CN115623552B

CN115623552B - Communication method for GEO satellite and 5G converged network trans-regional mobile

Info

Publication number: CN115623552B
Application number: CN202211612386.2A
Authority: CN
Inventors: 冯建元
Original assignee: APT Mobile Satcom Ltd
Current assignee: APT Mobile Satcom Ltd
Priority date: 2022-12-15
Filing date: 2022-12-15
Publication date: 2023-04-14
Anticipated expiration: 2042-12-15
Also published as: CN115623552A

Abstract

The invention provides a communication method for GEO satellite and 5G fusion network trans-regional movement, when user terminal UE trans-regional movement triggers switching of a satellite network control center NCC, a gateway function conversion module AGF receives a path switching notification message, sends a forward service to a target satellite network control center NCC, and completes switching; when a user terminal UE moves across areas to trigger switching of a gateway function conversion module AGF and a satellite network control center NCC, the user terminal UE sends a switching request to a satellite network management system NMS, and the satellite network management system NMS decides to start switching; and sending the forward service to a target gateway function conversion module AGF and a target satellite network control center NCC to complete switching, and ensuring that the communication service of the GEO satellite and the 5G fusion network is continuously connected when users move across areas.

Description

Communication method for GEO satellite and 5G converged network trans-regional movement

Technical Field

The invention relates to the technical field of satellite communication, in particular to a communication method for trans-regional movement of a GEO satellite and a 5G fusion network.

Background

High throughput GEO (geostationary orbit) satellite communications and 5G communications are important communications means used by people. However, the high-throughput GEO satellite communication system and the 5G communication system are two distinct communication systems, and the most important difference is that the technical systems of the high-throughput GEO satellite communication and the 5G communication are distinct except the space and the ground. The DVB-S2X body technology system is used for high-flux GEO satellite communication, the 5G technical system specified by 3GPP is adopted for 5G communication, and the technical systems are different, so that the types, formats and transmission modes of control information and service data information transmitted in a high-flux GEO satellite communication system and a 5G communication system are different.

Due to the development requirement of world integration, a high-throughput GEO satellite communication link is required to be used as an access network of a communication system, a 5G core network is required to be used as a core network of the communication system, and the two networks are combined to form a new converged communication system. Due to the difference of the technical systems, control information of the two communication systems cannot be interacted, service data cannot be circulated, and the two communication systems cannot be directly fused.

At present, a related technology solves the problem of fusion of a high-throughput GEO satellite and a 5G core network, but in a fusion network of the GEO satellite and the 5G core network, how to implement cooperative handover when a communication user needs to move across areas, so that communication services of the fusion network can be continuously and continuously connected in the user moving process still needs to be solved.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a communication method for the cross-regional mobile of a GEO satellite and a 5G fusion network, so as to solve the technical problems.

The technical method for solving the technical problem is as follows: a communication method for GEO satellite and 5G fusion network trans-regional movement comprises a user terminal UE, a satellite access network and a 5G core network 5GC, wherein the satellite access network comprises a satellite network control center NCC and a gateway function conversion module AGF which are connected;

the user terminal UE is respectively connected with a satellite network control center NCC and a gateway function conversion module AGF through a satellite link, and the gateway function conversion module AGF is connected with a 5G core network 5 GC;

the gateway function conversion module AGF comprises an N1 interface protocol conversion unit, an N2 interface protocol conversion unit and an N3 interface protocol conversion unit; the 5G core network comprises an access management function unit AMF and a user plane service transmission function unit UPF, and the user terminal UE and the access management function unit AMF are both connected to an N1 interface protocol conversion unit of a gateway function conversion module AGF; the N2 interface protocol conversion unit and the N3 interface protocol conversion unit are both connected to a satellite network control center NCC, wherein the N2 interface protocol conversion unit is connected with an access management function unit AMF, and the N3 interface protocol conversion unit is connected with a user plane service transmission function unit UPF;

when a user terminal UE moves across areas to trigger the switching of a satellite network control center NCC, a gateway function conversion module AGF receives a path switching notification message, sends a forward service to a target satellite network control center NCC and completes the switching;

when a user terminal UE moves across areas to trigger switching of a gateway function conversion module AGF and a satellite network control center NCC, the user terminal UE sends a switching request to a satellite network management system NMS, and the satellite network management system NMS decides to start switching; the 5G core network 5GC sends the forward service to a target gateway function conversion module AGF and a target satellite network control center NCC to complete switching;

the improvement is that:

the switching when the user terminal UE moves across areas to trigger the switching of the satellite network control center NCC comprises the following steps:

the target satellite network control center NCC sends a path switching notification message to the gateway function conversion module AGF, the gateway function conversion module AGF sends a forward data cache notification to the source target satellite network control center NCC, and the gateway function conversion module AGF stops sending forward data to the source target satellite network control center NCC and records the finally sent data; meanwhile, the gateway function conversion module AGF caches forward service data sent by the 5G core network to the NCC direction of the source target satellite network control center; a source target satellite network control center NCC sends a forward data cache notification to a user terminal UE, and the user terminal UE records the finally received data;

the gateway function conversion module AGF executes the path switching between the gateway function conversion module AGF and the satellite network control center NCC and switches to the target satellite network control center NCC;

the gateway function conversion module AGF sends a path switching result notice to a source satellite network control center NCC;

the source satellite network control center NCC sends forward cache data forwarding confirmation to a gateway function conversion module AGF;

forwarding forward cache data to a target satellite network control center NCC by a gateway function conversion module AGF;

the target satellite network control center NCC sends forward cache data to the user terminal UE;

the user terminal UE compares the consistency of the record of the last sent data in the gateway function conversion module AGF cache data with the consistency of the last received data recorded by the user terminal UE, if the comparison result is consistent, the user terminal UE sends forward cache data success confirmation to the target satellite network control center NCC, and eliminates repeated service data;

the target satellite network control center NCC sends forward cache data success confirmation to the gateway function conversion module AGF, and the switching process is completed;

or,

the switching when the user terminal UE moves across areas to trigger the switching of the gateway function conversion module AGF and the satellite network control center NCC comprises the following steps:

user Equipment (UE) sends a switching request to a satellite Network Management System (NMS);

the satellite network management system NMS decides to start switching, informs the target satellite network control center NCC to prepare satellite link resources, and confirms that the resource preparation is finished to the satellite network management system NMS by the target satellite network control center NCC;

the satellite network management system NMS sends a switching information notification to the source satellite network control center NCC, and the source satellite network control center NCC returns a switching information notification confirmation;

the satellite network management system NMS sends a switching command to the user terminal UE, and satellite beam switching starts to be executed;

the user terminal UE connects the new satellite beam, and sends a switching confirmation to a target satellite network control center NCC to which the new beam belongs, wherein the beam switching is indicated to be completed, and the target satellite network control center NCC sends a switching success confirmation to a satellite network management system NMS;

the method comprises the following steps that a satellite network management system NMS sends a satellite resource recovery command to a source satellite network control center NCC, and the source satellite network control center NCC returns a satellite resource recovery confirmation;

the method comprises the steps that a satellite Network Management System (NMS) sends an N2 interface switching trigger notification to a source gateway function conversion module (AGF), and the source gateway function conversion module (AGF) sends a switching requirement to an access management function unit (AMF) in a 5G core network (5 GC);

the access management functional unit AMF sends a switching request to a target gateway function conversion module AGF, and the target gateway function conversion module AGF feeds back switching confirmation information;

an access management function unit AMF sends a switching command to a source gateway function conversion module AGF, and simultaneously sends a forward data cache notification to a session management function unit SMF in a 5G core 5 GC;

the session management function unit SMF sends a forward data cache notice to a user plane service transmission function unit UPF, and the user plane service transmission function unit UPF records the last sent data and sends the record and the forward cache data to a target gateway function conversion module AGF;

a source gateway function conversion module AGF sends a forward data cache notification to a user terminal UE, and the user terminal UE records the finally received data;

as a response that the access management function unit AMF sends a switching command to the source gateway function conversion module AGF, the gateway function conversion module AGF performs switching;

after switching, the target gateway function conversion module AGF is activated, the target gateway function conversion module AGF sends a switching confirmation to the access management function unit AMF, the access management function unit AMF sends a forward cache data forwarding instruction to the target gateway function conversion module AGF, and the target gateway function conversion module AGF is instructed to send cache data to the user terminal UE;

the target gateway function conversion module AGF sends forward cache data to the user terminal UE, the user terminal UE compares the consistency of the record of the last sent data in the gateway function conversion module AGF cache data with the last received data recorded by the user terminal UE, if the comparison result is consistent, the forward cache data is sent to the target gateway function conversion module AGF for successful confirmation, and the repeated service data is eliminated;

the target gateway function conversion module AGF sends a forward cache data success confirmation message to an access management function unit AMF, the access management function unit AMF sends a forward data service restoring command to a session management function unit SMF, and the session management function unit SMF sends a forward data service restoring command to a user plane service transmission function unit UPF;

the user plane service transmission functional unit UPF recovers the service transmission and service recovery with the user terminal UE;

the access management functional unit AMF sends a user terminal UE environment release command to the source gateway function conversion module AGF, and the source gateway function conversion module AGF returns a user terminal UE environment release completion message to complete the switching.

In the above method, the step of performing protocol conversion by the N1 interface protocol conversion unit, the N2 interface protocol conversion unit, and the N3 interface protocol conversion unit includes:

s11, screening data, namely screening the content of relevant information of each interface from a satellite link data packet by an N1 interface protocol conversion unit, an N2 interface protocol conversion unit and an N3 interface protocol conversion unit;

s12, mapping data, namely establishing a one-to-one mapping table for parts of a satellite access network and a 5G core network 5GC which realize the same function according to a satellite network link data packet format and a 5G core network module structure, wherein satellite network data of a satellite network control center NCC can be converted into a protocol format of the corresponding function of the 5G core network 5GC according to a mapping relation;

s13, data encapsulation and transmission, wherein the N1 interface protocol conversion unit, the N2 interface protocol conversion unit and the N3 interface protocol conversion unit encapsulate the converted data and transmit the encapsulated data to respective interfaces; the 5G core network 5GC also comprises an authentication server function module AUSF, a unified data management function module UDM, a network storage function module NRF and a session management function unit SMF; the access management function unit AMF is respectively connected with an authentication server function module AUSF, a unified data management function module UDM, a network storage function module NRF and a session management function unit SMF, the authentication server function module AUSF and the unified data management function module UDM are connected with the network storage function module NRF, and the network storage function module NRF is connected with the session management function unit SMF; the user plane service transmission function unit UPF is connected with the session management function unit SMF, and the data network DN is connected with the user plane service transmission function unit UPF;

the method for fusing the GEO satellite access network and the 5G core network comprises the following steps:

s10, connecting a user terminal UE with a communication system, wherein the communication system is formed by fusing a satellite access network and a 5G core network, the user terminal UE initiates a connection request to the communication system through a gateway function conversion module AGF, and the user terminal UE is accessed to the communication system after the connection is successful;

s20, converting user QoS service level information and managing QoS priority, wherein a 5G core network 5GC issues the user QoS service level information to a gateway function conversion module AGF, the gateway function conversion module AGF converts the user QoS service level information into satellite communication system control information, the satellite communication system control information enters a satellite network control center NCC, and the QoS priority of the user using satellite communication link service is set through the satellite network control center NCC;

s30, the gateway function conversion module AGF synchronizes the distribution information of the satellite terminal and the 5G core network to the IP address, and synchronizes the IP address distributed to the user terminal by the satellite network control center NCC to the 5G core network 5GC by the gateway function conversion module AGF, so that the unification of the IP address of the user terminal between the satellite access network and the 5G core network 5GC is ensured;

s40, establishing a service request, initiating the service request by User Equipment (UE), converting the service request into 5G core network control information by a gateway function conversion module (AGF), transmitting the control information to a 5G core network (5 GC), receiving the control information by the 5G core network (5 GC) and establishing service data transmission session connection, wherein the service data transmission is the response of the service request.

The invention has the beneficial effects that: the communication connection of the user is cooperatively switched through the satellite access network, the gateway function conversion module AGF and the 5G network, so that the control information and the service data information of the satellite communication system and the 5G communication system are mutually transmitted and mutually operated, and the continuity of the communication service of the GEO satellite and the 5G fusion network is ensured when the user moves across areas on the basis of the fusion of the communication systems of two different technical systems.

Drawings

Fig. 1 is a network architecture of a high-throughput GEO satellite and 5G convergence network.

Fig. 2 is a schematic diagram of a transmission system between a satellite network control center NCC and a satellite network control center NCC.

Fig. 3 and 4 are schematic diagrams of a GEO satellite and 5G convergence network.

Fig. 5 is a schematic switching diagram of the GEO satellite and 5G converged network cross-region mobile communication method of the present invention when only the satellite network control center NCC is involved in switching.

Fig. 6 is a schematic switching diagram of a GEO satellite and 5G converged network cross-region mobile communication method according to the present invention when NCC handover and AGF handover are performed in a satellite network control center.

Fig. 7 is a schematic diagram illustrating a handover flow principle of the GEO satellite and 5G converged network cross-region mobile communication method when only the NCC of the satellite network control center is involved in handover.

Fig. 8 is a schematic diagram illustrating a handover flow principle of a GEO satellite and 5G converged network cross-region mobile communication method when NCC handover and AGF handover of a gateway function conversion module are involved in a satellite network control center.

Fig. 9 is a schematic diagram of a two-step handover manner adopted when the satellite network control center NCC handover and the gateway function conversion module AGF handover in fig. 8 are performed.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

The conception, the specific structure and the technical effects produced by the present invention will be clearly and completely described in conjunction with the embodiments and the attached drawings, so as to fully understand the objects, the features and the effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention. In addition, all the connection/connection relations referred to in the patent do not mean that the components are directly connected, but mean that a better connection structure can be formed by adding or reducing connection auxiliary components according to specific implementation conditions. The technical characteristics in the invention can be combined interactively on the premise of not conflicting with each other.

In order to facilitate understanding of the technical solutions of the present invention, the following terms are first explained in conjunction with the contents of the prior art:

GEO satellite: GEO, i.e., geostationary orbit (or "geostationary orbit", "geostationary satellite orbit"), refers specifically to a perfectly circular geosynchronous orbit, in which the satellite or satellite is at a height of 35786 kilometers above the earth's equator. An observer on the earth surface can always observe the GEO satellite at the same position in the sky at any time, and can find that the satellite is still in the sky.

An access network: the access network is composed of a communication network node interface (such as a base station, a WiFi hotspot and the like) and a series of transmission links (such as wireless transmission links) between user and communication network node interfaces, and the user can access data to a telecommunication backbone core network through the access network by providing a transmission system with data transmission bearing capacity for the backbone network to supply telecommunication services to the user. There is in principle no restriction on the type and number of UNIs and SNIs that the access network can implement. The access network does not interpret the signaling.

Satellite beam: a beam refers to the shape of an electromagnetic wave emitted by a satellite antenna on the earth's surface (e.g., a light beam emitted to the dark by a flashlight). The satellite can emit a large number of beams like the earth.

A satellite main station: a ground station, referred to as a satellite network control center, is capable of managing and allocating satellite network resources and has the function of a gateway of a communication system.

QoS: quality of service (qos) refers to a technology that a network can use various basic technologies to provide better service capability for specified network communication, and is used to solve problems such as network delay and congestion. QoS guarantees are important for capacity-limited networks, especially for streaming multimedia applications such as VoIP and IPTV, which often require fixed transmission rates and are sensitive to delay. For a system with limited resources, a higher-priority QoS guarantee is generally set for a high-value user, and a lower-priority QoS guarantee is set for a common user, so as to differentiate services according to the payment condition.

User authentication: the user authentication is one kind of authentication of mobile phone information, including user state authentication and user personalized authentication, and is mainly used for identifying legal users and refusing illegal users to access the network.

Authentication: refers to verifying that the user has the right to access the system. Traditional authentication is verified by means of a password.

AMF: the network element of the standard 5G core network, the access management function unit, completes the access and mobility management of the terminal user, which is equivalent to a part of the functions of the Mobility Management Entity (MME).

NAS: the NAS protocol handles the transmission of information between the user end and the core network, and the transmitted content may be user information or control information, such as service establishment, release or mobility management information.

SMF: the network element of the standard 5G core network, the session management function unit, is mainly responsible for interacting with the separated data plane, creating, updating, and deleting PDU sessions, and managing the session context (sessioncontext) with the UPF (user plane function).

5GC:5G core network.

AGF: and a gateway function conversion module.

TAC: the region code is tracked.

And NS: and the network section is used for network tracking during switching.

NCC: and a satellite network control center.

NMS: a satellite network management system.

UPF: network elements of a standard 5G core network, a user plane service transmission functional unit,

UE: a user terminal.

The patent application with publication number CN112994775B describes the convergence of high throughput GEO satellite communication with 5G communication, and the gateway function translation module AGF. Referring to fig. 1, a high-throughput GEO satellite has tens or even hundreds of beams, each of which is divided into multiple carriers according to different radio frequencies, each of which corresponds to a network segment (abbreviated as "NS"), and each of the NS corresponds to a cell (cell) in a handover procedure; for a high throughput GEO satellite, one NCC manages (or is called "corresponds to") one or more beams, the beams under one GEO satellite can be managed by multiple NCCs respectively, and all cells corresponding to each NCC define a Tracking Area Code (TAC); each AGF can serve one or more NCCs (non-core network controller), namely can correspond to a plurality of TACs; one or more AGFs access a common operator 5GC, and one operator 5GC is a registration area. Each NCC constitutes a ground transmission system of a satellite network, and all NCCs are designed to be in an interconnection mode, and a typical design mode is that a dedicated line is erected between every two NCCs to realize data interconnection transmission, and the ground transmission system is shown in fig. 2.

Referring to fig. 3 and 4, the invention provides a communication method for GEO satellite and 5G converged network trans-regional mobility, which includes a user terminal UE, a satellite access network and a 5G core network 5GC, wherein the satellite access network includes a satellite network control center NCC and a gateway function conversion module AGF connected to each other;

the step of protocol conversion by the N1 interface protocol conversion unit, the N2 interface protocol conversion unit and the N3 interface protocol conversion unit comprises:

s12, mapping data, namely establishing a one-to-one mapping table for parts of a satellite access network and a 5G core network 5GC realizing the same function according to a satellite network link data packet format and a 5G core network module structure, wherein satellite network data of a satellite network control center NCC can be converted into a protocol format of the corresponding function of the 5G core network 5GC according to a mapping relation;

s20, converting user QoS service level information and managing QoS priority, wherein a 5G core network 5GC issues the user QoS service level information to a gateway function conversion module AGF, the gateway function conversion module AGF converts the user QoS service level information into satellite communication system control information, the satellite communication system control information enters a satellite network control center NCC, and the QoS priority of a user using satellite communication link service is set through the satellite network control center NCC;

s40, establishing a service request, wherein a user terminal UE initiates the service request, a gateway function conversion module AGF converts the service request into 5G core network control information and transmits the control information to a 5G core network 5GC, and the 5G core network 5GC receives and establishes service data transmission session connection, and the service data transmission is the response of the service request;

specifically, the beam switching when the user terminal UE moves across the cell to trigger the switching of the satellite network control center NCC includes the following steps:

the target satellite network control center NCC sends a path switching notification message to the gateway function conversion module AGF, the gateway function conversion module AGF sends a forward data cache notification to the source target satellite network control center NCC, and the gateway function conversion module AGF stops sending forward data to the source target satellite network control center NCC and records the finally sent data; meanwhile, caching forward service data sent by the 5G core network to the NCC direction of the source target satellite network control center by the gateway function conversion module AGF; a source target satellite network control center NCC sends a forward data cache notice to user equipment UE, and the user equipment UE records the finally received data;

forwarding forward cache data to a target satellite Network Control Center (NCC) by a gateway function conversion module (AGF);

the target satellite network control center NCC sends forward cache data success confirmation to the gateway function conversion module AGF, and the beam switching process is completed;

when a user terminal UE moves across areas to trigger switching of a gateway function conversion module AGF and a satellite network control center NCC, the user terminal UE sends a switching request to a satellite network management system NMS, and the satellite network management system NMS decides to start switching; the 5G core network 5GC sends a forward service to a target gateway function conversion module AGF and a target satellite network control center NCC to complete switching;

specifically, the beam switching when the handover of the gateway function switching module AGF and the satellite network control center NCC is triggered by the user equipment UE moving across the cell includes the following steps:

the method comprises the steps that a satellite Network Management System (NMS) decides to start switching, a target satellite Network Control Center (NCC) is informed to prepare satellite link resources, and the target satellite Network Control Center (NCC) confirms that the resources are prepared to the NMS;

the method comprises the following steps that a satellite Network Management System (NMS) sends a switching command to User Equipment (UE), and satellite beam switching is started to be executed;

the user terminal UE connects the new satellite beam, and sends a switching confirmation to the target satellite network control center NCC to which the new beam belongs, wherein the switching confirmation indicates that the beam switching is completed, and the target satellite network control center NCC sends a switching success confirmation to the satellite network management system NMS;

the method comprises the steps that a satellite Network Management System (NMS) sends an N2 interface switching trigger notice to a source gateway function conversion module (AGF), wherein the N2 interface is one of connection interfaces of the gateway function conversion module (AGF) and a 5G core network 5GC, and the source gateway function conversion module (AGF) sends a switching requirement to an access management function unit (AMF) in the 5G core network 5 GC;

the AMF sends a switching command to the AGF, and simultaneously sends a forward data cache notification to the SMF in the 5G core 5 GC;

a user plane service transmission functional unit UPF recovers service transmission and service recovery with a user terminal UE;

The communication method for the GEO satellite and the 5G fusion network to move across areas can ensure that the communication service continuity of the GEO satellite and the 5G fusion network is continuous in two switching scenes:

in the first switching scenario, the user terminal switches between the satellite network control centers NCCs without switching the gateway function switching module AGF, as shown in fig. 5. In this scenario, the NMS on the satellite network side completes switching of the user terminal between beams, but when the control center of the user terminal is switched from the satellite network control center NCC1 to the satellite network control center NCC2, the forward service transmission needs to be changed from the gateway function conversion module AGF to the satellite network control center NCC1 to the gateway function conversion module AGF to the satellite network control center NCC2, and the process is completed by the satellite side device NCC in cooperation with the gateway function conversion module AGF, as shown in fig. 7, this flow design ensures that no packet is lost in the beam switching process;

after the user terminal is switched, the satellite network control center NCC and the gateway function conversion module AGF are both switched to be new, as shown in fig. 6. In this scenario, the switching of the gateway function conversion module AGF inevitably causes the switching of the satellite network control center NCC, and since the user terminal is to be switched from the source network control center NCC and the source gateway function conversion module AGF to the target network control center NCC and the target gateway function conversion module AGF, and the change of the gateway function conversion module AGF causes the switching of the N2 interface between the gateway function conversion module AGF and the 5G core network 5GC, the access management function unit AMF, the session management function unit SMF, and the user plane service transmission function unit UPF in the user terminal UE, the satellite network control center NCC, the gateway function conversion module AGF, and the 5G core network 5GC need to cooperate to complete the switching process, as shown in fig. 8, after the gateway function conversion module AGF is switched, in the link serving the user terminal UE, the N2 interface channel between the satellite network side and the 5GC side is not interrupted, the connection of the user is not interrupted, and the service can be continued. In order to ensure that the service connection is not interrupted, the process adopts a novel 2-point design: the first point is that a two-step switching mode is adopted, namely the satellite network control center NCC is switched first, then the gateway function conversion module AGF is switched, and a flow path is arranged in the middle of the switching mode, namely the connection state of the new satellite network control center NCC and the old gateway function conversion module AGF is matched, and the reference figure 9 shows that; the second point is that a service double comparison mode is adopted to confirm that the service data is not leaked, and the signaling flow mode is as follows: after the user terminal UE receives the forward cache data, the user terminal UE compares the consistency of the record of the last sent data in the cache data with the last received data recorded by the user terminal UE, and only if the result is consistent, the user terminal UE sends the forward cache data success confirmation and eliminates the repeated service data.

Taking one of the embodiments as an illustration, the existing high-throughput GEO satellite network and 5G fusion network, 5GC is a national unified core network of an operator X, the network has 1 set of unified satellite network management system NMS, and three satellite network control centers NCC of a city a center, a city b center, and a city c center, where the city a center and the city b center are jointly communicated and fused with the 5G core network 5GC by a gateway function conversion module AGF1, and the city c center is communicated and fused with the 5G core network 5GC by a gateway function conversion module AGF 2. A city a center manages beam 1, beam 2, b city center manages beam 3, beam 4, c city center manages beam 5, beam 6, and beam 7, and numbered adjacent beams are also geographically adjacent.

When the existing 1 satellite user moves from beam 2 to beam 3, the handover between different satellite network control centers NCC under the same gateway function conversion module AGF is triggered. The system starts the switching process as follows:

( Preamble: the NMS on the satellite network side performs the switching of the user terminal in terms of satellite resources from beam 2 to beam 3. )

1. The second city satellite network control center NCC sends a path switching notification message to the gateway function conversion module AGF1, the gateway function conversion module AGF1 sends a forward data cache notification to the first city satellite network control center NCC, and then the gateway function conversion module AGF1 stops sending forward data to the first city satellite network control center NCC and records the finally sent data; meanwhile, the gateway function conversion module AGF1 caches forward service data sent by the 5G core network 5GC to the NCC direction of the Jiacheng satellite network control center; the method comprises the steps that an A city satellite network control center NCC sends a forward data caching notice to user terminal UE, and the user terminal UE records the finally received data;

2. the gateway function conversion module AGF1 executes the path switching between the gateway function conversion module AGF1 and the satellite network control center NCC and switches to the second city satellite network control center NCC;

3. the gateway function conversion module AGF1 sends a path switching result to notify a first city satellite network control center NCC;

4. the first city satellite network control center NCC sends forward cache data forwarding confirmation to the gateway function conversion module AGF1;

5. the gateway function conversion module AGF1 forwards forward cache data to a second city satellite network control center NCC;

6. the method comprises the steps that a second city satellite network control center NCC sends forward cache data to user equipment UE;

7. the user terminal UE compares the consistency of the record of the last sent data in the gateway function conversion module AGF1 cache data with the last received data recorded by the user terminal UE, if the result is consistent, the user terminal UE sends forward cache data success confirmation to the second city satellite network control center NCC, and eliminates repeated service data;

8. and the NCC sends forward cache data success confirmation to the AGF1, and the switching process is completed.

When the satellite user moves continuously, the satellite user moves from the beam 4 to the beam 5, and the switching under different gateway function switching modules AGF (hereinafter abbreviated as AGF) and different satellite network control centers NCC (hereinafter abbreviated as NCC) is triggered. The system starts the switching process as follows:

1. a user terminal sends a switching request (HandoverRequest) to a satellite network management system NMS (NMS for short);

2. the NMS decides to start switching, informs the third city NCC to prepare satellite link resources, and the third city NCC confirms the completion of resource preparation to the NMS;

3. the NMS sends the switching information notification to the city B NCC, and the city B NCC returns the switching information notification confirmation;

4. NMS sends out switching command (Handover Command) to user terminal UE (UE for short), satellite beam switching starts to execute;

5. the UE connects the new satellite beam and sends a switching confirmation to the third city NCC to which the new beam belongs, the third city NCC sends a switching success confirmation to the NMS, and the beam switching is already completed;

6. the NMS sends a satellite resource recovery command to the city B NCC, and the city B NCC returns a satellite resource recovery confirmation;

7. the NMS sends an N2 interface switching trigger notification to the AGF1, and the AGF1 sends a switching requirement to an access management function unit AMF (hereinafter referred to as AMF) in a 5G core network 5GC (hereinafter referred to as 5 GC);

8. the AMF sends a switching request to the AGF2, and the AGF2 feeds back switching confirmation information;

9. AMF sends a switching command to AGF1, and simultaneously sends a forward data cache notice to a session management function unit SMF (SMF for short) in 5GC, SMF sends the forward data cache notice to a user plane service transmission function unit UPF (UPF for short), and the UPF records the last sending data and sends the record and the forward cache data to AGF2;

10. AGF1 sends a forward data cache notice to UE, and the UE records the finally received data;

11. the AGF performs switching as a response that the AMF sends a switching command to the AGF1;

12. after switching, AGF2 is activated, AGF2 sends a switching confirmation to AMF, AMF sends forward cache data forwarding to AGF2, and AGF2 is instructed to send cache data to UE;

13. the AGF2 sends forward cache data to the UE, the UE compares the consistency of the record of the last sent data in the AGF2 cache data with the last received data recorded by the UE, and if the result is consistent, the UE sends a successful confirmation of the forward cache data to the AGF2 and eliminates repeated service data;

14. the AGF2 sends a forward cache data success confirmation message to the AMF, the AMF sends a forward data service recovery command to the SMF, and the SMF sends a forward data service recovery command to the UPF;

15. UPF recovers the service transmission with UE and the service recovery;

16. AMF sends UE environment release command to AGF1, AGF1 returns UE environment release completion message. The handover is completed.

The invention also provides a communication system for the GEO satellite and 5G fusion network trans-regional movement, which comprises a user terminal UE, a satellite access network and a 5G core network 5GC, wherein the satellite access network comprises a satellite network control center NCC and a gateway function conversion module AGF which are connected;

the gateway function conversion module AGF comprises an N1 interface protocol conversion unit, an N2 interface protocol conversion unit and an N3 interface protocol conversion unit; the 5G core network comprises an access management function unit AMF and a user plane service transmission function unit UPF, and the user terminal UE and the access management function unit AMF are both connected to an N1 interface protocol conversion unit of a gateway function conversion module AGF; the N2 interface protocol conversion unit and the N3 interface protocol conversion unit are both connected to a satellite Network Control Center (NCC), wherein the N2 interface protocol conversion unit is connected with an access management function unit (AMF), and the N3 interface protocol conversion unit is connected with a user plane service transmission function Unit (UPF);

the steps of the protocol conversion of the N1 interface protocol conversion unit, the N2 interface protocol conversion unit and the N3 interface protocol conversion unit include:

s30, a gateway function conversion module AGF synchronizes the allocation information of the satellite terminal and the 5G core network to the IP address, and synchronizes the IP address allocated to the user terminal by the satellite network control center NCC to the 5G core network 5GC, so that the unification of the IP address of the user terminal between the satellite access network and the 5G core network 5GC is ensured;

the beam switching when the user terminal UE moves across areas to trigger the switching of the satellite network control center NCC comprises the following steps:

the target satellite network control center NCC sends a path switching notification message to the gateway function conversion module AGF, the gateway function conversion module AGF sends a forward data cache notification to the source target satellite network control center NCC, and the gateway function conversion module AGF stops sending forward data to the source target satellite network control center NCC and records the finally sent data; meanwhile, the gateway function conversion module AGF caches forward service data sent by the 5G core network to the NCC direction of the source target satellite network control center; a source target satellite network control center NCC sends a forward data cache notice to user equipment UE, and the user equipment UE records the finally received data;

the source satellite network control center NCC sends forward cache data forwarding confirmation to the gateway function conversion module AGF;

and the target satellite network control center NCC sends forward cache data success confirmation to the gateway function conversion module AGF, and the beam switching process is completed.

When a user terminal UE moves across regions to trigger switching of a gateway function conversion module AGF and a satellite network control center NCC, the user terminal UE sends a switching request to a satellite network management system NMS, and the satellite network management system NMS decides to start switching; the 5G core network 5GC sends the forward service to a target gateway function conversion module AGF and a target satellite network control center NCC to complete switching;

the beam switching when the user terminal UE is moved across the district to trigger the switching of the gateway function conversion module AGF and the satellite network control center NCC comprises the following steps:

user terminal UE sends switching request to satellite network management system NMS;

the gateway function conversion module AGF performs switching as a response that the access management function unit AMF sends a switching command to the source gateway function conversion module AGF;

the access management function unit AMF sends a user terminal UE environment release command to the source gateway function conversion module AGF, and the source gateway function conversion module AGF returns a user terminal UE environment release completion message to complete the switching.

The invention cooperatively switches the communication connection of users through the satellite access network and the gateway function conversion module AGF and the 5G network, so that the control information and the service data information of the satellite communication system and the 5G communication system are mutually transmitted and mutually operated, and the continuity of the communication service of the GEO satellite and the 5G fusion network is ensured when the users move across areas on the basis of the fusion of the communication systems of two different technical systems.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A communication method for GEO satellite and 5G fusion network trans-regional movement comprises a user terminal UE, a satellite access network and a 5G core network 5GC, wherein the satellite access network comprises a satellite network control center NCC and a gateway function conversion module AGF which are connected;

the method is characterized in that:

or,

the method comprises the following steps that a satellite Network Management System (NMS) sends a switching information notification to a source satellite Network Control Center (NCC), and the source satellite Network Control Center (NCC) returns a switching information notification confirmation;

the target gateway function conversion module AGF sends forward cache data to the user terminal UE, the user terminal UE compares the consistency of the last sending data record in the gateway function conversion module AGF cache data with the last receiving data record in the user terminal UE, if the comparison result is consistent, the forward cache data success confirmation is sent to the target gateway function conversion module AGF, and the repeated service data is eliminated;

the target gateway function conversion module AGF sends a forward cache data success confirmation message to an access management function unit AMF, the access management function unit AMF sends a forward data service recovery command to a session management function unit SMF, and the session management function unit SMF sends a forward data service recovery command to a user plane service transmission function unit UPF;

2. The method for communication between GEO satellite and 5G converged network in a trans-regional mobile manner according to claim 1, wherein:

s40, establishing a service request, wherein a user terminal UE initiates the service request, a gateway function conversion module AGF converts the service request into 5G core network control information and transmits the control information to a 5G core network 5GC, and the 5G core network 5GC receives and establishes service data transmission session connection, and the service data transmission is the response of the service request.