NTN satellite communication network selection method and system

Abstract

The invention provides an NTN satellite communication network selection method and system, and relates to the technical field of communication, and the method comprises the steps: storing satellite network selection information of adjacent satellites at a service satellite side; the method comprises the following steps of: adding an NTN (Network Temporary Network) preposition switch on a UE (User Equipment) interface, preferentially adopting an NTN network selection strategy when the UE turns on the NTN preposition switch, and automatically converting into an NTN preference mode and preferentially adopting the NTN network selection strategy when the UE does not turn on the NTN preposition switch and the speed per hour of the UE meets a preset speed per hour condition; when the UE opens the protocol stack of the NAS layer or returns to the coverage area from the non-coverage area, the protocol stack of the NAS layer initiates limited residence network selection based on the satellite network selection information and the NTN network selection strategy, so that the network selection residence time of the UE can be greatly shortened, and the problems of low network selection efficiency and overhigh power consumption of the UE in an NTN satellite communication scene of a traditional network selection strategy are effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication technology, in particular to a NTN satellite communication network selection method and system. BACKGROUND

[0002] The traditional network selection strategy is the frequency scanning strategy of cellular mobile communication, and the NTN (Non-Terrestrial Network) satellite communication places the base station on the satellite, which is significantly different from the cellular mobile communication. Therefore, the traditional network selection strategy has obvious limitations in the NTN satellite communication scenario.

[0003] Firstly, the satellite has a wide coverage range, and if the traditional network selection strategy is used, a large number of frequency points without effective information will be easily scanned, especially when the full-band network selection is triggered, the UE (User Equipment) will search for frequency points that do not exist in the current environment, which prolongs the network selection time and increases the power consumption of the UE. Secondly, the satellite has mobility characteristics and can only be scanned by the UE when it covers the service area. The traditional network selection strategy based on the PLMN (Public Land Mobile Network) priority and the network selection with stored information or the full-band network selection method will cause the PLMN selection to take too long due to the dynamic movement of the satellite, and even the registration will fail after the frequency point is located because the satellite is far away. In addition, the satellite needs to be periodically switched during movement, and if the traditional network selection strategy of measuring first and switching or reselecting later is used, the network selection time and the power consumption of the UE will be further increased. Finally, when the satellite covers the open sea area, the traditional network selection strategy may not match the RPLMN (Registerd Public Land Mobile Network) and the PLMN of the open sea area, and additional network selection process needs to be performed, which greatly increases the network selection time and the power consumption of the UE when entering the open sea area for the first time.

[0004] Therefore, it is necessary to provide a NTN satellite communication network selection method and system to solve the above technical problems. SUMMARY

[0005] To solve the above technical problems, the present application provides a NTN satellite communication network selection method and system to solve the problem of low network selection efficiency and high UE power consumption of the traditional network selection strategy in the NTN satellite communication scenario.

[0006] The NTN satellite communication network selection method provided by the present application comprises: storing satellite network selection information of adjacent satellites on the side of the serving satellite; Add an NTN preference switch to the UE interface. When the UE turns on the NTN preference switch, the NTN network selection strategy is preferentially adopted. When the UE does not turn on the NTN preference switch and the UE speed meets the preset speed condition, the UE automatically switches to the NTN preference mode and preferentially adopts the NTN network selection strategy. When the UE starts the protocol stack of the NAS layer or returns to the coverage area from the non-coverage area, the protocol stack of the NAS layer initiates restricted resident network selection based on the satellite network selection information and the NTN network selection policy.

[0007] Preferably, the serving satellite periodically sends the satellite network selection information to the UE in the form of a system message, or when the UE actively requests the satellite network selection information, the serving satellite sends the satellite network selection information to the UE through a preset signaling; The satellite network selection information includes band information, ARFCN information, PLMN information, over-the-top time and ephemeris information.

[0008] Preferably, the overhead time is the time when the adjacent satellite arrives at the coverage area.

[0009] Preferably, the preset speed condition is that the UE speed exceeds 500 km / h.

[0010] Preferably, when the protocol stack of the NAS layer initiates restricted resident network selection based on the satellite network selection information and the NTN network selection strategy, it is not necessary to perform full-band scanning, and stops when any of the adjacent satellites is determined.

[0011] Preferably, when the UE starts the protocol stack of the NAS layer or returns to the coverage area from the non-coverage area, the protocol stack of the NAS layer initiates restricted resident network selection based on the satellite network selection information and the NTN network selection strategy, specifically including: When the UE starts the protocol stack of the NAS layer or returns to the coverage area from the non-coverage area, the NAS layer reads the PLMN list in the user identification card and configuration file of the UE and prioritizes the PLMNs in the PLMN list; The UE interprets the system message sent by the serving satellite, obtains the satellite network selection information of the adjacent satellite, combines the user PLMN list, determines the first adjacent satellite, and directly initiates registration; When the serving satellite is away from the UE, a change of the second adjacent satellite is initiated according to the RRC state.

[0012] Preferably, the acquiring the satellite network selection information of the adjacent satellite, combining the user PLMN list, determining the first adjacent satellite and directly initiating registration specifically includes: Acquire the satellite network selection information of the adjacent satellite, and extract PLMN information from the satellite network selection information; The PLMN information of the neighboring satellite in the PLMN list is selected, the neighboring satellite corresponding to the PLMN information with the highest priority is determined to be the first neighboring satellite, and registration is directly initiated.

[0013] Preferably, when the UE detects that RSRP, RSRQ, and SINR are respectively lower than a preset power threshold, a preset quality threshold, and a preset noise ratio threshold, or when the distance between the service satellite and the UE calculated based on the time advance and frequency offset exceeds a safety distance threshold, it is determined that the service satellite is far away from the UE.

[0014] Preferably, the initiating a change of the second adjacent satellite according to the RRC state specifically includes: When the RRC state is an idle state, the UE makes a reselection request and initiates reselection of the second neighboring satellite; when the RRC state is a connected state, the serving satellite notifies the UE to initiate switching of the second neighboring satellite.

[0015] An NTN satellite communication network selection system, the system comprising: An information storage module is used to store satellite network selection information of adjacent satellites on the serving satellite side; a policy determination module, configured to add an NTN preference switch to the UE interface; when the UE turns on the NTN preference switch, the NTN network selection policy is preferentially adopted; and when the UE does not turn on the NTN preference switch and the UE speed meets a preset speed condition, the NTN preference mode is automatically switched to and the NTN network selection policy is preferentially adopted; The network selection initiating module is configured to initiate restricted resident network selection based on the satellite network selection information and the NTN network selection strategy when the UE starts the NAS layer protocol stack or returns to the coverage area from the non-coverage area.

[0016] Compared with related technologies, the NTN satellite communication network selection method and system provided by the present invention has the following beneficial effects: The application can store satellite network selection information of adjacent satellites on the service satellite side; an NTN preference switch is added to the UE interface, when the UE opens the NTN preference switch, the NTN network selection strategy is preferentially adopted, when the UE does not open the NTN preference switch and the UE speed meets the preset speed condition, the NTN preference mode is automatically converted, and the NTN network selection strategy is preferentially adopted; when the UE opens the protocol stack of the NAS layer or returns to the coverage area from the non-coverage area, the protocol stack of the NAS layer initiates the restricted camping network selection based on the satellite network selection information and the NTN network selection strategy, so that the UE network selection camping time can be greatly shortened, and the problems of low network selection efficiency and high UE power consumption of the traditional network selection strategy in the NTN satellite communication scene are effectively solved.

[0017] The application can store key information of adjacent satellites on the satellite side, and combine with the strategy optimization of the UE to ensure the accuracy and efficiency of the network selection process. When the UE opens the NTN preference switch or the UE speed meets the preset speed condition, the NTN network selection strategy is preferentially adopted, so that the NTN network selection strategy and the TN (Terrestrial Network, ground network) network selection strategy can be decoupled to avoid mutual interference. The restricted camping network selection mode saves the full-band scanning, and stops when the satellite meeting the condition is determined, so that the network selection time is greatly shortened. Based on the direct matching of the user network list and the satellite information, the traditional RPLMN stage is skipped, so that the suitable satellite can be matched at any time and quickly registered when the operator network is mature. When the service satellite is far away, reselection or switching is directly initiated according to the connection state, the UE measurement process is omitted, and the time consumption and power consumption are further reduced. Finally, through the cooperation of the satellite and the terminal, the network selection camping time is greatly shortened, the satellite mobility and wide coverage characteristics are adapted, and the stability and user equipment of the satellite communication are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A flowchart of an NTN satellite communication network selection method provided for an embodiment of the application; Figure 2 A flowchart of restricted camping network selection provided for an embodiment of the application; Figure 3 A system block diagram of an NTN satellite communication network selection system provided for an embodiment of the application; Figure 4 A hardware structure schematic diagram of an electronic device provided for an embodiment of the application. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0020] like Figure 1 FIG. 1 is a flow chart of a method for selecting a network for NTN satellite communication provided by an embodiment of the present invention. Figure 1 The execution subject of the method shown may be a software and / or hardware device. The execution subject of the present application may include but is not limited to at least one of the following: user equipment, network equipment, etc. Among them, the user equipment may include but is not limited to computers, smart phones, personal digital assistants (PDAs) and the electronic devices mentioned above. Network equipment may include but is not limited to a single network server, a server group consisting of multiple network servers, or a cloud based on cloud computing consisting of a large number of computers or network servers, wherein cloud computing is a type of distributed computing, a super virtual computer composed of a group of loosely coupled computers. This embodiment does not limit this. It includes steps S1 to S3, as follows: S1, storing the satellite network selection information of adjacent satellites on the serving satellite side; The term "serving satellite" refers to the satellite node currently providing real-time communication services to the UE. It is the satellite carrier through which the UE currently accesses and obtains communication resources, and is responsible for signal transmission and reception and data forwarding. Adjacent satellites refer to other satellites within the adjacent coverage area or communication reach of the serving satellite. When the serving satellite's coverage capability weakens, moves away from the UE's coverage area, or is no longer able to provide service, these satellites can serve as new connection targets for the UE, ensuring communication continuity. Satellite network selection information refers to a set of key data used to assist the UE in selecting adjacent satellites, providing data support for network selection decisions.

[0021] The serving satellite periodically sends the satellite network selection information to the UE in the form of a system message, or when the UE actively requests the satellite network selection information, the serving satellite sends the satellite network selection information to the UE through a preset signaling; The satellite network selection information includes band information, ARFCN (Absolute Radio Frequency Channel Number) information, PLMN information, over-the-top time and ephemeris information.

[0022] The over-the-top time is the time when the adjacent satellite arrives at the coverage area.

[0023] It should be noted that pre-defined signaling refers to pre-defined signal instructions used for information transmission within a satellite communication system. Band information identifies the frequency range used by the satellite for signal transmission between the satellite and the UE. ARFCN information uniquely identifies the radio frequency channel in satellite communications. PLMN information refers to the identification and attribute information of the network established and operated by the operator to provide land mobile communication services to the public. This information includes the network's operating identity and service range. It is key for the UE to determine whether the satellite's network matches its own supported network and ensures network compatibility when selecting a network. Overhead time refers to the time when a neighboring satellite moves into the UE's current coverage area. This time point is calculated based on the satellite's trajectory and reflects the moment when the neighboring satellite arrives in the area and provides communication services to the UE, providing a time reference for the UE to prepare for network handover. Ephemeris information is core data reflecting the satellite's operational status, including the satellite's real-time position, speed, orbital parameters, and other information. By recording the satellite's trajectory and status parameters in space, it accurately describes the satellite's operational patterns, providing data support for predicting satellite position changes and coverage adjustments, ensuring that the UE has accurate information about the satellite's operational status.

[0024] In satellite communication network selection, the serving satellite can store network selection data for neighboring satellites in its own system. This data is the foundation for efficient network selection by UEs, providing accurate references and preventing excessive resource consumption due to blind searches. This optimizes the network selection process from the very beginning.

[0025] The serving satellite delivers this critical information to UEs in a flexible and targeted manner. On the one hand, the serving satellite continuously sends neighboring satellite network selection information to UEs within its coverage area in the form of system messages at a fixed interval. This periodic delivery mechanism ensures that UEs regularly update the status of surrounding satellites, always having the latest network selection references, and ensuring continuous and stable communication. On the other hand, when a UE proactively initiates an information request based on its own communication needs, the serving satellite sends the neighboring satellite network selection information to the UE in a targeted manner using pre-set signal instructions. This on-demand delivery method quickly responds to the UE's real-time needs and ensures timely information acquisition.

[0026] The network selection information stored and delivered by the service satellite covers multiple core dimensions, which together constitute the complete network selection decision basis. Among them, the band information specifies the frequency range used during adjacent satellite communication, which is the basic parameter for UE to identify satellite signals; the ARFCN information uniquely identifies the communication channel, helping the UE to accurately lock the satellite communication channel and ensuring the accuracy of signal transmission. The PLMN information contains the operating identity and service attributes of the adjacent satellite network, which is the core basis for UE to judge network compatibility and ensures that the selected satellite network can provide effective services. The ephemeris information comprehensively records the running state of the adjacent satellite, including position, speed and orbit parameters, etc., providing data support for predicting the satellite's running track and coverage range changes. The over-the-top time as a key time parameter ensures that the UE can initiate connection in time when the satellite enters the effective coverage range, avoiding connection delay or failure caused by satellite mobility, further improving the efficiency and stability of network selection.

[0027] In the above manner, the service satellite and the UE can form an efficient cooperation to provide comprehensive support for the accuracy and timeliness of satellite communication network selection, effectively adapting to the satellite mobility and wide coverage characteristics.

[0028] S2, adding an NTN preference switch in the UE interface. When the UE opens the NTN preference switch, the NTN network selection strategy is preferred. When the UE does not open the NTN preference switch and the UE speed meets the preset speed condition, the NTN preference mode is automatically converted, and the NTN network selection strategy is preferred. The preset speed condition is that the UE speed exceeds 500 km / h.

[0029] The UE interface refers to a visual interface for realizing user interaction operation. The NTN preference switch refers to a functional control set in the UE interface. By opening and closing the NTN preference switch, the UE can autonomously decide the priority selection right of satellite network during communication. The NTN network selection strategy is a network selection strategy designed for non-terrestrial network satellite communication scenarios, which is used to preferentially select satellite network as a service object during communication connection establishment, and to realize efficient and accurate network selection by directing using the adjacent satellite information pre-installed on the satellite side. The preset speed condition refers to a pre-set speed standard for judging the moving state of the UE. When the moving speed of the UE reaches the standard, the system will automatically trigger the strategy adjustment, without the need for manual operation to adapt to the communication demand in high-speed moving scenarios. The NTN preference mode refers to the running state of the UE preferentially using the non-terrestrial network selection strategy. In this mode, the network selection logic of the UE takes the satellite network as the core target, preferentially meets the connection demand with the satellite network, and guarantees the communication continuity in the satellite coverage scenario.

[0030] In the UE's interface, set the NTN preference switch to control the communication strategy priority. When the UE actively turns on this switch, the NTN network selection strategy is prioritized during network selection to meet the UE's active demand for satellite communications.

[0031] For UEs that do not have this switch enabled, the system will monitor their speed in real time. When the UE's speed exceeds 500 km / h, the UE will automatically switch to NTN preference mode and prioritize the NTN network selection strategy without manual user intervention.

[0032] Through the above method, it not only respects the user's active choice intention and allows the satellite communication priority to be directly set through interface operations; it can also achieve intelligent adaptation based on the UE's motion status and automatically switch to a more suitable satellite communication strategy in high-speed mobile scenarios, thereby effectively realizing the decoupling of the NTN network selection strategy and the TN network selection strategy, avoiding mutual interference between the two, and ensuring that the UE can efficiently select the appropriate communication network in different scenarios, ensuring the continuity and stability of communication.

[0033] S3: When the UE turns on the protocol stack of the Non-Access Stratum (NAS) layer or returns to the coverage area from the coverage area, the protocol stack of the NAS layer initiates restricted resident network selection based on the satellite network selection information and the NTN network selection strategy.

[0034] Among them, the NAS layer refers to the functional layer in the UE that is responsible for storing network configuration data, user identification information, and processing network selection-related protocols. It assumes the dual responsibilities of data management and protocol execution, and provides data support and a logical operating environment for the network selection process. The protocol stack is a collection of multi-layer communication protocols, which is used to standardize the data transmission format, interaction process, and signal processing rules between the UE and the satellite to ensure the orderly transmission of communication instructions and data. The no-coverage area is the spatial range where the UE cannot receive satellite communication signals. Within this area, the UE cannot establish an effective communication connection with any satellite and is in a communication interruption or waiting to connect state. The coverage area is the spatial range where the UE can receive satellite communication signals. Within this area, the UE can establish a communication link with the satellite through signal interaction to achieve data transmission and service access.

[0035] When the protocol stack of the NAS layer initiates restricted resident network selection based on the satellite network selection information and the NTN network selection strategy, it is not necessary to perform full-band scanning, and stops when any adjacent satellite is determined.

[0036] It's understandable that when initiating restricted resident network selection, the NAS layer protocol stack operates based on satellite network selection information and the NTN network selection strategy. Unlike traditional full-band scanning, this process does not require a comprehensive search of all possible communication bands. Instead, the protocol stack performs a targeted search based on pre-set adjacent satellite information and immediately stops the subsequent search process once any eligible adjacent satellite is identified. This approach focuses on valid information, avoiding redundant scanning of invalid bands, significantly reducing network selection time and terminal resource usage, effectively improving network selection efficiency and ensuring that the UE can quickly complete a resident connection with the satellite network.

[0037] like Figure 2 As shown, when the UE turns on the NAS layer protocol stack or returns to the coverage area from the non-coverage area, the NAS layer protocol stack initiates restricted resident network selection based on the satellite network selection information and the NTN network selection strategy, specifically including: When the UE starts the protocol stack of the NAS layer or returns to the coverage area from the non-coverage area, the NAS layer reads the PLMN list in the user identification card and configuration file of the UE and prioritizes the PLMNs in the PLMN list; The UE interprets the system message sent by the serving satellite, obtains the satellite network selection information of the adjacent satellite, combines the user PLMN list, determines the first adjacent satellite, and directly initiates registration; When the serving satellite is away from the UE, a change of the second adjacent satellite is initiated according to the RRC state.

[0038] When the UE starts the NAS layer protocol stack or returns to a signal-receivable area from an area where it cannot receive signals, the NAS layer protocol stack will start the restricted resident network selection process based on satellite network selection information and NTN network selection strategy. The specific operation process is as follows: When the UE starts the NAS layer protocol stack, or enters a covered area from a non-covered area, the NAS layer will first read the PLMN list stored in the UE's user identification card and configuration file, and prioritize the networks in the list, thereby providing a clear user preference basis for subsequent network selection, ensuring that the network selection process fits the user's network usage habits and needs.

[0039] The UE then parses the system message sent by the serving satellite to obtain network selection information for neighboring satellites. Combined with the user's sorted PLMN list, it selects the first neighboring satellite with the highest match and directly initiates registration. As the serving satellite gradually moves away from the UE, the system initiates a change process for the second neighboring satellite based on the UE's RRC (Radio Resource Control) status to ensure communication link continuity. This process precisely matches user network preferences with satellite information, eliminating redundant steps and improving network selection efficiency while ensuring communication stability.

[0040] The obtaining of the satellite network selection information of the adjacent satellite, combining the information with the user PLMN list, determining the first adjacent satellite and directly initiating registration specifically includes: Acquire the satellite network selection information of the adjacent satellite, and extract PLMN information from the satellite network selection information; The PLMN information of the neighboring satellite in the PLMN list is selected, the neighboring satellite corresponding to the PLMN information with the highest priority is determined to be the first neighboring satellite, and registration is directly initiated.

[0041] In the process of determining the first adjacent satellite and initiating registration, it is first necessary to obtain the network selection information of the adjacent satellite and extract the PLMN information of the adjacent satellite from the information.

[0042] The UE then compares the extracted PLMN information for neighboring satellites with its stored user PLMN list. This list, derived from the user's identity card and configuration files, provides a visual representation of the UE's preference for different networks. During this comparison, the UE selects only the PLMN information for neighboring satellites in this list, ensuring that the selected satellite network is compatible with the UE's network capabilities.

[0043] After filtering out compatible PLMN information, the UE determines the highest-priority PLMN according to the priority sorting rules in the list. The adjacent satellite corresponding to this PLMN information is designated as the first adjacent satellite. The UE then directly initiates a registration request to this satellite, skipping the redundant verification steps in the traditional network selection process. This precise matching and priority-driven selection method ensures that the selected satellite not only meets the user's network preferences but also quickly establishes a communication connection, effectively improving the efficiency and accuracy of network selection and registration.

[0044] When the UE detects that RSRP (Reference Signal Receiving Power), RSRQ (Reference Signal Received Quality), and SINR (Signal to Interference plus Noise Ratio) are respectively lower than a preset power threshold, a preset quality threshold, and a preset noise ratio threshold, or when the distance between the serving satellite and the UE calculated based on the time advance and the frequency offset exceeds a safety distance threshold, it is determined that the serving satellite is away from the UE.

[0045] The initiating the change of the second adjacent satellite according to the RRC state specifically includes: When the RRC state is an idle state, the UE makes a reselection request and initiates reselection of the second neighboring satellite; when the RRC state is a connected state, the serving satellite notifies the UE to initiate switching of the second neighboring satellite.

[0046] During satellite communications, the UE must monitor the communication status of the serving satellite in real time to accurately determine whether the serving satellite is moving away. Specifically, if the UE detects that the received reference signal strength is lower than a preset strength standard, the reference signal quality parameter is lower than a preset quality standard, or the ratio of the useful signal strength to the interference noise intensity is lower than a preset noise ratio standard, it indicates that the signal quality of the serving satellite can no longer meet stable communication requirements.

[0047] In addition, the UE will also calculate the actual distance between itself and the service satellite through parameters such as time advance and signal frequency offset. If the distance exceeds the pre-set safety range threshold, it will also be determined that the service satellite is moving away from the UE.

[0048] This multi-indicator joint judgment method can comprehensively and accurately identify the distance status of the service satellite, providing a reliable basis for subsequent satellite switching.

[0049] When it is determined that the serving satellite has not moved away, the UE continues to register on the current first neighboring satellite.

[0050] When it is determined that the serving satellite is moving away, the process of changing the second adjacent satellite can be initiated based on the UE's current RRC state to ensure communication continuity. The RRC state reflects the connection status between the UE and the satellite and is mainly divided into two types: idle state and connected state.

[0051] If the UE is in the idle state (i.e., without an established data transmission connection with the serving satellite), it will proactively request a reselection and autonomously initiate the reselection process for a second adjacent satellite. Based on pre-acquired adjacent satellite network selection information and its own stored network priority list, the UE quickly selects a suitable second adjacent satellite and completes the reselection. This entire process requires no additional intervention from the serving satellite, ensuring efficient satellite handover even in a disconnected state.

[0052] If the UE is in the connected state (i.e., actively transmitting data with the serving satellite), the serving satellite proactively sends a command to the UE, instructing it to initiate a handover to the second adjacent satellite. This handover mechanism, led by the serving satellite, eliminates the UE's measurement process and directly executes the handover based on pre-set adjacent satellite information. This avoids the time delay and resource consumption associated with UE-independent measurements, ensures seamless handover during data transmission, and minimizes the possibility of communication interruptions.

[0053] Through the above method, when the service satellite is far away, the optimal change method can be selected according to the actual connection status of the UE, which not only ensures the continuity of communication but also reduces the power consumption of the UE by simplifying the process.

[0054] If the UE fails to reselect or handover to the second adjacent satellite, the service satellite change fails and the system attempts to interpret the satellite's system message. If the interpretation is successful, the system obtains the satellite network selection information of other adjacent satellites and attempts to initiate access on other adjacent satellites. If the interpretation fails, the UE initiates restricted resident network selection and searches for a new serving satellite.

[0055] When it is determined that the UE has successfully reselected or switched to the second adjacent satellite, the service satellite has been changed successfully. At this time, the second adjacent satellite continues to serve as the new service satellite. The UE actively initiates a position update request to the new service satellite and transmits the update information to the satellite core network through the new service satellite to maintain communication continuity.

[0056] like Figure 3 FIG. 1 is a system block diagram of an NTN satellite communication network selection system provided by an embodiment of the present invention. The system includes: An information storage module is used to store satellite network selection information of adjacent satellites on the serving satellite side; a policy determination module, configured to add an NTN preference switch to the UE interface; when the UE turns on the NTN preference switch, the NTN network selection policy is preferentially adopted; and when the UE does not turn on the NTN preference switch and the UE speed meets a preset speed condition, the NTN preference mode is automatically switched to and the NTN network selection policy is preferentially adopted; The network selection initiating module is configured to initiate restricted resident network selection based on the satellite network selection information and the NTN network selection strategy when the UE starts the NAS layer protocol stack or returns to the coverage area from the non-coverage area.

[0057] Figure 3 The apparatus of the embodiment shown can be used to perform Figure 1 The implementation principles and technical effects of the steps in the method embodiment shown are similar and will not be repeated here.

[0058] An electronic device includes a memory and a processor, wherein the memory stores a computer program. When the processor runs the computer program stored in the memory, the processor executes the steps of any one of the above-mentioned methods for selecting a network for NTN satellite communications.

[0059] like Figure 4 FIG. 4 is a schematic diagram of the hardware structure of an electronic device provided by an embodiment of the present invention. The electronic device 40 includes: a processor 41, a memory 42 and a computer program; The memory 42 is used to store the computer program, which may also be a flash memory. The computer program is, for example, an application program or a functional module for implementing the above method.

[0060] The processor 41 is configured to execute the computer program stored in the memory to implement the various steps performed by the device in the above method. For details, please refer to the relevant description in the above method embodiment.

[0061] Optionally, the memory 42 may be independent or integrated with the processor 41 .

[0062] When the memory 42 is a device independent of the processor 41, the device may further include: The bus 43 is used to connect the memory 42 and the processor 41 .

[0063] A readable storage medium having a computer program stored therein, wherein the computer program, when executed by a processor, is used to implement the steps of any one of the above-mentioned methods for selecting a network for NTN satellite communications.

[0064] The readable storage medium may be a computer storage medium or a communication medium. Communication media include any medium that facilitates the transfer of computer programs from one location to another. Computer storage media may be any available medium that can be accessed by a general-purpose or special-purpose computer. For example, a readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium may also be an integral part of the processor. The processor and the readable storage medium may be located in an application-specific integrated circuit (ASIC). In addition, the ASIC may be located in a user device. Of course, the processor and the readable storage medium may also exist as discrete components in a communication device. The readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like.

[0065] The present invention also provides a program product, which includes execution instructions stored in a readable storage medium. At least one processor of a device can read the execution instructions from the readable storage medium, and at least one processor executes the execution instructions so that the device implements the methods provided in the various embodiments described above.

[0066] In the embodiments of the above-mentioned devices, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASICs), etc. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly executed by a hardware processor or by a combination of hardware and software modules within the processor.

[0067] Through the introduction of the above embodiments, the present invention uses an NTN satellite communication network selection method and system to store satellite network selection information of adjacent satellites on the serving satellite side; add an NTN preference switch to the UE interface. When the UE turns on the NTN preference switch, the NTN network selection strategy is preferentially adopted. When the UE does not turn on the NTN preference switch and the UE speed meets the preset speed condition, it automatically switches to the NTN preference mode and preferentially adopts the NTN network selection strategy; when the UE turns on the NAS layer protocol stack or returns to the coverage area from an uncovered area, the NAS layer protocol stack initiates restricted resident network selection based on the satellite network selection information and the NTN network selection strategy, thereby significantly shortening the UE network selection dwell time and effectively solving the problems of low network selection efficiency and excessive UE power consumption in NTN satellite communication scenarios with traditional network selection strategies.

[0068] The present invention can store key information of adjacent satellites on the satellite side, and combined with UE strategy optimization, ensure the accuracy and efficiency of the network selection process. When the UE turns on the NTN preference switch or the UE speed meets the preset speed conditions, the NTN network selection strategy is preferentially adopted, so that the NTN network selection strategy and the TN network selection strategy can be decoupled to avoid mutual interference. The restricted resident network selection mode eliminates the need for full-band scanning and stops once a qualified satellite is determined, greatly shortening the network selection time. Based on the direct matching of the user network list and satellite information, the traditional RPLMN stage is skipped to ensure that the appropriate satellite can be matched at any time and quickly registered when the operator's network deployment is mature. When the service satellite is far away, reselection or switching is directly initiated according to the connection status, omitting the UE measurement process, further reducing time consumption and power consumption. Ultimately, through the collaboration between the satellite and the terminal, the network selection residence time is greatly shortened, the satellite mobility and wide coverage characteristics are adapted, and the stability of satellite communications and user equipment are improved.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for selecting a network for NTN satellite communication, characterized in that: The method comprises: Storing satellite network selection information of adjacent satellites on the serving satellite side; Add an NTN preference switch to the UE interface. When the UE turns on the NTN preference switch, the NTN network selection strategy is preferentially adopted. When the UE does not turn on the NTN preference switch and the UE speed meets the preset speed condition, the UE automatically switches to the NTN preference mode and preferentially adopts the NTN network selection strategy. When the UE starts the protocol stack of the NAS layer or returns to the coverage area from the non-coverage area, the protocol stack of the NAS layer initiates restricted resident network selection based on the satellite network selection information and the NTN network selection policy.

2. The NTN satellite communication network selection method according to claim 1, wherein: The serving satellite periodically sends the satellite network selection information to the UE in the form of a system message, or when the UE actively requests the satellite network selection information, the serving satellite sends the satellite network selection information to the UE through a preset signaling; The satellite network selection information includes band information, ARFCN information, PLMN information, over-the-top time and ephemeris information.

3. The NTN satellite communication network selection method according to claim 2, wherein: The over-the-top time is the time when the adjacent satellite arrives at the coverage area.

4. The NTN satellite communication network selection method according to claim 1, wherein: The preset speed condition is that the UE speed exceeds 500 km / h.

5. The NTN satellite communication network selection method according to claim 1, wherein: When the protocol stack of the NAS layer initiates restricted resident network selection based on the satellite network selection information and the NTN network selection strategy, it is not necessary to perform full-band scanning, and stops when any adjacent satellite is determined.

6. The NTN satellite communication network selection method according to claim 1, characterized in that: When the UE starts the NAS layer protocol stack or returns to the coverage area from the non-coverage area, the NAS layer protocol stack initiates restricted resident network selection based on the satellite network selection information and the NTN network selection strategy, specifically including: When the UE starts the protocol stack of the NAS layer or returns to the coverage area from the non-coverage area, the NAS layer reads the PLMN list in the user identification card and configuration file of the UE and prioritizes the PLMNs in the PLMN list; The UE interprets the system message sent by the serving satellite, obtains the satellite network selection information of the adjacent satellite, combines the user PLMN list, determines the first adjacent satellite, and directly initiates registration; When the serving satellite is away from the UE, a change of the second adjacent satellite is initiated according to the RRC state.

7. The NTN satellite communication network selection method according to claim 6, characterized in that: The obtaining of the satellite network selection information of the adjacent satellite, combining the information with the user PLMN list, determining the first adjacent satellite and directly initiating registration specifically includes: Acquire the satellite network selection information of the adjacent satellite, and extract PLMN information from the satellite network selection information; The PLMN information of the neighboring satellite in the PLMN list is selected, the neighboring satellite corresponding to the PLMN information with the highest priority is determined to be the first neighboring satellite, and registration is directly initiated.

8. The NTN satellite communication network selection method according to claim 6, characterized in that: When the UE detects that RSRP, RSRQ, and SINR are respectively lower than a preset power threshold, a preset quality threshold, and a preset noise ratio threshold, or the distance between the serving satellite and the UE calculated based on the time advance and the frequency offset exceeds a safety distance threshold, it is determined that the serving satellite is far away from the UE.

9. The NTN satellite communication network selection method according to claim 6, characterized in that: The initiating the change of the second adjacent satellite according to the RRC state specifically includes: When the RRC state is an idle state, the UE makes a reselection request and initiates reselection of the second neighboring satellite; when the RRC state is a connected state, the serving satellite notifies the UE to initiate switching of the second neighboring satellite.

10. An NTN satellite communication network selection system, applied to an NTN satellite communication network selection method according to any one of claims 1 to 9, characterized in that: The system comprises: An information storage module is used to store satellite network selection information of adjacent satellites on the serving satellite side; a policy determination module, configured to add an NTN preference switch to the UE interface; when the UE turns on the NTN preference switch, the NTN network selection policy is preferentially adopted; and when the UE does not turn on the NTN preference switch and the UE speed meets a preset speed condition, the NTN preference mode is automatically switched to and the NTN network selection policy is preferentially adopted; The network selection initiating module is configured to initiate restricted resident network selection based on the satellite network selection information and the NTN network selection strategy when the UE starts the NAS layer protocol stack or returns to the coverage area from the non-coverage area.

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