Satellite DVB and 5G different system access network switching management method and system

Abstract

The invention relates to the technical field of satellite communication, in particular to a satellite DVB and 5G different system access network switching management method and system, a user terminal sends a wireless connection measurement report during 5G communication, a 5G base station judges whether to switch a network according to the wireless connection measurement report, and a switching request is sent to a gateway function conversion module through a newly added inter-network interface. And the target satellite beam serving cell judges whether to accept or not, and after acceptance, the gateway function conversion module converts confirmation information and returns the confirmation information to the 5G base station. Then, the target satellite beam serving cell allocates resources, the 5G base station sends an instruction to trigger the user terminal to switch and processes a data packet, the gateway function conversion module converts a data format and then sends the data packet, the user terminal initiates access to complete switching, and efficient switching of different-system networks is achieved.

Description

Satellite DVB and 5G heterogeneous access network handover management method and system Technical Field

[0001] This application relates to the field of satellite communication technology, and in particular to a method and system for managing the handover between satellite DVB and 5G heterogeneous access networks. Background Technology

[0002] Satellite communication and 5G communication are crucial communication methods in people's lives, playing a key role in the field of communication. However, there are significant differences between satellite communication systems and 5G communication systems. Besides the difference between space-based and ground-based communication scenarios, the most significant difference lies in their fundamentally different technical systems. Currently, mainstream satellite communication uses the DVB-type system, such as the DVB-S2X technology, while 5G communication follows the 5G technology system defined by 3GPP. Due to these significant differences in technical systems, the control information and service data transmitted in satellite communication systems and 5G communication systems differ in type, format, and transmission method.

[0003] In practical applications, existing technologies have significant drawbacks when user terminals switch from 5G networks to satellite networks, or vice versa. For example, after a user terminal disconnects from the current network, it needs to re-enter the network access authentication process for the other network, resulting in a long interval and significant service interruption, severely impacting user experience. Furthermore, user terminals have independent identity accounts in both satellite and 5G networks, and these two accounts are not interoperable. This makes it difficult for operators to implement unified billing, creating obstacles to the release of integrated satellite-ground communication packages.

[0004] With the increasing demand for integrated space-ground communication, there is an urgent need to enable communication user terminals to switch between satellite communication networks and 5G networks using a unified identity account. Simultaneously, interoperability of handover signaling between the two networks is required, along with coordinated preparation between the outgoing and incoming networks. This improves the automation level of handover, reduces handover downtime, and enhances the user's communication experience. Therefore, existing technologies have proposed methods, architectures, and protocol procedures for cross-regional handover of user terminals within the satellite access network. These technologies utilize 5G technology, just like the terrestrial network. However, most commercial satellite communication systems and terminals on the market currently employ DVB technology, making these existing technologies unsuitable for the current market situation. To ensure compatibility with a large number of existing devices and considering the improved radio wave transmission efficiency of satellite communication using DVB technology, satellite-terrestrial convergence technology needs to be compatible with satellite DVB technology. Therefore, the heterogeneous integration of DVB and 5G technologies represents a promising development direction for integrated space-ground collaborative networks.

[0005] To adapt to the mobility characteristics of mobile vehicles such as aircraft, ships, and automobiles in a converged DVB-based satellite and 5G-based terrestrial network, and to meet the requirement of continuous communication after switching between 5G and satellite networks when mobile vehicles cross coverage areas, a method is needed to manage handover when user terminals switch between 5G and satellite networks. However, existing satellite network handover methods and 5G network handover methods are only applicable to handover within a single satellite communication network or a single 5G network, and cannot enable user terminals to switch between satellite access networks and 5G heterogeneous access networks with the same identity within a converged satellite and 5G network. Furthermore, some existing patents with similar scenarios only apply to situations where the satellite communication network also uses 5G technology, and are not applicable to the scenario where the satellite communication network uses DVB technology in this solution. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention provides a method and system for managing the handover between satellite DVB and 5G heterogeneous access networks. This enables user terminals to switch between DVB-based satellite networks (i.e., satellite access networks) and 5G-based networks (i.e., 5G access networks). When communication user terminals need to move across different technology networks, the handover ensures unified identity authentication for user terminals and a short handover time, thereby guaranteeing continuous communication services and unified billing across heterogeneous networks.

[0007] The first aspect of this application provides a method for managing handover between satellite DVB and 5G heterogeneous access networks, applied to a handover management system for satellite DVB and 5G heterogeneous access networks. The access network handover management system includes a user terminal, a 5G base station, a gateway function conversion module, and a target satellite beam serving cell. The method includes: when the user terminal is in a wireless communication state with the 5G base station, it sends a wireless connection measurement report to the 5G base station; the 5G base station determines whether to command the user terminal to switch networks based on the wireless connection measurement report, and sends an A1 handover request message to the gateway function conversion module through a newly added inter-network interface; the target satellite beam serving cell determines whether to accept the network handover request; when the gateway function conversion module determines that the target satellite beam serving cell accepts the network handover request, it converts the satellite DVB A1 handover confirmation message and returns it to the 5G base station to complete the network handover request confirmation. The target satellite beam serving cell allocates radio resources to the user terminal according to the network handover request; the 5G base station sends a radio resource reconfiguration command to the user terminal, triggering the user terminal to switch its current access network to the target satellite beam serving cell; the 5G base station sends a service data packet sequence number status transition message to the gateway function conversion module, determines the data packet number that has not been acknowledged by the target satellite beam serving cell, caches downlink data from the 5G core network, and forwards it to the gateway function conversion module; the gateway function conversion module converts the received data packet number into the satellite DVB system baseband data packet number format, encapsulates the downlink data into DVB system GSE protocol IP data packets, and sends them to the target satellite beam serving cell; the user terminal initiates a service random access procedure on the target satellite beam serving cell according to the received radio resource reconfiguration command, completing the network handover.

[0008] In an optional implementation, the method further includes: after the user terminal successfully accesses the target satellite beam serving cell, it sends a radio resource control reconfiguration completion message to the gateway function conversion module to confirm the completion of network handover; the gateway function conversion module sends an NGAP path handover request message to the AMF through the 5G core network to trigger the 5G core network to switch the downlink data transmission path from the 5G base station to the gateway function conversion module; the AMF returns an NGAP path handover request confirmation message to the gateway function conversion module through the NG interface; after receiving the NGAP path handover request confirmation message, the gateway function conversion module sends a UE context release message to the 5G base station through the newly added inter-network interface, so that the 5G base station releases the resources associated with the user terminal according to the UE context release message.

[0009] In one optional implementation, the wireless connectivity measurement report includes the signal strength of the 5G cell, the signal strength of adjacent satellite beam serving cells, the serving cell identification number, and the terminal's geographic location information; the 5G cell is the cell corresponding to the 5G base station to which the user terminal is currently connected.

[0010] In an optional implementation, the method further includes: when no mandatory prohibition of mobile handover is set for the user terminal, the 5G base station, based on the radio connectivity measurement report, commands the user terminal to switch networks when at least one of the following trigger conditions is met, and selects to switch to the target satellite beam serving cell based on the serving cell identification number: the signal strength received by the user terminal is insufficient to meet the contractually agreed rate standard; the user terminal's geographical location is at the edge of the 5G base station cell and continues to move away; the number of users carried by the 5G base station exceeds a preset first threshold, and the load reaches a preset second threshold, causing the rate of each user to drop below a preset third threshold; if none of the above trigger conditions are met, the 5G base station does not command the user terminal to switch networks.

[0011] In an optional implementation, when the target satellite beam serving cell accepts a network handover request, the gateway function conversion module converts the power information and QoS information of the satellite DVB system, carrier frequency and time slot information, and IP service list into target satellite beam serving cell radio resource control reconfiguration information, dedicated random access resource time and frequency information, and authorized and unauthorized PDU session lists in the standard 5G protocol format.

[0012] In an optional implementation, the method further includes: the user terminal receiving radio resource reconfiguration instruction information from the 5G base station; the user terminal converting the radio resource reconfiguration instruction information into a configuration on the satellite DVB module in the user terminal; and the user terminal performing a random access operation on the target satellite beam serving cell according to the power information, QoS information, carrier frequency, and time slot information in the radio resource reconfiguration instruction information.

[0013] In an optional implementation, the gateway function conversion module converts the handover request message into signal-to-noise ratio, beam identification number, and IP service list information in the satellite communication system architecture. The handover request message carries radio resource control messages, target satellite beam serving cell identification number, and PDU session list information in the 5G protocol.

[0014] A second aspect of this application provides a satellite DVB and 5G heterogeneous access network handover management system. The system includes: a user terminal, a 5G base station, a gateway function conversion module, and a target satellite beam serving cell. The user terminal is configured to send a wireless connection measurement report to the 5G base station when it is in a wireless communication state with the 5G base station. The 5G base station is configured to determine whether to command the user terminal to switch networks based on the wireless connection measurement report, and send an A1 handover request message to the gateway function conversion module through a new inter-network interface. The target satellite beam serving cell is configured to determine whether to accept the network handover request. The gateway function conversion module is configured to, when determining that the target satellite beam serving cell accepts the network handover request, convert the satellite DVB A1 handover confirmation message and return it to the 5G base station to complete the network handover request confirmation. The target satellite beam serving cell is further configured to... The network handover request allocates radio resources to the user terminal; the 5G base station is also used to send a radio resource reconfiguration command to the user terminal, triggering the user terminal to switch its current access network to the target satellite beam serving cell; send a service data packet sequence number status transition message to the gateway function conversion module to determine the data packet number that has not been acknowledged by the target satellite beam serving cell, cache downlink data from the 5G core network, and forward it to the gateway function conversion module; the gateway function conversion module is also used to convert the received data packet number into the satellite DVB system baseband data packet number format, encapsulate the downlink data into DVB system GSE protocol IP data packets, and send them to the target satellite beam serving cell; the user terminal is also used to initiate a service random access procedure on the target satellite beam serving cell according to the received radio resource reconfiguration command to complete the network handover.

[0015] In summary, the satellite DVB and 5G heterogeneous access network handover management method and system provided in this application have at least one of the following beneficial effects: 1. When the user terminal is in a wireless communication state with the 5G base station, it sends a wireless connection measurement report to the 5G base station. The 5G base station determines whether to command the user terminal to switch networks based on the report and sends a handover request message to the gateway function conversion module through the newly added inter-network interface. At the same time, the target satellite beam serving cell determines whether to accept the network handover request. This series of operations is performed in advance before the handover, enabling the outgoing network (5G network) and the incoming network (satellite network) to coordinate and prepare, instead of the user terminal disconnecting from the current network and then re-entering the other network as in the prior art. This reduces the waiting time during the handover process, reduces the handover interruption time, improves the degree of automation of the handover, effectively alleviates the problem of significant service interruption, and improves the user's communication experience.

[0016] 2. The 5G base station sends a service data packet sequence number status transition message to the gateway function conversion module to identify the data packet number that has not been acknowledged by the target satellite beam serving cell, and buffers downlink data from the 5G core network before forwarding it to the gateway function conversion module. The gateway function conversion module converts the received data packet number into the satellite DVB system baseband data packet number format, encapsulates the downlink data into DVB system GSE protocol IP data packets, and sends them to the target satellite beam serving cell. This method ensures that data is not lost or interrupted during handover, achieving continuous transmission of service data and further solving the service interruption problem.

[0017] 3. Applied to the satellite DVB and 5G heterogeneous access network handover management system, this system enables user terminals to switch between the satellite access network and the 5G access network with the same identity within the converged satellite and 5G networks. Unlike existing technologies, user terminals no longer need separate identity accounts in the satellite and 5G networks, thus enabling unified billing by operators and eliminating obstacles to the release of integrated space-ground communication packages.

[0018] 4. Considering that the vast majority of commercial satellite communication terminals on the market currently adopt the DVB technology system, in order to be compatible with a large number of existing devices and taking into account the improvement of satellite communication radio wave transmission efficiency of the DVB technology system, the proposed method is compatible with the satellite DVB technology system, realizes access network switching management between satellite DVB and 5G, and solves the problem that the existing methods cannot be applied to the scenario in which the satellite communication network adopts the DVB technology system in this solution.

[0019] 5. From the moment the user terminal sends a wireless connection measurement report, to the 5G base station determining and sending a handover request, the target satellite beam serving cell determining and accepting the request, the gateway function conversion module performing information conversion and returning confirmation, the target satellite beam serving cell allocating wireless resources, the 5G base station sending a wireless resource reconfiguration command to trigger the user terminal to switch networks, and then to the data transmission and the user terminal initiating a random access process to complete the network handover, the entire process is complete. This system can adapt to the mobility characteristics of mobile carriers such as airplanes, ships, and automobiles in the converged satellite and 5G network, and meet the need for continuous communication after switching between the two networks when mobile carriers cross the coverage areas of 5G and satellite networks. Attached Figure Description

[0020] Figure 1 is a flowchart illustrating a satellite DVB and 5G heterogeneous access network handover management method according to an embodiment of this application; Figure 2 is a structural diagram illustrating a satellite DVB and 5G heterogeneous access network handover management system according to an embodiment of this application; Figure 3 is a schematic diagram illustrating a pre-stored mapping table according to an embodiment of this application. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] The following will clearly and completely describe the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Furthermore, all connections / linkages involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this invention can be combined interactively without contradicting each other.

[0023] Referring to Figure 1, which is a flowchart illustrating a satellite DVB and 5G heterogeneous access network handover management method according to an embodiment of this application, the method is applied to a satellite DVB and 5G heterogeneous access network handover management system. The satellite DVB and 5G heterogeneous access network handover management includes the following steps.

[0024] The access network handover management system includes user terminals, 5G base stations, gateway function conversion modules (also known as gateway function conversion entities (AGF)) and target satellite beam service cells.

[0025] To facilitate understanding of the technical solution of this invention, the following terms are explained in conjunction with the content of the prior art: AGF: Gateway function conversion module, or gateway function conversion entity, including N1 interface protocol conversion unit, N2 interface protocol conversion unit and N3 interface protocol conversion unit.

[0026] 5GC: 5G core network, including the Access and Mobility Management Function Module (AMF) and the User Plane Function Module (UPF).

[0027] AMF: A network element in the standard 5G core network, serving as the functional unit for access management.

[0028] UPF: A network element in the standard 5G core network, serving as the user plane service transmission functional unit.

[0029] UE: User terminal.

[0030] PDU: Packet Data Unit.

[0031] NCC: Network Control Center in a satellite network.

[0032] Access network: The network and facilities between user terminals and the core network (or backbone network) are called the access network. Satellite access network consists of satellites and ground gateway stations and their supporting facilities, while 5G access network consists of 5G base stations and their supporting facilities.

[0033] The user terminal and the Access and Mobility Management Function (AMF) module are both connected to the N1 interface protocol conversion unit of the Gateway Function Conversion Module; the N2 interface protocol conversion unit and the N3 interface protocol conversion unit are both connected to the Satellite Network Control Center, wherein the N2 interface protocol conversion unit is connected to the AMF module and the N3 interface protocol conversion unit is connected to the User Plane Function (UPF) module.

[0034] Referring to Figure 2, the embodiment of this application uses a standard 5G core network, which includes other network elements besides the AMF. The UE communicates with the target satellite beam serving cell or the 5G base station via the DVB-S2x radio link or the 5G radio link, respectively. The 5G base station is connected to the gateway function conversion module (with NCC and AGF functions) through a newly added inter-network interface (hereinafter referred to as the A1 interface). The AGF is then connected to the satellite access network to which the target satellite beam serving cell belongs. At the same time, the 5G base station is also connected to the 5G core network through the AMF, thereby constructing a complete system connection architecture to ensure handover management between heterogeneous networks.

[0035] S11, when the user terminal is in a wireless communication state with the 5G base station, it sends a wireless connection measurement report to the 5G base station.

[0036] The UE is in a wireless communication state with the 5G base station and sends a wireless connection measurement report to the 5G base station. The wireless connection measurement report includes the signal strength of the 5G cell (the cell corresponding to the currently connected 5G base station, i.e., the 5G network cell that the UE is accessing for communication) and the adjacent satellite beam serving cell, the identification number of the serving cell (i.e., the 5G network cell that the UE is currently connected to), and the terminal's geographic location information.

[0037] S12, the 5G base station determines whether to command the user terminal to switch networks based on the wireless connection measurement report, and sends an A1 handover request message to the gateway function conversion module through the newly added inter-network interface.

[0038] The handover request sent via the A1 interface is called the A1 handover request message. In essence, it is an application sent by the 5G base station to the target satellite beam serving cell to "want to switch to the satellite serving cell" based on the user terminal's situation.

[0039] When a UE moves from the coverage area of ​​a 5G base station to the coverage area of ​​a target satellite beam service cell, a network handover is required.

[0040] When a 5G base station receives a wireless connectivity measurement report, it monitors its own load in real time, including base station resource utilization and the number of connected users, to determine whether the UE needs to be switched to another network due to excessive load. Simultaneously, it acquires terminal mobility restrictions and wireless capability information, such as system restrictions on the UE's service access, the UE's movement speed, and supported network frequency bands, to determine whether the UE is suitable for switching to a target network and the feasibility of the switch. Furthermore, it obtains the terminal's location information through positioning technology to accurately determine the UE's geographical location, enabling the selection of a target satellite beam service cell with suitable distance and good signal coverage.

[0041] Furthermore, the 5G base station can determine whether to command the UE to switch networks based on measurement reports, 5G base station load, terminal mobility restrictions and wireless capabilities, and terminal location information, and select the target satellite beam serving cell for switching using the serving cell's identification number. Specifically, under the condition that the system does not have a mandatory restriction prohibiting the user terminal from mobile handover, the handover triggering conditions (meeting any one of the following) are as follows: 1) The terminal's received signal is weak and insufficient to meet its contractually agreed rate standard; 2) The terminal's geographical location is already at the edge of the 5G base station cell and continues to move away; 3) The 5G base station is carrying too many users (i.e., the number of users exceeds the preset first threshold, for example, the number of users > 800), and the load is high (i.e., the load reaches or exceeds the preset second threshold, for example, the load > 80%), resulting in a severe drop in the rate of each user (i.e., the rate of each user drops below the preset third threshold, for example, the drop rate > 60%). If none of the above conditions are met, the terminal will not be commanded to switch networks.

[0042] The 5G base station sends an A1 handover request message to the AGF via the A1 interface. The A1 interface is a custom protocol interface, physically connected to the 5G base station and AGF via optical fiber, and then implemented through protocol procedures. Essentially, the A1 interface is a functional protocol interface. The A1 handover request message includes a Radio Resource Control (RRC) message from the 5G protocol, the target satellite beam serving cell identifier, and PDU session list information. The RRC message contains various parameters related to UE radio resource control, such as RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality). The target satellite beam serving cell identifier is a key identifier between the 5G base station and the satellite communication system for identifying the target cell; the selected target satellite beam serving cell identifier is filled into the target gNB cell identifier field. The PDU session list information contains relevant information about all PDU (Protocol Data Unit) sessions currently in progress for the UE, such as session identifiers and QoS (Quality of Service) parameters, ensuring that these sessions can be successfully continued to the target satellite beam serving cell during the handover process.

[0043] The 5G base station A1 uses the communication protocol and procedures specified to send the encapsulated A1 handover request message to the AGF.

[0044] Upon receiving the A1 handover request message, the AGF converts it into signal-to-noise ratio (SNR), beam identification number, and IP service list information for the satellite communication system, based on a pre-stored mapping table, as shown in Figure 3. The mapping table is generated before system deployment according to the planning and configuration of the 5G network and satellite communication network. Specifically, it converts the radio resource control message in the 5G protocol into SNR, for example, by combining RSRP and RSRQ using a specific algorithm to calculate a corresponding SNR value; it converts the target satellite beam serving cell identification number into a beam identification number, ensuring that each 5G target cell accurately corresponds to a satellite beam; and it converts the PDU session list information into IP service list information.

[0045] The AGF repackages the converted signal-to-noise ratio, beam identification number, and IP service list information of the satellite communication system according to the handover request message format specified by the satellite communication system, ensuring that the order, length, and encoding method of each field in the message conform to the requirements of the satellite communication system. Furthermore, through the interface with the satellite communication system, the repackaged handover request message is sent to the target satellite beam serving cell, completing the entire process of the 5G base station sending a handover request to the target satellite beam serving cell.

[0046] S13, the target satellite beam serving cell determines whether to accept the network handover request.

[0047] When a 5G base station initiates a handover request, after conversion and forwarding by the AGF (Advanced Gateway Function), the interface module of the target satellite beam serving cell receives the A1 handover request information. The target satellite beam serving cell collects various load indicators within the cell in real time, including but not limited to the number of connected users, the amount of radio resources in use (such as bandwidth, time slot resources, etc.), and service traffic. Based on pre-set load thresholds, it determines the current load status of the cell. For example, if the number of connected users is close to or exceeds a certain percentage (e.g., 80%) of the cell's maximum capacity, or if the amount of radio resources in use reaches more than 90% of the total resources, the cell is considered to be under high load. If the cell load is too high, continuing to accept newly handed-in UEs may lead to a decrease in the service quality of existing users, and the cell will tend to reject the handover request; conversely, if the load is low, there is a greater likelihood of accepting the handover request. Simultaneously, it continuously monitors network performance indicators within the cell, such as signal strength, signal-to-noise ratio (SNR), and bit error rate (BER). By comparing these with pre-set network quality standards, it assesses the current network quality of the cell. For example, if the signal strength is below a certain threshold, or the SNR cannot meet the requirements for normal service transmission, it indicates that the cell's network quality is poor. If the cell network quality is poor, it may be unable to provide reliable service to the newly handed UE, thus the handover request may be rejected. If the network quality is good, the likelihood of accepting the handover request increases. Alternatively, a mandatory instruction may be received from the upper-layer system management center. These instructions may be based on factors such as overall network planning and urgent service needs. When a mandatory handover acceptance instruction is received, the cell will ignore the load and network quality assessment results and directly decide to accept the handover request. If a mandatory handover rejection instruction is received, the handover request will be rejected regardless of the load and network quality.

[0048] The target satellite beam serving cell decides whether to accept network handover based on a comprehensive assessment of its own load, network quality, and mandatory system commands. Specifically, a handover request will not be accepted if any of the following conditions are met: 1) The system has mandatory restrictions on user terminals prohibiting handover during movement; 2) The terminal's received signal is weak and insufficient to meet the contractually agreed rate standard; 3) The terminal's geographical location is already at the edge of the satellite beam serving cell and continues to move away; 4) The satellite cell is carrying too many users, resulting in a heavy load and a significant decrease in the rate for each user. If none of the above conditions apply, the handover request will be accepted. If the target satellite beam serving cell does not accept the handover, the handover process ends.

[0049] S14, when the gateway function conversion module determines that the target satellite beam serving cell has accepted the network handover request, it converts the A1 handover confirmation message of the satellite DVB system and returns it to the 5G base station to complete the network handover request confirmation.

[0050] The A1 handover confirmation message is essentially a response confirmation from the target satellite beam serving cell to the 5G base station's handover request via the A1 interface. If the handover is accepted, the AGF returns an A1 handover confirmation message, converting the satellite DVB system's power and QoS information, carrier frequency and time slot information, and IP service list into target satellite beam serving cell radio resource control reconfiguration information, dedicated random access resource time-frequency information, and authorized and unauthorized PDU session lists in standard 5G protocol format. That is, based on a pre-stored mapping table, the satellite DVB system's power and QoS information are converted into target satellite beam serving cell radio resource control reconfiguration information. For example, power levels in satellite communication are mapped to 5G transmit power parameters, and QoS classifications for different services in satellite communication are converted into 5G QoS identifiers (QCIs). The carrier frequency and time slot information are also converted into dedicated random access resource time-frequency information, determining the specific carrier frequency and corresponding time slot allocation on the satellite band, so that the 5G base station can transmit information to the UE, and the UE can parse the parameter requirements of the random access operation according to the 5G protocol. The IP service list is converted into a list of authorized and unauthorized PDU sessions, clarifying which service sessions can continue after the switch (authorized sessions) and which need to be re-authorized or processed (unauthorized sessions).

[0051] The information conversion process is achieved through conversion software running within the target satellite beam service cell. This software accurately converts the collected satellite DVB system information according to pre-written mapping algorithms and rules.

[0052] Furthermore, the converted target satellite beam serving cell radio resource control reconfiguration information, dedicated random access resource time-frequency information, and lists of authorized and unauthorized PDU sessions are encapsulated according to the handover request confirmation message format specified in the 5G protocol. The target satellite beam serving cell sends the encapsulated message to the AGF. The AGF then forwards the message to the 5G base station through the A1 interface with the 5G base station, completing the handover request confirmation process.

[0053] S15, the target satellite beam serving cell allocates radio resources to the user terminal according to the network handover request.

[0054] Simultaneously, after deciding to accept the handover request, the radio resource management module of the target satellite beam serving cell performs resource assessment and planning based on the current radio resource usage of the cell and the resource allocation requirements for the new UE. For example, it reserves a certain carrier frequency and time slots for transmittable services on that frequency (collectively referred to as time-frequency resources) for the UE. This frequency and time slots are consistent with those sent by the AGF to the 5G base station. The radio resource information allocated to the UE is included in the previously converted and encapsulated handover request confirmation message, which is sent to the 5G base station through the AGF and finally communicated to the UE, enabling the UE to communicate according to the allocated resources after the handover is completed.

[0055] Therefore, the target satellite beam service cell can effectively handle handover requests from 5G base stations, enabling seamless handover between 5G networks and satellite communication networks, and providing users with more stable and reliable communication services.

[0056] S16, the 5G base station sends a radio resource reconfiguration command to the user terminal, triggering the user terminal to switch the current access network to the target satellite beam serving cell.

[0057] After receiving the handover information forwarded by the target satellite beam serving cell via the AGF, the 5G base station begins preparing the RRC (Radio Resource Control) reconfiguration message. The RRC reconfiguration information includes the target satellite beam serving cell's power information, QoS information, carrier frequency and timeslot information, and IP service list (which have already been converted and sent to the 5G base station by the target satellite beam serving cell during the initial handover preparation phase). Simultaneously, the 5G base station obtains the target satellite beam serving cell identification number, which uniquely identifies the target satellite beam serving cell, ensuring the UE can accurately access the target cell. The 5G base station assigns a temporary terminal identification number to each UE entering the satellite cell for temporary identification and management within the satellite cell.

[0058] Next, the 5G base station encapsulates the information collected from the target satellite cell, the target satellite beam serving cell identification number, and the terminal's temporary identification number entering the satellite cell, according to the RRC reconfiguration message format specified in the 3GPP standard. The message explicitly instructs the UE to perform a handover operation and details the radio resource parameters that need to be configured after the handover, such as power settings, carrier frequency, and time slot allocation, as well as service-related QoS requirements and instructions for the continuation of IP services.

[0059] Based on the UE's current location and wireless environment, the 5G base station selects an appropriate wireless channel (such as a specific frequency band and subcarrier spacing) to send the RRC reconfiguration command, ensuring reliable transmission to the UE while minimizing interference with other users' communications. Specifically, through the selected wireless channel, the 5G base station sends the encapsulated RRC reconfiguration message to the UE as a wireless signal. During transmission, an appropriate modulation and coding scheme (MCS) is used, dynamically adjusted according to the wireless channel quality to ensure message transmission reliability and efficiency. The 5G base station awaits confirmation from the UE. If no confirmation message is received from the UE within a specified time, the 5G base station will initiate a retransmission mechanism, retransmitting the RRC reconfiguration command until confirmation is received from the UE or the maximum number of retransmissions is reached.

[0060] The UE receives the RRC reconfiguration command sent by the 5G base station through its own radio receiving module. During the reception process, the UE performs demodulation and decoding operations on the signal to recover the original RRC reconfiguration message. The UE parses the received message according to the format specified in the RRC protocol, extracting key information such as the target satellite beam serving cell information, identification number, and terminal temporary identification number. The UE verifies the integrity and legality of the message to ensure that the message source is reliable and has not been tampered with. If the verification passes, subsequent operations continue; if the verification fails, an error feedback is sent to the 5G base station. According to the instructions in the RRC reconfiguration message, the UE begins the handover operation. It adjusts its own radio parameters, such as power settings, carrier frequency, and time slot allocation, to adapt to the requirements of the target satellite beam serving cell. Using the allocated terminal temporary identification number, it registers and accesses the target satellite beam serving cell, completing the handover process.

[0061] S17, the 5G base station sends a service data packet sequence number status transition message to the gateway function conversion module to determine the data packet number that has not been confirmed for reception by the target satellite beam serving cell, and caches downlink data from the 5G core network and forwards it to the gateway function conversion module.

[0062] The 5G base station continuously tracks the transmission status of data packets in uplink and downlink communications. For uplink data, it records the data packet numbers that the UE has sent but the 5G base station has not yet successfully received; for downlink data, it records the data packet numbers that the 5G base station has received from the 5G core network UPF (network element) but has not yet been confirmed by the target satellite beam serving cell. Based on the tracked data packet status information, the 5G base station generates a service data packet sequence number status transition message. The message explicitly lists the numbers of the relevant data packets in uplink and downlink communications. The generated message is encapsulated according to the message format pre-agreed with the AGF to ensure that the AGF can accurately parse and understand its content. The 5G base station sends the encapsulated service data packet sequence number status transition message to the AGF through the newly added inter-network interface between the 5G base station and the AGF. A reliable transmission protocol (such as TCP) is used during the transmission process to ensure reliable message transmission.

[0063] Simultaneously with sending the service data packet sequence number state transition message, the 5G base station activates the downlink data caching mechanism, starting to cache downlink data from the 5G core network UPF element to prevent data loss during handover. The 5G base station allocates dedicated storage space for the cached downlink data and establishes a corresponding data management structure, recording information such as the number, size, and arrival time of each data packet. Based on the data packet priority and service type, the cached data is categorized and managed to ensure that high-priority service data is processed and forwarded first. The 5G base station forwards the cached downlink data to the AGF through the A1 interface, which interacts with the AGF, at certain time intervals or data volume thresholds. Reliable transmission protocols are also used during forwarding to ensure data integrity and accuracy.

[0064] S18, the gateway function conversion module converts the received data packet number into the satellite DVB system baseband data packet number format, and encapsulates the downlink data into DVB system GSE protocol IP data packets, and sends them to the target satellite beam serving cell.

[0065] After receiving the service data packet sequence number state transition message from the 5G base station, the AGF parses the data packet number. According to pre-defined mapping rules, it converts the data packet number in the 5G network into the satellite DVB (Digital Stream Encapsulation) baseband data packet number format, ensuring the target satellite beam serving cell can recognize and process these data packets. After receiving downlink data from the UPF (Universal Stream Encapsulation) network element forwarded by the 5G base station, the AGF performs format conversion on this data. It converts the data format in the 5G network into the IP data packet format encapsulated by the DVB GSE (Genius Stream Encapsulation) protocol. Following the requirements of the GSE protocol, it encapsulates the IP data packets, adding the corresponding protocol headers and checksum information. The AGF sends the converted data packet number information (included in the feedback of the service data packet sequence number state transition message, if needed) and the format-converted downlink data to the target satellite beam serving cell. Data transmission is performed through the interface between the AGF and the target satellite beam serving cell (such as a satellite communication interface), ensuring the data accurately reaches the target cell.

[0066] S19, the user terminal initiates a random access procedure for services on the target satellite beam serving cell according to the received radio resource reconfiguration instruction, and completes the network handover.

[0067] The UE itself has a dual-mode communication module for DVB (Digital Video Broadcast) and 5G, which can initiate service access in the target satellite beam serving cell according to the radio resource reconfiguration command sent by the 5G base station to ensure the continuity of communication.

[0068] When both the DVB and 5G dual-mode communication modules are functioning normally, the UE's 5G communication module receives the radio resource reconfiguration command sent by the 5G base station through the wireless receiving module. During reception, the signal is demodulated and decoded to recover the original RRC reconfiguration message. The UE parses the received message according to the format specified in the RRC protocol, extracting key information such as the power information, QoS information, carrier frequency, and time slot information of the target satellite beam serving cell. The integrity and legality of the message are verified to ensure that the message source is reliable and has not been tampered with. If the verification passes, subsequent operations continue; if the verification fails, an error feedback is sent to the 5G base station, requesting a retransmission of the command.

[0069] The UE extracts satellite DVB-related parameter information from the parsed radio resource reconfiguration command. Based on pre-defined configuration conversion rules within the UE, it converts the parameter information from the 5G network into configuration parameters suitable for the satellite DVB module. For example, it converts power control parameters from the 5G network into transmit power and receive sensitivity settings recognizable by the satellite DVB module; it maps QoS parameters from the 5G network to service priority and bandwidth allocation parameters in the satellite DVB module; and it converts carrier frequency and time slot information from the 5G network into carrier frequency selection and time slot allocation methods corresponding to the satellite DVB module. The UE writes the converted configuration parameters into the corresponding registers or configuration files of the satellite DVB module, completing the configuration update. After configuration, the UE initializes the satellite DVB module to ensure it functions correctly according to the new configuration parameters.

[0070] The UE selects a suitable carrier frequency for access based on the carrier frequency information provided in the radio resource reconfiguration command. On the selected carrier frequency, it determines the available random access time slots based on the time slot information and selects a suitable time slot for access. The UE's satellite DVB module sends a random access preamble on the selected random access time slot according to the configured power information. The random access preamble is a predefined sequence used to identify the UE's access request. After receiving the random access preamble sent by the UE, the target satellite beam serving cell sends a random access response message within the corresponding time window. After sending the preamble, the UE's satellite DVB module listens for random access response messages within the specified time window. If a random access response message is received within the specified time, the UE parses the message to obtain the temporary identifier (such as C-RNTI, cell radio network temporary identifier), uplink resource allocation information, etc., contained within it. Based on the uplink resources allocated in the random access response message, the UE sends a connection establishment request message (such as an RRCConnection Request message) to the target satellite beam serving cell. The message contains the UE's identity information, access reason, service type, etc. Upon receiving the connection establishment request message from the UE, the serving cell of the target satellite beam performs operations such as authentication and resource allocation. If authentication is successful and resource allocation is successful, it sends a connection establishment complete message (such as an RRC Connection Setup Complete message) to the UE. Receiving the connection establishment complete message signifies that the UE has successfully initiated service access in the serving cell of the target satellite beam and can begin normal service communication.

[0071] Therefore, the UE can use the radio resource reconfiguration instruction information received from the 5G base station to successfully initiate service access on the target satellite beam serving cell, realize seamless switching between 5G and satellite communication networks, and provide users with stable and reliable communication services.

[0072] S20, after the user terminal successfully accesses the target satellite beam serving cell, it sends a radio resource control reconfiguration completion message to the gateway function conversion module to confirm the completion of network handover.

[0073] When a UE moves from the coverage area of ​​a 5G base station to the coverage area of ​​a target satellite beam serving cell and successfully accesses the network, its internal Radio Resource Control (RRC) module generates an RRC reconfiguration completion message based on the configuration information obtained during the access process. This message includes the UE's identity (such as IMSI or TMSI), access success status information, and some necessary parameter feedback. For example, the message may include the UE's confirmation of receiving the target cell's configuration parameters, such as carrier frequency, time slot allocation, and power control parameters, indicating that the UE has completed its configuration adjustments according to these parameters and can communicate normally in the target cell.

[0074] The UE sends the generated RRC reconfiguration complete message to the AGF via the radio channel of the target satellite beam serving cell. During transmission, the UE selects an appropriate modulation and coding scheme (MCS) and transmission power based on the target cell's configuration parameters to ensure reliable message transmission to the AGF. For example, if the target cell has good channel quality, the UE can choose a higher MCS to improve transmission efficiency; if the channel quality is poor, a lower MCS is chosen to enhance the message's anti-interference capability.

[0075] The Access Controller (AGF) receives the RRC reconfiguration complete message from the UE through its interface connected to the target satellite beam serving cell. The AGF parses the received message, verifying its integrity and validity. It checks if the UE's identity identifier in the message matches the previously recorded one, confirming that the UE has successfully accessed the target cell. If the verification passes, the AGF records the UE's access status information and prepares for subsequent path handover operations; if the verification fails, the AGF sends an error feedback message to the UE, requesting the UE to resend the reconfiguration complete message.

[0076] S21, the gateway function conversion module sends an NGAP path switching request message to the AMF through the 5G core network to trigger the 5G core network to switch the downlink data transmission path from the 5G base station to the gateway function conversion module; the AMF returns an NGAP path switching request confirmation message to the gateway function conversion module through the NG interface.

[0077] After confirming that the UE has successfully accessed the target cell, the AGF generates an NGAP path handover request message according to the NG interface protocol in the 5G technical standard. This message includes the UE's identity information, the target cell's identification information, the AGF's identification information, and the reason for the handover request (such as cell handover caused by UE movement). For example, the message may explicitly state that the UE has switched from the original 5G base station coverage area to the target satellite beam serving cell, requesting the 5GC to switch the downlink data path to the AGF.

[0078] The AGF sends the generated NGAP path switching request message to the AMF via the NG interface. During transmission, the AGF encapsulates and encrypts the message according to the NG interface signaling transmission specifications to ensure message security and integrity. For example, the AGF encrypts the message using a pre-configured security key and adds necessary signaling header information, such as message type and sequence number, before sending the message to the AMF via the NG interface physical link.

[0079] The AMF receives NGAP path handover request messages from the AGF via the NG interface. The AMF decrypts and parses the received messages, extracting key information such as the UE's identity, target cell identifier, and request reason. Based on this information, the AMF makes a judgment and decision. If it agrees to the path handover, it generates an NGAP path handover request confirmation message; if it disagrees, it generates a rejection message and sends it back to the AGF. For example, the AMF checks the UE's subscription information and current network status to determine whether to allow the UE to hand over to the target satellite beam serving cell. If allowed, the AMF updates its internal database, records the UE's new location information, and generates a confirmation message.

[0080] The AMF receives NGAP path handover request messages from the AGF via the NG interface. The AMF decrypts and parses the received messages, extracting key information such as the UE's identity, target cell identifier, and request reason. Based on this information, the AMF makes a judgment and decision. If it agrees to the path handover, it generates an NGAP path handover request confirmation message; if it disagrees, it generates a rejection message and sends it back to the AGF. For example, the AMF checks the UE's subscription information and current network status to determine whether to allow the UE to handover to the target satellite beam serving cell. If allowed, the AMF updates its internal database, records the UE's new location information, and generates a confirmation message.

[0081] The AGF receives NGAP path handover request confirmation messages from the AMF via the NG interface. The AGF parses the confirmation messages, extracts key information, and updates its own configuration accordingly. For example, based on the new data transmission path information, the AGF adjusts its internal routing table to ensure downlink data is correctly forwarded to the target cell; and based on QoS parameter adjustments, it optimizes the UE's service transmission accordingly.

[0082] S22, after receiving the NGAP path switching request confirmation message, the gateway function conversion module sends a UE context release message to the 5G base station through the newly added inter-network interface, so that the 5G base station releases the resources associated with the user terminal according to the UE context release message.

[0083] After receiving the NGAP path handover request confirmation message from the AMF, the AGF confirms that the downlink data path has successfully switched to itself. At this point, it can release the resources associated with the UE in the 5G base station. The AGF generates an A1 interface UE context release message according to the A1 interface protocol. This message includes the UE's identity information and the reason for release (such as path handover completion). For example, the message may explicitly state that since the UE has successfully switched to the target satellite beam serving cell and the downlink data path has switched to the AGF, it is necessary to release the radio resources and signaling connection resources associated with the UE in the 5G base station.

[0084] The AGF sends the generated A1 interface UE context release message to the 5G base station via the A1 interface. During transmission, the AGF encapsulates and processes the message according to the signaling transmission specifications of the A1 interface to ensure that the message arrives at the 5G base station accurately. For example, the AGF uses the transmission protocol and parameters pre-negotiated with the 5G base station to encapsulate the message into a suitable frame structure and sends it to the 5G base station through the physical link of the A1 interface.

[0085] The 5G base station receives the A1 interface UE context release message sent by the AGF through the A1 interface. The 5G base station parses the received message to extract key information, such as the UE identity and the reason for release. Based on this information, the 5G base station releases resources associated with the UE, including radio resources (such as allocated carriers, time slots, and power), signaling connection resources (such as RRC connections and S1 interface connections), and internally stored UE context information (such as UE capability information and service status information). For example, the 5G base station will release the radio spectrum resources allocated to the UE, allowing them to be reallocated to other UEs in need; simultaneously, it will clear the context information related to the UE from the internal database to save storage space and improve system efficiency.

[0086] Compared to existing technologies, this application employs two distinctive designs to ensure consistent user terminal identity and uninterrupted service continuity: First, it adds an A1 interface for exchanging radio resource control configuration information between 5G base stations and satellite beam serving cells; second, it utilizes the AGF to convert satellite DVB signaling information to standard 5G signaling, supporting the A1 interface in exchanging information between 5G base stations and satellite beam serving cells, enabling the two networks with different technology systems to recognize the signaling. This application enables user terminals to switch between satellite access networks and 5G access networks while ensuring consistent user terminal identity, unified billing, and uninterrupted service continuity.

[0087] To facilitate understanding of the inventive concept of this application, a user terminal (UE) installed in a car will be used as an example for illustration.

[0088] Step 1: The UE in the car is currently connected to a 5G base station for data communication. As the car moves out of the base station cell, the 5G base station signal received by the UE weakens to below the level required for normal service. The UE's measured and reported radio connection information shows a weak signal strength from this 5G cell, while the signal strength of the adjacent satellite beam serving cell (with its identification number) is strong. Based on the measurement report, the 5G base station determines that the UE can receive better service by switching to the adjacent satellite beam serving cell and commands the UE to switch networks, selecting the target satellite beam serving cell based on the serving cell's identification number.

[0089] Step 2: The 5G base station sends an A1 handover request message to the AGF via the A1 interface. This message carries the Radio Resource Control (RRC) message from the 5G protocol, the target satellite beam serving cell identifier, and the PDU session list information. The AGF converts this information into the signal-to-noise ratio, beam identifier, and IP service list information for the satellite communication system. This enables the 5G base station to send a handover request to the target satellite beam serving cell.

[0090] Step 3: The target satellite beam serving cell selected by the 5G base station checks and finds that the cell has a light load and good network quality, and decides to accept the UE's handover. The AGF converts the power information, QoS information, carrier frequency and time slot information, and IP service list of the target satellite beam serving cell in the DVB mode into standard 5G protocol format, radio resource reconfiguration information, dedicated random access resource time and frequency information, and authorized and unauthorized PDU session lists, and sends them to the 5G base station to complete the handover request confirmation process. At the same time, the target satellite beam serving cell allocates radio resources to the UE, completing the handover preparation phase.

[0091] Step 4: The 5G base station sends a radio resource reconfiguration command to the UE to trigger the handover. The message includes the information sent by the satellite cell in Step 3, as well as the target satellite beam serving cell identification number and the terminal temporary identification number entering the satellite cell.

[0092] Step 5: The 5G base station sends a service data packet sequence number state transition message to the AGF, assigning the sequence numbers of data packets that have been sent in the 5G network and received by the 5G base station but not yet confirmed by the target satellite beam serving cell during uplink and downlink communication. It also begins buffering downlink data from the 5G core network UPF elements and forwards it to the AGF. The AGF converts the sequence numbers of the data packets received by the 5G base station but not yet confirmed by the target satellite beam serving cell into satellite DVB-based baseband data packet number format. It converts the downlink data received from the UPF elements from the 5G base station into IP data packets encapsulated using the DVB-based GSE protocol and sends them to the target satellite beam serving cell.

[0093] Step 6: UE initiates service access in the target satellite beam serving cell: The UE has a dual-mode communication module of DVB and 5G. It uses the radio resource reconfiguration instruction information received from the 5G base station to convert it into the configuration on the UE's satellite DVB module. In the target satellite beam serving cell, it initiates a random service access process according to the power information, QoS information, carrier frequency and time slot information of the satellite DVB system in the radio resource reconfiguration instruction information.

[0094] Step 7: After the UE successfully connects to the target cell, it sends a Radio Resource Control reconfiguration complete message to the AGF to complete the handover process.

[0095] Step 8: The AGF sends an NGAP path switching request message to the AMF through the NG interface in the 5G technical standard, triggering the 5GC to switch the downlink data path to the AGF. The AMF confirms the switch with an NGAP path switching request confirmation message.

[0096] Step 9: A1 Interface UE Context Release: After receiving the NGAP path handover request confirmation message from the AMF, the AGF sends an A1 interface UE context release message to the 5G base station, and the 5G base station releases the resources associated with the UE.

[0097] Therefore, the UE installed in the car successfully switched from the 5G access network to the satellite access network.

[0098] 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.

[0099] In the above embodiments, 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.

[0100] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for managing handover between satellite DVB and 5G heterogeneous access networks, characterized in that, A handover management system for satellite DVB and 5G heterogeneous access networks is applied. The system includes a user terminal, a 5G base station, a gateway function conversion module, and a target satellite beam serving cell. The method includes: when the user terminal is in wireless communication with the 5G base station, it sends a wireless connection measurement report to the 5G base station; the 5G base station determines whether to command the user terminal to switch networks based on the wireless connection measurement report, and sends an A1 handover request message to the gateway function conversion module through a new inter-network interface; the target satellite beam serving cell determines whether to accept the network handover request; when the gateway function conversion module determines that the target satellite beam serving cell accepts the network handover request, it converts the satellite DVB A1 handover confirmation message and returns it to the 5G base station to complete the network handover request confirmation; the target satellite beam serving cell then... The handover request allocates radio resources to the user terminal; the 5G base station sends a radio resource reconfiguration command to the user terminal, triggering the user terminal to switch its current access network to the target satellite beam serving cell; the 5G base station sends a service data packet sequence number status transition message to the gateway function conversion module, determines the data packet number that has not been acknowledged by the target satellite beam serving cell, caches downlink data from the 5G core network, and forwards it to the gateway function conversion module; the gateway function conversion module converts the received data packet number into the satellite DVB system baseband data packet number format, encapsulates the downlink data into DVB system GSE protocol IP data packets, and sends them to the target satellite beam serving cell; the user terminal initiates a service random access procedure on the target satellite beam serving cell according to the received radio resource reconfiguration command, completing the network handover.

2. The method for managing handover between satellite DVB and 5G heterogeneous access networks according to claim 1, characterized in that, The method further includes: after the user terminal successfully accesses the target satellite beam serving cell, it sends a radio resource control reconfiguration completion message to the gateway function conversion module to confirm the completion of network handover; the gateway function conversion module sends an NGAP path handover request message to the AMF through the 5G core network to trigger the 5G core network to switch the downlink data transmission path from the 5G base station to the gateway function conversion module; the AMF returns an NGAP path handover request confirmation message to the gateway function conversion module through the NG interface; after receiving the NGAP path handover request confirmation message, the gateway function conversion module sends a UE context release message to the 5G base station through the newly added inter-network interface, so that the 5G base station releases the resources associated with the user terminal according to the UE context release message.

3. The method for managing handover between satellite DVB and 5G heterogeneous access networks according to claim 1, characterized in that, The wireless connectivity measurement report includes the signal strength of the 5G cell, the signal strength of the adjacent satellite beam serving cell, the serving cell identification number, and the terminal's geographic location information; the 5G cell is the cell corresponding to the 5G base station to which the user terminal is currently connected.

4. The method for managing handover between satellite DVB and 5G heterogeneous access networks according to claim 3, characterized in that, The method further includes: when no mandatory prohibition of mobile handover is set for the user terminal, the 5G base station, based on the wireless connectivity measurement report, commands the user terminal to switch networks when at least one of the following trigger conditions is met, and selects to switch to the target satellite beam serving cell based on the serving cell identification number: the signal strength received by the user terminal is insufficient to meet the contractually agreed rate standard; the user terminal's geographical location is at the edge of the 5G base station cell and continues to move away; the number of users carried by the 5G base station exceeds a preset first threshold, and the load reaches a preset second threshold, causing the rate of each user to drop below a preset third threshold; if none of the above trigger conditions are met, the 5G base station does not command the user terminal to switch networks.

5. The method for managing handover between satellite DVB and 5G heterogeneous access networks according to claim 1, characterized in that, When the target satellite beam serving cell accepts a network handover request, the gateway function conversion module converts the power information and QoS information, carrier frequency and time slot information, and IP service list of the satellite DVB system into target satellite beam serving cell radio resource control reconfiguration information, dedicated random access resource time and frequency information, and authorized and unauthorized PDU session lists in the standard 5G protocol format.

6. The method for managing handover between satellite DVB and 5G heterogeneous access networks according to claim 5, characterized in that, The method further includes: the user terminal receiving radio resource reconfiguration instruction information from the 5G base station; the user terminal converting the radio resource reconfiguration instruction information into a configuration on the satellite DVB module in the user terminal; and the user terminal performing a random access operation on the target satellite beam serving cell according to the power information, QoS information, carrier frequency, and time slot information in the radio resource reconfiguration instruction information.

7. The method for managing handover between satellite DVB and 5G heterogeneous access networks according to claim 1, characterized in that, The gateway function conversion module converts the handover request message into signal-to-noise ratio, beam identification number, and IP service list information in the satellite communication system architecture. The handover request message carries radio resource control messages, target satellite beam serving cell identification number, and PDU session list information in the 5G protocol.

8. A satellite DVB and 5G heterogeneous access network handover management system, characterized in that, The system, used to implement any one of the satellite DVB and 5G heterogeneous access network handover management methods according to claims 1 to 7, comprises: a user terminal, a 5G base station, a gateway function conversion module, and a target satellite beam serving cell; the user terminal is used to send a wireless connection measurement report to the 5G base station when it is in a wireless communication state with the 5G base station; the 5G base station is used to determine whether to command the user terminal to switch networks based on the wireless connection measurement report, and to send an A1 handover request message to the gateway function conversion module through a new inter-network interface; the target satellite beam serving cell is used to determine whether to accept the network handover request; the gateway function conversion module is used to, when it is determined that the target satellite beam serving cell accepts the network handover request, convert the satellite DVB A1 handover confirmation message and return it to the 5G base station to complete the network handover request confirmation; the target satellite beam serving cell also uses... The 5G base station is configured to allocate radio resources to the user terminal according to the network handover request; the 5G base station is also configured to send a radio resource reconfiguration command to the user terminal, triggering the user terminal to switch its current access network to the target satellite beam serving cell; send a service data packet sequence number status transition message to the gateway function conversion module, determine the data packet number that has not been acknowledged by the target satellite beam serving cell, cache downlink data from the 5G core network, and forward it to the gateway function conversion module; the gateway function conversion module is also configured to convert the received data packet number into the satellite DVB system baseband data packet number format, encapsulate the downlink data into DVB system GSE protocol IP data packets, and send them to the target satellite beam serving cell; the user terminal is also configured to initiate a service random access procedure on the target satellite beam serving cell according to the received radio resource reconfiguration command, and complete the network handover.

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