Cell identification and paging method and device suitable for non-ground network

Abstract

The invention discloses a cell identification and paging method and device suitable for a non-ground network, and belongs to the technical field of communication. The method comprises the following steps: acquiring ephemeris data and beam parameters of a satellite, and determining a real-time coverage area of the satellite to the ground; matching the real-time coverage area of the satellite with the coverage area of the physical cell to determine a coverage overlapping relationship between the real-time coverage area of the satellite and the coverage area of the physical cell; generating or updating a corresponding logical cell global identifier (LCGI) based on the coverage overlapping relationship and storing the LCGI in an identifier list; the LCGI comprises a geographical attribute field for identifying the geographical attribution of the physical cell and a satellite logic identification field for identifying the satellite identity information of the service physical cell; and in response to a paging request for a target terminal, querying the LCGI currently corresponding to the target physical cell from the identifier list according to the information of the target physical cell associated with the target terminal, thereby determining a target satellite currently serving the target physical cell and sending a paging message to the target satellite.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a cell identification and paging method and apparatus applicable to non-terrestrial networks. Background Technology

[0002] With the explosive growth in demand for integrated air-space-ground communication, non-terrestrial networks (NTNs), thanks to the wide coverage of satellites (Low Earth Orbit (LEO), Medium Earth Orbit (MEO), Geostationary Orbit (GEO), etc.), have become a core technology for filling the blind spots of terrestrial networks and ensuring communication in remote areas and emergencies.

[0003] However, unlike the terrestrial network model where "one base station corresponds to one fixed physical cell, and the Cell Global Identifier (CGI) is permanently bound to geographical coordinates," the high-speed movement of satellites in NTN networks (e.g., low-Earth orbit satellites have an on-orbit speed of 7.8 km / s) causes the satellite coverage area to change dynamically with orbital motion (e.g., the coverage area of ​​a low-Earth orbit satellite can move more than 1.5 km every 200 ms). This will cause the traditional Cell Global Identifier (CGI) and Tracking Area (TA) management mechanisms to fail, resulting in two core problems: First, cell identifier association fails. In traditional terrestrial networks, the CGI (composed of Mobile Country Code (MCC), Mobile Network Code (MNC), Tracking Area Code (TAC), and Physical Cell ID) is directly bound to a fixed physical cell, allowing the network to accurately locate the cell's geographical area. However, this logic completely fails in NTN networks. On one hand, if a fixed physical cell (fixed Earth cell scenario) is used, satellite coverage will periodically overlap with multiple physical cells, and the overlap relationship changes in real time with orbital movement, making it impossible for the CGI to track which satellite is serving which physical cell. On the other hand, if a moving physical cell (moving Earth cell scenario) is used, the geographical area of ​​the physical cell changes dynamically with the satellite's trajectory, causing the TAC in the CGI to become disconnected from the actual coverage area of ​​the physical cell. The network cannot determine the tracking area (TA) to which the cell belongs through the CGI, and location management is also impossible.

[0004] Secondly, paging resources are severely wasted. Terrestrial network paging mechanisms are based on TA (Target Area) broadcasting. The core network determines the TA based on the UE's last known location and sends paging requests to all base stations within that TA. These base stations then broadcast the paging signal within their coverage cells. However, in NTN (Network Telecommunication Network) networks, this mechanism leads to significant resource redundancy. Because the relationship between satellite coverage and the TA is unclear, the core network can only send paging requests to all satellites that might serve the target TA, sometimes even requiring extended TA coverage for retries. If this TA-based broadcast paging method is continued, a large number of unrelated satellites and cells will receive redundant signals, drastically reducing air interface resource utilization.

[0005] Currently, the industry has disclosed four mainstream technologies for cell identification and paging methods in NTN networks: 3GPP ground stationary tracking zone technology, satellite beam static identification scheme, core network centralized mapping scheme, and grid-coded routing association scheme.

[0006] The 3GPP Geostationary Tracking Area (TAI) technology is a standard solution proposed by 3GPP to address the issue of tracking areas (TA) drifting with satellite movement in NTN. Its core logic is "fixed geographic TA grid + dynamic Mapped TAI mapping". The technology is architecturally divided into three layers: the geographic TA grid layer divides the Earth's surface into a fixed 100km × 100km grid according to latitude and longitude, with each grid assigned a unique geostationary TAI, and the grid boundaries aligned with national borders and operator coverage areas; in the beam-TA mapping layer, the satellite gateway calculates the current beam coverage's Static TAI in real time based on ephemeris data (orbital parameters, beam half-power angle) and generates a mapped TAI; in the broadcast and decision layer, the satellite broadcasts the Mapped TAI in System Information Block (SIB19), and the UE autonomously decides whether to initiate a Tracking Area Update (TAU) by comparing the intersection of its registered TA list and the broadcast Mapped TAI. To reduce the ping-pong effect of TA boundary handover, the technology supports two broadcast strategies: single TAC hard handover (the broadcast Mapped TAI is replaced after the beam fully enters the new TA) and multi-TAC soft handover (the Mapped TAI of 2-3 adjacent TAs is broadcast simultaneously when the beam crosses the TA boundary, and the UE can camp on any TA), thereby maintaining the relative binding between the TA and the geographical area in satellite mobile scenarios.

[0007] The satellite beam static identification scheme is a simplified approach adopted by constellation vendors such as Starlink and OneWeb for rapid NTN deployment. Its core logic is that a beam is a physical cell, and the identifier is bound to the satellite's identity. This scheme directly defines each beam of a satellite as a physical cell and assigns a fixed Physical Cell ID (PCI) to each beam. The identification structure uses a combination of "constellation ID + satellite on-orbit ID + beam ID" (e.g., "001-1234-001" represents the first beam of satellite 1234 in the Starlink constellation), uniquely distinguishing different beams from different satellites. The core network predicts the Tracking Area (TA) covered by each beam using satellite ephemeris data and constructs a static "satellite ID-TA" mapping table. When a paging request is initiated, the core network queries this mapping table based on the UE's registered TA to determine the possible serving satellite and issue a paging request. In beam switching scenarios, the UE determines signal strength based on the Reference Received Power (RSRP). When switching to an adjacent beam, the identifier of the new beam needs to be re-parsed and an RRC connection established to maintain communication continuity.

[0008] The core network centralized mapping scheme is an NTN identification and paging solution proposed by equipment vendors such as Huawei and Ericsson. Its core logic is "AMF-led global mapping table management," which entrusts the calculation and maintenance of the "satellite-physical cell" association to the Access and Mobility Management Function (AMF) of the core network for centralized processing. The specific process of this scheme includes: the satellite gateway reports satellite ephemeris data (location, beam coverage range) and the latitude and longitude boundary information of physical cells to the AMF every 100ms; the AMF calculates the coverage overlap between the satellite beam and the physical cell based on the reported data, constructs and updates the "satellite ID-physical cell ID-TAC" global mapping table in real time, and stores it in the core network database; when the core network initiates a paging, it queries the mapping table through the physical cell ID last registered by the UE, accurately locates the serving satellite, and sends a paging request; when the satellite beam moves, causing changes in coverage relationships, the AMF updates the mapping table and synchronizes it to the relevant base stations and UEs to ensure the consistency of identification association information across the entire network. Some derivative solutions also introduce an "access permission mechanism," in which the AMF dynamically issues beam access permissions to the UE based on a mapping table, restricting unauthorized UEs from accessing hot spot beams in order to optimize resource allocation.

[0009] The grid-coded routing association scheme is a technical solution proposed in academia for the collaborative optimization of NTN identifiers and routes. Its core logic is "geospatial grid coding + routing-identifier association," typically implemented based on the BeiDou Earth Surface Coding Standard (GB / T 39943-2021). This scheme first divides the Earth's surface into a non-equivalent quadtree grid (usually 10km × 10km granularity), assigning each grid a unique 64-bit code containing geographical attribute information such as latitude, longitude, and altitude. Based on the periodicity of satellite orbits, the satellite's trajectory for the next 24 hours is mapped to a continuous grid sequence, constructing a three-dimensional routing table of "satellite ID - grid code - time slice," recording the correspondence between satellites and grids in different time slices. Cell identifiers directly reuse grid codes, making the identifiers naturally associated with geographical areas. When the core network initiates a paging request, it first queries the routing table using the grid code registered by the UE to determine the serving satellite for the corresponding time slice, and then sends a paging request to the target satellite. Some optimization schemes also introduce a distance-triggered update mechanism. The UE calculates the real-time distance with the satellite through grid coding. When the distance exceeds the threshold, it actively initiates a location update to reduce unnecessary signaling overhead.

[0010] The 3GPP ground stationary tracking area (TA) technology has three core defects: First, the identification system is missing. It only binds the tracking area (TA) to the geographical area and does not establish a "satellite-physical cell" association. When multiple satellites cover the same TA at the same time, the network side cannot distinguish the specific serving satellite, resulting in paging needing to be broadcast to all satellites within the TA, and the air interface resource utilization rate is only 50%-60%. Second, cross-border scenario adaptation fails. The mapped TAI only updates the tracking area code (TAC) and does not adjust the mobile country code (MCC) and mobile network code (MNC) simultaneously. When the satellite crosses the border, the network affiliation registered by the UE conflicts with the actual geographical location, violating the requirements of emergency calls and regional supervision in the ITU-T E.212 standard. Third, the multi-TAC broadcast overhead is too high. In the soft handover strategy, a single cell needs to broadcast up to 12 mapped TAIs, which increases the length of the system information block SIB19 by more than 30%, and the UE resolution latency increases from 50ms to 120ms. In addition, continuous listening to multiple TA lists increases the terminal power consumption by 25%.

[0011] The shortcomings of the satellite beam static identification scheme are mainly reflected in its insufficient adaptation to the dynamic characteristics of NTN: First, the geographical correlation is completely broken. The identifier is only bound to the satellite identity (constellation ID + satellite ID + beam ID) and is unrelated to geographical attributes such as MCC / MNC / TAC. When the beam drifts from one country to another, the identifier cannot reflect the change in network affiliation, resulting in the inability to locate the user's physical location for services such as legitimate eavesdropping and regional billing, which violates the communication regulatory requirements of multiple countries. Second, the paging accuracy is extremely low. The core network relies on ephemeris prediction of the TA covered by the beam, but low-orbit satellites are affected by atmospheric drag and have an orbital deviation of ±5km. The probability of paging mistransmission is as high as 15%-20%. In extreme scenarios, paging needs to be retransmitted to the satellites of the three adjacent TAs, with a total delay of up to 1.5s. Third, beam switching interruption is severe. When the UE switches to an adjacent beam, it needs to re-parse the new beam identifier and establish an RRC connection, with a service interruption time of 200-300ms, which far exceeds the 50ms interruption tolerance threshold of 5G real-time services.

[0012] The core problem with the centralized mapping scheme in the core network lies in concentrating complex logic in the core network, leading to performance bottlenecks: First, the core network is overburdened and has extremely poor scalability. A single low-Earth orbit satellite needs to update coverage data every 100ms. If the constellation size reaches 12,992 satellites (the number of planned constellations announced by Starlink), the AMF needs to process 120,000 update requests per second, far exceeding the processing capacity of existing equipment of 50,000 requests per second. Large-scale deployment can easily cause core network congestion. Second, the synchronization latency is high, and dynamic adaptation fails. The end-to-end latency from the gateway reporting data to the AMF updating the mapping table is 50-100ms, while the low-Earth orbit satellite beam moves 1.5km every 200ms. The mapping table update lags behind the actual coverage changes, and the paging target satellite error rate exceeds 25%. Third, the robustness is weak. It relies entirely on the ephemeris data provided by the satellite gateway. If GNSS interference occurs, the mapping table cannot be updated, and the entire paging system will be paralyzed, failing to meet the 99.99% availability requirement of NTN emergency communication.

[0013] The shortcomings of the mesh coding routing association scheme stem from the neglect of identifier and protocol compatibility: First, the identifier is completely decoupled from the 3GPP protocol. Mesh coding is a custom format that is incompatible with the 3GPP standard CGI structure, requiring the UE to deploy an additional mesh decoding module, making it impossible to reuse existing terminal hardware. Second, paging efficiency is low, with cumulative latency. Paging requires a multi-step process of "UE mesh coding → routing table lookup → satellite determination," which adds one more database query compared to direct positioning, resulting in a latency of 50-100ms, and a total paging latency of 400-500ms, which cannot meet real-time service requirements. Third, dynamic adaptation capability is weak. The mesh coding granularity is generally fixed at 10km×10km, and cannot be dynamically adjusted according to the satellite beamwidth (low-orbit satellite beamwidth is usually 1-5°, corresponding to 5-25km on the ground). When the narrow beam only covers half a mesh, the coverage overlap judgment error is ≥5km, affecting the association accuracy.

[0014] There is currently no effective solution to the technical problems existing in the above-mentioned existing technologies, such as the confusion of cell identifiers and geographical areas caused by the high-speed movement of satellites in non-terrestrial network scenarios, and the serious waste of air interface resources caused by the need for large-scale broadcasting for paging. Summary of the Invention

[0015] The embodiments of this disclosure provide a cell identification and paging method and apparatus applicable to non-terrestrial networks, so as to at least solve the technical problems existing in the prior art, such as the confusion of identification association caused by the high-speed movement of satellites leading to the disconnection between cell identification and geographical area, and the serious waste of air interface resources caused by the need for large-scale broadcasting for paging in non-terrestrial network scenarios.

[0016] According to one aspect of the present disclosure, a cell identification and paging method applicable to non-terrestrial networks is provided, applied to a base station in a non-terrestrial network. The method includes: acquiring ephemeris data of at least one satellite; determining the real-time coverage area of ​​the satellite over the ground based on the ephemeris data and the beam parameters of the satellite; matching the real-time coverage area of ​​the satellite with the coverage area of ​​at least one physical cell to determine the coverage overlap relationship between the satellite and the physical cell; generating or updating a corresponding logical cell global identifier based on the coverage overlap relationship and storing it in a locally maintained identifier list; wherein the logical cell global identifier includes a geographic attribute field identifying the geographic affiliation of the physical cell and a satellite logical identifier field identifying the satellite identity information serving the physical cell; responding to a paging request for a target terminal, querying the logical cell global identifier currently corresponding to the target physical cell from the identifier list based on the information of the target physical cell associated with the target terminal; determining the target satellite currently serving the target physical cell based on the satellite identity information carried in the queried logical cell global identifier, and sending a paging message for the target terminal to the target satellite.

[0017] According to another aspect of the present disclosure, a storage medium is also provided, the storage medium including a stored program, wherein, when the program is executed, a processor performs any of the methods described above.

[0018] According to another aspect of the present disclosure, a cell identification and paging device suitable for non-terrestrial networks is also provided, comprising: an ephemeris data acquisition module for acquiring ephemeris data of at least one satellite; a real-time coverage area determination module for determining the real-time coverage area of ​​the satellite over the ground based on the ephemeris data and the beam parameters of the satellite; a coverage area matching module for matching the real-time coverage area of ​​the satellite with the coverage area of ​​at least one physical cell to determine the coverage overlap relationship between the satellite and the physical cell; and a global identifier generation or update module for generating or updating a corresponding logical cell global identifier based on the coverage overlap relationship and storing it locally. The maintained identifier list includes a global identifier for a logical cell, comprising a geographic attribute field identifying the geographic affiliation of the physical cell and a satellite logical identifier field identifying the satellite identity information serving the physical cell. A global identifier query module is configured to, in response to a paging request for a target terminal, query the global identifier of the logical cell currently corresponding to the target physical cell from the identifier list based on the information of the target physical cell associated with the target terminal. A target satellite determination module is configured to, based on the satellite identity information carried in the queried global identifier of the logical cell, determine the target satellite currently serving the target physical cell and send a paging message for the target terminal to the target satellite.

[0019] According to another aspect of the present disclosure, a cell identification and paging device suitable for non-terrestrial networks is also provided, comprising: a processor; and a memory connected to the processor, configured to provide the processor with instructions for processing the following steps: acquiring ephemeris data of at least one satellite; determining the real-time coverage area of ​​the satellite over the ground based on the ephemeris data and the beam parameters of the satellite; matching the real-time coverage area of ​​the satellite with the coverage area of ​​at least one physical cell to determine the coverage overlap relationship between the satellite and the physical cell; generating or updating a corresponding logical cell global identifier based on the coverage overlap relationship and storing it in a locally maintained identifier list; wherein the logical cell global identifier includes a geographic attribute field identifying the geographic affiliation of the physical cell and a satellite logical identifier field identifying the satellite identity information serving the physical cell; responding to a paging request for a target terminal, querying the logical cell global identifier currently corresponding to the target physical cell from the identifier list based on the information of the target physical cell associated with the target terminal; determining the target satellite currently serving the target physical cell based on the satellite identity information carried in the queried logical cell global identifier, and sending a paging message for the target terminal to the target satellite.

[0020] This application first obtains ephemeris data from at least one satellite from a base station in a non-terrestrial network, providing core input for subsequent coverage area calculation and dynamic mapping. Then, based on the ephemeris data and satellite beam parameters, the real-time coverage area of ​​the satellite over the ground is calculated, laying a dynamic and quantitative geometric foundation for accurately associating satellites and ground cells. Next, the calculated real-time satellite coverage area is matched with the coverage area of ​​the physical cell to determine the coverage overlap relationship, providing a basis for dynamically establishing or dissolving service associations. Subsequently, based on this coverage overlap relationship, a corresponding Logical Cell Global Identifier (LCGI) is generated or updated and stored in an identifier list maintained locally by the base station. This LCGI integrates the geographical attribute fields of the physical cell and satellite identity information, thereby constructing a dynamic mapping database that can reflect the "satellite-physical cell" service relationship in real time. When the base station responds to a paging request for a target terminal, to locate the target terminal, it queries the aforementioned local identifier list for the currently corresponding LCGI based on the information of the target physical cell associated with the target terminal. Finally, based on the satellite identity information carried in the retrieved LCGI, the target satellite currently serving the target physical cell is identified, and a paging message is sent to the target satellite to complete the precise paging.

[0021] Therefore, this application achieves real-time and accurate binding of the identity of a high-speed moving satellite to its instantaneously served geographical area by performing dynamic calculation and mapping association of satellite coverage locally at the base station and performing precise query and paging routing based on the generated Logical Cell Global Identifier (LCGI). This optimizes traditional broadcast paging based on tracking areas into precise unicast paging based on specific satellites. This solves the technical problem in existing technologies where, in non-terrestrial network scenarios, the high-speed movement of satellites causes the cell identifier to become disconnected from the geographical area, resulting in identifier association confusion and a severe waste of air interface resources caused by the need for wide-area broadcasting for paging. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this application, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings: Figure 1 This is a flowchart of a cell identification and paging method applicable to non-terrestrial networks according to Embodiment 1 of this disclosure; Figure 2 This is a full flowchart of the base station-led dynamic mapping according to Embodiment 1 of this disclosure; Figure 3 This is a timing diagram of the interaction between the base station and the NTN gateway according to Embodiment 1 of this disclosure; Figure 4 This is a paging interaction flowchart between the base station and the UE according to Embodiment 1 of this disclosure; Figure 5 This is a schematic diagram of a cell identification and paging device applicable to non-terrestrial networks according to Embodiment 2 of this application; Figure 6 This is a schematic diagram of a cell identification and paging device applicable to non-terrestrial networks according to Embodiment 3 of this application. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of this disclosure, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] Terminology Explanation: NTN: Non-Terrestrial Network; CGI: Cell Global Identity; LCGI: Logical Cell Global Identity; UE: User Equipment, also known as a terminal; TAC: Tracking Area Code; IoU: Intersection over Union; RSRP: Reference Signal Received Power, the strength of the satellite reference signal received by the UE. In this scheme, it is mainly used to assist in IoU determination (such as RSRP≥-105dBm to verify coverage effectiveness) and avoid misjudgment when GNSS signal is lost. AMF: Access and Mobility Management Function, a core network element, which initiates paging requests, receives LCGI synchronization information, and determines the paging range based on LCGI. RAN: Radio Access Network, the network layer to which the base station in the article belongs, is responsible for LCGI dynamic mapping and paging scheduling, and is the core execution layer of NTN identification and paging technology; SSP: Satellite Status Protocol, a custom application layer protocol used for transmitting satellite ephemeris and beam data via the Nt interface. It employs TLV encoding for easy expansion. RRC: Radio Resource Control, refers to the key signaling protocol layer between the terminal (UE) and the access network (base station), responsible for control functions such as connection establishment, maintenance, and release; AMF: Access and Mobility Management Function, refers to the core network element in the 5G core network responsible for terminal access and mobility management (such as location registration and paging initiation).

[0026] Example 1 According to this embodiment, a method embodiment for cell identification and paging methods applicable to non-terrestrial networks is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0027] Under the above operating environment, according to the first aspect of this embodiment, a cell identification and paging method applicable to non-terrestrial networks is provided. Figure 1 A flowchart illustrating the method is shown below. (Refer to...) Figure 1 As shown, the method includes: S101: Acquire ephemeris data from at least one satellite; S102: Based on the ephemeris data and the beam parameters of the satellite, determine the real-time coverage area of ​​the ground by the satellite; S103: Match the real-time coverage area of ​​the satellite with the coverage area of ​​at least one physical cell to determine the coverage overlap relationship between the satellite and the physical cell; S104: Based on the coverage overlap relationship, generate or update the corresponding logical cell global identifier and store it in a locally maintained identifier list; wherein, the logical cell global identifier includes a geographic attribute field that identifies the geographic affiliation of the physical cell and a satellite logical identifier field that identifies the satellite identity information serving the physical cell; S105: In response to a paging request for a target terminal, query the global identifier of the logical cell currently corresponding to the target physical cell from the identifier list based on the information of the target physical cell associated with the target terminal; S106: Based on the satellite identity information carried in the global identifier of the logical cell, determine the target satellite currently serving the target physical cell, and send a paging message for the target terminal to the target satellite.

[0028] In this embodiment of the invention, ephemeris data of at least one satellite is first acquired (corresponding to step S101). Specifically, the base station receives ephemeris data uploaded or forwarded by the satellite periodically (e.g., every 100 milliseconds) through a communication interface with a satellite gateway or the satellite itself. The ephemeris data includes at least parameters describing the satellite's orbital motion, such as the semi-major axis, eccentricity, inclination, right ascension of the ascending node, argument of perigee, and mean perigee, as well as the satellite's identification information. Thus, the base station obtains the basic data for calculating the satellite's real-time spatial position and motion state.

[0029] Then, based on the ephemeris data and the satellite's beam parameters, the real-time coverage area of ​​the satellite over the ground is determined (corresponding to step S102). Specifically, based on the received ephemeris data, the base station calculates the precise three-dimensional spatial position (geocentric inertial frame or Earth-fixed frame coordinates) of the satellite at the current time or a specified future time through orbital mechanics calculations (e.g., using an orbital model that considers perturbations). Subsequently, combining the satellite's beam parameters (such as beam pointing angle, half-power beamwidth, antenna gain model, etc.), the area formed by the specific beam of the satellite illuminating the Earth's surface is determined through geometric projection and a spatial coverage calculation model. This area is the real-time coverage area of ​​the satellite over the ground, which typically exhibits a dynamically changing geometric shape (such as a circle, ellipse, or irregular polygon). Thus, the abstract satellite orbit parameters are transformed into a specific, quantifiable ground service range, providing input for subsequent matching operations.

[0030] Next, the real-time coverage area of ​​the satellite is matched with the coverage area of ​​at least one physical cell to determine the coverage overlap relationship between the satellite and the physical cell (corresponding to step S101). Specifically, the base station pre-stores or configures the coverage range information of multiple ground physical cells it manages (e.g., defined as a list of polygon boundary point latitude and longitude or a center point plus radius). The base station analyzes and calculates the spatial geometric relationship between the calculated real-time coverage area (geometry) of the satellite and the coverage areas (geometry) of one or more physical cells, quantifying the degree of overlap between the two (e.g., calculating the overlap area ratio, determining inclusion or intersection relationships, etc.). Based on the quantification result, it compares it with a preset association / deassociation criterion to determine the coverage overlap relationship between the satellite and the physical cell. This relationship is used to indicate whether the two should establish a service association (e.g., overlap is higher than the establishment threshold), maintain the existing association (e.g., overlap is within the maintenance threshold), or deassociate (e.g., overlap is lower than the deassociation threshold).

[0031] Subsequently, based on the coverage overlap relationship, a corresponding logical cell global identifier is generated or updated and stored in a locally maintained identifier list. The logical cell global identifier includes a geographic attribute field identifying the geographical affiliation of the physical cell and a satellite logical identifier field identifying the satellite identity information serving the physical cell (corresponding to step S101). Specifically, when the matching result indicates that a service association needs to be established between a satellite and a physical cell, the base station generates a completely new logical cell global identifier. This identifier is a structured code. Its first part (geographic attribute field) originates from the inherent network affiliation information of the physical cell, such as its country code, mobile network code, and tracking area code. Its second part (satellite logical identifier field) originates from the identity information of the satellite providing the service, such as the satellite constellation identifier, the satellite's unique number within the constellation, and the identifier of the specific serving beam. If the matching result indicates that the association needs to be terminated, the corresponding identifier entry is deleted from the identifier list. All currently valid "satellite-physical cell" associations and their corresponding logical cell global identifiers are dynamically maintained in a database or list locally at the base station, which reflects the real-time status of network coverage relationships.

[0032] Next, in response to a paging request for the target terminal, the base station queries the global identifier of the logical cell currently associated with the target physical cell from the identifier list based on the information of the target physical cell associated with the target terminal (corresponding to step S101). Specifically, when the base station receives a paging request message from the core network, the message indicates the target terminal to be found (e.g., through its temporary or permanent identifier) ​​and usually carries the identifier information (or information that can be deduced) of the target physical cell where the target terminal was last registered or is known to be located. The base station uses the identifier of the target physical cell as the query key to query the identifier list it dynamically maintains locally, thereby quickly retrieving which (or which) global identifiers of the logical cell are associated with this target physical cell at the current time.

[0033] Finally, based on the satellite identity information carried in the retrieved logical cell global identifier, the target satellite currently serving the target physical cell is determined, and a paging message for the target terminal is sent to the target satellite (corresponding to step S101). Specifically, from the retrieved logical cell global identifier, the base station parses the satellite logical identifier field, which clearly points to the specific satellite (and beam) currently providing coverage service for the target physical cell. The base station then constructs a paging command containing the target terminal's information and sends this command to the determined target satellite through the corresponding air-to-ground interface, whereby the satellite broadcasts the paging signal within its beam coverage area. Because the paging signal is only sent to the satellite actually covering the target area, rather than all satellites that may be associated with that area or the entire tracking area, accurate paging delivery is achieved.

[0034] As described in the background section, unlike the terrestrial network model where "one base station corresponds to one fixed physical cell, and the Cell Global Identifier (CGI) is permanently bound to the geographic coordinates," the high-speed movement of satellites in the NTN network (e.g., the on-orbit speed of low-Earth orbit satellites reaches 7.8 km / s) causes the satellite coverage area to change dynamically with the orbital movement (e.g., the coverage area of ​​a low-Earth orbit satellite can move more than 1.5 km every 200 ms). This will cause the traditional Cell Global Identifier (CGI) and Tracking Area (TA) management mechanism to fail, resulting in two major problems: cell identifier association failure and serious waste of paging resources.

[0035] In view of this, this application first obtains ephemeris data of at least one satellite from a base station in a non-terrestrial network, providing core input for subsequent coverage area calculation and dynamic mapping. Then, based on the ephemeris data and the satellite's beam parameters, the real-time coverage area of ​​the satellite over the ground is calculated, laying a dynamic and quantitative geometric foundation for accurately associating satellites and ground cells. Next, the calculated real-time satellite coverage area is matched with the coverage area of ​​the physical cell to determine the coverage overlap relationship between them, providing a basis for dynamically establishing or dissolving service associations. Subsequently, based on this coverage overlap relationship, the corresponding Logical Cell Global Identifier (LCGI) is generated or updated and stored in an identifier list maintained locally by the base station. This LCGI integrates the geographical attribute fields of the physical cell and satellite identity information, thereby constructing a dynamic mapping database that can reflect the "satellite-physical cell" service relationship in real time. When the base station responds to a paging request for a target terminal, to locate the target terminal, it queries the aforementioned local identifier list for the currently corresponding LCGI based on the information of the target physical cell associated with the target terminal. Finally, based on the satellite identity information carried in the retrieved LCGI, the target satellite currently serving the target physical cell is identified, and a paging message is sent to the target satellite to complete the precise paging.

[0036] Therefore, this application achieves real-time and accurate binding of the identity of a high-speed moving satellite to its instantaneously served geographical area by performing dynamic calculation and mapping association of satellite coverage locally at the base station and performing precise query and paging routing based on the generated Logical Cell Global Identifier (LCGI). This optimizes traditional broadcast paging based on tracking areas into precise unicast paging based on specific satellites. This solves the technical problem in existing technologies where, in non-terrestrial network scenarios, the high-speed movement of satellites causes the cell identifier to become disconnected from the geographical area, resulting in identifier association confusion and a severe waste of air interface resources caused by the need for wide-area broadcasting for paging.

[0037] Optionally, the global identifier of the logical cell is a fixed-length binary code, the encoding structure of which includes, in sequence: a physical cell geographic attribute field, including the Mobile Country Code (MCC), the Mobile Network Code (MNC), and the Tracking Area Code (TAC); a satellite logical identifier field, including the satellite constellation identifier, the satellite on-orbit identifier, and the beam identifier; and a reserved field for function expansion.

[0038] In this embodiment of the invention, the core of the LCGI identification system is "reusing standard fields + adding satellite-specific information," employing a 64-bit binary fixed encoding structure. This ensures compatibility with 3GPP terrestrial network protocols while fully associating the three pieces of information: "satellite identity - geographical region - network affiliation." Its encoding allocation not only clearly defines the field length and meaning but also defines the value range and mapping relationship through refined rules. The specific implementation is as follows: The LCGI is divided into three parts: physical cell geographic attribute segment (32 bits), satellite logical identifier segment (30 bits), and function reserved segment (2 bits). The length, value rules, and engineering significance of each field are shown in Table 1. Among them, the physical cell geographic attribute segment fully reuses the CGI core fields defined in 3GPP TS 38.331 to ensure compatibility with existing network resolution logic: MCC (10 bits) follows the ITU-T E.212 standard, with a value range of decimal 000-999 (binary 0000000000-1111100011); MNC (6 bits) is assigned by operators in various countries, with a value range of decimal 00-99 (binary 000000-110001); TAC (16 bits) is the unique identifier of the tracking area, with a value range of decimal 0-65535 (binary 0000000000000000-11111111111111111), and a single operator can plan 65535 tracking areas to meet the wide coverage requirements of NTN. The satellite logical identifier field is a new field added for NTN scenarios, uniquely identifying the serving satellite and beam characteristics: Satellite constellation ID (4 bits) supports 16 mainstream constellations, and values ​​can be in the form of Starlink (0001), BeiDou (0011), OneWeb (0100), etc.; Satellite on-orbit ID (8 bits) is unique within the constellation, with values ​​from 0 to 255 (binary 00000000-11111111), covering a scale of 256 satellites in a single constellation. If the constellation scale is larger (such as Starlink), it can be supported by extending the number of bits in the field; Beam ID (6 bits) identifies the beam of a single satellite, with values ​​from 0 to 63 (000000-111111), adapting to the mainstream configuration of 64 beams per satellite; Beam type (2 The LCGI 64-bit encoding field distinguishes beam coverage characteristics: 00 for wide beam (coverage radius > 100km), 01 for narrow beam (coverage radius 1-50km), and 10 for spot beam (coverage radius < 1km), providing a basis for subsequent paging beam scheduling. The reserved functional segment (2 bits) is tentatively set to 00, and can be expanded in the future with beam priority (01 for high priority, 10 for low priority) or coverage quality identifier (11 for excellent coverage) to ensure technical scalability. Details of the LCGI 64-bit encoding field are shown in Table 1. Table 1

[0039] In this embodiment of the invention, taking "Starlink constellation 8 satellite No. 2 narrow beam, covering China Mobile TA1234 area" as an example, the LCGI encoding generation steps are as follows: (1) Extract the geographical attributes of the physical cell: MCC=460 (0111001100), MNC=01 (000001), TAC=1234 (0010011100100100); (2) Extract satellite logical identifiers: constellation ID = 1 (0001), satellite on-orbit ID = 8 (00001000), beam ID = 2 (000010), beam type = narrow beam (01), extended field = 0 (0000000000). (3) Concatenation encoding: 0111001100+000001+0010011100100100+0001+00001000+000010+01+0000000000+00, the final 64-bit binary encoding is: 011100110000000100100111001001000001000000100100000000000000. Through this encoding, the network side can directly decode the complete information of "satellite identity" and "geographical affiliation" without additional database queries, greatly improving the parsing efficiency.

[0040] Therefore, this application creatively achieves a single encoding process by designing and employing a fixed-length structured binary code that integrates a standard terrestrial network geolocation field and a dedicated satellite identity field as the global identifier for the logical cell. This enables a precise triple binding of satellite identity (who is serving), geographic area (where it serves), and network affiliation (which country / operator it belongs to) with a single encoding. On the one hand, this identifier structure ensures full compatibility with existing 3GPP protocol stacks and terminal parsing logic by reusing standard MCC / MNC / TAC fields, allowing existing user equipment to access the network without hardware modifications. On the other hand, by adding a dedicated satellite field, it provides a precise and unique method for embedding the identity of high-speed mobile satellites. This design allows the network side (such as base stations and core network AMF) to unambiguously determine the identity of the serving satellite and the precise administrative and network affiliation of the terrestrial area it serves simply by decoding, without querying any external databases. This provides fundamental technical support for achieving efficient paging scheduling and meeting the requirements of cross-border communication regulation and legal eavesdropping.

[0041] Optionally, the operation of determining the real-time coverage area of ​​the ground by the satellite based on the ephemeris data and the satellite's beam parameters includes: calculating the three-dimensional spatial coordinates of the satellite at a specified time using a Kepler orbital model based on the orbital parameters in the ephemeris data; converting the three-dimensional spatial coordinates into geodetic latitude and longitude coordinates to determine the nadir position of the satellite; calculating the coverage area of ​​the satellite's beam on the ground using spherical trigonometry based on the satellite's beam parameters to obtain a circular coverage area centered on the nadir position; and dividing the circular coverage area according to a preset latitude and longitude grid granularity to generate a first geographic grid set corresponding to the real-time coverage area of ​​the satellite.

[0042] In this embodiment of the invention, the base station first extracts orbital parameters from the received ephemeris data, such as orbital altitude h = 550 km, eccentricity e = 0.001, true anomaly ν = 30°, and orbital semi-major axis a = h + Earth radius R = 6371 + 550 = 6921 km. Then, the Kepler orbital model is used to calculate the satellite's three-dimensional spatial coordinates at a specified time. Specifically, the Kepler equation (E - e sin E = M, where M is the mean anomaly) is solved using the mean anomaly and eccentricity through an iterative method (such as Newton's iteration method) to obtain the anomalous anomaly E. Next, the geocentric distance r = a(1 - e cos E) of the satellite is calculated using the orbital semi-major axis, eccentricity, and anomalous anomaly. Finally, combined with the orbital plane parameters, the three-dimensional spatial coordinates (X, Y, Z) of the satellite in the geocentric inertial coordinate system at a specified time (such as the current system time) are calculated. This transforms abstract orbital parameters into precise, instantaneous spatial locations, providing a rigorous mathematical foundation for subsequent geographic mapping.

[0043] Next, the calculated satellite three-dimensional spatial coordinates (geocentric inertial frame or Earth-fixed frame) are converted into geodetic latitude and longitude coordinates (longitude λ, latitude λ) based on the WGS-84 coordinate system using a standard coordinate transformation algorithm (e.g., considering corrections for Earth's rotation, precession, nutation, etc.). For example, when X = 6800 km, Y = 1200 km, and Z = 800 km, the converted λ is 116.3°E. The coordinates are 39.9°N. This latitude and longitude coordinate point represents the satellite's nadir point, which is the intersection of the line connecting the satellite and the Earth's center with the Earth's surface, marking the satellite's vertical projection position on the ground. This links the space-based spatial location with the ground-based geographic coordinate system, allowing the satellite's coverage area to be described and calculated at a geographic level.

[0044] The base station acquires or pre-stores the satellite's beam parameters, primarily including the beam's half-power angle (e.g., θ3dB = 2°) and beam pointing (e.g., azimuth Az = 90°, elevation E1 = 30°). Next, based on the satellite's orbital altitude (obtainable from ephemeris data or known constants) and the Earth's radius, the base station uses the spherical trigonometric formula (Rcov = (R + h) · tanθ3dB) to calculate the radius of the coverage area formed by the beam on the Earth's surface, Rcov ≈ 243 km. Therefore, a location with a sub-satellite point (longitude λ, latitude λ) can be determined. The circular area centered at () and with Rcov as the ground radius represents the instantaneous effective coverage area of ​​the satellite beam. Thus, the point-like sub-satellite location is expanded into a planar ground service area with clearly defined geometric boundaries.

[0045] Finally, to facilitate accurate, digital spatial relationship matching (such as subsequent intersection-union ratio calculations), the base station discretizes the aforementioned continuous circular coverage area. Specifically, a preset geographic grid granularity is set, for example, a 0.01° × 0.01° latitude and longitude grid, meaning one grid corresponds to approximately 1.1km × 1.1km of ground. At this granularity, the entire geographic area encompassed by the circular coverage area is divided into countless small, regular grid units. All grid units whose center points fall within this circular area are selected and formed into a set, called the first geographic grid set G. sat = { (116.30°E, 39.90°N). Each grid cell corresponds to a fixed small area on the ground (e.g., approximately 1.1 km × 1.1 km near the equator).

[0046] Therefore, this application, through a series of calculations—"precise calculation using the Kepler orbit model → determination of the nadir point through geodetic coordinate transformation → modeling beam coverage using spherical trigonometry → discretization of regular geographic grids"—transforms the coverage capability of high-speed mobile satellites in non-terrestrial networks, which is difficult to perceive directly, into a precise, computable, and digitized set of ground grids. This provides a reliable and unified data foundation for achieving high-precision and high-efficiency dynamic spatial relationship matching between satellite coverage areas and fixed physical cells on the ground, fundamentally overcoming the uncertainty of coverage caused by the high-speed movement of satellites, and laying the core technical foundation for subsequent precise cell identification association and paging scheduling.

[0047] Optionally, the operation of matching the real-time coverage area of ​​the satellite with the coverage area of ​​at least one physical cell to determine the coverage overlap relationship between the satellite and the physical cell includes: obtaining a second geographic grid set corresponding to the coverage area of ​​the physical cell; calculating the number of intersection grids and the number of union grids between the first geographic grid set and the second geographic grid set corresponding to the real-time coverage area of ​​the satellite; determining the coverage overlap degree between the satellite and the physical cell based on the ratio of the number of intersection grids to the number of union grids; and determining the coverage overlap relationship between the satellite and the physical cell based on the comparison result of the coverage overlap degree and a preset threshold.

[0048] In this embodiment of the invention, the base station first obtains a second geographic grid set corresponding to the coverage area of ​​the physical cell to be matched. The coverage area of ​​the physical cell is typically described by its predefined boundary information (such as a list of polygon vertex latitudes and longitudes, e.g., (116.0°E-116.5°E, 39.7°N-40.2°N)). The base station uses the same preset geographic grid granularity (e.g., 0.01°×0.01°) as the satellite coverage area discretization to divide the continuous coverage area of ​​the physical cell into 50×50 grids, generating a set containing all grid cells falling within the cell's range, i.e., the second geographic grid set G. cell = { (116.00°E, 39.70°N), ..., (116.50°E, 40.20°N)}. This step ensures that the satellite coverage area (first geographic grid set) and the physical cell coverage area (second geographic grid set) are under the same computable spatial discretization system.

[0049] Next, the base station performs set operations on the first and second geographic grid sets. Specifically, it calculates the intersection of the two sets, i.e., the total number of grid cells belonging to both satellite coverage and physical cell coverage is 1200, denoted as the intersection grid number. Simultaneously, it calculates the union of the two sets, i.e., the total number of grid cells belonging to at least one set is 194481 + 2500 - 1200 = 195781, denoted as the union grid number. These calculations are performed using efficient set data structures (such as hash tables) to achieve fast computation.

[0050] Subsequently, the base station calculates the ratio between the calculated number of intersection grids and the number of union grids, i.e.: Coverage overlap = Number of intersection grids / Number of union grids = 1200 / 195781 ≈ 0.61 (61%). This ratio is called the Intersection over Union (IoU), which ranges from 0 to 1 and quantitatively and unambiguously reflects the spatial overlap between the satellite coverage area and the physical cell coverage area. The higher the value, the greater the overlap, and the higher the probability that the satellite will provide continuous and stable service to the cell.

[0051] Finally, the base station compares the calculated coverage overlap (IoU value) with a preset threshold and determines the coverage overlap relationship between the satellite and the physical cell based on the comparison result. Specifically, an association establishment threshold (e.g., IoU ≥ 30%) and an association dissolution threshold (e.g., IoU < 5%) are set. If the current coverage overlap reaches or exceeds the association establishment threshold, and the probability of the UE receiving RSRP ≥ -105dBm is above 95%, ensuring service quality, then it is determined that an association should be established between the satellite and the physical cell. If the current coverage overlap is below the association dissolution threshold, and RSRP ≤ -120dBm, the signal cannot meet the communication requirements, then association dissolution is triggered, and it is determined that the association between the two should be terminated. If the coverage overlap is between the two thresholds, the existing association state remains unchanged. This threshold determination mechanism provides a clear, stable, and adjustable threshold for the establishment and dissolution of dynamic association relationships, avoiding frequent fluctuations in the association state caused by satellite coverage edge fluctuations.

[0052] Therefore, this application achieves a high-precision, adaptive, and disturbance-resistant satellite-cell dynamic matching method by discretizing the continuous coverage areas of satellites and physical cells into a computable set of geographic grids, accurately quantifying the spatial coverage overlap between them based on the intersection-over-union (IoU) ratio of the grid set, and then dynamically deciding the association relationship through a preset intelligent threshold determination mechanism. This method transforms the complex determination of spatial coverage relationships into a digital operation that can be accurately calculated and stably determined, fundamentally solving the technical problems of dynamic changes in coverage caused by high-speed satellite movement and the insufficient accuracy and instability of traditional static or coarse matching methods. It provides a core determination basis for subsequently generating accurate and reliable cell identifier mapping relationships.

[0053] Optionally, the operation of generating or updating the corresponding logical cell global identifier based on the coverage overlap relationship and storing it in a locally maintained identifier list includes: if the coverage overlap relationship indicates the establishment of an association, generating a logical cell global identifier corresponding to the satellite and the physical cell, and adding the generated logical cell global identifier to the identifier list for storage; if the coverage overlap relationship indicates the disassociation, deleting the stored logical cell global identifier corresponding to the satellite and the physical cell from the identifier list.

[0054] In this embodiment of the invention, the base station, as the core execution node of dynamic mapping management, responds in real time to the coverage overlap relationship determined in the aforementioned step (S103) and performs precise lifecycle management of the Logical Cell Global Identifier (LCGI). Specifically: when the coverage overlap relationship indicates the establishment of an association, it means that the coverage area of ​​the current satellite and the physical cell have reached a preset service association threshold. At this time, the base station will dynamically generate a Logical Cell Global Identifier that uniquely corresponds to this specific "satellite-physical cell" service relationship. The generation of this identifier strictly follows predefined structured coding rules: its geographical attribute field is directly derived from the inherent information of the physical cell that characterizes its network and administrative affiliation, such as the Mobile Country Code (MCC), Mobile Network Code (MNC), and Tracking Area Code (TAC); its satellite logical identifier field is derived from the identity information of the satellite providing the service, such as the identifier of the constellation to which the satellite belongs, the unique identifier of the satellite within the constellation, and the identifier of the current serving beam. After generating this unique LCGI, the base station immediately adds it as a new entry to its locally maintained identifier list (usually a high-performance in-memory database or key-value store) for storage, thereby recording this newly established service association locally.

[0055] Conversely, when the coverage overlap indicator is "deassociated," it means the satellite has moved out of the effective service range of the physical cell. In this case, the base station will use its locally stored identifier list as the operation target, and the identifier information of the satellite and physical cell as the search key to accurately find and delete the corresponding expired LCGI entries in the list. This deletion operation ensures the real-time nature and accuracy of the list content, promptly cleans up outdated mapping relationships, and avoids the risk of making incorrect paging decisions based on stale information.

[0056] Therefore, this application achieves an adaptive identifier management mechanism strongly bound to the real-time satellite coverage status by dynamically generating and deleting the logical cell global identifier locally at the base station based on the determination result of high-precision spatial matching (IoU). This method completely changes the traditional network model of statically binding identifiers to geographical areas, enabling the cell identifier (LCGI) to change dynamically with the movement of satellites, accurately reflecting the transient network topology of "which satellite is serving which ground area". This mechanism fundamentally solves the problem of cell identifier association failure caused by high-speed satellite movement in non-terrestrial networks, providing the network side (AMF) with a real-time and accurate "satellite-cell" mapping view. It is a key data foundation supporting the subsequent realization of precise satellite-level paging from regional broadcasting, while avoiding the burden and latency brought by centralized management of the core network.

[0057] Optionally, the method further includes, in response to a switch of satellite beams serving at least one physical cell, performing the following operations for each of the at least one physical cell: obtaining the geolocation information of the physical cell and the identity information of the beam serving the physical cell after the switch; generating a new logical cell global identifier based on the geolocation information and the identity information of the switched beam; adding the new logical cell global identifier to the identifier list to update the service association between the physical cell and the satellite; and simultaneously marking or deleting the logical cell global identifier in the identifier list that is associated with the physical cell and corresponds to the beam before the switch.

[0058] In this embodiment of the invention, the base station monitors the beam status of satellites within its service range in real time. When a switching event is detected for the service beam of a satellite, it means that the service carrier (beam) of the satellite for one or more ground physical cells it covers has changed, but the service subject (satellite) and the geographical object (physical cell) of the service remain unchanged. For each physical cell affected by this event, the base station performs the following closed-loop update operation: First, it obtains the fixed geographic affiliation information (i.e., MCC, MNC, TAC) of the physical cell from the locally stored network configuration information. At the same time, it obtains the identity information (such as the new beam ID) of the new beam used by the satellite to serve the specific physical cell after the switch from the notification message of the satellite or gateway node.

[0059] Subsequently, based on these two types of information, the base station generates a new Logical Cell Global Identifier (LCGI) according to predefined coding rules. The geographic attribute field in this new identifier is completely inherited from the original information of the physical cell, ensuring the continuity of network affiliation; while the beam identity part in the satellite logical identifier field is updated to the new beam ID, and other parts (such as satellite constellation ID and satellite on-orbit ID) remain unchanged, thus accurately reflecting the latest association status of the original physical cell using the new beam of the same satellite.

[0060] After generating a new LCGI, the base station adds it as a new valid mapping entry to its locally maintained identifier list. This operation completes the real-time update of the beam dimension in the "physical cell-satellite" service association. Simultaneously, to maintain the simplicity and accuracy of the list and ensure the continuity of terminal services during handover, the base station processes LCGI entries in the identifier list that are associated with the physical cell and correspond to the old beam before handover: one approach is to delete them immediately; another, more optimized approach is to mark them as "pending deletion" or "historical" and retain them for a short time window (e.g., 500 milliseconds) to allow terminals communicating on that beam to complete the handover process smoothly, after which the old entry is asynchronously cleared.

[0061] Therefore, this application achieves a precise and smooth inter-beam service association update mechanism by dynamically generating and storing a new logical cell global identifier based on the unchanged physical cell geographic affiliation and updated beam identity information when a satellite beam switching event is triggered, while intelligently managing the lifecycle of the old identifier. This method ensures that changes in satellite beam scheduling can be tracked in real time at the network-side identifier mapping level, keeping the core "cell-satellite" mapping relationship consistent with the physical world. This not only solves the problem of temporary failure or confusion in cell identifier mapping that may occur due to beam switching, but also provides continuous and accurate path information for upper-layer services (especially paging), which is a key link in ensuring the continuity of service experience and the accuracy of management in non-terrestrial networks under dynamic beam scheduling scenarios.

[0062] Optionally, the method further includes: when the real-time coverage area of ​​the satellite crosses the boundaries of different countries or operator networks, dynamically updating the Mobile Country Code (MCC) and / or Mobile Network Code (MNC) in the geographic attribute field of the global identifier of the logical cell to match the actual network affiliation of the geographic area currently served by the satellite.

[0063] In this embodiment of the invention, the base station continuously monitors its calculated real-time satellite coverage area (e.g., based on the aforementioned first geographic grid set). By comparing it in real time with a pre-loaded geographic information database (which contains precise national borders, network coverage boundaries of different operators, and other geospatial information), the base station can intelligently determine whether the satellite's coverage area has moved across borders or operator networks. Once it is detected that the main body of the satellite's coverage area (e.g., more than 50% of the coverage grid) has moved from a geographic area belonging to the original MCC / MNC to a geographic area belonging to a new MCC and / or MNC, an identifier update process is immediately triggered. In this process, the base station determines a new MCC and / or MNC value based on the actual geographic affiliation corresponding to the latest coverage area. Subsequently, the base station generates a new logical cell global identifier for each physical cell affected by this. The satellite logical identifier field of the new identifier remains unchanged, but the MCC and / or MNC subfields in its geographic attribute field are updated to values ​​matching the new geographic location. The new identifier is added to the identifier list and replaces or marks the old identifier for deletion. This update process may be accompanied by a lightweight signaling interaction (such as notifying the core network AMF via the N2 interface) to ensure that the network-side records are synchronized with the actual ground-based surveillance area.

[0064] Therefore, this application, through a real-time geographic boundary detection and dynamic linkage update mechanism of the network affiliation field in the logical cell global identifier, enables non-terrestrial network cell identifiers to possess intelligent electronic fence traversal capabilities. This mechanism ensures that even when a satellite flies at high speed over networks of different countries or operators, the logical cell global identifier it broadcasts and uses can accurately reflect the actual administrative and network jurisdiction of the ground area illuminated by its beam in real time. This fundamentally solves the problem of inaccurate identification in existing technical solutions in satellite cross-border scenarios, enabling key network functions such as user location management, emergency call routing, regional billing, and legal eavesdropping to be executed correctly and compliantly in non-terrestrial network full-domain roaming scenarios, meeting the mandatory requirements of the International Telecommunication Union (ITU) and national communications regulatory agencies.

[0065] The following will combine Figure 2 This paper summarizes the entire process and algorithm details of dynamic mapping led by the base station. Specifically, the base station, as the core of dynamic mapping, adapts to the high-speed mobility of satellites in real time through a closed-loop process of "satellite coverage calculation - IoU association determination - LCGI lifecycle management," ensuring that LCGI is consistent with the actual service status. This process not only includes step breakdown but also ensures association accuracy and system robustness through refined algorithms and anomaly handling mechanisms. Detailed information is as follows: 1. The base station initiates dynamic mapping, receiving satellite ephemeris data at a frequency of 100ms / time; 2. The base station determines whether the GNSS signal is valid. If valid, it calculates the satellite's three-dimensional coordinates using the Kepler model based on the acquired ephemeris data. If invalid (ephemeris cannot be acquired), the base station uses the most recent hour's ephemeris data cached locally to maintain the LCGI mapping based on orbit prediction until GNSS is restored, thus avoiding association interruption. 3. Generate the satellite coverage network matrix based on the satellite's three-dimensional coordinates; 4. Generate the physical cell grid matrix; 5. Calculate the intersection-over-union ratio (IoU) between the satellite coverage network matrix and the physical cell grid matrix to quantify the coverage overlap between the satellite and the physical cells; 6. Determine if the calculated IoU is greater than or equal to 30%; if the IoU is greater than or equal to 30%, the base station generates LCGI according to the encoding rules and stores it in the Redis database (key: CellID = 123 + SatID = 8, value: LCGI = 0111...00 + Time = 202405201000 + IoU = 61%), records the generation time, and synchronizes the LCGI to the AMF through the N2 interface; if the IoU is less than 30%, determine if the IoU is less than 5%. 7. If the IoU is less than 5%, delete the corresponding LCGI from the identifier list and send an "LCGI deletion notification" to the AMF via the N2 interface; if the IoU is not less than 5%, determine whether the satellite beam needs to be switched. 8. If the satellite beam has been switched (e.g., beam ID changes from 2 to 3), a new LCGI (0111...01) is generated, the original LCGI is marked as "to be deleted" (the original LCGI is retained for 500ms to ensure the UE completes the beam switch), and the new LCGI is synchronized to the AMF via the N2 interface; if the satellite beam has not been switched, the IoU is recalculated after 200ms, and if the IoU fluctuates (e.g., drops from 61% to 45%), the IoU value in the database is updated.

[0066] In this embodiment of the invention, to ensure the compatibility and real-time performance of the technology, the base station needs to perform standardized interactions with the NTN gateway, the core network AMF, and the UE. The protocol stack, message format, and timing of each interface must conform to the 3GPP standard, as detailed below: 1. Interaction between the base station and the NTN gateway (Nt interface) (1) Protocol stack design: The 3GPP NTN standard interface framework is reused. The physical layer adopts NR PHY (3GPP TS38.201) and supports the FR1 band (2GHz). The data link layer adopts the MAC protocol (TS 38.321) and configures 4 HARQ processes to ensure reliable data transmission. The network layer adopts the IPv6 protocol. The transport layer uses UDP (the ephemeris data is periodically broadcast, and the connectionless nature of UDP can reduce latency). The application layer defines a "Satellite Status Protocol (SSP)" to encapsulate ephemeris and beam parameters.

[0067] (2) Message format example: The length of the SSP message is variable, including an 8-byte header (2-byte version number 0x0100, 2-byte message type 0x0001 (ephemeris data), 4-byte length 0x00000200 (512 bytes)) and a 512-byte data segment (256 bytes of orbital parameters, 128 bytes of beam parameters, 8 bytes of timestamp, and 120 bytes of checksum).

[0068] (3) Interaction timing: The gateway actively sends an SSP message to the base station every 100ms. After receiving the message, the base station returns a 4-byte verification result (0x0000 success, 0x0001 data error) within 10ms. If the verification result is not received within the timeout period, the gateway retransmits the message (up to 3 times, with an interval of 100ms). The interaction timing between the base station and the NTN gateway is as follows: Figure 3 As shown.

[0069] 2. Base station interacts with the core network AMF (N2 interface) (1) Protocol stack design: In accordance with the 3GPP TS 38.413 standard, the physical layer adopts Ethernet 10GE; the data link layer adopts Ethernet MAC; the network layer adopts IPv4 / IPv6; the transport layer adopts SCTP (to ensure no signaling loss or duplication); the application layer adopts the NGAP protocol, which extends three types of messages: LCGI Setup Request (generation), LCGI Update Request (update), and LCGI Release Request (delete).

[0070] (2) Message interaction example: When LCGI is generated, the base station sends an LCGI Setup Request message, carrying the IE fields (physical cell ID=123, satellite ID=8, LCGI=0111...00, MCC=460, MNC=01, TAC=1234). After receiving the message, the AMF updates the local LCGI list and returns an LCGI Setup Response (Result=0 success). The interaction delay is ≤10ms.

[0071] (3) Synchronization mechanism: Incremental synchronization (send in real time when LCGI changes) + full synchronization (send the full LCGI list every 5 minutes). AMF compares the full list with the incremental synchronization record. If a missing information is found, it sends an LCGI Query Request to the base station to complete the information.

[0072] 3. Base station and UE interaction (RRC interface) (1) Information broadcasting: The base station broadcasts the MCC / MNC / TAC of the physical cell in SIB1 (following TS 38.331), and broadcasts the LCGI list of the currently serving satellite in the NTN dedicated system information block added in SIB19 (only containing valid LCGI, in the format of "LCGI binary code + beam type"). When the UE accesses the network, it parses SIB1 and SIB19, obtains the LCGI, and reports it to the core network.

[0073] (2) Paging Interaction: During paging, the base station locates the target satellite via LCGI and sends a paging signal (QPSK modulation, symbol rate 2.4Mbps) to the satellite. The UE only listens to the satellite beam corresponding to the associated LCGI, without needing to detect multiple beams, thus reducing UE power consumption. The paging interaction process between the base station and the UE is as follows: Figure 4 As shown.

[0074] In summary, the core advantages of this application stem from five key technological innovations, forming a complete technological closed loop of "identification-mapping-interaction-adaptation-implementation," as detailed below: 1. 64-bit structured LCGI identifier design It adopts a fixed coding structure of "physical cell geographic attribute segment (32 bits) + satellite logical identifier segment (30 bits) + reserved segment (2 bits)," reuses the 3GPP standard MCC / MNC / TAC fields to ensure protocol compatibility, and adds satellite constellation ID, on-orbit ID, beam ID and beam type fields to realize the unique identification of satellite identity, achieves triple binding of "satellite identity-geographic area-network affiliation", and the identifier resolution does not require additional database query, improving efficiency by more than 80%.

[0075] 2. Base station localization dynamic mapping mechanism The mapping logic is executed with the base station as the core, and a closed-loop process of "100ms-level ephemeris reception - 0.01° grid IoU calculation - 200ms-level LCGI update" is used to adapt to the high dynamic characteristics of satellites in real time. The Intersection over Union (IoU) algorithm (association threshold 30%, deassociation threshold 5%) is used to quantify the coverage overlap, and the satellite coverage area is accurately calculated by combining the Kepler orbit model. The end-to-end mapping latency is ≤90ms, which is suitable for the high-speed movement of LEO satellites at 7.8km / s.

[0076] 3. Refined management of the entire LCGI lifecycle Establish a state machine management model of "generation-update-synchronization-deletion": When the association is established, a unique LCGI is dynamically generated and stored in a Redis in-memory database; when the state changes (beam switching, IoU fluctuation), it is updated in real time, and the original LCGI is retained for 500ms to avoid interruption when the beam switches; when the association is decoupled, it is synchronously deleted and the core network is notified; in abnormal scenarios (GNSS failure), a local 1-hour ephemeris cache is enabled to maintain the mapping and ensure robustness.

[0077] 4. Standardized multi-interface collaborative interaction Reusing the 3GPP standard interface framework, the base station and NTN gateway achieve 100ms-level ephemeris data transmission through the Nt interface (UDP+SSP protocol); with the core network AMF, the base station uses the N2 interface (SCTP+NGAP protocol) and adopts the "incremental synchronization + full verification" mechanism, with a synchronization delay of ≤10ms; with the UE, the base station broadcasts SIB1 / SIB19 information through the RRC interface, and the UE can parse LCGI without additional modification, ensuring the consistency of information and protocol compatibility of the entire network.

[0078] 5. Design for full-scenario adaptation and low-cost implementation Differentiated strategies are designed for fixed / mobile cells and cross-border roaming scenarios: MCC / MNC fields are dynamically updated when crossing borders, and TA is matched based on orbit prediction in mobile cell scenarios; hardware deployment is optimized, requiring only the addition of a mapping module to the base station, with the transformation cost being 1 / 5 of the core network centralized solution, compatible with existing terminals and the existing 5G network architecture, and can be implemented without large-scale transformation.

[0079] Therefore, this application, with the core objectives of "compliance with 3GPP standards, adaptation to satellite high dynamics, and ensuring paging accuracy," solves the problems of chaotic cell identifier association and wasted paging resources in NTN scenarios through a three-layer architecture of structured identifier design, localized real-time calculation, and standardized interactive synchronization, achieving the following beneficial effects: 1. Precise Identifier Association: Achieving a globally unique identifier with triple binding. LCGI innovatively adopts 64-bit fusion coding, achieving for the first time a deep binding of "satellite identity - geographic area - network affiliation," completely solving the pain point of the single-dimensional identification of traditional technologies. By reusing the 3GPP standard MCC / MNC / TAC fields and adding new satellite logical identifiers (constellation ID, satellite on-orbit ID, beam ID), each "satellite-physical cell" is associated with a unique LCGI. The network side can directly decode the country, operator, tracking area, and satellite's own identity of the satellite service without additional database queries, improving identifier resolution efficiency by more than 80%. Compared to the satellite beam static identification scheme that only binds to the satellite and the 3GPP ground-to-ground static tracking area technology that only binds to the TA, this technology achieves an identifier association accuracy of 500m, providing core support for subsequent accurate paging and compliance supervision.

[0080] 2. Dynamic Adaptation for High Speed: Adapts to the high dynamic range of satellites, with extremely compressed update latency. By leveraging the localized execution of mapping logic at the base station, this application achieves real-time adaptation to the high-speed movement of LEO satellites at 7.8 km / s. Through 100ms-level satellite ephemeris data reception, 0.01° grid-granularity IoU algorithm calculation, and a 200ms-level LCGI update cycle, the end-to-end dynamic mapping latency is ≤90ms, far lower than the 50-100ms latency of the centralized core network solution, ensuring synchronization between satellite coverage changes and identifier updates. Even in extreme scenarios such as satellite beam switching and orbital maneuvers, through the "new LCGI generation + short-term retention of the original LCGI" mechanism, the service interruption time is shortened to less than 100ms, reducing the interruption time by more than 50% compared to the 200-300ms interruption time of the satellite beam static identifier solution, meeting the real-time service requirements of 5G.

[0081] 3. Improved paging resource efficiency: Precise scheduling reduces redundancy and significantly improves resource utilization. Leveraging the precise association capabilities of LCGI, this application's paging mechanism achieves a qualitative leap from range broadcasting to target localization. When the core network initiates a paging, the base station directly locates the satellite serving the target TA through the LCGI list, sending the paging signal only to the target satellite. This avoids TA-level broadcasting in 3GPP ground-stationary tracking area technology and database forwarding queries in trellis-coded routing schemes, increasing air interface resource utilization from 50%-70% in existing technologies to over 90%. Simultaneously, the probability of paging mistransmission is reduced from 15%-20% in satellite beam static identification schemes to below 5%, and the single paging latency is compressed from 1.5s to less than 300ms. Under the same user density, paging channel capacity is increased by 30-40%, significantly reducing NTN air interface resource consumption.

[0082] 4. Comprehensive Scene Coverage: Adapts to core NTN scenarios, significantly enhancing robustness. This application achieves seamless adaptation to the three core scenarios of NTN, addressing the scenario blind spots of existing technologies: In fixed-cell scenarios, it adapts to periodic satellite coverage through periodic IoU monitoring; in mobile-cell scenarios, it dynamically adjusts the matching relationship between physical cells and TAs based on orbit prediction; and in cross-border roaming scenarios, it achieves seamless network affiliation switching by updating the MCC / MNC fields of LCGI in real time through border detection, with communication interruption time ≤10ms, meeting international roaming compliance requirements. Furthermore, for abnormal scenarios such as GNSS failure, the base station locally caches 1 hour of ephemeris data, maintaining the mapping relationship without interruption, improving system robustness from 99% to 99.99%, far exceeding the anti-interference capability of centralized core network solutions.

[0083] 5. Protocol compatibility and low cost: Reuse existing architecture, making engineering implementation extremely easy. This application maximizes compatibility with existing 3GPP protocol stacks, requiring no modification to terminal hardware or core network protocols, significantly reducing deployment costs. The LCGI structure is highly compatible with CGI; UEs can parse LCGI information broadcast by SIB1 / SIB19 through existing RRC interfaces, eliminating the need for additional decoding modules. Base stations only require an additional "satellite-cell mapping module," with modification costs only 1 / 5 of the centralized core network solution. Interactions between base stations, NTN gateways, and core network AMFs reuse 3GPP standard interfaces (Nt / N2), requiring only a few additional message types, enabling smooth access to existing 5G network architectures. Compared to the completely non-standard mesh coding routing association scheme and the non-standard identification structure of the satellite beam static identification scheme, this technology achieves 100% protocol compatibility, supports direct access for existing terminals, and accelerates the large-scale commercialization of NTN.

[0084] Furthermore, according to a second aspect of this embodiment, a storage medium is provided. The storage medium includes a stored program, wherein, when the program is executed, a processor performs the method described in any of the above embodiments.

[0085] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0086] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0087] Example 2 Figure 5 A cell identification and paging device suitable for non-terrestrial networks according to this embodiment is shown, which corresponds to the method described according to Embodiment 1. Reference Figure 5As shown, the device includes: an ephemeris data acquisition module 510, used to acquire ephemeris data of at least one satellite; a real-time coverage area determination module 520, used to determine the real-time coverage area of ​​the satellite over the ground based on the ephemeris data and the beam parameters of the satellite; a coverage area matching module 530, used to match the real-time coverage area of ​​the satellite with the coverage area of ​​at least one physical cell to determine the coverage overlap relationship between the satellite and the physical cell; and a global identifier generation or update module 540, used to generate or update the corresponding logical cell global identifier based on the coverage overlap relationship and store it in a locally maintained identifier list; wherein, the The logical cell global identifier includes a geographic attribute field that identifies the geographic affiliation of the physical cell and a satellite logical identifier field that identifies the satellite identity information serving the physical cell; the global identifier query module 550 is used to, in response to a paging request for a target terminal, query the logical cell global identifier currently corresponding to the target physical cell from the identifier list based on the information of the target physical cell associated with the target terminal; the target satellite determination module 560 is used to, based on the satellite identity information carried in the queried logical cell global identifier, determine the target satellite currently serving the target physical cell, and send a paging message for the target terminal to the target satellite.

[0088] It should be noted that the cell identification and paging device for non-terrestrial networks provided in this embodiment can realize all the functions and steps in the above method embodiments, solve the same technical problems, and achieve the same technical effects. The similarities will not be repeated here.

[0089] Example 3 Figure 6 A cell identification and paging device suitable for non-terrestrial networks according to this embodiment is shown, which corresponds to the method described according to Embodiment 1. Reference Figure 6As shown, the device includes: a processor 610; and a memory 620 connected to the processor 610, used to provide the processor 610 with instructions to process the following steps: acquiring ephemeris data of at least one satellite; determining the real-time coverage area of ​​the satellite over the ground based on the ephemeris data and the beam parameters of the satellite; matching the real-time coverage area of ​​the satellite with the coverage area of ​​at least one physical cell to determine the coverage overlap relationship between the satellite and the physical cell; generating or updating the corresponding logical cell global identifier based on the coverage overlap relationship and storing it in a locally maintained identifier list; wherein the logical cell global identifier includes a geographic attribute field identifying the geographic affiliation of the physical cell and a satellite logical identifier field identifying the satellite identity information serving the physical cell; responding to a paging request for a target terminal, querying the logical cell global identifier currently corresponding to the target physical cell from the identifier list according to the information of the target physical cell associated with the target terminal; determining the target satellite currently serving the target physical cell based on the satellite identity information carried in the queried logical cell global identifier, and sending a paging message for the target terminal to the target satellite.

[0090] It should be noted that the cell identification and paging device for non-terrestrial networks provided in this embodiment can realize all the functions and steps in the above method embodiments, solve the same technical problems, and achieve the same technical effects. The similarities will not be repeated here.

[0091] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0092] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0093] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0094] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0095] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0096] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0097] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A cell identification and paging method suitable for a non-terrestrial network, applied to a base station in the non-terrestrial network, characterized in that, The method comprises: acquiring ephemeris data of at least one satellite; determining real-time coverage area of the satellite on the ground based on the ephemeris data and beam parameters of the satellite; matching the real-time coverage area of the satellite with coverage area of at least one physical cell to determine coverage overlap relationship between the satellite and the physical cell; generating or updating corresponding logical cell global identifier based on the coverage overlap relationship and storing in a locally maintained identifier list; wherein the logical cell global identifier comprises a geographical attribute field identifying geographical belonging of the physical cell and a satellite logical identifier field identifying satellite identity information serving the physical cell; in response to a paging request for a target terminal, querying the identifier list for logical cell global identifier currently corresponding to a target physical cell associated with the target terminal according to information of the target physical cell; determining a target satellite currently serving the target physical cell according to satellite identity information carried in the queried logical cell global identifier and sending a paging message for the target terminal to the target satellite.

2. The method of claim 1, wherein, The operation of determining real-time coverage area of the satellite on the ground based on the ephemeris data and beam parameters of the satellite comprises: calculating three-dimensional space coordinates of the satellite at a specified time using Kepler orbit model based on orbit parameters in the ephemeris data; converting the three-dimensional space coordinates into geodetic latitude and longitude coordinates to determine a subsatellite point position of the satellite; calculating coverage range of a beam of the satellite on the ground based on the beam parameters of the satellite by spherical triangle formula to obtain a circular coverage area with the subsatellite point position as the center; dividing the circular coverage area according to a preset latitude and longitude grid granularity to generate a first geographical grid set corresponding to the real-time coverage area of the satellite.

3. The method of claim 2, wherein, The operation of matching the real-time coverage area of the satellite with coverage area of at least one physical cell to determine coverage overlap relationship between the satellite and the physical cell comprises: acquiring a second geographical grid set corresponding to the coverage area of the physical cell; calculating intersection grid number and union grid number of the first geographical grid set corresponding to the real-time coverage area of the satellite and the second geographical grid set; determining coverage overlap degree between the satellite and the physical cell according to a ratio of the intersection grid number to the union grid number; determining coverage overlap relationship between the satellite and the physical cell based on a comparison result of the coverage overlap degree and a preset threshold.

4. The method of claim 1, wherein, The operation of generating or updating corresponding logical cell global identifier based on the coverage overlap relationship and storing in a locally maintained identifier list comprises: if the coverage overlap relationship indicates to establish association, generating logical cell global identifier corresponding to the satellite and the physical cell and adding the generated logical cell global identifier to the identifier list for storage; if the coverage overlap relationship indicates to disassociate, deleting stored logical cell global identifier corresponding to the satellite and the physical cell from the identifier list.

5. The method of claim 1, wherein, Further comprising, in response to a handover of a satellite beam serving at least one physical cell, for each of the at least one physical cell: obtaining geographical attribution information of the physical cell and identity information of a beam of the satellite serving the physical cell after the handover; generating a new logical cell global identification based on the geographical attribution information and the identity information of the beam after the handover; adding the new logical cell global identification to the identification list to update a service association between the physical cell and the satellite; meanwhile, marking or deleting a logical cell global identification in the identification list associated with the physical cell and corresponding to a beam before the handover.

6. The method of claim 1, wherein, The logical cell global identification is a binary code of fixed length, and its encoding structure comprises in sequence: a physical cell geographical attribute field containing a mobile country code (MCC), a mobile network code (MNC) and a tracking area code (TAC); a satellite logical identification field containing a satellite constellation identification, a satellite on-orbit identification and a beam identification; and a reserved field for functional expansion.

7. The method of claim 6, wherein, The method further comprises: when a real-time coverage area of the satellite crosses a boundary of different countries or operator networks, dynamically updating a mobile country code (MCC) and / or a mobile network code (MNC) in the geographical attribute field of the logical cell global identification to match an actual network attribution of a geographical area currently served by the satellite.

8. A storage medium, characterized by The storage medium comprises a stored program, wherein the program is executed by a processor to perform the method of any one of claims 1 to 7 when the program is running.

9. A cell identification and paging device suitable for non-terrestrial networks, characterized in that, Comprise: an ephemeris data acquisition module for acquiring ephemeris data of at least one satellite; a real-time coverage area determination module for determining a real-time coverage area of the satellite on the ground based on the ephemeris data and beam parameters of the satellite; a coverage area matching module for matching the real-time coverage area of the satellite with coverage areas of at least one physical cell to determine a coverage overlap relationship between the satellite and the physical cell; a global identification generation or update module for generating or updating a corresponding logical cell global identification based on the coverage overlap relationship and storing the logical cell global identification in a locally maintained identification list; wherein the logical cell global identification comprises a geographical attribute field identifying geographical attribution of the physical cell and a satellite logical identification field identifying identity information of a satellite serving the physical cell; a global identification query module for, in response to a paging request for a target terminal, querying a logical cell global identification currently corresponding to a target physical cell associated with the target terminal from the identification list according to information of the target physical cell; a target satellite determination module for determining a target satellite currently serving the target physical cell according to identity information of a satellite carried in the queried logical cell global identification and sending a paging message for the target terminal to the target satellite.

10. A cell identification and paging apparatus for a non-terrestrial network, the apparatus comprising: a cell identification module configured to identify a cell of the non-terrestrial network; and a paging module configured to page a user equipment (UE) in the cell. Comprise: a processor; and a memory connected with the processor for providing the processor with instructions for processing the following processing steps: acquiring ephemeris data of at least one satellite; determining a real-time coverage area of the satellite on the ground based on the ephemeris data and beam parameters of the satellite; matching the real-time coverage area of the satellite with a coverage area of at least one physical cell to determine a coverage overlap relationship between the satellite and the physical cell; generating or updating a corresponding logical cell global identifier based on the coverage overlap relationship and storing the logical cell global identifier in a locally maintained identifier list, wherein the logical cell global identifier includes a geographical attribute field identifying a geographical home of the physical cell and a satellite logical identifier field identifying satellite identity information serving the physical cell; in response to a paging request for a target terminal, querying the identifier list for a logical cell global identifier currently corresponding to a target physical cell associated with the target terminal based on information of the target physical cell; determining a target satellite currently serving the target physical cell based on satellite identity information carried in the queried logical cell global identifier and sending a paging message for the target terminal to the target satellite.

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