregistered by the network device according to the first information, or the UE determines that the UE will be deregistered by the network device according to the first information. Alternatively, the UE determines that the UE cannot communicate with the network device according to the first information, which can include that the UE determines that the UE cannot communicate with the network device according to the first information when an implicit detach timer configured by the first information is timed out or will be timed out, or that the UE determines that the UE cannot communicate with the network device according to the first information when a first timer configured by the first information is timed out or will be timed out. Alternatively, the UE determines that the UE cannot communicate with the network device according to the first information, which can include that the UE determines that the implicit detach timer configured by the first information is timed out or will be timed out, or that the UE determines that the first timer configured by the first information is timed out or will be timed out. When the implicit detach timer or the first timer is timed out, the UE can be deregistered by the network device. The UE is deregistered by the network device, which indicates that the UE cannot communicate with the network device.

[0124] Alternatively, in this way, the UE can also not determine that it cannot communicate with the network device, i.e., S402 is not performed, but in S403, the prompt information is output according to the first information. For example, the UE outputs the prompt information when or before the implicit detach timer configured by the first information expires. Alternatively, the UE outputs the prompt information when or before the first timer configured by the first information expires.

[0125] In this way, the first information can have different implementations. As an optional implementation of the first information, the first information can include a periodic TAU timer and an implicit detach timer. The periodic TAU timer can be used by the UE to perform TAU; the implicit detach timer can be used by the network device to deregister the UE, or used by the UE to output the prompt information. Optionally, the first information can be from the network device, e.g., the UE receives the first information sent by the network device. The network device can also maintain the periodic TAU timer and the implicit detach timer. For example, the periodic TAU timer configured by the first information for the UE is referred to as the first periodic TAU timer, and the implicit detach timer configured by the first information for the UE is referred to as the first implicit detach timer; the periodic TAU timer maintained by the network device is referred to as the second periodic TAU timer, and the implicit detach timer maintained by the network device is referred to as the second implicit detach timer. Wherein, the timing duration of the first periodic TAU timer can be equal to the timing duration of the second periodic TAU timer; the timing duration of the first implicit detach timer can be equal to or not equal to the timing duration of the second implicit detach timer, e.g., the timing duration of the first implicit detach timer can be shorter than the timing duration of the second implicit detach timer.

[0126] For example, for the network device, the second periodic TAU timer and the second implicit detach timer can be run according to a corresponding detach policy, for example, the detach policy includes: when the second periodic TAU timer is continuously timed out for the Nth time (where the second periodic TAU timer is timed out, which means that the UE does not initiate TAU; the first periodic TAU timer is also timed out in the same way), the network device can start the second implicit detach timer, N is a positive integer; when the second implicit detach timer is timed out, the network device will deregister the UE. Optionally, the first information can indicate the detach policy, and for the UE, the same mechanism as the network device can be used, for example, when the first periodic TAU timer is continuously timed out for the Nth time, the UE can also start the first implicit detach timer (optionally, the first information indicates the detach policy, for example, the first information can configure N. Alternatively, N can be preconfigured in the UE or predefined by the protocol). If the timing duration of the first implicit detach timer is equal to the timing duration of the second implicit detach timer, it means that when the first implicit detach timer is timed out, the UE will be deregistered. Alternatively, if the timing duration of the first implicit detach timer is not equal to the timing duration of the second implicit detach timer, for example, the timing duration of the first implicit detach timer is shorter than the timing duration of the second implicit detach timer, it means that after the first implicit detach timer is timed out, the UE will be deregistered. It can be seen that through the first periodic TAU timer and the first implicit detach timer, the UE can know the time when the UE can be deregistered by the network device.

[0127] The UE can output prompt information when the first implicit detach timer is timed out, or can also output prompt information before the first implicit detach timer is timed out. For example, if the timing duration of the first implicit detach timer is shorter than the timing duration of the second implicit detach timer, the UE can output prompt information when the first implicit detach timer is timed out. When the first implicit detach timer is timed out, the second implicit detach timer maintained by the network device has not been timed out, and there is still a certain time for the network device to deregister the UE. The UE can output prompt information before being deregistered, so that the UE can be timely registered with the network, and the time for the UE to lose contact with the network is reduced.

[0128] For example, if the first implicit detach timer has the same time length as the second implicit detach timer, the UE can output the prompt information before the first implicit detach timer expires. When the first implicit detach timer expires, the second implicit detach timer maintained by the network device also expires, and the network device can deregister the UE. Therefore, the UE can output the prompt information before the first implicit detach timer expires, which means that the UE can output the prompt information before being deregistered, so that the UE can be in contact with the network in time and the time of losing contact between the UE and the network can be reduced. The specific time offset can be configured by the network device, for example, the first information is configured; or the UE can set the time offset by itself.

[0129] Optionally, before or when the first implicit detach timer expires, the UE can determine the state of the UE and then output the prompt information. For example, when the first implicit detach timer expires or before the first implicit detach timer expires, if the UE is in the camped on alert (resilient) state, the UE can output the prompt information; or when the first implicit detach timer expires or before the first implicit detach timer expires, if the UE is not in the camped on alert (resilient) state, the UE can not output the prompt information. If the UE is not in the camped on alert (resilient) state, it means that the UE can communicate with the network device even if the UE is not in contact with the network device, so the UE can not be in contact with the network device, which reduces the interference to the user and reduces the power consumption of the UE.

[0130] As another optional embodiment of the first information, the first information can configure a first timer. The first timer can be used to determine the time when the network device deregisters the UE, or to output the prompt information by the UE. The network device can maintain a second timer corresponding to the first timer, and no longer maintain the periodic TAU timer and the implicit detach timer. The time length of the first timer can be equal to or different from the time length of the second timer, for example, the time length of the first timer can be shorter than the time length of the second timer. For the network device, if the second timer expires, the network device can deregister the UE. For the UE, if the time length of the first timer is equal to the time length of the second timer, it means that the UE will be deregistered when the first timer expires. Or, if the time length of the first timer is different from the time length of the second timer, for example, the time length of the first timer is shorter than the time length of the second timer, it means that the UE will be deregistered after the first timer expires.

[0131] Alternatively, the network device can still maintain a periodic TAU timer (e.g., a second periodic TAU timer) and an implicit detach timer (e.g., a second implicit detach timer), without maintaining the second timer. Optionally, the timing length of the first timer can be determined according to the timing length of the second periodic TAU timer and the timing length of the second implicit detach timer. For example, the policy of the network device is that when the second periodic TAU timer times out for the Nth time in succession, the network device can start the second implicit detach timer; when the second implicit detach timer times out, the network device will deregister the UE. Then the timing length of the first timer can be less than or equal to Nxt1+t2, where t1 represents the timing length of the second periodic TAU timer, and t2 represents the timing length of the second implicit detach timer.

[0132] Optionally, the UE can restart the first timer after each TAU. In this way, the UE can avoid the first timer timing out as much as possible in the case that the UE can normally perform TAU.

[0133] The UE can output the prompt information when the first timer times out, or can output the prompt information before the first timer times out. For example, if the timing length of the first timer is shorter than Nxt1+t2, the UE can output the prompt information when the first timer times out. When the first timer times out, the second implicit detach timer or the second timer maintained by the network device has not timed out, and there is still a certain time before the network device deregisters the UE. The UE can output the prompt information before being deregistered, so that the UE can be aligned with the network in time, and the time for the UE to lose contact with the network is reduced.

[0134] For another example, if the timing length of the first timer is equal to Nxt1+t2, the UE can output the prompt information before the first timer times out. When the first timer times out, the second implicit detach timer or the second timer maintained by the network device also times out, and the network device will deregister the UE. Therefore, the UE can output the prompt information before the first timer times out, which is equivalent to the UE outputting the prompt information before being deregistered, so that the UE can be aligned with the network in time, and the time for the UE to lose contact with the network is reduced. The specific time offset in advance can be configured by the network device, for example, the first information configuration, or can be set by the UE itself.

[0135] Optionally, before or when the first timer expires, the UE can determine the state of the UE, and then output the prompt information. For example, before or when the first timer expires, if the UE is in the camped on alert (resilient) state, the UE can output the prompt information; or, before or when the first timer expires, if the UE is not in the camped on alert (resilient) state, the UE can not output the prompt information. Because if the UE is not in the camped on alert (resilient) state, it indicates that the UE can communicate with the network device even without the satellite, thus the UE can not need to be pointed to the satellite, reducing the interference to the user, and reducing the power consumption of the UE due to pointing to the satellite.

[0136] For example, the UE can output the prompt information by means of ringing and / or UI, etc., which can prompt the user to point the UE to the satellite. If the user points the UE to the satellite, the channel condition between the UE and the network device can become better. Optionally, the UE can enter the camped normally state and normally communicate with the network device.

[0137] Optionally, after the UE camps on the first cell, the UE can perform TAU or location area update (LAU) or registration request (RR), so that the network device knows the location change of the UE. The first cell is, for example, a suitable cell, and the UE camps on the first cell, for example, enters the camped normally state. Thus, it can also be understood that the UE enters the camped normally state and can perform TAU or LAU or RR.

[0138] Optionally, in the second optional implementation in which the UE determines that it cannot communicate with the network, the first information is included in the system information and / or included in the dedicated signaling. Optionally, the dedicated signaling is a NAS message, for example, a registration complete message, or other signaling. For example, the first information can be all included in the system information, or all included in the dedicated signaling. Alternatively, the first information can be partially included in the system information, and the remaining part included in the dedicated signaling. For example, the information related to the first periodic TAU timer can be included in the system information, and the information related to the first implicit detach timer and the detach policy can be included in the NAS message.

[0139] 3. The third optional implementation in which the UE determines that it cannot communicate with the network.

[0140] In this way, the UE determining, according to the first information, that the UE cannot communicate with the network device can include that the UE determining, according to the first information, that the UE moves out of a TAL (e.g., referred to as a first TAL) corresponding to the UE. The first TAL can be configured for the UE by the network device (e.g., a core network device or an access network device). If the UE moves out of the first TAL, the UE cannot receive an alert signal for searching for the UE sent by the network device in the first TAL, and the network device does not send the alert signal for searching for the UE in a new TAL in which the UE is located, because the network device does not know the new TAL. Therefore, the UE cannot receive the alert signal for searching for the UE, which is also regarded as that the UE cannot communicate with the network device.

[0141] The UE can determine whether the UE moves out of the first TAL in different manners. As a first optional implementation of the UE determining whether the UE moves out of the first TAL, the UE can determine whether the UE moves out of a geographical location (e.g., referred to as a first geographical location) corresponding to the first TAL according to positioning information of the UE. If the UE is located in the first geographical location, the UE does not move out of the first TAL, or if the UE is not located in the first geographical location, the UE moves out of the first TAL. The first geographical location can include a point or a geographical area. For example, the UE determining, according to the first information, that the UE cannot communicate with the network device can include that the UE determining that the UE moves out of the first geographical location. The first geographical location can be indicated by the first information, for example, an association relationship between the first TAL and the first geographical location is indicated by the first information. Alternatively, the first geographical location can be a global positioning system (GPS) location.

[0142] For the first optional implementation of the UE determining whether the UE moves out of the first TAL, an optional process corresponding to the implementation can refer to FIG. 5.

[0143] In S501, the core network device sends information of the first TAL to the UE. Correspondingly, the UE receives the information of the first TAL.

[0144] The information of the first TAL can indicate the first TAL, and the UE can determine that the UE corresponds to the first TAL according to the information of the first TAL. Alternatively, the first TAL can be configured for the UE by the access network device. FIG. 5 is an example in which the core network device configures the first TAL for the UE. The first TAL can include one or more TAs.

[0145] S502, the core network device sends TAL information to the network device. Correspondingly, the network device receives the TAL information. Wherein, S502 can occur before S501, or after S501, or simultaneously with S501. Wherein, the network device is, for example, an access network device, and is referred to as an access network device in FIG. 5 in order to distinguish from the core network device.

[0146] The TAL information can indicate the TAL corresponding to the TA to which the access network device belongs. Wherein, there can be one or more TALs including the TA to which the access network device belongs, and the TAL information can indicate the one or more TALs, the one or more TALs are all TALs corresponding to the TA to which the access network device belongs, and the one or more TALs include the first TAL.

[0147] Optionally, the core network device can also configure a geographical location corresponding to each TAL in the one or more TALs for the access network device. For example, the TAL information can indicate the correspondence between each TAL in the one or more TALs and the geographical location. In various embodiments of the present application, the "correspondence" can also be understood or replaced as "association relationship". Wherein, different TALs can correspond to different geographical locations. The geographical location corresponding to one TAL can include one location point (for example, including one geographical coordinate), or include one or more geographical areas, which can be adjacent or not adjacent in space.

[0148] The core network device is, for example, an AMF, or can also be other core network side devices.

[0149] S503, the access network device sends first information. Correspondingly, the UE receives the first information.

[0150] The access network device receives the configuration of the core network device, and then can send the first information. The first information is, for example, included in a broadcast message or a unicast message, and the broadcast message is, for example, system information. The first information can indicate the association relationship between the one or more TALs and the geographical location, and the one or more TALs include, for example, the first TAL.

[0151] The UE receives the first information, and can determine the first geographical location associated with the first TAL corresponding to the UE.

[0152] S504, the UE can determine whether the UE moves out of the first TAL according to the position of the UE and the first geographical location.

[0153] For example, if the position of the UE is located in the first geographical location, the UE does not move out of the first TAL; or if the position of the UE is not located in the first geographical location, the UE moves out of the first TAL.

[0154] As the second optional implementation for the UE to determine whether the UE moves out of the first TAL, the UE can determine whether the UE moves out of the first TAL according to a synchronization signal in the received alert signal. For example, the synchronization signal received by the UE is referred to as a first synchronization signal, where if the first synchronization signal is a synchronization signal corresponding to the first TAL, the UE does not move out of the first TAL; or if the first synchronization signal does not belong to the synchronization signal corresponding to the first TAL, the UE moves out of the first TAL. For example, the UE determines that the UE cannot communicate with the network device according to the first information can include that the UE determines that the first synchronization signal does not belong to the synchronization signal corresponding to the first TAL.

[0155] Optionally, the first synchronization signal is, for example, an FCCH in a satellite system. For example, one or more FCCH sequences can be newly defined, for example, one or more slopes are added, where each slope corresponds to a chirp sequence, and each chirp can be used as an FCCH sequence.

[0156] Alternatively, the first synchronization signal can also be a synchronization signal in an NR system (for example, an NR NTN system) or an Internet of Things system (for example, an IoT NTN system). Wherein if the first synchronization signal is a synchronization signal in the NR system or the Internet of Things system, the first synchronization signal can be newly defined in the embodiments of the application. In the NR system or the Internet of Things system, the original synchronization signal (for example, SSB) cannot be received by the UE in the camped on alert (resilient) state, or cannot meet the synchronization requirement after being received, so the application embodiment can define a new synchronization signal (for example, the first synchronization signal) for the NR system or the Internet of Things system. The UE can receive the first synchronization signal even if it is in the camped on alert (resilient) state. The first synchronization signal is referred to as SSB X, for example, or can also have other names. The structure of the first synchronization signal can be similar to that of SSB, or can also have other structures. Alternatively, the first synchronization signal can also be used in combination with the current SSB, or the first synchronization signal can also include the signal of the existing SSB, which is used for the UE to synchronize with the network. For example, the UE can receive the first synchronization signal and receive the synchronization signal in the SSB, and can synchronize with the network according to the sequences corresponding to the two synchronization signals.

[0157] For the second optional implementation for the UE to determine whether the UE moves out of the first TAL, an optional process corresponding to the implementation can be referred to in FIG. 6. In FIG. 6, the network device is also taken as an access network device as an example.

[0158] S601, the first access network device is configured with a first synchronization signal set. The second access network device is configured with a second synchronization signal set.

[0159] The first access network device and the second access network device can belong to different TAs, for example, the first access network device belongs to TA1, and the second access network device belongs to TA2. For example, TA1 belongs to the first TAL, and TA2 does not belong to the first TAL. The first TAL is a TAL corresponding to the UE, which can camp on the first access network device, for example, the first TAL is a core network device or a TAL configured by the first access network device for the UE.

[0160] The first synchronization signal set is, for example, a synchronization signal set corresponding to TA1, or a synchronization signal set corresponding to a cell under the first access network device, or a synchronization signal set corresponding to a TAC corresponding to the first access network device; and the second synchronization signal set is, for example, a synchronization signal set corresponding to TA2, or a synchronization signal set corresponding to a cell under the second access network device, or a synchronization signal set corresponding to a TAC corresponding to the second access network device. For example, S601 includes that an operation administration and maintenance (OAM) configures corresponding synchronization signal sets for access network devices in different TAs, wherein the synchronization signal sets configured for access network devices in one TA can be the same; and the synchronization signal sets configured for access network devices in different TAs can be different. S601 is an example of configuring the first synchronization signal set for the first access network device in TA1 and configuring the first synchronization signal set for the second access network device in TA2.

[0161] Optionally, one synchronization signal set can include one or more synchronization signals, for example, include a synchronization signal sequence corresponding to the one or more synchronization signals. Wherein the sequences corresponding to different types of synchronization signals can be different. For example, the first synchronization signal is FCCH, and the sequence corresponding to the first synchronization signal is FCCH sequence; or the first synchronization signal is, for example, a newly defined synchronization signal in the NR system, and the sequence corresponding to the first synchronization signal can be a sequence corresponding to the newly defined synchronization signal.

[0162] S602, the first access network device sends information of the first synchronization signal set. Correspondingly, the UE receives the information of the first synchronization signal set.

[0163] For example, the UE camps on the first access network device, and the UE can receive the information of the first synchronization signal set. Therefore, the UE can determine that the first synchronization signal set is a synchronization signal set corresponding to the first TAL, and the synchronization signal included in the first synchronization signal set is a synchronization signal corresponding to the first TAL. For example, the first access network device can send the information of the first synchronization signal set through system information.

[0164] Optionally, the information of the first synchronization signal set is included in the first information, for example, the first information indicates the association between the first synchronization signal set and the TA1.

[0165] In addition, the second access network device can also send the information of the second synchronization signal set, and the UE camping on the second access network device can receive the information of the second synchronization signal set, and no limitation is made to this.

[0166] S603, the first access network device sends a synchronization signal. Correspondingly, the UE receives the synchronization signal. For example, the synchronization signal is called synchronization signal 1.

[0167] S604, the UE determines that the UE has not moved out of the first TAL according to the received synchronization signal 1.

[0168] S605, the second access network device sends a synchronization signal. Correspondingly, the UE receives the synchronization signal. For example, the synchronization signal is called synchronization signal 2.

[0169] S606, the UE determines that the UE has moved out of the first TAL according to the received synchronization signal 2.

[0170] For example, the synchronization signal 1 and the synchronization signal 2 are collectively referred to as the first synchronization signal. For S604 and S606, it can be understood that the UE determines whether it has moved out of the first TAL according to the first synchronization signal. S603-S606 are uniformly introduced as follows.

[0171] As an optional implementation for the UE to determine whether it has moved out of the first TAL according to the first synchronization signal, the UE determines whether the sequence corresponding to the first synchronization signal belongs to the sequence corresponding to the first TAL. For example, the UE receives the first synchronization signal, if the sequence corresponding to the first synchronization signal does not belong to the sequence corresponding to the first TAL, for example, does not belong to the synchronization signal sequence included in the first synchronization signal set, the UE moves out of the first TAL; or if the sequence corresponding to the first synchronization signal belongs to the sequence corresponding to the first TAL, for example, belongs to the synchronization signal sequence included in the first synchronization signal set, the UE has not moved out of the first TAL. For example, the sequence corresponding to the synchronization signal 1 belongs to the sequence corresponding to the first TAL, for example, the sequence corresponding to the synchronization signal 1 is included in the first synchronization signal set, so the UE determines that it has not moved out of the first TAL in S604; while the sequence corresponding to the synchronization signal 2 does not belong to the sequence corresponding to the first TAL, for example, the sequence corresponding to the synchronization signal 1 is not included in the first synchronization signal set, so the UE determines that it has moved out of the first TAL in S606.

[0172] For the second optional implementation of the UE determining whether to move out of the first TAL, another optional process corresponding to the implementation can be referred to FIG. 7. The difference between the process shown in FIG. 6 and the process shown in FIG. 7 is that the UE determines whether to move out of the first TAL according to the first synchronization signal, and the specific determination manner is different. In FIG. 7, in order to distinguish from the core network device, the network device is taken as an access network device as an example.

[0173] S701, the core network device sends information of the first TAL to the UE. Correspondingly, the UE receives the information of the first TAL.

[0174] The information of the first TAL can indicate the first TAL, and the UE can determine that the UE corresponds to the first TAL according to the information. Alternatively, the first TAL can be configured for the UE by the access network device, and FIG. 7 is taken as an example that the core network device configures the first TAL for the UE. The first TAL can include one or more TAs.

[0175] S702, the first access network device sends a synchronization signal. Correspondingly, the UE receives the synchronization signal. For example, the synchronization signal is referred to as synchronization signal 1.

[0176] S703, the UE determines that the UE does not move out of the first TAL according to the received synchronization signal 1.

[0177] S704, the second access network device sends a synchronization signal. Correspondingly, the UE receives the synchronization signal. For example, the synchronization signal is referred to as synchronization signal 2.

[0178] S705, the UE determines that the UE moves out of the first TAL according to the received synchronization signal 2.

[0179] For example, the synchronization signal 1 and the synchronization signal 2 are collectively referred to as the first synchronization signal. For S703 and S705, it can be understood that the UE determines whether to move out of the first TAL according to the first synchronization signal. S702-S705 are introduced as follows.

[0180] As another optional implementation of the UE determining whether the UE moves out of the first TAL according to the first synchronization signal, the UE determines whether the TA corresponding to the first synchronization signal belongs to the TA included in the first TAL. For example, the first synchronization signal can carry indication information A, which can indicate the TA corresponding to the first synchronization signal. If the TA corresponding to the first synchronization signal belongs to the TA included in the first TAL, it indicates that the UE does not move out of the first TAL; or if the TA corresponding to the first synchronization signal does not belong to the TA included in the first TAL, it indicates that the UE moves out of the first TAL. For example, the TA indicated by the indication information A included in the first synchronization signal 1 belongs to the TA included in the first TAL, so the UE determines in S703 that the UE does not move out of the first TAL; while the TA indicated by the indication information A included in the second synchronization signal 2 does not belong to the TA included in the first TAL, so the UE determines in S705 that the UE moves out of the first TAL.

[0181] Optionally, the indication information A includes a tracking area code (TAC), which can indicate the TA corresponding to the first synchronization signal.

[0182] Wherein, the UE determines whether the UE moves out of the first TAL according to the synchronization signal, and the step can be performed by the RRC layer or the NAS layer of the UE. If performed by the NAS layer, the RRC layer can send the content indicated by the first information to the NAS layer, for example, send the association relationship between the first TAL and the first geographical location, or send the TA included in the first TAL, or send the information of the first synchronization signal set, etc.

[0183] As a third optional implementation of the UE determining whether the UE moves out of the first TAL, the UE can determine whether the UE moves out of the first TAL according to the alert message in the received alert signal. As an optional implementation of the UE determining whether the UE moves out of the first TAL according to the alert message, the UE determines whether the TA corresponding to the alert message belongs to the TA included in the first TAL. For example, the alert message received by the UE includes indication information B, which can indicate the TAC corresponding to the sending end of the alert message (which can be a certain network device, such as an access network device or a core network device). Thus, the UE can determine the TA where the sending end of the alert message is currently located according to the indication information A. The UE can determine whether the UE moves out of the first TAL by determining whether the TA belongs to the first TAL, or determining whether the TA is the TA corresponding to the UE.

[0184] For example, the indication information B is the TAC corresponding to the sending end of the alert message.

[0185] For example, the indication information B is an index of a TA corresponding to a sending end of the alert message, or an index of a TAL corresponding to the sending end of the alert message. For example, a core network device (e.g., an AMF or another core network device) can configure an index of a TAL to which an access network device belongs or an index corresponding to a TAC corresponding to the access network device for the access network device. The UE in the camped on normal state can receive fourth information from the core network device or the access network device, and the fourth information can indicate an index of a TA corresponding to the UE or an index of a TAL corresponding to the UE. After receiving the alert message, the UE can determine whether to move out of the first TAL according to the index of the TAL or the index of the TA carried in the alert message.

[0186] For a third optional implementation of the UE determining whether to move out of the first TAL, an optional process corresponding to the implementation can be referred to FIG. 8. In FIG. 8, in order to distinguish from the core network device, an example of the network device being an access network device is taken.

[0187] S801, the core network device sends fourth information to the UE. Correspondingly, the UE receives the fourth information.

[0188] The fourth information can indicate the first TAL, for example, the fourth information includes an index of the first TAL. Alternatively, the fourth information can indicate the first TA, for example, the fourth information includes an index of the first TA. The UE can determine that the UE corresponds to the first TAL or the first TA according to this. The first TAL can include one or more TAs, for example, the one or more TAs include the first TA.

[0189] Alternatively, the fourth information can also be sent by the access network device, and FIG. 8 takes the core network device sending the fourth information as an example.

[0190] S802, the core network device sends fifth information. Correspondingly, the access network device receives the fifth information.

[0191] The fifth information can indicate an index of a TAL to which the access network device belongs or an index corresponding to a TAC to which the access network device belongs.

[0192] S803, the access network device sends sixth information. Correspondingly, the UE receives the sixth information.

[0193] The sixth information can indicate an index of a TAL to which the access network device belongs or an index corresponding to a TA to which the access network device belongs. The sixth information is sent, for example, through a broadcast message or a unicast message, and the broadcast message is, for example, system information, for example, a SIB.

[0194] If the indication information B in the alert message is the index of the TA corresponding to the sending end of the alert message, or the index of the TAL corresponding to the sending end of the alert message, S802 and S803 can be performed; or if the indication information B in the alert message is the TAC corresponding to the sending end of the alert message, S802 and S803 can not be performed.

[0195] S804, the access network device sends the alert message. Correspondingly, the UE receives the alert message. For example, the alert message is referred to as a first alert message 1.

[0196] S805, the UE determines whether the UE moves out of the first TAL according to the received first alert message.

[0197] For example, the first alert message can carry the indication information B, which can indicate the TA corresponding to the first alert message, for example, the indication information B is the index of the TA. If the TA corresponding to the first alert message belongs to the TA included in the first TAL, or the TA corresponding to the first alert message is the first TA, it indicates that the UE has not moved out of the first TAL; or if the TA corresponding to the first alert message does not belong to the TA included in the first TAL, or the TA corresponding to the first alert message is not the first TA, it indicates that the UE has moved out of the first TAL.

[0198] Or, the indication information B indicates the TAL corresponding to the first alert message, for example, the indication information B is the index of the TAL. If the TAL corresponding to the first alert message is the first TAL, or the TAL corresponding to the first alert message includes the first TA, it indicates that the UE has not moved out of the first TAL; or if the TAL corresponding to the first alert message is not the first TAL, or the TAL corresponding to the first alert message does not include the first TA, it indicates that the UE has moved out of the first TAL.

[0199] Or, the indication information B can indicate the TAC corresponding to the first alert message, for example, the indication information B is the TAC. If the TA indicated by the TAC corresponding to the first alert message belongs to the TA included in the first TAL, or the TA indicated by the TAC corresponding to the first alert message is the first TA, it indicates that the UE has not moved out of the first TAL; or if the TA indicated by the TAC corresponding to the first alert message does not belong to the TA included in the first TAL, or the TA indicated by the TAC corresponding to the first alert message is not the first TA, it indicates that the UE has moved out of the first TAL.

[0200] If the UE determines that it moves out of the first TAL, the UE can output a prompt information. For example, the UE can output the prompt information by ringing and / or UI, etc. The prompt information can prompt the user to align the UE with the satellite. If the user aligns the UE with the satellite, the channel condition between the UE and the network device can become better. Optionally, the UE can enter the camped normally state and communicate with the network device normally.

[0201] Optionally, after the UE camps on the first cell, the UE can perform TAU or LAU or RR, so that the network device knows the location change of the UE. The first cell is, for example, a suitable cell. The UE camps on the first cell, for example, enters the camped normally state. Therefore, it can also be understood that the UE enters the camped normally state and can perform TAU or LAU or RR.

[0202] Optionally, in the third optional implementation in which the UE determines that it cannot communicate with the network, the first information is included in the system information or the alert signal.

[0203] In the embodiments of the present application, if the UE determines that it cannot communicate with the network (for example, the UE determines that the configuration information of the alert signal changes, or determines that the UE will be deregistered by the network device, or determines that the UE moves out of the first TAL), the UE can output a prompt information to prompt the user to align the UE with the satellite, for example, the user can align the UE with the satellite according to the prompt information. After aligning the UE with the satellite, the UE can resume the communication with the network. It can be seen that the embodiments of the present application enable the UE and the network to resume the communication.

[0204] The embodiments of the present application provide another communication method. Please refer to FIG. 9, which is a flowchart of the method.

[0205] S901, the network device sends first information. Correspondingly, the UE receives the first information.

[0206] Optionally, the first information is included in an alert signal, for example, the alert signal includes a synchronization signal for receiving an alert message, and / or includes the alert message, for example, the alert signal is referred to as a first alert signal. For example, the first information can also be referred to as change indication information, or SI change indication information, or can also have other names. For example, in S901, the UE is in a camped on alert (resilient) state, and the UE can detect the alert signal. For example, the UE can detect the alert signal according to configuration information (for example, second configuration information) of the alert signal configured by the system information, and for this, reference can be made to the related description of the embodiment shown in FIG. 4.

[0207] For example, the first information includes first configuration information of the alert signal, or the first information is the first configuration information. Optionally, the first configuration information can include information of a first time domain resource and / or information of a first frequency domain resource, that is, the first configuration information configures a resource for transmitting the alert signal, and the UE can determine the specific resource according to the first information.

[0208] Alternatively, the first configuration information can include a first index, and the first index can be an index of the first time domain resource and / or the first frequency domain resource. The UE can determine the first time domain resource and / or the first frequency domain resource according to the first index, and the first time domain resource and / or the first frequency domain resource can be used for transmitting the alert signal. Optionally, the UE can know the correspondence between the index and the resource in the camped on normal state through the system information, or the UE can also determine the correspondence between the index and the resource through a protocol, so as to determine the first time domain resource and / or the first frequency domain resource according to the first configuration information and the correspondence.

[0209] S902, the UE detects the alert signal according to the first configuration information.

[0210] Since the UE has obtained the new configuration information (the first configuration information) of the alert signal, the UE can detect the alert signal in the first time domain resource and / or the first frequency domain resource indicated by the first configuration information, so as to maintain the communication with the network device.

[0211] In the embodiment of the application, the UE can detect the alert signal according to the new configuration information of the alert signal, without prompting the user to perform the satellite alignment on the UE, so as to reduce the interference to the user, and also to maintain the state (for example, the camped on alert (resilient) state) of the UE unchanged.

[0212] FIG. 10 shows a structural schematic diagram of an apparatus provided in an embodiment of the present application. The communication apparatus 1000 can be the network device or the circuitry of the network device in the embodiments of FIG. 4, for implementing the methods corresponding to the network device in the above method embodiments. Alternatively, the communication apparatus 1000 can be the access network device or the circuitry of the access network device in the embodiments of FIG. 5 or FIG. 9, for implementing the methods corresponding to the access network device in the above method embodiments. Alternatively, the communication apparatus 1000 can be the core network device or the circuitry of the core network device in the embodiments of FIG. 5, for implementing the methods corresponding to the core network device in the above method embodiments. Alternatively, the communication apparatus 1000 can be the first access network device or the circuitry of the first access network device in the embodiments of any one of FIG. 6 to FIG. 8, for implementing the methods corresponding to the first access network device in the above method embodiments. Alternatively, the communication apparatus 1000 can be the second access network device or the circuitry of the second access network device in the embodiments of any one of FIG. 6 to FIG. 8, for implementing the methods corresponding to the second access network device in the above method embodiments. Alternatively, the communication apparatus 1000 can be the UE or the circuitry of the UE in the embodiments of any one of FIG. 4 to FIG. 9, for implementing the methods corresponding to the UE in the above method embodiments. For example, one circuitry can be a chip system.

[0213] The communication apparatus 1000 includes at least one processor 1001. The processor 1001 can be used for internal processing of the apparatus, to implement certain control processing functions. Optionally, the processor 1001 includes instructions. Optionally, the processor 1001 can store data. Optionally, different processors can be independent devices, can be located in different physical locations, and can be located on different integrated circuits. Optionally, different processors can be integrated in one or more processors, for example, integrated on one or more integrated circuits.

[0214] Optionally, the communication apparatus 1000 includes one or more memories 1003 for storing instructions. Optionally, the memory 1003 can also store data. The processor and the memory can be separately provided, or integrated together.

[0215] Optionally, the communication apparatus 1000 includes a communication line 1002 and at least one communication interface 1004. Since the memory 1003, the communication line 1002 and the communication interface 1004 are all optional, they are all represented by dashed lines in FIG. 10.

[0216] Optionally, the communication device 1000 can further include a transceiver and / or an antenna. The transceiver can be used to send information to other devices or receive information from other devices. The transceiver can be referred to as a transceiver, transceiver circuit, input / output interface, etc., and is used to realize the transceiver function of the communication device 1000 through the antenna. Optionally, the transceiver includes a transmitter and a receiver. Illustratively, the transmitter can be used to generate a radio frequency signal from a baseband signal, and the receiver can be used to convert a radio frequency signal into a baseband signal.

[0217] The processor 1001 can include a general central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs of the solutions of the present application.

[0218] The communication line 1002 can include a path for transmitting information between the above-mentioned components.

[0219] The communication interface 1004 uses any transceiver-like device for communicating with other devices or communication networks, such as an Ethernet, a radio access network (RAN), a wireless local area networks (WLAN), a wired access network, etc.

[0220] The memory 1003 can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM), or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, a magnetic disk storage or other magnetic storage devices, or any other medium capable of storing desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to this. The memory 1003 can exist independently, and is connected to the processor 1001 through the communication line 1002. Alternatively, the memory 1003 can be integrated with the processor 1001.

[0221] The memory 1003 is configured to store computer-executed instructions for implementing the solutions of the present application, and the processor 1001 is configured to control the execution of the computer-executed instructions. The processor 1001 is configured to execute the computer-executed instructions stored in the memory 1003, so as to implement the steps performed by the network device or the UE or the core network device or the access network device or the first access network device or the second access network device in the embodiments shown in any one of FIGs. 4 to 9.

[0222] Optionally, the computer-executed instructions in the embodiments of the present application can also be referred to as application program codes, and the embodiments of the present application do not make a specific limitation in this regard.

[0223] In a specific implementation, as an example, the processor 1001 can include one or more CPUs, such as CPU0 and CPU1 in FIG. 10.

[0224] In a specific implementation, as an example, the communication apparatus 1000 can include multiple processors, such as the processor 1001 and the processor 1005 in FIG. 10. Each of these processors can be a single-CPU processor or a multi-CPU processor. The processor herein can refer to one or more devices, circuits, and / or processing cores for processing data (for example, computer program instructions).

[0225] When the apparatus shown in FIG. 10 is a chip, for example, a chip of a network device or a chip of a UE or a chip of an access network device or a chip of a core network device or a chip of a first access network device or a chip of a second access network device, the chip includes the processor 1001 (may also include the processor 1005), the communication line 1002, and the communication interface 1004, and optionally, the chip includes the memory 1003. Specifically, the communication interface 1004 can be an input interface, a pin, or a circuit, etc. The memory 1003 can be a register, a cache, etc. The processor 1001 and the processor 1005 can be a general-purpose CPU, a microprocessor, an ASIC, or one or more integrated circuits for executing programs for controlling the communication method of any of the above embodiments.

[0226] The embodiments of the present application can divide the functions of the apparatus according to the above-mentioned method embodiments, for example, each function module can be divided according to each function, or two or more functions can be integrated into one processing module. The integrated module can be realized in the form of hardware or in the form of a software function module. It should be noted that the division of the modules in the embodiments of the present application is illustrative, and is only a logical function division. When each function module is divided according to each function, for example, FIG. 11 is a schematic diagram of an apparatus 1100, which can be a network device or a UE or an access network device or a core network device or a first access network device or a second access network device involved in each of the above method embodiments, or a chip in the network device or a chip in the UE or a chip in the access network device or a chip in the core network device or a chip in the first access network device or a chip in the second access network device. The apparatus 1100 includes a processing unit 1102 and a transceiver unit 1101.

[0227] It should be understood that the apparatus 1100 can be used to implement the steps performed by the network device or the UE or the access network device or the core network device or the first access network device or the second access network device in the communication method of the embodiments of the present application, and the related features can refer to the embodiments shown in any one of FIGS. 4 to 9, which will not be described here.

[0228] Optionally, the functions / implementation processes of the transceiver unit 1101 and the processing unit 1102 in FIG. 11 can be realized by the processor 1001 in FIG. 10 calling computer-executable instructions stored in the memory 1003. Alternatively, the functions / implementation processes of the processing unit 1102 in FIG. 11 can be realized by the processor 1001 in FIG. 10 calling computer-executable instructions stored in the memory 1003, and the functions / implementation processes of the transceiver unit 1101 in FIG. 11 can be realized by the communication interface 1004 in FIG. 10.

[0229] Optionally, when the apparatus 1100 is a chip or circuit, the functions / implementation processes of the transceiver unit 1101 can also be implemented through pins or circuits, etc. Optionally, the transceiver unit 1101 can include a sending unit and / or a receiving unit, the sending unit is used to implement the sending function, and the receiving unit is used to implement the receiving function; or the transceiver unit 1101 can be an integral module, which can implement the sending function and / or the receiving function. Optionally, the transceiver unit 1101 can be implemented through a transceiver.

[0230] The embodiments of the present application further provide a computer readable storage medium, which stores computer programs or instructions, when the computer programs or instructions are executed, the method executed by the network device or the UE or the access network device or the core network device or the first access network device or the second access network device in the foregoing method embodiments is implemented. Thus, the functions described in the foregoing embodiments can be implemented in the form of software function units and sold or used as independent products. Based on this understanding, the technical solutions of the present application can be embodied in the form of software product in essence or the part that contributes or the part of the technical solutions. The computer software product is stored in a storage medium and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in the embodiments of the present application. The storage medium includes a U disk, a mobile hard disk, a ROM, a RAM, a magnetic disk or an optical disk, and various storage program codes.

[0231] The embodiments of the present application further provide a computer program product, which includes computer program codes, when the computer program codes are executed on a computer, the computer program codes make the computer execute the method executed by the network device or the UE or the access network device or the core network device or the first access network device or the second access network device in any of the foregoing method embodiments.

[0232] The embodiments of the present application further provide a processing apparatus, which includes a processor and an interface; the processor is used to execute the method executed by the network device or the UE or the access network device or the core network device or the first access network device or the second access network device involved in any of the foregoing method embodiments.

[0233] In the embodiments described above, all or some of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or some of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded into and executed by a computer, all or some of the procedures or functions described in the embodiments of the present application are performed. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from a website, a computer, a server or a data center to another website, computer, server or data center through a wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media sets. The available media can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, DVD), or a semiconductor medium (for example, solid state disk (SSD)) and the like.

[0234] The various illustrative logical blocks, modules, circuits, and algorithms described in connection with the embodiments disclosed herein can be implemented or performed by a general purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the described functions. The general purpose processor can be a microprocessor, optionally, the general purpose processor can also be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other similar configuration.

[0235] The steps of methods or algorithms described in the embodiments of the present application can be directly embedded in hardware, a software unit executed by a processor, or a combination of the two. The software unit can be stored in a RAM, a flash memory, a ROM, an erasable programmable read-only memory (EPROM), an EEPROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium in the art. The storage medium can be connected to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Alternatively, the storage medium can also be integrated into the processor. The processor and the storage medium can be located in an ASIC, which can be located in the terminal device. Alternatively, the processor and the storage medium can also be located in different components of the terminal device.

[0236] These computer program instructions can also be loaded onto a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to generate a computer implemented process such that the instructions executed by the computer or other programmable device provide steps for implementing the functions specified in the flowchart block or blocks and / or the block or blocks in the block diagram.

[0237] The contents in various embodiments of the present application can be mutually referred to, and the terms and / or descriptions between different embodiments are consistent and can be mutually referred to if there is no special description and logical conflict. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0238] It can be understood that one or more of the network device, the UE, the access network device, the core network device, the first access network device, or the second access network device in the embodiments of the present application can perform part or all of the steps in the embodiments of the present application. These steps or operations are only examples, and other operations or modifications of various operations can also be performed in the embodiments of the present application. In addition, the various steps can be performed in different orders presented in the embodiments of the present application, and it is possible that not all operations in the embodiments of the present application are performed.

Claims

1. A communication method characterized by comprising: The method comprises: receiving first information; determining, according to the first information, that the terminal cannot communicate with the network device; outputting prompt information, the prompt information being used for prompting the terminal to be paired with a satellite.

2. The method of claim 1, wherein, Determining, according to the first information, that the terminal cannot communicate with the network device comprises: determining, according to the first information, that configuration information of an alarm signal has changed, the alarm signal being used for prompting the terminal that a service has arrived.

3. The method of claim 2, wherein, Determining, according to the first information, that configuration information of an alarm signal has changed comprises: determining, according to the first information and stored second information, that configuration information of the alarm signal has changed, the first information comprising first configuration information of the alarm signal, and the second information being used for indicating second configuration information of the alarm signal, the first configuration information being different from the second configuration information.

4. The method of claim 3, wherein, The method further comprises: receiving system information, the system information comprising the second information.

5. The method of claim 2, wherein, The first information is used for indicating that configuration information of the alarm signal has changed.

6. The method according to any one of claims 1 to 5, characterized in that, The first information is comprised in a first alarm signal.

7. The method of claim 1, wherein: the first information is used for configuring a periodic tracking area update (TAU) timer and an implicit detach timer, the periodic TAU timer being used for the terminal to perform a periodic tracking area update, and the implicit detach timer being used for the network device to deregister the terminal; or the first information is used for configuring a first timer, the first timer being used for determining a time at which the network device deregisters the terminal.

8. The method of claim 7, wherein: the method further comprises starting the implicit detach timer when the periodic TAU timer times out for an Nth time in succession, N being a positive integer; outputting the prompt information comprises outputting the prompt information when or before the implicit detach timer times out.

9. The method of claim 8, wherein, The first information is further used for configuring the N.

10. The method of claim 7, wherein, Outputting the prompt information comprises: outputting the prompt information when or before the first timer times out.

11. The method of claim 1, wherein, The first information indicates a first geographical location, the first geographical location corresponding to a first tracking area list (TAL), the first TAL being a TAL corresponding to the terminal, and determining, according to the first information, that the terminal cannot communicate with the network device comprises: determining that the terminal has moved out of the first geographical location.

12. The method of claim 1, wherein: the method further comprises receiving a first synchronization signal; the first information indicates a first TAL or a synchronization signal corresponding to the first TAL, the first TAL being a TAL corresponding to the terminal, and wherein determining, according to the first information, that the terminal cannot communicate with the network device comprises determining that the first synchronization signal does not belong to the synchronization signals corresponding to the first TAL.

13. The method of claim 12, wherein, Determining that the first synchronization signal does not belong to the synchronization signals corresponding to the first TAL comprises: determining that a sequence corresponding to the first synchronization signal does not belong to the synchronization signal sequences corresponding to the first TAL; or determining that a TA corresponding to the first synchronization signal does not belong to the TAs included in the first TAL.

14. The method according to any one of claims 7 to 13, characterized in that, The method further comprises: camping on a first cell; performing a periodic location update.

15. A method of communication, comprising: The method comprises: sending first information, the first information being used to determine that the terminal is unable to communicate with the network device.

16. The method of claim 15, wherein, The first information is used to determine that configuration information of an alarm signal has changed, the alarm signal being used to prompt the terminal that a service has arrived.

17. The method of claim 16, wherein, The first information is used to determine that configuration information of an alarm signal has changed, comprising: The first information and second information are used to determine that configuration information of the alarm signal has changed, the first information comprising first configuration information of the alarm signal, and the second information being used to indicate second configuration information of the alarm signal, the first configuration information being different from the second configuration information; or, The first information is used to indicate that configuration information of the alarm signal has changed.

18. The method of claim 17, wherein, The method further comprises: sending information, the system information comprising the second information.

19. The method according to any one of claims 15 to 18, characterized in that, The first information is comprised in a first alarm signal.

20. The method of claim 15, wherein The first information is used to configure a periodic TAU timer and an implicit detach timer, the periodic TAU timer being used for the terminal to perform a periodic tracking area update, and the implicit detach timer being used for the network device to deregister the terminal; or The first information is used to configure a first timer, the first timer being used to determine a time at which the network device deregisters the terminal.

21. The method of claim 20, wherein, The first information is further used to configure N, wherein the implicit detach timer is started when the periodic location update timer times out for a continuous Nth time, N being a positive integer.

22. The method of claim 20, wherein, A timing duration of the first timer is determined according to a timing duration of the periodic location update timer and a timing duration of the implicit detach timer.

23. The method of claim 15, wherein The first information is used to indicate a correspondence between a first TAL and a first geographical location, the first TAL being a TAL corresponding to the terminal; or The first information is used to configure a synchronization signal corresponding to a first TAL, the first TAL being a TAL corresponding to the terminal; or The first information is used to configure a first TAL, the first TAL being a TAL corresponding to the terminal.

24. A communications device, characterized by The communication apparatus comprises a module for performing the method of any one of claims 1-14, or a module for performing the method of any one of claims 15-23.

25. A communications device, characterized by The communication apparatus comprises a processor configured to perform the method of any one of claims 1-14, or to perform the method of any one of claims 15-23.

26. A computer-readable storage medium, characterized in that, The computer readable storage medium is configured to store a computer program which, when executed on a computer, causes the method of any one of claims 1-14 to be performed, or causes the method of any one of claims 15-23 to be performed.

27. A computer program product, characterised in that, The computer program product comprises a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 1 to 14, or causes the computer to perform the method of any one of claims 15 to 23.

28. A communication system, characterized by The communication system comprises a network device and a terminal, wherein, The terminal is configured to perform the method of any one of claims 1 to 14; The network device is configured to perform the method of any one of claims 15 to 23.

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