Satellite communication method and related equipment

Abstract

The embodiment of the invention provides a satellite communication method and related equipment. A satellite-borne base station is deployed on the satellite, the satellite is provided with a satellite-borne network element, the satellite-borne network element comprises the satellite-borne base station or a satellite-borne core network element, and the method is executed by the satellite-borne network element. The method comprises the following steps: receiving a data packet sent by a first terminal; and sending the data packet to the second terminal without passing through the network element of the ground core network according to the indication information.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and in particular to a satellite communication method, a satellite-borne network element, a communication device, a computer-readable storage medium, and a computer program product. Background Art

[0002] In wireless communication technology research, satellite communications are considered a key future development direction. Satellite communications refers to the technology by which terrestrial wireless communication devices access a network via satellite, or by the technology by which terrestrial wireless communication devices communicate with each other using satellites as relays. Satellite communications offer a wide range and are less susceptible to land-based disasters. As a complementary access method for mobile communications, satellite communications effectively address the limited coverage and high construction costs of mobile communication systems.

[0003] In the future, satellite communication systems will be integrated with terrestrial mobile networks (such as 4G and 5G networks) to form a global, integrated communications network with seamless coverage across land, sea, air, and space, meeting the diverse needs of users everywhere. When all core network functions of a satellite-ground integrated system are located on the ground, inter-terminal communications must be relayed via satellite and then back to the terrestrial core network for data exchange. This results in long communication links and significant latency. Summary of the Invention

[0004] The present disclosure provides a satellite communications method, wherein the satellite is deployed with an onboard base station and an onboard network element, wherein the onboard network element includes the onboard base station or an onboard core network element, and the method is performed by the onboard network element. The method includes: receiving a data packet sent by a first terminal; and, based on instruction information, sending the data packet to a second terminal without passing through a ground core network element.

[0005] The present disclosure provides an onboard network element, the onboard network element being located on a satellite, the satellite having an onboard base station deployed thereon, the onboard network element including the onboard base station or an onboard core network element. The onboard network element includes: a receiving unit configured to receive a data packet sent by a first terminal; and a sending unit configured to send the data packet to a second terminal without passing through a ground core network element according to instruction information.

[0006] An embodiment of the present disclosure provides a communication device, comprising: one or more processors; and a memory configured to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the communication device implements the satellite communication method described in the embodiment of the present disclosure.

[0007] An embodiment of the present disclosure provides a computer-readable storage medium having a computer program stored thereon. When the computer program is run on a computer, the computer implements the satellite communication method described in the embodiment of the present disclosure.

[0008] The embodiments of the present disclosure provide a computer program product, including a computer program. When the computer program is executed by a computer, the satellite communication method described in the embodiments of the present disclosure is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of a communication system architecture provided by an embodiment of the present disclosure.

[0010] Figure 2 This is a system architecture diagram of the 5G network provided by an embodiment of the present disclosure.

[0011] Figure 3 A network architecture diagram of a transparent forwarding mode according to an embodiment of the present disclosure is schematically shown.

[0012] Figure 4 The diagram schematically shows the circuitous routing and increased delay caused by transferring data through the terrestrial core network.

[0013] Figure 5 The diagram schematically shows a network architecture diagram of a regeneration mode according to an embodiment of the present disclosure.

[0014] Figure 6 A network architecture diagram of a regeneration mode according to another embodiment of the present disclosure is schematically shown.

[0015] Figure 7 A network architecture diagram of a regeneration mode according to another embodiment of the present disclosure is schematically shown.

[0016] Figure 8 The figure schematically shows a network architecture diagram of a regeneration mode according to yet another embodiment of the present disclosure.

[0017] Figure 9 The figure schematically shows a network architecture diagram of a regeneration mode according to yet another embodiment of the present disclosure.

[0018] Figure 10 The flowchart schematically shows a satellite communication method according to an embodiment of the present disclosure.

[0019] Figure 11 The interactive diagram of the satellite communication method according to an embodiment of the present disclosure is schematically shown.

[0020] Figure 12 The interactive diagram of a satellite communication method according to another embodiment of the present disclosure is schematically shown.

[0021] Figure 13 The interactive diagram schematically shows a satellite communication method according to yet another embodiment of the present disclosure.

[0022] Figure 14 The figure schematically shows a satellite communication method according to an embodiment of the present disclosure.

[0023] Figure 15 The interactive diagram schematically shows a satellite communication method according to yet another embodiment of the present disclosure.

[0024] Figure 16 The interactive diagram schematically shows a satellite communication method according to yet another embodiment of the present disclosure.

[0025] Figure 17 The interactive diagram schematically shows a satellite communication method according to yet another embodiment of the present disclosure.

[0026] Figure 18 The figure schematically shows a satellite communication method according to an embodiment of the present disclosure.

[0027] Figure 19 The block diagram of a satellite-borne network element according to an embodiment of the present disclosure is schematically shown.

[0028] Figure 20 The schematic structural diagram of a communication device according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present disclosure more apparent, exemplary embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the accompanying drawings, like reference numerals represent like elements throughout. It should be understood that the embodiments described herein are merely illustrative and should not be construed as limiting the scope of the present disclosure.

[0030] In the embodiments of the present disclosure, the term "module" or "unit" refers to a computer program or a part of a computer program that has a predetermined function and works together with other related parts to achieve a predetermined goal, and can be implemented in whole or in part by using software, hardware (such as processing circuits or memories) or a combination thereof. Similarly, a processor (or multiple processors or memories) can be used to implement one or more modules or units. In addition, each module or unit can be part of an overall module or unit that includes the function of the module or unit.

[0031] The technical solutions of the embodiments of the present disclosure can be applied to various communication systems, such as: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, 5G system or future evolved mobile communication system, etc.

[0032] For example, the communication system 100 used in the embodiment of the present disclosure is as follows: Figure 1As shown. The communication system can be a communication system based on cellular mobile communication technology. The communication system 100 can include a network device 110, which can be a device that communicates with a terminal 120 (or also referred to as a communication terminal or terminal). The network device 110 provides communication coverage for a specific geographical area and can communicate with terminals located within the coverage area. Optionally, the network device 110 can be a base station (Base Transceiver Station, BTS) in a GSM system or a CDMA system, a base station (NodeB, NB) in a WCDMA system, an evolved base station (Evolutional Node B, eNB or eNodeB) in an LTE (also known as 4G) system, a base station (gNB) in a 5G communication system, or a wireless controller in a cloud radio access network (Cloud Radio Access Network, CRAN), or the network device can be a mobile switching center, a relay station, an access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, a network side device in a 5G network, a network side device in a 5G network and a satellite system fusion system, a network side device in a 5G system with new air interface satellite access technology, a network side device in a 5G network using satellite transmission as base station backhaul, or a network device in a future evolved public land mobile network (Public Land Mobile Network, PLMN), etc.

[0033] Among them, the base station can be provided with a packet data convergence protocol (PDCP) layer, a radio link layer control protocol (RLC) layer, a media access control (MAC) layer protocol stack, and a physical (PHY) layer protocol stack. The embodiment of the present disclosure does not limit the specific implementation method of the base station.

[0034] The communication system 100 also includes at least one terminal 120 located within the coverage area of the network device 110. As used herein, "terminal" includes, but is not limited to, a connection via a wired line, such as via a Public Switched Telephone Network (PSTN), a Digital Subscriber Line (DSL), a digital cable, a direct cable connection; and / or another data connection / network; and / or via a wireless interface, such as for a cellular network, a Wireless Local Area Network (WLAN), a digital television network, a satellite network, a broadcast transmitter; and / or another terminal configured to receive / send communication signals; and / or an Internet of Things (IoT) device. A terminal configured to communicate via a wireless interface may be referred to as a "wireless communication terminal," "wireless terminal," or "mobile terminal." Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; Personal Communications System (PCS) terminals that may combine cellular radiotelephones with data processing, fax, and data communications capabilities; Personal Digital Assistants (PDAs) that may include a radiotelephone, pager, Internet / Intranet access, a web browser, a notepad, a calendar, and / or a Global Positioning System (GPS) receiver; and conventional laptop and / or handheld receivers or other electronic devices that include a radiotelephone transceiver. A terminal may be referred to as an access terminal, user equipment / terminal (UE), a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. The access terminal can be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, a device for an unmanned aerial vehicle, a vehicle-mounted device (for example, a driving computer with wireless communication capabilities, or a wireless communication device connected to an external driving computer), a wearable device, a terminal in a 5G network or a terminal in a future evolved PLMN, a roadside device (for example, a street lamp, a traffic light or other roadside device with wireless communication capabilities, etc.), etc.

[0035] A wireless connection can be established between the base station and the terminal via a wireless air interface. The wireless air interface can be a wireless air interface based on the 4G standard; or a wireless air interface based on the 5G standard, for example, a new air interface; or a wireless air interface based on the next generation mobile communication network technology standard of 5G.

[0036] In some embodiments, the above-mentioned communication system may further include a network management device (not shown in the figure). One or more (two or more) base stations are respectively connected to the network management device. The network management device may be a core network device (including core network elements) in the wireless communication system. For example, the network management device may be a mobility management entity (MME) in the evolved packet core (EPC), providing non-access stratum (NAS) signaling transmission with the UE (providing encryption and integrity protection for NAS signaling), and processing the UE's ESM (EPS Session Management) and EMM (EPS Mobility Management) transactions through the NAS layer. Alternatively, the network management device may also be other core network devices, such as a serving gateway (S-GW), a public data network gateway (P-GW), a policy and charging rules function (PCRF), or a home subscriber server (HSS). The embodiments of the present disclosure do not limit the implementation form of the network management device.

[0037] Figure 1 One network device and two terminals are shown as an example. Optionally, the communication system 100 may include multiple network devices and each network device may include another number of terminals within its coverage area, which is not limited in the embodiments of the present disclosure.

[0038] It should be understood that the device with communication function in the network / system in the embodiment of the present disclosure can be called a communication device. Figure 1 Taking the communication system 100 as an example, the communication equipment may include a network device 110 and a terminal 120 having communication functions. The network device 110 and the terminal 120 may be the specific devices described above and will not be described in detail here.

[0039] It should be understood that the terms "system" and "network" are often used interchangeably herein. The term "and / or" is simply a description of an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone.

[0040] Figure 2 This is a system architecture diagram of a 5G network according to an embodiment of the present disclosure. Figure 2 As shown in the figure, the equipment involved in the 5G network system include: terminal (UE), radio access network (Radio Access Network, RAN), user plane function (UserPlane Function, UPF) network element, data network (Data Network, DN), access and mobility management function (Accessand Mobility Management Function, AMF) network element, session management function (Session ManagementFunction, SMF) network element, policy control function (Policy Control Function, PCF) network element, application function (Application Function, AF) network element, authentication server function (Authentication Server Function, AUSF) network element, unified data management (Unified Data Management, UDM) network element, network slice selection function (Network Slice Selection Function, NSSF).

[0041] exist Figure 2 In the network architecture shown in the figure, each network element can communicate with each other through the interfaces shown in the figure. Figure 2As shown, the UE and AMF can interact via the N1 interface, which is used to deliver Quality of Service (QoS) control rules to the UE. N2 is the interface between the AMF and the RAN, which is used to deliver radio bearer control information from the core network to the RAN. The N2 interface can be used to send NAS messages, etc. The RAN and the UPF can interact via the N3 interface, which can be used to transmit user plane data, etc. N4 is the interface between the SMF and the UPF, which is used to transmit information between the control plane and the user plane, including the issuance of forwarding rules, QoS control rules, traffic statistics rules, etc. for the user plane, as well as the reporting of user plane information. The UPF and the DN can interact via the N6 interface, which can be used to transmit user plane data, etc. N7 is the interface between the PCF and the SMF, which is used to deliver Protocol Data Unit (PDU) session granularity and service data flow granularity control policies. N15 is the interface between the PCF and the AMF, which is used to deliver UE policies and access control-related policies. N5 is the interface between AF and PCF, used for issuing application service requests and reporting network events. N11 is the interface between SMF and AMF, used for transmitting PDU session tunnel information between RAN and UPF, transmitting control messages sent to UE, transmitting radio resource control information sent to RAN, etc. N8 is the interface between AMF and UDM, used for AMF to obtain subscription data and authentication data related to access and mobility management from UDM, and for AMF to register information related to the current mobility management of UE with UDM, etc. N10 is the interface between SMF and UDM, used for SMF to obtain subscription data related to session management from UDM, and for SMF to register information related to the current UE session with UDM, etc. N12 is the interface between AMF and AUSF, used for AMF to initiate an authentication process to AUSF, which can carry SUCI as a subscription identifier. N13 is the interface between UDM and AUSF, used for AUSF to obtain the user authentication vector from UDM to execute the authentication process. N22 is the interface between AMF and NSSF.

[0042] It should be understood that the naming in the embodiments of the present disclosure is only defined to facilitate the distinction between different functions and should not constitute any limitation to the present disclosure.

[0043] This disclosure does not exclude the possibility of adopting other nomenclatures in 5G networks and other future networks. For example, in 6G networks, some or all of the above network elements may continue to use 5G terminology or may adopt other names. Figure 2The interface names between the various network elements in the embodiment are merely examples. In specific implementations, the interface names may be other names, and this disclosure does not specifically limit this. In addition, the names of the messages (or signaling) transmitted between the various network elements are merely examples and do not limit the functions of the messages themselves.

[0044] It is understood that the above-mentioned network elements or functions can be network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform). For ease of explanation, the following description of this disclosure takes the base station as an example of a radio access network RAN.

[0045] It should be understood that the above-mentioned network architecture applied to the embodiment of the present disclosure is only an example, and the network architecture applicable to the embodiment of the present disclosure is not limited to this. Any network architecture that can realize the functions of the above-mentioned network elements is applicable to the embodiment of the present disclosure.

[0046] The network architecture and business scenarios described in the embodiments of the present disclosure are intended to more clearly illustrate the technical solutions of the embodiments of the present disclosure, and do not constitute a limitation on the technical solutions provided by the embodiments of the present disclosure. A person skilled in the art will appreciate that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided by the embodiments of the present disclosure are equally applicable to similar technical problems.

[0047] The integration of 5G and satellite networks is an important technical direction for the integrated space-air-ground network. Figure 3 The transparent forwarding mode shown starts to Figures 5 to 9 The regeneration mode transition is shown.

[0048] like Figure 3 As shown, all functions of the core network (such as EPC / 5G core network (5G core network, 5GC)) 33 and the base station (such as eNB in 4G or gNB in 5G) 34 are deployed on the ground, and the service link (Service link) and feedback link (feeder link) of the satellite 31 are carried as the underlying link of the Uu port to provide support for communication between the base station and the UE. The Uu port is the interface between the base station and the UE, which is used to transmit signaling and data. The non-terrestrial network gateway (NTN-GW) 32 is connected to the EPC / 5GC 33 through the eNB / gNB 34. The EPC / 5GC 33 is connected to the application server 35. In Figure 3 In the transparent forwarding mode shown, the satellite link is only responsible for relaying signals between the UE and the eNB / gNB 34, and 4G / 5G related protocol processing is all performed within the 4G / 5G network.

[0049] This transparent forwarding model suffers from high latency because base stations and core network equipment are deployed on the ground. Furthermore, since this model treats satellites only as signal relay links and does not utilize them for signal processing or conversion, communication between satellites cannot be achieved. Therefore, this model does not support inter-satellite links (ISLs), making it difficult to expand coverage of the Earth's surface using satellite constellations. Furthermore, the path between satellites and base stations is long, resulting in high latency.

[0050] Figure 3 The disadvantage of the proposed solution is that it struggles to support flexible and efficient data transmission between UEs. Specifically, when two UEs exchange data via a satellite link, the data must first reach the core network element on the ground before being forwarded to the other UE. This is because satellite links are primarily used for wide coverage and long-distance transmission, while core network elements are responsible for tasks such as data processing, routing, and flow control. Therefore, data forwarding between two different UEs requires both uplink and downlink transmission on both the serving link and the feedback link, which increases latency and wastes resources on the feedback link.

[0051] For example, Figure 4 As shown, the first terminal (UE1) first sends data to the satellite 31 through the service link between UE1 and the satellite 31, and the satellite 31 then sends the data received from UE1 to the base station (e.g., eNB / gNB) 34 through the feedback link between NTN-GW 32 and the satellite 31. Then, the base station 34 transmits the data received from the NTN-GW 32 to the ground core network element (e.g., EPC / 5GC) 33 through the ground network. EPC / 5GC 33 processes and forwards the data. For example, the core network element 33 can encrypt, decrypt, filter, and screen the data to ensure data security and privacy protection. In addition, the core network element 33 can also perform access control and traffic management based on the user's authentication, authorization, and billing information to ensure normal communication. EPC / 5GC 33 then sends the processed data to UE2 through the eNB / gNB 34, NTN-GW 32, satellite 31, and the service link between satellite 31 and the second terminal (UE2). From Figure 4 It can be seen that redundant transmission leads to increased delay and waste of link resources.

[0052] To this end, the industry is developing another approach, namely the regeneration mode, which places the base station (optionally, at least part of the 4G / 5G core network) on the satellite. This can shorten the link processing delay and realize satellite networking through ISL.

[0053] To this end, the embodiments of the present disclosure provide a method and apparatus for supporting on-board local data exchange in satellite Internet, which can realize UE1-satellite-UE2 communication, so that data transmission between two UEs under the same satellite or between different satellites does not need to be forwarded through the core network elements on the ground, thereby shortening the communication delay and saving feedback link transmission resources between the satellite and the ground.

[0054] The method provided in the embodiment of the present disclosure can be based on the following Figures 5 to 9 The network architecture of the regeneration mode shown can be oriented to the 5G system and can also be applied to the 4G system.

[0055] exist Figure 5 In the network architecture shown, a base station (e.g., eNB / gNB) 511 is deployed on a satellite 51 and is referred to as a satellite-borne base station 511. Functional entities of the core network are deployed on the ground and are referred to as ground-based core network elements (e.g., EPC / 5GC) 53. When no core network equipment / core network elements are deployed on the satellite 51, in order to enable communication between UE1, the satellite, and UE2, the satellite-borne base station 511 has local data forwarding capabilities. That is, data between different UEs can be transmitted through the satellite-borne base station 511 without passing through the ground-based core network element 53, thereby optimizing data routing and saving transmission resources. Specifically, data sent by UE1 is transmitted to the satellite 51 via the service link between UE1 and the satellite 51. The satellite-borne base station 51 sends the data to UE2 based on the service link between the satellite 51 and UE2, eliminating the need for uplink and downlink transmission between the NTN-GW 52 and the satellite 51. Figure 5 In the embodiment, the EPC / 5GC 53 is in communication with the application server 55 .

[0056] exist Figure 6In the network architecture shown, base station 611 and some core network functional entities are deployed on satellite 61, while other core network functional entities are deployed on the ground. That is, the functional entities of the core network (e.g., EPC / 5GC) can be distributed both on the satellite and on the ground. The core network functional entities deployed on the ground are referred to as ground core network elements (EPC / 5GC-ground part, i.e., the core network functional entities deployed on the ground) 631, and the core network functional entities deployed on the satellite are referred to as onboard core network elements (EPC / 5GC-onboard part, i.e., the core network functional entities deployed on the satellite) 632. When both onboard base station 611 and onboard core network element 632 are deployed on satellite 61, onboard core network element 632 has local data forwarding capabilities. That is, data transmission between different UEs (e.g., UE1 and UE2) can be achieved through onboard core network element 632 rather than through ground core network element 631, optimizing data routing and saving transmission resources. Specifically, the data sent by UE1 is transmitted to satellite 61 through the service link between UE1 and satellite 61. The onboard core network element 632 sends the data to UE2 based on the service link between satellite 61 and UE2, and no longer needs to be transmitted uplink and downlink between the feedback link between NTN-GW 62 and satellite 61. Figure 6 In the embodiment, the ground EPC / 5GC 631 is in communication with the application server 65 .

[0057] exist Figure 7In the network architecture shown, the base station 711 and the functional entities of the core network (such as EPC / 5GC) are deployed on the satellite 71. The functional entity of the core network deployed on the satellite is called the onboard core network element 712. At this time, the satellite 71 may also be deployed with a corresponding application server (Application Server, abbreviated as AS). Optionally, another core network functional entity and a corresponding application server may be deployed on the ground. For the sake of distinction, the core network element deployed on the satellite 71 and the corresponding application server are respectively marked as the first core network element (EPC / 5G 5GC 1) 712 and the first application server (Application Server 1, AS1) 713, and the core network element deployed on the ground and the corresponding application server are respectively marked as the second core network element (EPC / 5G5GC 2) 74 and the second application server (Application Server 2, AS2) 75. EPC / 5G5GC 1 has local data forwarding capabilities, meaning that data can be transmitted between different UEs (e.g., UE1 and UE2) through EPC / 5G 5GC 1, optimizing data routing and saving transmission resources. Specifically, data sent by UE1 is transmitted to satellite 71 via the service link between UE1 and satellite 71. Onboard core network element 712 then sends the data to UE2 based on the service link between satellite 71 and UE2, eliminating the need for uplink and downlink transmission between the feedback link between NTN-GW 72 and satellite 71. Figure 7 In the embodiment, the ground EPC / 5GC 2 is in communication with its corresponding AS2. Figure 7 In the embodiment, UE1 and / or UE2 can also implement data exchange through EPC / 5G 5GC 2 and AS2, that is, local data exchange and data exchange paths through the terrestrial core network can exist at the same time.

[0058] exist Figure 8In the illustrated network architecture, UE1 and UE2 are located under different satellites. For example, UE1 is located under first satellite 81, i.e., UE1 accesses the network or transmits data through first satellite 81; UE2 is located under second satellite 86, i.e., UE2 accesses the network or transmits data through second satellite 86. A base station 811 is deployed on first satellite 81, and a base station may or may not be deployed on second satellite 86. The functional entities of the core network (e.g., EPC / 5GC) 83 are deployed on the ground. The base station 811 deployed on the first satellite 81 has local data forwarding capabilities, that is, when the base station 811 on the first satellite 81 receives data sent by UE1 through the service link between the first satellite 81 and UE1, it first sends the data to the second satellite 86 through the ISL between the first satellite 81 and the second satellite 86, and then sends the data to UE2 through the service link between the second satellite 86 and UE2. It does not need to be sent to the ground core network element 83 through the feedback link between the NTN-GW 82 and the second satellite 86, that is, data transmission between UE1 and UE2 can be realized, data routing is optimized, and transmission resources are saved. Figure 8 In the embodiment, the ground core network element 83 is communicatively connected to the application server 85 .

[0059] It should be noted that although Figure 8 Only the ISL between the first satellite 81 and the second satellite 86 is shown in the figure, but the present disclosure is not limited thereto. Local data exchange between UE1 and UE2 can also be achieved through multiple ISLs between multiple satellites.

[0060] exist Figure 9 In the illustrated network architecture, UE1 is located under a first satellite 91, and UE2 is located under a second satellite 96. A base station 911 and at least a portion of the core network's functional entities (e.g., onboard EPC / 5GC) 932 are deployed on the first satellite 91. The second satellite 96 may or may not have a base station and at least a portion of the core network's functional entities deployed. The functional entities of another portion of the core network (e.g., EPC / 5GC) 931 may be deployed on the ground. The onboard core network element 932 deployed on the first satellite 91 has local data forwarding capability, that is, when the onboard core network element 932 receives data sent by UE1 through the service link between the first satellite 91 and UE1, it first sends the data to the second satellite 96 through the ISL between the first satellite 91 and the second satellite 96, and then sends the data to UE2 through the service link between the second satellite 96 and UE2. It does not need to be sent to the ground core network element 931 through the feedback link between the NTN-GW 92 and the second satellite 96, that is, data transmission between UE1 and UE2 can be realized, data routing is optimized, and transmission resources are saved. Figure 9In the embodiment, the ground core network element 931 is communicatively connected to the application server 95 .

[0061] Similar, although Figure 9 FIG. 4 shows only the ISL between the first satellite 91 and the second satellite 96 , but the present disclosure is not limited thereto. Local data exchange between UE1 and UE2 may also be achieved through multiple ISLs between multiple satellites.

[0062] like Figure 10 As shown, the embodiment of the present disclosure provides a method for satellite communication. Figure 10 In the embodiment, a satellite is deployed with an onboard base station, and the satellite has onboard network elements, which include onboard base stations or onboard core network elements.

[0063] In an exemplary embodiment, the onboard network element stores a terminal-related context, and the terminal-related context includes indication information that the first terminal and the second terminal perform local data exchange via the onboard network element.

[0064] In the embodiments of the present disclosure, a satellite-based network element refers to a network element deployed on a satellite. It can be a base station deployed on a satellite, i.e., a satellite-based base station; or a core network element deployed on a satellite, i.e., a satellite-based core network element. The satellite-based core network element can have at least some core network functional entities.

[0065] In the disclosed embodiment, the onboard network element has a local data exchange capability, that is, it can realize data forwarding between different UEs without passing through the ground core network element. In order to enable the onboard network element to support local data exchange, a terminal-related context (UE context) is stored in the onboard network element, and the terminal-related context refers to a context stored in the onboard network element and related to the UE. The terminal-related context indicates that the onboard network element supports local data exchange. When the onboard network element receives a data packet sent by a UE (for example, UE1) that supports local data exchange and is contained in the terminal-related context, the onboard network element can transmit the received data packet to another UE (for example, UE2) without passing through the ground core network element according to the terminal-related context.

[0066] Figure 10 The method provided in the embodiment is executed by a satellite-borne network element. Figure 10 As shown, the method provided by the embodiment of the present disclosure may include the following steps.

[0067] In S10, a data packet sent by the first terminal is received.

[0068] In S20, according to the instruction information, the data packet is sent to the second terminal without passing through the ground core network element.

[0069] In an embodiment of the present disclosure, the terminal-related context stored in the onboard network element includes indication information that the first terminal and the second terminal are performing local data exchange through the onboard network element. For example, the indication information may include a mapping relationship between an identifier of the first terminal as the source address and an identifier of the second terminal as the destination address. When the onboard network element receives a data packet sent by the first terminal, the onboard network element determines, based on the mapping relationship, that local data exchange can be performed between the first terminal and the second terminal. Therefore, the onboard network element can directly send the data packet to the second terminal without forwarding it through the ground core network element.

[0070] The satellite communication method provided by the embodiment of the present disclosure deploys on-board network elements on a satellite, enabling the on-board network elements to support local data exchange, thereby enabling data transmission between two UEs on the same satellite or between different satellites without the need for forwarding through core network elements on the ground. That is, a method for supporting on-board local data exchange in a satellite Internet is disclosed, which can realize UE-1 satellite-UE2 communication, thereby shortening communication latency and saving feedback link transmission resources between the satellite and the ground.

[0071] In an exemplary embodiment, the method provided by the embodiment of the present disclosure further includes: during the process of establishing a session or connection between the first terminal and the second terminal through the satellite base station and the core network element, the satellite network element obtains a terminal-related context. The core network element includes a terrestrial core network element and / or a satellite core network element.

[0072] In an embodiment of the present disclosure, when the first terminal and the second terminal establish a session or connection through the onboard base station and the core network network element, if the core network network element determines that both the first terminal and the second terminal support local data exchange, the core network network element can provide the onboard network element with signaling interaction and corresponding configuration so that it has the ability to locally exchange data transmitted between the first terminal and the second terminal, that is, the onboard network element obtains a terminal-related context containing indication information that the first terminal and the second terminal perform local data exchange through the onboard network element.

[0073] In some embodiments, the signaling interaction and corresponding configuration of local data exchange on the satellite can be retained in the ground core network element, and the satellite network element obtains the signaling interaction and corresponding configuration of local data exchange from the ground core network element. After the ground core network element performs the signaling interaction and corresponding configuration of local data exchange based on the satellite network element, the satellite network element can process the input provided by the ground core network element and derive the context related to the terminal. However, the present disclosure is not limited to this. In other embodiments, the satellite network element can also obtain the signaling interaction and corresponding configuration of local data exchange from the onboard core network element. In this case, the context related to the terminal can be established through the interaction between the satellite core network element and the ground core network element.

[0074] In an exemplary embodiment, the terminal-related context includes a first key of the first terminal and a second key of the second terminal. The method of transmitting the data packet to the second terminal without passing through the ground core network element according to the instruction information includes: decrypting the data packet using the first key of the first terminal; encrypting the decrypted data packet using the second key of the second terminal; and transmitting the data packet encrypted using the second key of the second terminal to the second terminal. In the disclosed embodiment, the key of UE1 and the key of UE2 are different. Therefore, before transmitting the data packet to the onboard network element, UE1 first encrypts the data packet using UE1's key. When the onboard network element receives the data packet sent by UE1 via the service link between the satellite and UE1, it first decrypts the data packet using UE1's first key, then encrypts the decrypted data packet using UE2's second key, and then transmits the data packet encrypted using UE2's second key to UE2 via the service link between UE2 and the satellite, thereby ensuring security for local data exchange between UE1 and UE2.

[0075] In an exemplary embodiment, the terminal-related context also includes parameters of the satellite. The method of sending the data packet to the second terminal without passing through a terrestrial core network element based on the indication information includes: determining whether the first terminal and the second terminal are located under the same satellite based on the satellite parameters; if the first terminal and the second terminal are located under the same satellite, sending the data packet to the second terminal via an onboard network element of the satellite; and if the first terminal and the second terminal are located under different first and second satellites, sending the data packet to the second terminal located under the second satellite via an inter-satellite link (ISL) between the first and second satellites. In other words, in this embodiment of the present disclosure, the terminal-related context stored on the onboard network element may also include parameters of the satellite. For example, if UE1 is located under a first satellite and UE2 is located under a second satellite, the ISL between the first and second satellites can be determined, and local data exchange between UE1 and UE2 can be achieved via the ISL between the first and second satellites. For another example, if UE1 and UE2 are both located under the same satellite, local data exchange between UE1 and UE2 can be achieved directly via the onboard network element of the satellite.

[0076] In an exemplary embodiment, when all core network elements are deployed on the ground, the satellite-borne network element is the satellite-borne base station.

[0077] In an exemplary embodiment, the indication information includes a local data exchange index (index), a source address (source) corresponding to the local data exchange index includes a first data radio bearer (DRB) of the first terminal, and a destination address (dest) includes a second data radio bearer (DRB) of the second terminal. That is, in the embodiment of the present disclosure, local data exchange (also known as local switching) between different UEs is implemented through an onboard network element, which can be DRB-granular. That is, when the onboard network element detects that a data packet transmitted by UE1 through a first DRB is transmitted to UE2 through a second DRB of UE2, the onboard network element can transmit the data packet to UE2 through the second DRB based on the indication information.

[0078] In an exemplary embodiment, the indication information includes a local data exchange index, the source address corresponding to the local data exchange index includes multiple (including some or all) data radio bearers of the first terminal, and the destination address includes at least one data radio bearer of the second terminal. In some embodiments, local data exchange between different UEs is implemented through an onboard network element, which can be UE-granular. That is, the indication information can indicate that all data packets of UE1 are transmitted to UE2 via a local switch. That is, at this time, the source address corresponding to the local data exchange index includes all data radio bearers of the first terminal, and the destination address includes one or more data radio bearers of the second terminal.

[0079] In an exemplary embodiment, the terminal-related context also includes information indicating that the first terminal and the second terminal exchange data via the onboard network element and the terrestrial core network element. That is, while the onboard network element supports local data exchange between different UEs, it can also support a path for data exchange between different UEs via the terrestrial core network element, thereby further improving the reliability of data transmission.

[0080] In an exemplary embodiment, when at least some core network elements are deployed on the satellite, the onboard network element is the onboard core network element. In the disclosed embodiment, when there are onboard core network elements and onboard base stations on the satellite, local data exchange between different UEs is achieved through the onboard core network elements.

[0081] In an exemplary embodiment, the indication information includes a local data exchange index, the source address corresponding to the local data exchange index includes the first tunnel identification information of the first terminal, and the destination address includes the second tunnel identification information of the second terminal. In some embodiments, when local data exchange is implemented through an onboard core network element, the indication information stored by the onboard core network element includes a mapping relationship between the first tunnel identification information of UE1 and the second tunnel identification information of UE2. In this way, when the onboard core network element receives a data packet sent by UE1 through the tunnel indicated by the first tunnel identification information, it can send the data packet to UE2 through the tunnel corresponding to the second tunnel identification information according to the indication information.

[0082] In an exemplary embodiment, the indication information includes a local data exchange index, the source address corresponding to the local data exchange index includes the first evolved radio access bearer (E-UTRAN Radio Access Bearer, E-RAB) of the first terminal, and the destination address includes the second evolved radio access bearer of the second terminal. In other embodiments, when local data exchange is implemented through an onboard core network element, the indication information stored in the onboard core network element includes a mapping relationship between the first E-RAB of UE1 and the second E-RAB of UE2, so that when the onboard core network element receives a data packet sent by UE1 through the first E-RAB, it can send the data packet to UE2 through the second E-RAB according to the indication information. That is, in the embodiment of the present disclosure, local data exchange between different UEs is implemented through the onboard core network element, which can be at the E-RAB granularity, but the present disclosure is not limited to this, and can also be at the UE granularity, that is, the indication information can indicate that all data packets of UE1 are transmitted to UE2 through the local switch.

[0083] The method provided by the disclosed embodiments enables onboard local data exchange in satellite internet, enabling UE1-satellite-UE2 communication. Data transmission between two UEs on the same or different satellites does not need to be forwarded through the core network elements on the ground, thereby shortening communication latency and conserving feedback link transmission resources between the satellite and the ground. At the same time, it can also support flexible conversion between local forwarding and ground forwarding modes, supporting communication between UEs and cloud-edge-end collaboration between UEs, the onboard "edge cloud," and the ground-based "central cloud."

[0084] The following combination Figures 11 to 14 As an example, the protocol flow design for implementing local data forwarding using satellite-borne base stations is described below, combining the architecture of integrating 4G and 5G networks with satellite networks. Examples of local data forwarding by different network elements in different scenarios are as follows.

[0085] Figures 11 to 14 This is a scenario where the base station is located on the satellite and the core network is entirely on the ground.

[0086] like Figure 11 As shown in FIG, it is a flow chart of the main steps for realizing local data exchange by satellite base station.

[0087] In S11, the terminal initiates PDU session / PDN connection establishment and service initiation, obtains signaling interaction and corresponding configuration of the core network, and can perform local switching.

[0088] In S12, after obtaining signaling interaction and corresponding configuration from the core network, the satellite-borne base station eNB / gNB establishes a local interaction context and key. The local interaction context may include a terminal-related context indicating that the satellite-borne base station can support local data exchange.

[0089] In S13, local data exchange is performed through the base station. For example, the satellite-borne base station eNB / gNB performs local data exchange between UE1 and UE2 based on the local exchange context and key.

[0090] Specifically, Figure 11 The GS in the figure stands for ground station (e.g., NTN-GW). UEs (including UE1 and UE2) establish a PDU session or a public data network (PDN) connection through a 4G or 5G satellite base station (eNB / gNB) and core network equipment (CN) on the ground. During service request initiation and connection establishment, the eNB / gNB receives signaling and configuration from the core network, enabling local data exchange.

[0091] Among them, PDU session and PDN connection are used for 5G and 4G systems respectively.

[0092] In order to realize local data exchange, it is explicitly indicated in the terminal-related context of the satellite base station eNB / gNB that local exchange can be performed.

[0093] The terminal-related context stored in the satellite base station eNB / gNB includes user information, terminal information, bearer information, etc., which is used to establish and maintain a communication connection with the UE. For example, it may include at least one of the following information:

[0094] User identifier: includes Subscription Permanent Identifier (SUPI), Subscription Concealed Identifier (SUCI), Permanent Equipment Identifier (PEI), etc., used to uniquely identify a user;

[0095] Mobility management restrictions and terminology: including registration area, prohibited area, service-restricted area, etc., used to restrict user mobility and access rights.

[0096] For example, in a converged 4G and satellite network, the terminal-related context of the satellite base station eNB includes information such as UE status information, security information, UE capability information, the association between the UE and the S1 logical connection, the association between the UE and the X2 logical connection, and information related to roaming and access restrictions. This is used to maintain the services provided by the E-UTRAN to active UEs. This information is used to establish and maintain communication connections with the UE to ensure normal communication. For another example, in a converged 5G and satellite network, the terminal-related context of the satellite base station gNB includes information such as UE status information, security information, UE capability information, the association between the UE and the N2 / N3 logical connection, the association between the UE and the Xn logical connection, and information related to roaming and access restrictions. This is used to maintain the services provided by the RAN to active UEs. This information is used to establish and maintain communication connections with the UE to ensure normal communication.

[0097] In the disclosed embodiments, the local data exchange supported by the satellite-based base station eNB / gNB itself requires obtaining relevant parameters, including security parameters (e.g., various keys), from the terrestrial core network element (CN element), such as the MME / AMF. These relevant parameters may be included in the terminal-related context.

[0098] Specifically, since the 4G and 5G base station eNB / gNB itself needs to support protocol layer processing such as the SDAP layer and the PDCP layer from the perspective of the protocol stack, and the PDCP key needs to be configured by the ground core network elements such as MME / AMF, the base station that supports the local forwarding function on the satellite must maintain a connection with the ground core network elements such as MME / AMF. This connection can be used to derive the key.

[0099] The key derive process includes: generating NAS layer keys, including IK (Integrity Key) and CK (Cipher Key), from the MME / AMF and UE NAS layers, and generating AS layer keys at the AS layer of the eNB / gNB and UE. Both steps involve the core network elements (CN elements) located on the ground. When configuring PDCP keys, NAS layer keys and AS layer keys need to be generated first. NAS layer keys are mainly used to protect the confidentiality and integrity of NAS signaling, while AS layer keys are used to protect the confidentiality and integrity of RRC signaling, as well as the confidentiality of user plane data. Generating these keys before configuring PDCP keys can ensure that PDCP data transmission is carried out in a secure environment.

[0100] The process of obtaining the base station's PDCP keys from the MME / AMF is achieved through security context exchange. After the UE successfully accesses the base station, the base station obtains the UE's security context from the MME / AMF, which includes the keys used for PDCP encryption and decryption. In this way, the base station can use these keys to encrypt and decrypt data to ensure the security of communications. This process involves certain specific protocols and processes, such as NAS security context and the NAS security context exchange process. These protocols and processes ensure that the base station can securely obtain PDCP keys from the MME / AMF, thereby achieving secure communications. PDCP layer keys are mainly used to encrypt and decrypt user plane data and provide integrity protection for data. These keys are generated at the RRC layer and configured for the PDCP layer when AS layer security is activated.

[0101] In the embodiment of the present disclosure, NAS security is designed to securely transmit signaling information between the radio link UE and CN network elements (such as MME / AMF, etc.) to perform integrity check and encryption of NAS signaling messages. For example, it may include the integrity key K NASint and encryption key K NASenc NAS-layer keys are generated during the security context exchange process between the MME / AMF and the UE. When the UE successfully accesses the network, the MME / AMF and the UE exchange a security context, including the NAS security context. During this process, the MME / AMF and the UE jointly generate NAS-layer keys.

[0102] AS security is used to ensure the security of data transmission between the UE and the satellite base station eNB / gNB on the radio link. Integrity checking and encryption are performed on the control side for RRC signaling messages, and encryption is performed on the user side for IP (Internet Protocol) data packets (such as the above data packets). Different keys are used for integrity checking / encryption of RRC signaling messages and encryption of IP data packets. AS security keys, such as K RRCint , K RRCenc and K UPenc , which is generated by UE and satellite base station eNB / gNB from K eNB Derived from K RRCint and K RRCenc Used for integrity checking and encryption of control plane data, K UPenc Used for encryption of user plane data. Optionally, the AS security key may also include K UPint . Integrity check and encryption can be performed at the PDCP layer. UE can ASME K is derived from eNB , K ASME It is not transmitted to the satellite base station eNB / gNB, but is transmitted from K ASME K is derived from eNB , which is then passed to the onboard base station, the eNB / gNB. AS-layer keys are generated between the eNB / gNB and the UE through the security context exchange process. These keys are jointly generated by the eNB and UE and are used to encrypt and decrypt RRC signaling and user plane data.

[0103] For example, in a 5G network, after the UE receives the terminal-related context from the 5GC, the RAN uses the initial radio access AS security activation procedure to activate AS security (encryption and integrity protection). After the RRC message (command and successful response) for activating AS security is integrity protected, the RAN initiates DRB establishment. In 5G wireless networks, all RRC reconfiguration messages used to establish DRBs are encrypted and integrity protected.

[0104] like Figure 12 As shown in FIG, a flowchart of the main steps for the satellite-borne base station eNB to realize local data exchange in the scenario of 4G network and satellite network integration.

[0105] In S11a, the terminal initiates PDN connection establishment and service initiation, obtains signaling interaction and corresponding configuration of functional entities such as MME / P-GW in the ground core network, and can perform local switching.

[0106] In S12a, after obtaining the signaling interaction and corresponding configuration of the MME / P-GW and other functional entities in the core network, the satellite base station eNB establishes a local interaction context and key. The local interaction context may include a terminal-related context indicating that the satellite base station eNB can support local data exchange.

[0107] In S13a, local data exchange is performed through the satellite-borne base station eNB. For example, the satellite-borne base station eNB performs local data exchange between UE1 and UE2 based on the local exchange context and key.

[0108] Figure 12 For other contents of the embodiment, reference can be made to the other embodiments mentioned above.

[0109] like Figure 13 The figure shows the main steps for the satellite-borne base station gNB to implement local data exchange in the scenario of 5G network and satellite network integration.

[0110] In S11b, the terminal initiates PDU session establishment and service initiation, obtains signaling interaction and corresponding configuration of functional entities such as AMF / SMF / UPF in the ground core network, and can perform local switching.

[0111] For example, a UE (including UE1 and UE2) sends an RRC Connection Establishment Request to the gNB, carrying the initial terminal identifier and establishment reason. The gNB replies with an RRC Connection Establishment Response, carrying the complete configuration information for the signaling channel between the UE and the gNB. The UE then sends an RRC Connection Establishment Complete message to the gNB, carrying an uplink NAS message, i.e., a Registration Request. The gNB selects an appropriate CN (core network) and forwards the Registration Request message. The CN initiates an authentication process with the terminal through the gNB, performing mutual authentication between the UE and CN. After authentication is complete, the UE and CN perform a NAS security mode activation (security mode command) process, initiating NAS signaling encryption, decryption, and integrity protection. The CN sends an Initial Context Establishment Request to the gNB, carrying a Registration Success NAS message. The gNB initiates an AS security mode control process to the terminal, initiating AS signaling encryption, decryption, and integrity protection. The gNB then sends an RRC Connection Reconfiguration Request to the UE and forwards the Registration Success NAS message. The UE sends a response to the gNB: RRC Connection Reconfiguration Complete. The service channel between the UE and the gNB is now established. The gNB sends an Initial UE Context Setup Response to the CN. The UE has now joined the network and established a PDU session.

[0112] In some embodiments, UE1 initiates a request to the CN to establish a local data exchange path to UE2. The CN reviews the local data exchange service capabilities of UE1 and UE2 and assigns keys to them respectively. The CN retrieves the base station locations of UE1 and UE2, allocates an inter-satellite path for the local data exchange service, and initiates a PDU Session Modify request to the satellite base station gNB (if UE1 and UE2 are on different satellites, the request is sent to the first satellite base station on the first satellite corresponding to UE1 and the second satellite base station on the second satellite corresponding to UE2) to establish a local data exchange path between UE1 and UE2. If UE1 and UE2 are on different satellites, the satellite base stations gNB send each other service direct transmission channel establishment messages based on the inter-satellite path to establish a service transmission tunnel between the satellite base stations gNB.

[0113] In other embodiments, the CN may perform route optimization and establish local data exchange between UE1 and UE2 via the satellite-borne base station gNB.

[0114] In S12b, after obtaining signaling interaction and corresponding configuration from the AMF / SMF / UPF functional entities in the core network, the gNB establishes a local interaction context and key. The local interaction context may include a terminal-related context indicating that the gNB can support local data exchange.

[0115] For example, a ground CN network element obtains an identification list, which includes identification information of one or more UEs that support local data exchange under a satellite and access a satellite. The identification list corresponds to the relevant information of the satellite. The identification information of the UE can be the IP address of the UE, or the identification information of the UE can also be other types of identification, such as the UE's SUPI / Cell-Radio Network Temporary Identifier (C-RNTI), etc., which is not limited in this disclosure.

[0116] In the embodiment of the present disclosure, the ground CN network element can determine whether to allow the UE to perform local data exchange under the satellite based on the UE's subscription information or policy information, for example, the subscription information or policy information indicates that the UE can perform local data exchange, thereby generating the above-mentioned identification list.

[0117] The relevant information (or parameters) of the satellite may refer to any information associated with the satellite. For example, the relevant information of the satellite may be any one of the following information: the data network access identifier corresponding to the satellite, the identifier of the satellite, etc., which is not limited in this disclosure.

[0118] As an example, the ground CN network element determines the satellite-related information based on the UE's location information. Optionally, the satellite-related information may be determined in combination with other information. For example, the satellite-related information may be determined based on the UE's location information, the satellite type (e.g., high orbit, low orbit, etc.), and the satellite return type information. For another example, the satellite-related information may be determined based on the UE's location information, the satellite return type information, and the satellite's constellation information.

[0119] The ground CN network element configures a local interaction context and key with the gNB on the satellite. This local interaction context is used to forward data packets whose destination address contains the address of a UE corresponding to the identifier list to that UE. For example, UE1 accesses the network via satellite. Assume that the identifier list corresponding to the satellite's relevant information includes UE2. UE1 sends a data packet to UE2, whose destination address is UE2's IP address. When the gNB receives the data packet, it determines, based on the local interaction context, that the destination address is included in the identifier list. The gNB then forwards the data packet to UE2. Data packets destined for terminals on the identifier list can be sent directly from the gNB on the satellite to the corresponding terminals, without passing through the ground core network equipment. This shortens the data transmission path and reduces transmission latency.

[0120] In S13b, local data exchange is performed via the gNB. For example, the gNB performs local data exchange between UE1 and UE2 based on the local exchange context and key.

[0121] Figure 13 For other contents of the embodiment, reference can be made to the other embodiments mentioned above.

[0122] In an exemplary embodiment, the onboard eNB / gNB supports local data exchange while also supporting mapping with the GTP-u tunnels of the S1-u and N3 interfaces of the terrestrial core network. The GTP-tunnels of the S1-u and N3 interfaces of the core network are primarily used to transmit user data.

[0123] Specifically, if Figure 14 As shown, UE1, UE2 and the satellite base station eNB / gNB use their own DRBs to transmit data. The satellite base station eNB / gNB that supports local switching can support <ue1-drbx>and <ue2-drby>( Figure 14 In the example illustrated in FIG1 , x=1 and y=3 are used, but the present disclosure is not limited thereto) for data exchange. Data exchange with S1-u / GTP-tunneling can also be supported. For example, assuming that UE1 corresponds to GTP-u tunneling x (first tunnel identification information) and UE2 corresponds to GTP-u tunneling y (second tunnel identification information). In other words, in the embodiments of the present disclosure, data paths for local on-board switching and switching through the terrestrial core network can coexist.

[0124] Figure 14 An example of a mapping table for implementing local switching in a satellite base station eNB / gNB is shown in Figure 1, which also reflects an example of switching through the core network. The mapping table can be used as part of the established local interaction context. For example, assuming that the direction corresponding to index = 1 is local switch, the source address is UE1-DRB1, and the destination address is UE2-DRB3, through this indication information, when the satellite base station eNB / gNB receives a data packet from UE1 through DRB1, the satellite base station eNB / gNB uses Figure 14 , if the mapping table entry is configured with an entry such as index=1, the data packet of UE1's DRB1 can be decrypted first, and then encrypted according to the instruction of the table entry of index=1 and transmitted to UE2 through DRB3 established between the satellite base station eNB / gNB and UE2. In this case, the satellite base station eNB / gNB does not determine whether to perform local data exchange according to the destination IP address carried by the data packet sent by UE1, that is, the data packet sent by UE1 at this time may not carry the IP address of UE2 as the destination IP address. For another example, assuming that the direction corresponding to index=2 is uplink, the source address is UE1-DRB1, and the destination address is GTP-utunneling x, when the satellite base station eNB / gNB receives a data packet from UE1 through DRB1, it can also transmit it to the ground CN network element through GTP-utunneling x. For another example, assuming that the direction corresponding to index = 3 is uplink, the source address is UE2-DRB3, and the destination address is GTP-u tunneling y, then when the satellite base station eNB / gNB receives a data packet from UE2 via DRB3, it can transmit it to the ground CN network element via GTP-utunneling y. For another example, assuming that the direction corresponding to index = 4 is downlink, the source address is GTP-u tunneling x, and the destination address is UE1-DRB1, then when the satellite base station eNB / gNB receives a data packet from the ground CN network element via GTP-u tunneling x, it can transmit it to the ground UE1 via DRB1.

[0125] In some embodiments, local data exchange is performed based on the context on the satellite base station eNB / gNB, and the exchange can be composed of mutual mapping of DRBs. For example, in a local data exchange between UE1-satellite-UE2, the uplink data of a corresponding DRB is first decrypted and then encrypted into another DRB (the AS keys of different UEs are different). That is, the AS keys of different UEs are stored in the satellite base station eNB / gNB, such as the AS key (first key) of UE1 and the AS key (second key) of UE2. When a data packet transmitted by UE1 through DRBx is received, the data packet is first decrypted with the AS key of UE1, and then encrypted with the AS key of UE2, and then transmitted to UE2 through DRBy.

[0126] It is understandable that Figure 14 The mapping table stored on the satellite base station is only used for illustration and is not used to limit the representation method of the indication information. It is not limited to the DRB granularity and can also be the UE granularity.

[0127] Using the satellite base station for forwarding requires the AS layer protocol stack to be enhanced, which is not the only solution. The present disclosure also proposes another embodiment, that is, the satellite core network function entity (satellite core network element or satellite core network device) performs local forwarding. Figures 15 to 18 For example, Figures 15 to 18 In the embodiment, it is assumed that some core network functional entities are located on the satellite (denoted by CN-NT), and another part of the core network functional entities are located on the ground (denoted by CN-T).

[0128] like Figure 15 The protocol flow shown, combined with the architecture of 4G and 5G network integration with satellite network, is a flowchart of the main steps for the onboard core network element (CN-NT) to realize local data exchange.

[0129] In S21, the terminal initiates PDU session / PDN connection establishment and service initiation, obtains signaling interaction and corresponding configuration of the core network (which can be CN-T, CN-NT and CN-T), and can perform local switching.

[0130] UEs (including UE1 and UE2) establish PDU sessions or PDN connections through 4G or 5G satellite base stations and onboard and terrestrial core network equipment. During the service request and connection establishment process, they obtain signaling interaction and corresponding configuration from the core network, enabling local data exchange, which is completed by the onboard core network functional entity (CN-NT). To achieve local data exchange, it is necessary to explicitly indicate that local exchange is possible in the terminal-related context of the CN-NT.

[0131] In S22, after obtaining the signaling interaction and corresponding configuration of the core network, the onboard core network device establishes a local interaction context and key. The local interaction context may include a context related to a terminal indicating that the onboard core network device can support local data exchange.

[0132] In S23, local data exchange is performed through the onboard core network device. For example, the onboard core network device performs local data exchange between UE1 and UE2 based on the local exchange context and key.

[0133] In an exemplary embodiment, the local data exchange supported by CN-NT itself needs to obtain relevant parameters, including security parameters, from the ground core network element CN-T (such as AMF / MME).

[0134] The CN-NT, which supports local forwarding onboard the satellite, maintains a connection with the terrestrial core network element CN-T (e.g., AMF / MME) (assuming the key derive function is anchored in the terrestrial core network entity CN-T, but this disclosure is not limited to this). This connection can be used for key deriving. The key deriving process includes generating NAS layer keys, including IK and CK, from the AMF / MME and UE NAS layers, and generating AS layer keys at the AS layer of the eNB / gNB and UE. Both steps require the involvement of core network elements on the ground and onboard the satellite.

[0135] Figure 15 For other contents of the embodiment, reference can be made to the above contents.

[0136] like Figure 16 The protocol flow shown, combined with the architecture of 4G network and satellite network integration, is a flowchart of the main steps for the onboard core network element (CN-NT) to realize local data exchange.

[0137] In S21a, the terminal initiates PDN connection establishment and service initiation, obtains signaling interaction and corresponding configuration of the core network (which can be the core network functional entities such as the satellite MME / P-GW, or the core network functional entities such as the satellite MME / P-GW and the ground MME / P-GW), and can perform local switching.

[0138] UEs (including UE1 and UE2) establish PDN connections through 4G satellite base stations (eNBs) and onboard and terrestrial core network equipment (MME / P-GW, etc.). During the service request and connection establishment process, they receive signaling interaction and corresponding configuration from the core network, enabling local data exchange, which is completed by the onboard core network functional entities (MME / P-GW, etc.). To enable local data exchange, the terminal-related context of the onboard core network functional entities (MME / P-GW, etc.) must explicitly indicate that local exchange is possible.

[0139] In S22a, after obtaining the signaling interaction and corresponding configuration of the core network, the onboard core network device (MME / P-GW, etc.) establishes a local interaction context and key. The local interaction context may include a terminal-related context indicating that the onboard core network device (MME / P-GW, etc.) can support local data exchange.

[0140] In S23a, local data exchange is performed through the onboard core network equipment (MME / P-GW, etc.). For example, the onboard core network equipment (MME / P-GW, etc.) performs local data exchange between UE1 and UE2 based on the local exchange context and key.

[0141] Figure 16 For other contents of the embodiment, reference can be made to the above contents.

[0142] like Figure 17 The protocol flow shown, combined with the architecture of 5G network and satellite network integration, is a flowchart of the main steps for the onboard core network element (CN-NT) to realize local data exchange.

[0143] In S21b, the terminal initiates PDU session establishment and service initiation, obtains signaling interaction and corresponding configuration from the core network, and can perform local switching. The core network that provides signaling interaction and corresponding configuration here can be the satellite AMF / SMF and other core network functional entities, or the satellite AMF / SMF and other core network functional entities and the terrestrial AMF / SMF and other core network functional entities.

[0144] In the disclosed embodiment, the UPF network element on the satellite is a local UPF, and the UPF network element deployed on the ground is a PSA (PDU session anchor) UPF.

[0145] UEs (including UE1 and UE2) establish PDU sessions through the 5G gNB and onboard and terrestrial core network equipment (such as the AMF and SMF). During service request initiation and connection establishment, they receive signaling interaction and corresponding configuration from the core network, enabling local data exchange, which is accomplished by the onboard core network functional entities (such as the AMF, SMF, and local UPF). Local data exchange requires explicit indication of local exchange within the terminal-related context of the onboard core network functional entities (such as the AMF, SMF, and local UPF).

[0146] In S22b, after obtaining the signaling interaction and corresponding configuration of the core network, the onboard core network device establishes a local interaction context and key. The local interaction context may include a terminal-related context indicating that the onboard core network device (AMF / SMF / localUPF, etc.) can support local data exchange.

[0147] In S23b, local data exchange is performed through the onboard core network device. For example, the onboard core network device performs local data exchange between UE1 and UE2 based on the local exchange context and key.

[0148] Figure 17 For other contents of the embodiment, reference can be made to the above contents.

[0149] In an exemplary embodiment, the CN-NT supports local data exchange while also supporting mapping with the GTP-u tunnels of the core network's S1-u and N3 ports. In other words, data paths for local exchange via the onboard core network and exchange via the terrestrial core network can coexist.

[0150] For example, Figure 18 As shown, UE1, UE2 and the satellite base station eNB / gNB use their own DRBs to transmit data. When the satellite base station eNB / gNB receives a data packet from UE1 through DRB1, it transmits it to the satellite core network function part (i.e., the satellite core network element) through S1-u / GTP-u tunneling x. The satellite core network element can support<UE1-GTP-utunneling x> and<UE2-GTP-u tunneling y> It can exchange data and also support data exchange with ground core network elements.

[0151] Figure 18 This is an example of a mapping table for implementing local switching in a core network element onboard a satellite. Assume that index 1 in the mapping table corresponds to direction local switching, the source address is UE1-GTP-u tunneling x, and the destination address is UE2-GTP-u tunneling y.

[0152] In an exemplary embodiment, local data exchange is based on the context on the CN-NT, and the exchange is performed by mapping between E-RABs (in the EPS case). In the 5G case, the mapping is between N3 GTP-tunnels. That is, a local data exchange between UE1, satellite, and UE2 corresponds to mapping data on one GTP-u tunnel to another GTP-u. In the 4G case, the E-RAB is composed of an S1 bearer (GTP-u tunneling) and a data radio bearer (DRB) on the air interface in series.

[0153] In scenarios where a local UPF / UPF ULCL (Uplink Classifier) is deployed on a satellite for local switching, it can be different from deploying a base station on a satellite for local switching. The on-satellite UPF can route the data packet sent by UE1 to UE2 according to the source IP address and destination IP address carried in the data packet. That is, the source address in the entry indicating local switch in the mapping table can be the IP address of UE1, and the destination address can be the IP address of UE2. Therefore, using an on-satellite UPF to implement local switching between different UEs is more flexible because the UPF has processing capabilities at the IP layer and above.

[0154] like Figure 19 As shown, embodiments of the present disclosure further provide an onboard network element 1900. Onboard network element 1900 is located on a satellite, on which an onboard base station is deployed. Onboard network element 1900 includes an onboard base station or an onboard core network element. Onboard network element 1900 stores terminal-related context, which includes indication information indicating that a first terminal and a second terminal are exchanging local data via onboard network element 1900. Onboard network element 1900 includes a receiving unit 1910 and a sending unit 1920.

[0155] The receiving unit 1910 is configured to receive a data packet sent by the first terminal. The sending unit 1920 is configured to send the data packet to the second terminal without passing through a terrestrial core network element according to the instruction information.

[0156] In an exemplary embodiment, the receiving unit 1910 is further configured to, during a process in which the first terminal and the second terminal establish a session or connection respectively through the onboard base station and the core network element, the onboard network element obtains the terminal-related context from the core network element.

[0157] In an exemplary embodiment, the onboard network element obtains the terminal-related context from a ground core network element.

[0158] In an exemplary embodiment, the terminal-related context includes a first key of the first terminal and a second key of the second terminal. Onboard network element 1900 further includes a processing unit configured to decrypt the data packet using the first key of the first terminal and encrypt the decrypted data packet using the second key of the second terminal. Transmitting unit 1920 is further configured to transmit the encrypted data packet using the second key of the second terminal to the second terminal.

[0159] In an exemplary embodiment, the terminal-related context also includes parameters of the satellite. The onboard network element 1900 further includes a processing unit configured to determine, based on the satellite parameters, whether the first terminal and the second terminal are located under the same satellite. The sending unit 1920 is further configured to: if the first terminal and the second terminal are located under the same satellite, send the data packet to the second terminal via the onboard network element of the satellite; if the first terminal and the second terminal are located under different first and second satellites, respectively, send the data packet to the second terminal located under the second satellite via the intersatellite link between the first and second satellites.

[0160] In an exemplary embodiment, when all core network elements are deployed on the ground, the satellite-borne network element is the satellite-borne base station.

[0161] In an exemplary embodiment, the indication information includes a local data exchange index, a source address corresponding to the local data exchange index includes a first data radio bearer of the first terminal, and a destination address includes a second data radio bearer of the second terminal.

[0162] In an exemplary embodiment, the indication information includes a local data exchange index, a source address corresponding to the local data exchange index includes all data radio bearers of the first terminal, and a destination address includes all data radio bearers of the second terminal.

[0163] In an exemplary embodiment, the terminal-related context further includes indication information that the first terminal and the second terminal exchange data through the onboard network element and the ground core network element.

[0164] In an exemplary embodiment, when at least part of the core network elements are deployed on the satellite, the onboard network element is the onboard core network element.

[0165] In an exemplary embodiment, the indication information includes a local data exchange index, a source address corresponding to the local data exchange index includes first tunnel identification information of the first terminal, and a destination address includes second tunnel identification information of the second terminal.

[0166] In an exemplary embodiment, the indication information includes a local data exchange index, a source address corresponding to the local data exchange index includes a first evolved radio access bearer of the first terminal, and a destination address includes a second evolved radio access bearer of the second terminal.

[0167] Figure 19 For other contents of the satellite-borne network element provided in the embodiment, reference can be made to the other embodiments mentioned above.

[0168] Figure 20 The schematic diagram shows a schematic structural diagram of a communication device 2000 according to an embodiment of the present disclosure. The communication device may be a terminal such as a UE, or a network device such as a base station, or an AMF and / or UPF and / or PCF and / or NEF and / or AF and / or SMF network element and / or MME and / or P-GW and / or S-GW and / or HSS. Figure 20 The communication device 2000 shown includes a processor 2010. The processor 2010 can call and execute a computer program from a memory to implement the method in the embodiment of the present disclosure.

[0169] Alternatively, as Figure 20 As shown, the communication device 2000 may further include a memory 2020. The processor 2010 may call and execute a computer program from the memory 2020 to implement the method in the embodiment of the present disclosure.

[0170] The memory 2020 may be a separate device independent of the processor 2010 , or may be integrated into the processor 2010 .

[0171] Alternatively, as Figure 20 As shown, the communication device 2000 may further include a transceiver 2030 , and the processor 2010 may control the transceiver 2030 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices.

[0172] The transceiver 2030 may include a transmitter (which may be used as the transmitting unit in the above embodiment) and a receiver (which may be used as the receiving unit in the above embodiment). The transceiver 2030 may further include an antenna, and the number of antennas may be one or more.

[0173] Optionally, the communication device 2000 may specifically be various network elements of the embodiments of the present disclosure, and the communication device 2000 may implement the corresponding processes implemented by each network element in each method of the embodiments of the present disclosure. For the sake of brevity, they will not be repeated here.

[0174] Optionally, the communication device 2000 may specifically be a mobile terminal / terminal of an embodiment of the present disclosure, and the communication device 2000 may implement the corresponding processes implemented by the mobile terminal / terminal in each method of the embodiment of the present disclosure. For the sake of brevity, they will not be repeated here.

[0175] Optionally, the processor 2010 , the memory 2020 , and the transceiver 2030 may implement bidirectional communication with each other via the communication bus 2040 .

[0176] It should be understood that the processor of the embodiment of the present disclosure may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment may be completed by hardware integrated logic circuits in the processor or software instructions.

[0177] The above-mentioned processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present disclosure can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in conjunction with the embodiments of the present disclosure can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above-mentioned method in combination with its hardware.

[0178] It is understood that the memory in the embodiments of the present disclosure may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory. It should be understood that the above memory is provided by way of example and not limitation.

[0179] The embodiment of the present disclosure also provides a computer-readable storage medium for storing a computer program.

[0180] Optionally, the computer-readable storage medium can be applied to each network element in the embodiments of the present disclosure, and the computer program enables the computer to execute the corresponding processes implemented by each network element in each method of the embodiments of the present disclosure. For the sake of brevity, they will not be repeated here.

[0181] Optionally, the computer-readable storage medium can be applied to the mobile terminal / terminal in the embodiments of the present disclosure, and the computer program enables the computer to execute the corresponding processes implemented by the mobile terminal / terminal in the various methods of the embodiments of the present disclosure. For the sake of brevity, they are not repeated here.

[0182] An embodiment of the present disclosure also provides a computer program product, including computer program instructions.

[0183] Optionally, the computer program product can be applied to each network element in the embodiments of the present disclosure, and the computer program instructions enable the computer to execute the corresponding processes implemented by each network element in each method of the embodiments of the present disclosure. For the sake of brevity, they will not be repeated here.

[0184] Optionally, the computer program product can be applied to the mobile terminal / terminal in the embodiments of the present disclosure, and the computer program instructions enable the computer to execute the corresponding processes implemented by the mobile terminal / terminal in the various methods of the embodiments of the present disclosure. For the sake of brevity, they are not repeated here.

[0185] The embodiments of the present disclosure also provide a computer program.

[0186] Optionally, the computer program can be applied to each network element in the embodiments of the present disclosure. When the computer program runs on a computer, the computer executes the corresponding processes implemented by each network element in the various methods of the embodiments of the present disclosure. For the sake of brevity, they will not be repeated here.

[0187] Optionally, the computer program can be applied to the mobile terminal / terminal in the embodiments of the present disclosure. When the computer program runs on the computer, the computer executes the corresponding processes implemented by the mobile terminal / terminal in the various methods of the embodiments of the present disclosure. For the sake of brevity, they are not repeated here.

[0188] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0189] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0190] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A satellite communication method, characterized in that: The satellite is deployed with an onboard base station, and the satellite has an onboard network element, the onboard network element includes the onboard base station or the onboard core network element, and the method is performed by the onboard network element; wherein the method includes: receiving a data packet sent by the first terminal; According to the instruction information, the data packet is sent to the second terminal without passing through the ground core network element.

2. The method according to claim 1, characterized in that The onboard network element stores a terminal-related context, and the terminal-related context includes indication information that the first terminal and the second terminal perform local data exchange through the onboard network element.

3. The method according to claim 2, characterized in that Also includes: In the process of establishing a session or connection between the first terminal and the second terminal respectively through the onboard base station and the core network element, the onboard network element obtains context related to the terminal; The core network elements include the ground core network elements and / or satellite-borne core network elements.

4. The method according to claim 2, characterized in that The terminal-related context includes a first key of the first terminal and a second key of the second terminal; wherein, according to the instruction information, sending the data packet to the second terminal without passing through a terrestrial core network element includes: decrypting the data packet using a first key of the first terminal; encrypting the decrypted data packet using a second key of the second terminal; The data packet encrypted by using the second key of the second terminal is sent to the second terminal.

5. The method according to claim 2, characterized in that The terminal-related context further includes parameters of the satellite; wherein, according to the instruction information, sending the data packet to the second terminal without passing through a ground core network element includes: determining, based on parameters of the satellite, whether the first terminal and the second terminal are located under the same satellite; If the first terminal and the second terminal are located under the same satellite, sending the data packet to the second terminal through an onboard network element of the satellite; If the first terminal and the second terminal are located under different first and second satellites respectively, the onboard network element of the first satellite sends the data packet to the second terminal located under the second satellite through the intersatellite link between the first satellite and the second satellite.

6. The method according to claim 2, characterized in that When all core network elements are deployed on the ground, the satellite-borne network element is the satellite-borne base station.

7. The method according to claim 6, characterized in that The indication information includes a local data exchange index, a source address corresponding to the local data exchange index includes a first data radio bearer of the first terminal, and a destination address includes a second data radio bearer of the second terminal.

8. The method according to claim 6, characterized in that The indication information includes a local data exchange index, a source address corresponding to the local data exchange index includes multiple data radio bearers of the first terminal, and a destination address includes at least one data radio bearer of the second terminal.

9. The method according to claim 6, characterized in that The terminal-related context also includes indication information of the first terminal and the second terminal exchanging data through the onboard network element and the ground core network element.

10. The method according to claim 1, characterized in that When at least part of the core network elements are deployed on the satellite, the onboard network element is the onboard core network element.

11. The method according to claim 10, characterized in that The indication information includes a local data exchange index, a source address corresponding to the local data exchange index includes first tunnel identification information of the first terminal, and a destination address includes second tunnel identification information of the second terminal.

12. The method according to claim 10, characterized in that The indication information includes a local data exchange index, a source address corresponding to the local data exchange index includes a first evolved radio access bearer of the first terminal, and a destination address includes a second evolved radio access bearer of the second terminal.

13. A satellite-borne network element, characterized in that: The onboard network element is located on a satellite, a satellite base station is deployed on the satellite, and the onboard network element includes the onboard base station or an onboard core network element; wherein the onboard network element includes: a receiving unit, configured to receive a data packet sent by the first terminal; The sending unit is used to send the data packet to the second terminal without passing through the ground core network element according to the indication information.

14. A communication device, characterized in that: include: one or more processors; The memory is configured to store one or more programs, and when the one or more programs are executed by the one or more processors, the communication device implements the method according to any one of claims 1 to 12.

15. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is run on a computer, the computer is caused to execute the method according to any one of claims 1 to 12.

16. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 12 is implemented.

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