Seamless switching method and system for data service in 5G communication of low earth orbit satellite

Abstract

The invention discloses a seamless switching method and system for data services in low earth orbit satellite 5G communication, and the method comprises the steps: building a session from a user terminal to a satellite base station and then to a satellite-borne UPF under the control of a ground core network after a user starts up and connects the satellite base station, and distributing an Internet access IP address for the user, all information of the session is stored in a network element of the ground core network SMF, before the satellite base station is about to be switched, the ground core network SMF inquires a new target satellite base station and a satellite-borne UPF, session information is sent to the new satellite base station and the satellite-borne UPF in advance, the same session is established, and when the satellite base station is switched, the satellite base station is switched to the satellite-borne UPF. The new satellite base station and the satellite-borne UPF can directly receive the user service and delete session information on the original old satellite and the old satellite-borne UPF, seamless switching of the data service is achieved, signaling overhead and time delay caused by frequent offline and reconnection are reduced, and the overall efficiency of a communication system is improved.

Description

Technical Field

[0001] The present invention relates to the field of 5G network communication technology, and in particular to a method and system for seamless switching of data services in low-orbit satellite 5G communications. Background Art

[0002] 3GPP's non-terrestrial network (NTN) aims to use non-terrestrial nodes such as satellites to expand the coverage of communication networks and improve the reliability and availability of communications. In 3GPP's R17 and R18, NTN mainly studies the satellite transparent forwarding mode. In this mode, the satellite only serves as a link for signal relay, plays the role of transparent forwarding in a curved pipe, does not process signals, and connects mobile phones and gateways. As part of the ground network, the base station is deployed behind the gateway. The UE accesses the 5G network via satellite and ground gateway based on the 5G NR wireless interface, and the data interaction is consistent with that of the ground mobile communication system. In addition to the satellite transparent forwarding mode, the existing low-orbit satellite Internet technology also has a solution that launches the satellite base station and the core network user plane function (UPF) into the sky together. Under this technology, users can directly land on the target network through the satellite base station, and the satellite-borne UPF does not need to detour to the ground core network after landing on the ground gateway like the transparent forwarding mode, and then go to the target network, which reduces the transmission nodes and distance and reduces the latency of data services.

[0003] The solution of launching satellite base stations and core network user plane network elements (UPF) into space together is referred to as the onboard UPF solution. UPF is the user plane network element of the core network and the gateway for the user data service export. All data exchanges with the target network need to go through UPF. In the onboard UPF mode, due to the high-speed movement of low-orbit satellites relative to the earth, frequent satellite switching causes the onboard UPF to switch accordingly, which in turn causes users to frequently disconnect, seriously affecting the user experience.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] The main purpose of the present invention is to provide a method and system for seamless switching of data services in low-orbit satellite 5G communications, aiming to solve the problem in the prior art that in the onboard UPF mode, due to the high-speed movement of low-orbit satellites relative to the earth, frequent satellite switching causes the onboard UPF to switch accordingly, which in turn causes users to frequently disconnect and seriously affects the user experience.

[0006] To achieve the above object, the present invention provides a method for seamless switching of data services in low-orbit satellite 5G communication, and the method for seamless switching of data services in low-orbit satellite 5G communication comprises the following steps:

[0007] When the user terminal is turned on and connected to the satellite, registration authentication and session establishment are completed through the ground core network. A new ground core network SMF is added to save the session information. According to the user's location information and ephemeris information, the satellite service time is calculated and the timer is set;

[0008] According to the user's location, the ground core network SMF establishes a session for the new satellite base station and the new onboard UPF in advance before the service ends, and deletes the original session information after the switch is completed to complete the seamless switching of satellite Internet data services.

[0009] Optionally, the method for seamless switching of data services in low-orbit satellite 5G communication, when the user terminal is powered on and connected to the satellite, registration authentication and session establishment are completed through the ground core network, a ground core network SMF is added to save session information, and the satellite service time is calculated according to the user's location information and ephemeris information, and a timer is set, specifically including:

[0010] The satellite terminal sends a registration request to the satellite base station;

[0011] The satellite base station forwards the registration request to the ground core network AMF, and the ground core network AMF initiates a user information verification request to the ground core network UDM. After verification, the ground core network UDM returns the user verification result to the ground core network AMF;

[0012] The ground core network AMF triggers a session establishment request to the ground core network SMF according to the user verification result, the ground core network SMF initiates a session creation instruction to the satellite UPF, and the satellite UPF returns a session creation response to the ground core network SMF;

[0013] The ground core network SMF stores session information, calculates the time the satellite serves the user based on the ephemeris information and the user location information, and sets a timer based on the time the satellite serves the user.

[0014] Optionally, in the method for seamless switching of data services in low-orbit satellite 5G communications, the timer is used to notify the ground core network SMF to start establishing a session with a new satellite base station and a new onboard UPF at a preset time before the end of the service, and the ground core network SMF returns a session establishment completion response to the ground core network AMF, which is then fed back to the satellite terminal through the satellite base station in turn, informing the satellite terminal that the registration and session establishment are successful.

[0015] Optionally, in the method for seamless switching of data services in low-orbit satellite 5G communications, the session information includes: user identification information, IP address allocation information, QoS parameters, security context information and service flow information.

[0016] Optionally, in the method for seamless switching of data services in low-orbit satellite 5G communications, the user identification information includes a unique identity of the user;

[0017] The IP address allocation information records the Internet access IP address allocated to the user;

[0018] The QoS parameters include bandwidth requirements and delay requirements;

[0019] The security context information includes encryption keys and authentication information;

[0020] The service flow information includes the type of service being performed by the user and the data transmission path.

[0021] Optionally, the method for seamless switching of data services in low-orbit satellite 5G communication, wherein the ground core network SMF establishes a session for the new satellite base station and the new onboard UPF in advance before the end of the service according to the location of the user, and deletes the original session information after the switching is completed to complete the seamless switching of satellite Internet data services, specifically including:

[0022] The ground core network SMF notifies the new satellite base station and the new satellite-borne UPF to establish a session respectively, and the established session parameters are sent by the ground core network SMF to the new satellite base station and the new satellite-borne UPF according to the original session information previously saved;

[0023] The original satellite base station triggers the satellite base station switching process, and the satellite terminal negotiates with the new satellite base station to complete the RRC connection establishment;

[0024] The new satellite base station initiates a satellite UPF switching request to the ground core network SMF, and the ground core network SMF confirms that the switching is in progress;

[0025] After the ground core network SMF confirms that the new satellite base station and the new onboard UPF have completed the session switching, it notifies the original satellite base station and the original onboard UPF to delete the local session information, and receives the session information deletion result fed back by the original satellite base station and the original onboard UPF;

[0026] The ground core network SMF replies to the new satellite base station and the new onboard UPF that the onboard UPF switching request has been completed.

[0027] Optionally, in the method for seamless switching of data services in low-orbit satellite 5G communications, the RRC connection is a signaling connection between the satellite terminal and the network, used to transmit control plane information.

[0028] Optionally, in the method for seamless switching of data services in low-orbit satellite 5G communications, the RRC connection is also used to manage wireless resources between the terminal and the base station, including establishment, reconfiguration and release operations of wireless bearers.

[0029] Optionally, the method for seamless switching of data services in low-orbit satellite 5G communication, the method for seamless switching of data services in low-orbit satellite 5G communication further includes:

[0030] In a satellite communication scenario, when a satellite base station is switched, an RRC connection is established between the terminal and the new satellite base station to achieve normal communication under the new satellite coverage.

[0031] In addition, to achieve the above-mentioned purpose, the present invention also provides a seamless switching system for data services in low-orbit satellite 5G communication, wherein the seamless switching system for data services in low-orbit satellite 5G communication includes: a satellite terminal, a satellite base station, a ground core network AMF, a ground core network SMF, a ground core network UDM, a satellite-borne UPF, a new satellite base station and a new satellite-borne UPF;

[0032] When the user terminal is turned on and connected to the satellite, registration authentication and session establishment are completed through the ground core network. The session information is saved through the ground core network SMF. According to the user's location information and ephemeris information, the satellite service time is calculated and the timer is set;

[0033] According to the user's location, the ground core network SMF establishes a session for the new satellite base station and the new onboard UPF in advance before the service ends, and deletes the original session information after the switch is completed to complete the seamless switching of satellite Internet data services.

[0034] In the present invention, after the user turns on the phone and connects to the satellite base station, under the control of the ground core network, a session is established from the user terminal to the satellite base station and then to the satellite UPF, and an IP address for Internet access is allocated to the user. All information of this session is stored in the ground core network SMF network element. Before the satellite base station is about to switch, the ground core network SMF queries the new target satellite base station and the satellite UPF, sends the session information to the new satellite base station and the satellite UPF in advance, and establishes an identical session. When the satellite base station switches, the new satellite base station and the satellite UPF can directly take over the user service, and then delete the session information on the original old satellite and the old satellite UPF, thereby realizing seamless switching of data services. The present invention avoids user disconnection caused by satellite UPF switching by preparing a new session in advance and realizing seamless handover when the satellite switches, ensures business continuity during the satellite switching process, reduces the risk of communication failure, reduces the signaling overhead and time delay caused by frequent disconnection and reconnection, and improves the overall efficiency of the communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the existing user data service access process;

[0036] Figure 2It is a flow chart of a preferred embodiment of a method for seamless switching of data services in low-orbit satellite 5G communication of the present invention;

[0037] Figure 3 It is a schematic diagram of the flow of satellite communication in a preferred embodiment of the method for seamless switching of data services in low-orbit satellite 5G communication of the present invention;

[0038] Figure 4 It is a flowchart of switching satellite Internet data services in a preferred embodiment of the method for seamless switching of data services in low-orbit satellite 5G communications of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] The solution of launching satellite base stations and core network user plane elements (UPF) into space together is referred to as the onboard UPF solution. UPF is the user plane element of the core network and the gateway for the user data service export. All data exchanges with the target network need to go through UPF. The user data service access process is as follows Figure 1 As shown, in this mode, the user uses the satellite network to access the target network, and the user-side data flow passes through the satellite base station, the onboard UPF, and the ground gateway station to the target network in sequence. For example, the user browses the web through the satellite Internet, and the access request for browsing the web page is sent by the satellite terminal to the satellite base station, and the satellite base station forwards it to the onboard UPF. After the onboard UPF resolves the target IP address to be accessed, it sends the access request to the ground gateway station, and the ground gateway station forwards it to the web server. The web server returns the web data packet to the satellite terminal by the original route.

[0041] Low orbit refers to low earth orbit (LEO). Generally speaking, the altitude of low earth orbit ranges from 160 kilometers to 2000 kilometers from the earth's surface. This altitude is much lower than medium and high orbits such as geostationary orbit (about 36,000 kilometers). Satellites operating in low orbits have a relatively short time to orbit the earth. For example, a low-orbit satellite at an altitude of several hundred kilometers may have an operating cycle of about 90 minutes. In this case, the time for low-orbit communication satellites to serve fixed targets on the ground is very limited. When users need continuous data transmission services, satellite base station switching will occur frequently. Under the satellite-borne UPF solution, since the core network UPF network elements are deployed in low orbits together with satellite base stations, the satellite-borne UPF will also switch frequently with the satellite base station. Due to the switching of the satellite-borne UPF, users need to reattach and re-establish the session to continue the data service. During this period, the ongoing data transmission will be interrupted, and users will feel that they are often disconnected and the network is extremely unstable.

[0042] The present invention aims to solve the problem in the onboard UPF mode of existing low-orbit satellite communications that, due to the high-speed movement of low-orbit satellites relative to the earth, frequent satellite switching causes the onboard UPF to switch accordingly, which in turn causes users to frequently disconnect, seriously affecting the user experience.

[0043] The basic idea of ​​the present invention is: when the user turns on the phone and connects to the satellite base station, under the control of the ground core network, a session is established from the user terminal to the satellite base station and then to the satellite UPF, and an IP address for Internet access is allocated to the user. All information of this session is stored in the ground core network SMF (Session Management Function). Before the satellite base station is about to be switched, the ground core network SMF queries the new target satellite base station and the satellite UPF, sends the session information to the new satellite base station and the satellite UPF in advance, and establishes an identical session. When the satellite base station is switched, the new satellite base station and the satellite UPF can directly take over the user service, and then delete the session information on the old satellite and the old satellite UPF, thereby realizing seamless switching of data services.

[0044] The method for seamless switching of data services in low-orbit satellite 5G communication described in the preferred embodiment of the present invention is as follows: Figure 2 As shown, the method for seamless switching of data services in low-orbit satellite 5G communication includes the following steps:

[0045] Step S10: When the user terminal is turned on and connected to the satellite, registration authentication and session establishment are completed through the ground core network. A new ground core network SMF is added to save session information. According to the user's location information and ephemeris information, the satellite service time is calculated and a timer is set.

[0046] Specifically, Figure 3 As shown, the step S10 specifically includes:

[0047] Step S11: The satellite terminal sends a registration request to the satellite base station, starting the entire process.

[0048] Step S12: The satellite base station forwards the registration request to the ground core network AMF (Access and Mobility Management Function), and the ground core network AMF initiates a user information verification request to the ground core network UDM (Unified Data Management), and the ground core network UDM returns the user verification result to the ground core network AMF after verification.

[0049] Step S13: The ground core network AMF triggers a session establishment request to the ground core network SMF according to the user verification result. The ground core network SMF initiates a session creation instruction to the satellite UPF. The satellite UPF returns a session creation response to the ground core network SMF.

[0050] Step S14: The ground core network SMF saves the session information, calculates the time the satellite serves the user according to the ephemeris information and the user location information, and sets a timer according to the time the satellite serves the user.

[0051] Among them, the timer is used to notify the ground core network SMF to start establishing a session with a new satellite base station and a new satellite-borne UPF at a preset time (for example, 5 seconds, and the advance amount can be modified according to actual conditions) before the end of the service. The ground core network SMF returns a session establishment completion response to the ground core network AMF, which is then fed back to the satellite terminal through the satellite base station in turn, informing the satellite terminal that the registration and session establishment are successful.

[0052] In the above process, when the ground core network SMF saves the session information, the following contents are mainly saved:

[0053] (1) User identification information: This includes the user's unique identity information, ensuring that the user can be accurately identified during the switching process between different satellite base stations and onboard UPFs.

[0054] (2) IP address allocation information: This records the Internet access IP address allocated to the user so that the same IP address can be reassigned to the user when a new session is established, thus ensuring business continuity.

[0055] (3) QoS (Quality of Service) parameters: such as bandwidth requirements and delay requirements, to ensure that the new session can provide users with the same quality of service as the original session.

[0056] (4) Security context information: including encryption keys, authentication information, etc., to ensure the security of user data during the switching process.

[0057] (5) Service flow information: such as the type of service the user is currently performing, the data transmission path, etc., so that the new satellite base station and onboard UPF can quickly take over the user's service and achieve seamless switching.

[0058] In addition to storing session information, the ground core network SMF also sets a timer. The ground core network SMF calculates the time when the satellite currently serving the user can serve the user through the user location information and ephemeris information. When the ground core network SMF determines the service time of the satellite, it sets the timer according to this time. During the process of the satellite serving the user, the timer continues to run. When the timer is close to the set time, it means that the current satellite service for the user is about to end. At this time, the ground core network SMF will be triggered by the timer to start the process of establishing a new session.

[0059] This session information can support the ground core network SMF to establish an identical session for the new satellite base station and the onboard UPF, ensuring that users will not experience service interruption during the satellite switching process.

[0060] Step S20: According to the user's location, the ground core network SMF establishes a session for the new satellite base station and the new onboard UPF in advance before the service ends, and deletes the original session information after the switching is completed to complete the seamless switching of satellite Internet data services.

[0061] Specifically, Figure 4 As shown, the step S20 specifically includes:

[0062] Step S21, the ground core network SMF notifies the new satellite base station and the new satellite-borne UPF to establish a session respectively, and the established session parameters are sent to the new satellite base station and the new satellite-borne UPF by the ground core network SMF according to the original session information previously saved; at this time, the RRC connection from the satellite base station to the satellite terminal is not established, and some internal collaborative feedback can be performed between the two to prepare for session-related operations.

[0063] Step S22: The original satellite base station triggers the satellite base station switching process, and the satellite terminal negotiates with the new satellite base station to complete the RRC connection establishment.

[0064] Step S23: The new satellite base station initiates a satellite UPF switching request to the ground core network SMF, and the ground core network SMF confirms that it is aware that the switching is in progress.

[0065] Step S24: After the ground core network SMF confirms that the new satellite base station and the new onboard UPF have completed the session switching, it notifies the original satellite base station and the original onboard UPF to delete the local session information, and receives the session information deletion result fed back by the original satellite base station and the original onboard UPF (the feedback part can be strictly implemented according to actual conditions).

[0066] Step S25: The ground core network SMF replies to the new satellite base station and the new onboard UPF that the onboard UPF switching request has been completed, and the entire onboard UPF optimization switching process is completed.

[0067] Among them, the RRC (Radio Resource Control) connection is a signaling connection between the satellite terminal and the network, which is used to transmit control plane information. It is mainly responsible for managing the wireless resources between the terminal and the base station, including the establishment, reconfiguration and release of wireless bearers. Through the RRC connection, the terminal can obtain network configuration information, such as cell selection, switching and other related parameters, which is an important link in realizing communication between the terminal and the network. In the satellite communication scenario, when the satellite base station is switched, an RRC connection is established between the terminal and the new satellite base station, so that normal communication can be achieved under the new satellite coverage.

[0068] During the satellite base station switching process, in order to ensure the effective use of resources and avoid conflicts, when the new satellite base station and the new onboard UPF session are established, it is necessary to notify the deletion of the original session. Because the original session is established based on the old satellite base station and the old onboard UPF, the old session is no longer necessary. Moreover, if the old session is not deleted, it may lead to a waste of network resources. And if two sessions exist at the same time, it may cause confusion in data transmission. For example, user data may be mistakenly sent to the old satellite base station or old onboard UPF corresponding to the old session, resulting in data loss or failure to receive it correctly. There will also be problems in billing and security, and there may be duplicate billing or security vulnerabilities because the two sessions may have different security configurations and billing rules. Therefore, the session on the original satellite needs to be deleted after the switch is completed.

[0069] The innovative features of the present invention are as follows:

[0070] (1) The SMF network element of the satellite ground 5G core network has been innovated, and a new capability has been added to save the session information of each user. This allows the SMF to send the original session parameters to the new satellite base station and the new satellite UPF when the satellite UPF is switched, and guide the new satellite base station and the new satellite UPF to establish the same session as the original one.

[0071] (2) The SMF network element of the satellite ground 5G core network has been innovated and a service duration timer has been added. Based on the user's location information and ephemeris information, the SMF can calculate how long the satellite can provide service to the user, and set the service duration timer accordingly. When the timer expires, the SMF is notified to establish a subsequent session.

[0072] (3) The switching process of the satellite base station is innovated. After the existing satellite base station switching is completed, the onboard UPF switching will not be performed. The present invention adds a satellite-borne UPF switching process, which is initiated by the satellite base station after the base station switching is completed. Since the satellite base station does not know which satellite will take over later, it is necessary to initiate the onboard UPF switching process to the ground core network AMF, and the ground core network AMF forwards it to the SMF, which executes the satellite-borne UPF switching.

[0073] (4) The SMF network element of the satellite ground 5G core network has been innovated, and a new process has been added to notify the original satellite base station and onboard UPF to delete the original session, reducing the waste of network resources and ensuring that only one session provides services to users at the same time.

[0074] The beneficial effects of the present invention are as follows:

[0075] (1) Effectively solve the problem of frequent user disconnection: By preparing new sessions in advance and achieving seamless handover when switching satellites, user disconnection caused by onboard UPF switching is avoided, greatly improving the user experience.

[0076] (2) Improve the stability and reliability of the communication system: ensure business continuity during satellite switching and reduce the risk of communication failure.

[0077] (3) Improve communication efficiency: Reduce the signaling overhead and time delay caused by frequent disconnection and reconnection, and improve the overall efficiency of the communication system.

[0078] Furthermore, if Figure 3 and Figure 4 As shown, based on the above-mentioned method for seamless switching of data services in low-orbit satellite 5G communication, the present invention also provides a system for seamless switching of data services in low-orbit satellite 5G communication, wherein the system for seamless switching of data services in low-orbit satellite 5G communication includes: a satellite terminal, a satellite base station (i.e. Figure 4 The original satellite base station in the ground core network), ground core network AMF, ground core network SMF, ground core network UDM, satellite UPF (i.e. Figure 4 The original satellite-borne UPF), new satellite base station and new satellite-borne UPF;

[0079] When the user terminal is turned on and connected to the satellite, registration authentication and session establishment are completed through the ground core network. The session information is saved through the ground core network SMF. According to the user's location information and ephemeris information, the satellite service time is calculated and the timer is set. According to the user's location, the ground core network SMF establishes a session for the new satellite base station and the new onboard UPF in advance before the service ends, and deletes the original session information after the switch is completed to complete the seamless switching of satellite Internet data services.

[0080] Specifically, the satellite terminal sends a registration request to the satellite base station; the satellite base station forwards the registration request to the ground core network AMF, the ground core network AMF initiates a user information verification request to the ground core network UDM, and the ground core network UDM returns the user verification result to the ground core network AMF after verification; the ground core network AMF triggers a session establishment request to the ground core network SMF according to the user verification result, the ground core network SMF initiates a session creation instruction to the satellite UPF, and the satellite UPF returns a session creation response to the ground core network SMF; the ground core network SMF saves the session information, calculates the time for the satellite to serve the user according to the ephemeris information and the user location information, and sets a timer according to the time for the satellite to serve the user. The timer is used to notify the ground core network SMF to start a new satellite base station and a new satellite UPF to establish a session at a preset time before the end of the service. The ground core network SMF returns a session establishment completion response to the ground core network AMF, which is finally fed back to the satellite terminal through the satellite base station in turn, informing the satellite terminal that the registration and session establishment are successful.

[0081] Specifically, the ground core network SMF notifies the new satellite base station and the new satellite-borne UPF to establish a session respectively, and the established session parameters are sent to the new satellite base station and the new satellite-borne UPF by the ground core network SMF according to the original session information previously saved; the original satellite base station triggers the satellite base station switching process, and the satellite terminal negotiates with the new satellite base station to complete the RRC connection establishment; the new satellite base station initiates a satellite-borne UPF switching request to the ground core network SMF, and the ground core network SMF confirms that it knows that the switching is in progress; after the ground core network SMF confirms that the new satellite base station and the new satellite-borne UPF have completed the session switching, it notifies the original satellite base station and the original satellite-borne UPF to delete the local session information, and receives the session information deletion result fed back by the original satellite base station and the original satellite-borne UPF; the ground core network SMF replies to the new satellite base station and the new satellite-borne UPF that the satellite-borne UPF switching request has been completed.

[0082] In summary, the present invention provides a method and system for seamless switching of data services in low-orbit satellite 5G communication, the method comprising: when the user turns on the phone and connects to the satellite base station, under the control of the ground core network, a session is established from the user terminal to the satellite base station and then to the satellite UPF, and an IP address for Internet access is allocated to the user, all information of this session is stored in the ground core network SMF network element, before the satellite base station is about to switch, the ground core network SMF queries the new target satellite base station and the satellite UPF, sends the session information to the new satellite base station and the satellite UPF in advance, and establishes an identical session, when the satellite base station switches, the new satellite base station and the satellite UPF can directly take over the user service, and then delete the session information on the original old satellite and the old satellite UPF, thereby realizing seamless switching of data services. The present invention avoids user disconnection caused by satellite UPF switching by preparing a new session in advance and realizing seamless handover when the satellite switches, ensures business continuity during satellite switching, reduces the risk of communication failure, reduces the signaling overhead and time delay caused by frequent disconnection and reconnection, and improves the overall efficiency of the communication system.

[0083] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or terminal including the element.

[0084] Of course, those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the program can be stored in a computer-readable storage medium that can be read by a computer, and the program can include the processes of the above-mentioned method embodiments when executed. The computer-readable storage medium can be a memory, a disk, an optical disk, etc.

[0085] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for seamless switching of data services in low-orbit satellite 5G communications, characterized in that: The method for seamless switching of data services in low-orbit satellite 5G communication includes: When the user terminal is turned on and connected to the satellite, registration authentication and session establishment are completed through the ground core network. A new ground core network SMF is added to save the session information. According to the user's location information and ephemeris information, the satellite service time is calculated and the timer is set; According to the user's location, the ground core network SMF establishes a session for the new satellite base station and the new onboard UPF in advance before the service ends, and deletes the original session information after the switch is completed to complete the seamless switching of satellite Internet data services.

2. The method for seamless switching of data services in low-orbit satellite 5G communication according to claim 1, characterized in that: When the user terminal is powered on and connected to the satellite, registration authentication and session establishment are completed through the ground core network, a ground core network SMF is added to save session information, and the satellite service time is calculated according to the user's location information and ephemeris information, and a timer is set, which specifically includes: The satellite terminal sends a registration request to the satellite base station; The satellite base station forwards the registration request to the ground core network AMF, and the ground core network AMF initiates a user information verification request to the ground core network UDM. After verification, the ground core network UDM returns the user verification result to the ground core network AMF; The ground core network AMF triggers a session establishment request to the ground core network SMF according to the user verification result, the ground core network SMF initiates a session creation instruction to the satellite UPF, and the satellite UPF returns a session creation response to the ground core network SMF; The ground core network SMF stores session information, calculates the time the satellite serves the user based on the ephemeris information and the user location information, and sets a timer based on the time the satellite serves the user.

3. The method for seamless switching of data services in low-orbit satellite 5G communication according to claim 2 is characterized in that: The timer is used to notify the ground core network SMF to start establishing a session with a new satellite base station and a new satellite-borne UPF at a preset time before the end of the service. The ground core network SMF returns a session establishment completion response to the ground core network AMF, which is then fed back to the satellite terminal through the satellite base station in turn, informing the satellite terminal that the registration and session establishment are successful.

4. The method for seamless switching of data services in low-orbit satellite 5G communication according to claim 1 or 2, characterized in that: The session information includes: user identification information, IP address allocation information, QoS parameters, security context information and service flow information.

5. The method for seamless switching of data services in low-orbit satellite 5G communication according to claim 4 is characterized in that: The user identification information includes the user's unique identity; The IP address allocation information records the Internet access IP address allocated to the user; The QoS parameters include bandwidth requirements and delay requirements; The security context information includes encryption keys and authentication information; The service flow information includes the type of service being performed by the user and the data transmission path.

6. The method for seamless switching of data services in low-orbit satellite 5G communication according to claim 3, characterized in that: According to the user's location, the ground core network SMF establishes a session for the new satellite base station and the new satellite-borne UPF in advance before the service ends, and deletes the original session information after the handover is completed to complete the seamless handover of the satellite Internet data service, specifically including: The ground core network SMF notifies the new satellite base station and the new satellite-borne UPF to establish a session respectively, and the established session parameters are sent by the ground core network SMF to the new satellite base station and the new satellite-borne UPF according to the original session information previously saved; The original satellite base station triggers the satellite base station switching process, and the satellite terminal negotiates with the new satellite base station to complete the RRC connection establishment; The new satellite base station initiates a satellite UPF switching request to the ground core network SMF, and the ground core network SMF confirms that the switching is in progress; After the ground core network SMF confirms that the new satellite base station and the new onboard UPF have completed the session switching, it notifies the original satellite base station and the original onboard UPF to delete the local session information, and receives the session information deletion result fed back by the original satellite base station and the original onboard UPF; The ground core network SMF replies to the new satellite base station and the new onboard UPF that the onboard UPF switching request has been completed.

7. The method for seamless switching of data services in low-orbit satellite 5G communication according to claim 6, characterized in that: The RRC connection is a signaling connection between the satellite terminal and the network, used to transmit control plane information.

8. The method for seamless switching of data services in low-orbit satellite 5G communication according to claim 7, characterized in that: The RRC connection is also used to manage radio resources between the terminal and the base station, including the establishment, reconfiguration and release operations of radio bearers.

9. The method for seamless switching of data services in low-orbit satellite 5G communication according to claim 6, characterized in that: The method for seamless switching of data services in the low-orbit satellite 5G communication also includes: In a satellite communication scenario, when a satellite base station is switched, an RRC connection is established between the terminal and the new satellite base station to achieve normal communication under the new satellite coverage.

10. A seamless switching system for data services in low-orbit satellite 5G communications, characterized in that: The seamless switching system for data services in the low-orbit satellite 5G communication includes: a satellite terminal, a satellite base station, a ground core network AMF, a ground core network SMF, a ground core network UDM, a satellite-borne UPF, a new satellite base station and a new satellite-borne UPF. When the user terminal is turned on and connected to the satellite, registration authentication and session establishment are completed through the ground core network. The session information is saved through the ground core network SMF. According to the user's location information and ephemeris information, the satellite service time is calculated and the timer is set. According to the user's location, the ground core network SMF establishes a session for the new satellite base station and the new onboard UPF in advance before the service ends, and deletes the original session information after the switch is completed to complete the seamless switching of satellite Internet data services.

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